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Suppose that you have an abstract for a scientific paper: let @xmath0 , where @xmath1 denotes the @xmath2th smallest prime , and let @xmath3 ( the `` erds rankin '' function ) . we consider the sequence @xmath4 of normalized prime gaps , and show that its limit point set contains at least @xmath5 of nonnegative real numbers . we also show that the same result holds if @xmath6 is replaced by any `` reasonable '' function that tends to infinity more slowly than @xmath7 . we also consider `` chains '' of normalized prime gaps . our proof combines breakthrough work of maynard and tao on bounded gaps between primes with subsequent developments of ford , green , konyagin , maynard and tao on long gaps between consecutive primes . . And you have already written the first three sentences of the full article: let @xmath0 , where @xmath1 denotes the @xmath2th smallest prime . one variant of the prime number theorem states that @xmath8 that is , @xmath9 is approximately @xmath10 on average over @xmath11 . as to the finer questions pertaining to the distribution of primes , we have little more than conjecture in the way of answers .. Please generate the next two sentences of the article

heuristics based on cramr s model suggest that for any given real numbers @xmath12 , @xmath13 however , we do not even know of any specific limit point of the sequence @xmath14 , except for @xmath15 and @xmath16 , the former having been known for just a decade , thanks to the groundbreaking work of goldston pintz yildirim @xcite . ( the latter follows from a 1931 result of westzynthius @xcite . ) this limit point lacuna notwithstanding , hildebrand and maier @xcite showed in 1988 that a positive ( but unspecified ) proportion of nonnegative real numbers are limit points of @xmath14 . more recently , the second author , banks and maynard @xcite have shown that in fact at least @xmath17 of nonnegative real numbers are limit points of @xmath14 .

Suppose that you have an abstract for a scientific paper: ultra high energy gamma rays produce electron positron pairs in interactions on the geomagnetic field . the pair electrons suffer magnetic bremsstrahlung and the energy of the primary gamma ray is shared by a bunch of lower energy secondaries . these processes reflect the structure of the geomagnetic field and cause experimentally observable effects . the study of these effects with future giant air shower arrays can identify the nature of the highest energy cosmic rays as either @xmath0rays or nuclei . the nature of the highest energy cosmic rays @xmath1 bartol research institute , university of delaware , newark , de 19716 + @xmath2 institute for nuclear research and nuclear energy , sofia # # , bulgaria + . And you have already written the first three sentences of the full article: ever since the reports of the detection of two cosmic ray showers of energy well above @xmath3 ev @xcite the origin and the nature of such events have been subjects of strong interest and intense discussion . it is not only very difficult @xcite to extend our understanding of particle acceleration to such extraordinarily high energies but the propagation of these particles in the microwave background and possibly other universal radiation fields restricts the distance to their potential sources to several tens of mpc . conservatively minded astrophysicists are looking for astrophysical sources which may contain the environment necessary for stochastic particle acceleration to energies in excess of @xmath3 ev . powerful ( frii ) radio galaxies @xcite have been suggested as possible sources .. Please generate the next two sentences of the article

if this suggestion were true , the highest energy cosmic rays ( hecr ) would be most likely protons , reflecting the composition of the matter that is available for injection in the termination shocks of frii jets . others @xcite search for powerful astrophysical sources in the cosmologically nearby universe . hecr then could also be heavier nuclei , for which the acceleration is less demanding .

Suppose that you have an abstract for a scientific paper: any network studied in the literature is inevitably just a sampled representative of its real - world analogue . additionally , network sampling is lately often applied to large networks to allow for their faster and more efficient analysis . nevertheless , the changes in network structure introduced by sampling are still far from understood . in this paper , we study the presence of characteristic groups of nodes in sampled social and information networks . we consider different network sampling techniques including random node and link selection , network exploration and expansion . we first observe that the structure of social networks reveals densely linked groups like communities , while the structure of information networks is better described by modules of structurally equivalent nodes . however , despite these notable differences , the structure of sampled networks exhibits stronger characterization by community - like groups than the original networks , irrespective of their type and consistently across various sampling techniques . hence , rich community structure commonly observed in social and information networks is to some extent merely an artifact of sampling . complex networks , network sampling , node group structure , communities , modules + _ pacs : _ 64.60.aq , 89.75.fb , 89.90.+n . And you have already written the first three sentences of the full article: any network found in the literature is inevitably just a sampled representative of its real - world analogue under study . for instance , many networks change quickly over time and in most cases merely incomplete data is available on the underlying system . additionally , network sampling techniques are lately often applied to large networks to allow for their faster and more efficient analysis . since the findings of the analyses and simulations on such sampled networks are implied for the original ones , it is of key importance to understand the structural differences between the original networks and their sampled variants . a large number of studies on network sampling focused on the changes in network properties introduced by sampling .. Please generate the next two sentences of the article

lee et al . @xcite showed that random node and link selection overestimate the scale - free exponent @xcite of the degree and betweenness centrality @xcite distributions , while they preserve the degree mixing @xcite . on the other hand ,

Suppose that you have an abstract for a scientific paper: understanding the interaction between cavity photons and electronic nanocircuits is crucial for the development of mesoscopic quantum electrodynamics ( qed ) . one has to combine ingredients from atomic cavity qed , like orbital degrees of freedom , with tunneling physics and strong cavity field inhomogeneities , specific to superconducting circuit qed . it is therefore necessary to introduce a formalism which bridges between these two domains . we develop a general method based on a photonic pseudo - potential to describe the electric coupling between electrons in a nanocircuit and cavity photons . in this picture , photons can induce simultaneously orbital energy shifts , tunneling , and local orbital transitions . we study in details the elementary example of a single quantum dot with a single normal metal reservoir , coupled to a cavity . photon - induced tunneling terms lead to a non - universal relation between the cavity frequency pull and the damping pull . our formalism can also be applied to multi quantum dot circuits , molecular circuits , quantum point contacts , metallic tunnel junctions , and superconducting nanostructures enclosing andreev bound states or majorana bound states , for instance . . And you have already written the first three sentences of the full article: cavity quantum electrodynamics ( cavity qed ) enables the study of the interaction between light and matter at the most elementary level , thanks to the achievement of a strong coupling between a single atom and a single photon trapped in a microwave or optical cavity@xcite . this paradigm has been recently brought into superconducting circuits : artificial atoms consisting of two level superconducting circuits have been coupled to superconducting cavities@xcite , in the context of circuit qed . these experiments provide an ideal playground to test the basic laws of quantum mechanics because they can be described in terms of simple models like the jaynes - cummings hamiltonian .. Please generate the next two sentences of the article

however , such models conceal essential physical differences between cavity and circuit qed . on the one hand , the coupling between isolated atoms and cavity photons mainly occurs due to the sensitivity of the atom electric dipole to the cavity electric field .

Suppose that you have an abstract for a scientific paper: the fully - packed loop model of closed paths covering the honeycomb lattice is studied through its identification with the @xmath0 integrable lattice model . some known results from the bethe ansatz solution of this model are reviewed . the free energy , correlation length , and the ensemble average loop length are given explicitly for the many - loop phase . the results are compared with the known result for the model s surface tension . a perturbative formalism is introduced and used to verify results . 8.5 in 6.5 in -.35 in arch - ive/9411132 + .2 in * correlation length and average loop length of the fully - packed loop model * .5 in anton kast + .5 in . And you have already written the first three sentences of the full article: 18.5pt in a recent article @xcite blte and nienhuis performed numerical investigations of what they termed the fully - packed loop ( fpl ) model . this is a statistical model where the ensemble is the set of all combinations of closed paths on the honeycomb lattice that visit every vertex and do not intersect . the boltzmann weight of such a filling set of paths is just the exponential of the number of paths , i.e. the energy of a configuration is the number of closed loops used to cover the lattice .. Please generate the next two sentences of the article

an example of a fully - packed configuration of loops on this lattice is shown in figure [ example ] . the partition function for this model may be represented as @xmath1 where the sum is over all @xmath2 , the coverings of the vertices of the hexagonal lattice by closed nonintersecting paths , @xmath3 is the number of paths in the covering @xmath2 , and @xmath4 is a generalized activity .

Suppose that you have an abstract for a scientific paper: an undirected graph consists of a set of vertices and a set of undirected edges between vertices . such a graph may contain an abundant number of cycles , then a feedback vertex set ( fvs ) is a set of vertices intersecting with each of these cycles . constructing a fvs of cardinality approaching the global minimum value is a optimization problem in the nondeterministic polynomial - complete complexity class , therefore it might be extremely difficult for some large graph instances . in this paper we develop a simulated annealing local search algorithm for the undirected fvs problem . by defining an order for the vertices outside the fvs , we replace the global cycle constraints by a set of local vertex constraints on this order . under these local constraints the cardinality of the focal fvs is then gradually reduced by the simulated annealing dynamical process . we test this heuristic algorithm on large instances of erdos - renyi random graph and regular random graph , and find that this algorithm is comparable in performance to the belief propagation - guided decimation algorithm . . And you have already written the first three sentences of the full article: an undirected graph is formed by a set of vertices and a set of undirected edges , with each edge connecting between two different vertices . a feedback vertex set ( fvs ) for such a graph is a set of vertices intersecting with every cycle of the graph . in other words , the subgraph induced by the vertices outside the fvs contains no cycle ( it is a forest ) @xcite . the feedback vertex set problem aims at constructing a fvs of small cardinality for a given undirected graph . it is a fundamental nondeterministic polynomial - complete ( np - complete ) combinatorial optimization problem with global cycle constraints @xcite . in terms of complete algorithms ,. Please generate the next two sentences of the article

whether a graph @xmath0 has a fvs of cardinality smaller than @xmath1 can be determined in time @xmath2 @xcite . and an fvs of cardinality at most two times the optimal value can be easily constructed by an efficient polynomial algorithm @xcite . an optimal fvs is a feedback vertex set whose cardinality is the global minimum value among all the feedback vertex sets of the graph . for a given graph

Suppose that you have an abstract for a scientific paper: the formulation of general relativity in which the @xmath0-dimensional space - time is embedded in a flat host space of higher dimension is reconsidered . new classes of embeddings ( modeled after nash s classical free embeddings ) are introduced . they present the important advantage of being deformable and therefore physically realistic . explicit examples of embeddings whose deformations _ do _ describe gravitational waves around their respective backgrounds are given for several space - times , including the schwarzschild black hole . new variational principles which give back einstein s general relativity are proposed . in this framework , the 4-d space - time is a membrane moving in a flat host space . * pacs numbers:04.20.cv , 04.20.fy , 04.30.nk * * keywords : * general relativity ; embeddings ; variational formulations ; waves . . And you have already written the first three sentences of the full article: general relativity is commonly regarded as the correct approach to non - quantum gravitation @xcite . einstein s theory views gravity as a manifestation of the curvature of the @xmath0-d space - time @xcite . several authors have proposed to consider this physical curved @xmath0-d space - time as a membrane embedded in a flat space - time of higher dimension called the host space .. Please generate the next two sentences of the article

this point of view is computationally convenient and is also extremely natural in the context of modern string and brane theory @xcite . the aim of the present article is to complement the existing literature on this topic .

Suppose that you have an abstract for a scientific paper: we have carried out an in - depth study of the peripheral region of the molecular cloud l1204/s140 , where the radiation and the density are relatively low . our observations test theories of photon - dominated regions ( pdrs ) in a regime that has been little explored . knowledge of such regions will also help to test theories of photoionization - regulated star formation . 158 and 63 lines are detected by iso at all 16 positions along a 1-dimensional cut in right ascension . emission from rotational transitions 20 and 31 , at 28 and 17 , was also detected at several positions . the , , and intensities along the cut show much less spatial variation than do the rotational lines of and other co isotopes . the average and intensities and their ratio are consistent with models of pdrs with low radiation ( ) and density . the best - fitting model has @xmath0 and density , @xmath1 . standard pdr models underpredict the intensity in the rotational lines by up to an order of magnitude . this problem has also been seen in bright pdrs and attributed to factors , such as geometry and gas - grain drift , that should be much less important in the regime studied here . the fact that we see the same problem in our data suggests that more fundamental solutions , such as higher formation rates , are needed . also , in this regime of low density and small line width , the line is sensitive to the radiative transfer and geometry . using the ionization structure of the models , a quantitative analysis of timescales for ambipolar diffusion in the peripheral regions of the s140 cloud is consistent with a theory of photoionization - regulated star formation . observations of in other galaxies differ both from those of high pdrs in our galaxy and from the low regions we have studied . the extragalactic results are not easily reproduced with mixtures of high and low regions . . And you have already written the first three sentences of the full article: photon - dominated regions ( or photodissociation regions , pdrs ) are regions of the neutral interstellar medium ( ism ) where far - ultraviolet ( fuv ) ( 6 ev @xmath2 ev ) photons control the heating and chemical processes . they are the interface between regions and cold molecular cores . the physical and chemical structure of pdrs depends critically on the fuv intensity and the gas density . in the peripheral regions of the molecular cloud l1204/s140 , the fuv intensity and the gas density. Please generate the next two sentences of the article

are low , allowing tests of the models in an important regime . we are motivated by two primary goals : understanding pdrs in a regime of parameter space that has not been extensively studied ; and understanding the role of the regions with relatively low fuv and density in global star formation , both in our own galaxy and in other galaxies .

Suppose that you have an abstract for a scientific paper: the observables notion is shown to apply only to a limited range of theories . relational mechanics , slightly inhomogeneous cosmology and supergravity are used as examples that require further notions of observables . a suitably general notion of a - observables is then given to cover all of these cases . ` a ' here stands for ` algebraic substructure ' ; a - observables can be defined by association with each closed algebraic substructure of a theory s constraints . both constrained algebraic structures and associated notions of a - observables form bounded lattices . * edward anderson * _ damtp , centre for mathematical sciences , wilberforce road , cambridge cb3 owa . _ . And you have already written the first three sentences of the full article: consider a classical constrained theory @xcite , with configurations @xmath0 , conjugate momenta @xmath1 , classical brackets @xmath2|}$ ] and constraints @xmath3 . _ observables _ @xcite are then objects forming zero brackets with the constraints , _ o _ 0 . [ basic - obs ] there are multiple such notions due to ` zero ' , ` brackets ' and ` the constraints ' taking a variety of different precise meanings @xcite. Please generate the next two sentences of the article

. some such notions of observables can be more physically useful than just any functions ( or functionals ) of @xmath0 and @xmath1 . this is because of their greater physical content ; moreover , at least some versions of such notions of observables would be expected to contain physical information only . at the very least this property

Suppose that you have an abstract for a scientific paper: we investigate the nature of the substantial population of high - redshift galaxies with @xmath0 colours recently discovered as part of our faint infrared extragalactic survey ( fires ) . this colour cut efficiently isolates galaxies at @xmath1 with red rest - frame optical colors ( `` distant red galaxies , '' or `` drgs '' ) . we select @xmath0 objects in both fires fields , the @xmath2 hubble deep field south ( hdf - s ) and the @xmath3 field around the @xmath4 cluster at @xmath5 ; the surface densities at @xmath6 are @xmath7 and @xmath8 , respectively . we here discuss a sub - sample of 34 drgs at @xmath9 : 11 at @xmath10 in hdf - s and 23 at @xmath11 in the @xmath4 field . this sample enables for the first time a robust assessment of the population properties of drgs . we analyze the @xmath12 spectral energy distributions ( seds ) constructed from our very deep near - infrared ( nir ) and optical imaging collected at the eso very large telescope and from the hubble space telescope . we develop diagnostics involving the @xmath13 , @xmath14 , and @xmath15 colours to argue that the red nir colours of our drg sample can not be attributed solely to interstellar dust extinction and require for many the presence of an evolved stellar population with a prominent balmer/4000 break . in the rest - frame , the optical colours of drgs fall within the envelope of normal nearby galaxies and the ultraviolet colours suggest a wide range in star formation activity and/or extinction . this is in stark contrast with the much bluer and more uniform seds of lyman - break galaxies ( lbgs ) . from evolutionary synthesis modeling assuming constant star formation ( csf ) , we derive for the drgs old ages , large extinctions , and high stellar masses , mass - to - light ratios , and star formation rates . for solar metallicity , a salpeter imf between 0.1 and 100@xmath16 , and the calzetti et al . extinction law , the median values for the hdf - s ( @xmath4 field ) sample are 1.7 ( 2.0 ) gyr , @xmath17 (.... And you have already written the first three sentences of the full article: understanding how galaxies formed and evolved is a central challenge of modern astronomy . in the past decade , spectacular progress in instrumentation and observing techniques has enabled major advances as the high - redshift universe has been opened up for research . our current view has been largely influenced by the discovery of an abundant population of actively star - forming galaxies at redshifts @xmath29 selected by the efficient lyman - break technique @xcite .. Please generate the next two sentences of the article

these lyman - break galaxies ( lbgs ) are among the best - studied classes of high - redshift objects : large samples have been spectroscopically confirmed at @xmath29 ( e.g. * ? ? ? * ) and extensive investigations have focussed notably on their stellar populations , star formation histories , chemical abundances , kinematics , and clustering properties ( e.g. * ? ? ?

Suppose that you have an abstract for a scientific paper: we present high angular resolution ( @xmath0 ) multi - tracer spectral line observations toward the hot core associated with g34.26 + 0.15 between 87109 ghz . we have mapped emission from ( i ) complex nitrogen- and oxygen - rich molecules like , , , , , ; ( ii ) sulfur - bearing molecules like ocs , so and so@xmath1 ; and ( iii ) the recombination line h53@xmath2 . the high angular resolution enables us to directly probe the hot molecular core associated with g34.26 + 0.15 at spatial scales of 0.018 pc . at this resolution we find no evidence for the hot core being internally heated . the continuum peak detected at @xmath3 mm is consistent with the free - free emission from component c of the ultracompact h ii region . velocity structure and morphology outlined by the different tracers suggest that the hot core is primarily energized by component c. emission from the n- and o - bearing molecules peak at different positions within the innermost regions of the core ; none are coincident with the continuum peak . lack of high resolution complementary datasets makes it difficult to understand whether the different peaks correspond to separate hot cores , which are not resolved by the present data , or manifestations of the temperature and density structure within a single core . based on the brightness temperatures of optically thick lines in our sample , we estimate the kinetic temperature of the inner regions of the hmc to be @xmath4 k. comparison of the observed abundances of the different species in g34.26 + 0.15 with existing models does not produce a consistent picture . there are uncertainties due to : ( i ) the unavailability of temperature and density distribution of the mapped region within the hot core , ( ii ) typical assumption of centrally peaked temperature distribution for a hot core with an accreting protostar at the center , by the chemical models , an aspect not applicable to externally heated hot cores like g34.26 + 0.15 and ( iii ) inadequate knowledge about the.... And you have already written the first three sentences of the full article: hot cores are compact ( 0.1 pc ) , warm ( @xmath5 100300 k ) , dense ( 10@xmath6 h nuclei ) clouds of gas and dust near or around sites of recent star formation ( see e.g. * ? ? ? * ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

the hot - core phase is thought to last about 10@xmath7 yr @xcite to 10@xmath8 yr @xcite and represents the most chemically rich phase of the interstellar medium , characterized by complex molecules like , , , and . the complex chemical and physical processes occurring in the hot - cores are not fully understood . until recently hot cores were thought to be associated with high - mass protostars ( m@xmath9 8 @xmath10 ) only and to represent an important phase in their evolution toward ultracompact and compact h ii regions .

Suppose that you have an abstract for a scientific paper: cake cutting is one of the most fundamental settings in fair division and mechanism design without money . in this paper , we consider different levels of three fundamental goals in cake cutting : fairness , pareto optimality , and strategyproofness . in particular , we present robust versions of envy - freeness and proportionality that are not only stronger than their standard counter - parts but also have less information requirements . we then focus on cake cutting with piecewise constant valuations and present three desirable algorithms : _ ccea ( controlled cake eating algorithm ) _ , _ mea ( market equilibrium algorithm ) _ and _ csd ( constrained serial dictatorship)_. ccea is polynomial - time , robust envy - free , and non - wasteful . it relies on parametric network flows and recent generalizations of the probabilistic serial algorithm . for the subdomain of piecewise uniform valuations , we show that it is also group - strategyproof . then , we show that there exists an algorithm _ ( mea ) _ that is polynomial - time , envy - free , proportional , and pareto optimal . mea is based on computing a market - based equilibrium via a convex program and relies on the results of @xcite and @xcite . moreover , we show that mea and ccea are equivalent to mechanism 1 of chen et . al . for piecewise uniform valuations . we then present an algorithm _ csd _ and a way to implement it via randomization that satisfies strategyproofness in expectation , robust proportionality , and unanimity for piecewise constant valuations . for the case of two agents , it is robust envy - free , robust proportional , strategyproof , and polynomial - time . many of our results extend to more general settings in cake cutting that allow for variable claims and initial endowments . we also show a few impossibility results to complement our algorithms . the impossibilities show that the properties satisfied by ccea and mea are maximal subsets of properties that can be satisfied by any algorithm for.... And you have already written the first three sentences of the full article: cake cutting is one the most fundamental topics in fair division ( see * ? ? ? * ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

it concerns the setting in which a cake is represented by an interval @xmath0 $ ] and each of the @xmath1 agents has a value function over the cake . the main aim is to divide the cake fairly .

Suppose that you have an abstract for a scientific paper: we define a generalization of the fixed point set , called the bounded fixed set , for a group acting by isometries on a metric space . an analogue of the p. a. smith theorem is proved for metric spaces of finite asymptotic dimension , which relates the coarse homology of the bounded fixed set to the coarse homology of the total space . . And you have already written the first three sentences of the full article: one of the most important tools in transformation groups is p. a. smith theory @xcite , ( * ? ? ? iii ) , which gives constraints on the homology of the fixed point set for actions of finite @xmath0-groups . for topological actions the fixed point sets may not be manifolds , but generalized manifolds " with complicated local topology ( in the sense of wilder ( * ? ? ? * chap . this means that an appropriate homology theory must be used to capture the essential features .. Please generate the next two sentences of the article

smith theory in the generalized manifold setting , as developed in the 1960 classic seminar on transformation groups " @xcite , was used recently by bridson and vogtmann @xcite to study the actions of @xmath1 , the automorphism group of a free group , on acyclic homology manifolds and generalized homology @xmath2-spheres . in this paper

Suppose that you have an abstract for a scientific paper: the standard post - newtonian approximation to gravitational waveforms , called t - approximants , from non - spinning black hole binaries are known not to be sufficiently accurate close to the last stable orbit of the system . a new approximation , called p - approximants , is believed to improve the accuracy of the waveforms rendering them applicable up to the last stable orbit . in this study we apply p - approximants to the case of a test - particle in equatorial orbit around a kerr black hole parameterized by a spin parameter @xmath0 that takes values between @xmath1 and @xmath2 in order to assess the performance of the two approximants we measure their _ effectualness _ ( i.e. larger overlaps with the exact signal ) , and _ faithfulness _ ( i.e. smaller biases while measuring the parameters of the signal ) with the exact ( numerical ) waveforms . we find that in the case of prograde orbits , that is orbits whose angular momentum is in the same sense as the spin angular momentum of the black hole , t - approximant templates obtain an effectualness of @xmath3 for spins @xmath4 for @xmath5 the effectualness drops to about 0.82 . the p - approximants achieve effectualness of @xmath6 for all spins up to @xmath7 the bias in the estimation of parameters is much lower in the case of p - approximants than t - approximants . we find that p - approximants are both effectual and faithful and should be more effective than t - approximants as a detection template family when @xmath8 for @xmath9 both t- and p - approximants perform equally well so that either of them could be used as a detection template family . . And you have already written the first three sentences of the full article: stellar mass compact binaries consisting of double neutron stars ( ns ) , double black holes ( bh ) or a mixed binary consisting of a neutron star and a black hole , are the primary targets for a direct first detection of gravitational waves ( gw ) by interferometric detectors , ligo @xcite , virgo @xcite , geo600 @xcite , and tama @xcite . under radiation reaction the orbit of a binary slowly decays , emitting a signal whose amplitude and frequency increases with time and is termed a `` chirp '' signal . while it is believed that there is a greater population of ns - ns binaries @xcite , it is the bh - bh binaries that are the strongest candidates for detection since they can be seen from a greater volume , about two orders - of - magnitude greater than ns - ns binaries @xcite . in order to detect such sources. Please generate the next two sentences of the article

one employs the method of matched filtering @xcite . briefly , the method works as follows : firstly , one creates a set of waveforms , or templates as they are called , that depend on a number of parameters of the source and its location and orientation relative to the detector .

Suppose that you have an abstract for a scientific paper: we use oblate axisymmetric dynamical models including dark halos to determine the orbital structure of intermediate mass to massive coma early - type galaxies . we find a large variety of orbital compositions . averaged over all sample galaxies the unordered stellar kinetic energy in the azimuthal and the radial direction are of the same order , but they can differ by up to 40 percent in individual systems . in contrast , both for rotating and non - rotating galaxies the vertical kinetic energy is on average smaller than in the other two directions . this implies that even most of the rotating ellipticals are flattened by an anisotropy in the stellar velocity dispersions . using three - integral axisymmetric toy models we show that flattening by stellar anisotropy maximises the entropy for a given density distribution . collisionless disk merger remnants are radially anisotropic . the apparent lack of strong radial anisotropy in observed early - type galaxies implies that they may not have formed from mergers of disks unless the influence of dissipational processes was significant . [ firstpage ] galaxies : kinematics and dynamics galaxies : elliptical and lenticular , cd galaxies : formation . And you have already written the first three sentences of the full article: the way in which a galaxy has assembled its stars is reflected in the distribution of stellar orbits . for example , collisionless @xmath0-body collapse simulations predict a predominance of radial orbits in the final remnant @xcite . in contrast , collisionless galaxy merger simulations predict a variety of orbital compositions , depending on progenitor properties @xcite , the merging geometry @xcite , the progenitor mass ratios @xcite and the presence of dissipational components @xcite .. Please generate the next two sentences of the article

stars in galaxies are approximately collisionless and the orbital structure once a galaxy has approached a quasi - steady - state is conserved for a long time . to a certain extent then , the assembly mechanism of early - type galaxies can be constrained from their present - day orbital structure .

Suppose that you have an abstract for a scientific paper: we present the results of the virgo high - resolution co survey ( vics ) obtained with the nobeyama millimeter - wave array ( nma ) . this survey was made in the course of a long - term project at nobeyama from 1999 december through 2002 april . the objects were selected from virgo cluster members , considering co richness from single dish flux , mild inclination , and lack of strong tidal perturbations . the central @xmath0 regions ( @xmath1 kpc ) of 15 spiral galaxies were observed with resolutions of @xmath2 and @xmath3 , and sensitivities of @xmath4 for a @xmath5 channel . the objects lie at the same distance of the virgo cluster ( 16.1 mpc ) , which is advantageous for comparisons among individual galaxies . we describe the details of observations and data reduction , and present an atlas of integrated co intensity maps , velocity fields and position - velocity diagrams along the major axes . the molecular gas morphology in the virgo galaxies shows a wealth of variety , not specifically depending on the hubble types . several galaxies show strong concentration of gas in the central few kpc region , where the co morphology shows either `` single - peak '' or `` twin - peaks '' . morphology of more extended co components can be classified into `` arm - type '' , `` bar - type '' , and `` amorphous - type '' . * key words * : galaxies : spiral galaxies : ism galaxies : structure galaxies : virgo = -5 mm = -5 mm = -10 mm . And you have already written the first three sentences of the full article: co - line observations play an essential role in studying the kinematics and interstellar physics in the central regions of spiral galaxies , where the interstellar matter is mostly in the molecular - gas phase and is strongly concentrated ( sofue et al . 1995 ; honma et al . there have been numerous observations of nearby galaxies in the co line emissions with single dish telescopes ( young & scoville 1991 ; braine et al .. Please generate the next two sentences of the article

1993 ; young et al . 1995 ; nishiyama & nakai 2001 ) . large - scale co line surveys of the virgo galaxies have been obtained using the fcrao 14-m telescope at an angular resolution of 45@xmath6 by kenney & young ( 1988 ) , and the btl 7-m telescope by stark et al .

Suppose that you have an abstract for a scientific paper: possible origins of the molecular absorption discovered in some ulirgs are investigated , based on a 3-d hydrodynamic model of star - forming interstellar gas in a galactic central region . the blue - shifted , warm ( @xmath0 k ) , dense ( @xmath1 @xmath2 ) molecular gas suggested by co absorption in iras 08752 + 3915 could be caused by the innermost region of the inhomogeneous inter - stellar medium ( ism ) around a supermassive black hole . the infrequent observations of the dense gas with absorption in ulirgs and seyfert 2 galaxies could simply suggest that the high - density regions occupy only a very small volume fraction of the obscuring material . this is naturally expected if the inhomogeneous structure of the ism is caused by non - linear development of instabilities . the model predicts a turbulent velocity field in the obscuring material , therefore blue- and red - shifted gases should be observable with nearly the same probability for the large enough statistical samples . . And you have already written the first three sentences of the full article: active galactic nuclei ( agns ) are believed to be highly obscured by dusty dense gas , and this contributes to huge radiative energy in some ultra - luminous infrared galaxies ( ulirg ) @xcite . the central engines of type-2 seyfert galaxies are also likely obscured by optically thick molecular gas , for which a torus - like geometry is often assumed . however , detailed structures of the ism in deep centers of ulirgs and seyfert galaxies are still unclear .. Please generate the next two sentences of the article

there are some indirect ways to infer their geometry and distribution using x - ray spectroscopy ( e.g. , @xcite ) , optical / infrared spectral energy distribution ( sed ) in comparison with model sed assuming the geometry of the torus ( e.g. , @xcite ) , and optical / infrared absorption lines ( e.g. , @xcite ) . lutz et al .

Suppose that you have an abstract for a scientific paper: the experimental observation of quantum jumps is an example of single open quantum systems that , when monitored , evolve in terms of stochastic trajectories conditioned on measurements results . here we present a proposal that allows the experimental observation of a much larger class of quantum trajectories in cavity qed systems . in particular , our scheme allows for the monitoring of engineered thermal baths that are crucial for recent proposals for probing entanglement decay and also for entanglement protection . the scheme relies on the interaction of a three - level atom and a cavity mode that interchangeably play the roles of system and probe . if the atom is detected the evolution of the cavity fields follows quantum trajectories and vice - versa . . And you have already written the first three sentences of the full article: one of the most remarking properties of quantum mechanics is that the state of a quantum system changes not only via the deterministic evolution given by the schrdinger equation but also when it is measured . although the system can be measured directly , in many situations it is probed by an auxiliary system ( ancilla ) that is then detected , providing information about the system of interest . this is a typical situation in cavity qed where atoms and light interact and the detection of either of them alters the state of the other . in the microwave regime , for example. Please generate the next two sentences of the article

, it is usually the atoms that behave as a probe for the field . this configuration has led to a number of experiments on fundamental aspects of quantum mechanics including the measurement of the decoherence of a cat state @xcite , qnd measurement of single photons @xcite , and the observation of quantum jumps of light @xcite .

Suppose that you have an abstract for a scientific paper: dirac equation describes the dynamics of a relativistic spin-1/2 particle regarding its spatial motion and intrinsic degrees of freedom . here we adopt the point of view that the spinors describe the state of a massive particle carrying two qubits of information : helicity and intrinsic parity . we show that the density matrix for a gas of free fermions , in thermal equilibrium , correlates helicity and intrinsic parity . our results introduce the basic elements for discussing the spin - parity correlation for a fermi gas : ( 1 ) at the ultra - relativistic domains , when the temperature is quite high , @xmath0 , the fermions have no definite intrinsic parity ( 50% : 50% ) , which is maximally correlated with the helicity ; ( 2 ) at very low temperature , @xmath1 , a unique parity dominates ( conventionally chosen positive ) , by @xmath2 to @xmath3 , while the helicity goes into a mixed state for spin up and down , and the quantum correlation decoheres . for the anti - fermions we get the opposite behavior . in the framework of quantum information , our result could be considered as a plausible explanation of why we do accept , as a fact ( consistent with the experimental observation ) , that fermions ( and anti - fermions ) , in our present epoch of a cool universe , have a unique intrinsic parity . the framework for constructing spin - parity entangled states is established . . And you have already written the first three sentences of the full article: dirac invented his relativistic equation in order to explain the quantum properties of the electron ( spin @xmath4 ) in the relativistic framework : the equation had to ( _ a _ ) display the formula @xmath5 as the eigenenergy of a particle in free motion ( with @xmath6 ) ; ( _ b _ ) be covariant under a lorentz transformation that links the particle dynamical properties between two inertial frames . dirac found that the sound equation had to be expressed , necessarily , in terms of @xmath7 matrices . its more familiar form is @xmath8 , with the hamiltonian being linear in the momentum @xmath9 , @xmath10 and the @xmath7 matrices @xmath11 and @xmath12 , have to satisfy forcefully the relations @xmath13 with @xmath14 for the unit matrix ( in dirac s book @xcite , instead of @xmath15 we find a @xmath7 matrix @xmath16 multiplying the @xmath7 direct product of pauli matrices @xmath17 ) .. Please generate the next two sentences of the article

an usual approach consists in the introduction of the chiral representation , where the components of the matrix vector , @xmath18 and @xmath19 , are respectively in contravariant and covariant forms , in the same fashion that one has @xmath20 and @xmath21 @xcite . the state vector solution to the dirac equation can be written as the sum , @xmath22 of left and right chiral spinors @xmath23 and @xmath24 , @xmath25 . from dirac equation plus eq

Suppose that you have an abstract for a scientific paper: we consider the problem of star consumption by supermassive black holes in non - spherical ( axisymmetric , triaxial ) galactic nuclei . we review the previous studies of the loss - cone problem and present a novel simulation method which allows to separate out the collisional ( relaxation - related ) and collisionless ( related to non - conservation of angular momentum ) processes and determine their relative importance for the capture rates in different geometries . we show that for black holes more massive than @xmath0 , the enhancement of capture rate in non - spherical galaxies is substantial , with even modest triaxiality being capable of keeping the capture rate at the level of few percent of black hole mass per hubble time . . And you have already written the first three sentences of the full article: the study of stellar dynamics around massive black holes begins in 1970s in application to ( still hypothetical ) intermediate - mass black holes in globular clusters @xcite . the early studies established the importance of two - body relaxation which changes angular momenta of individual stars and drives them into the loss cone the region in phase space in which a star would be captured by the black hole in at most one orbital period . later , the loss cone theory was applied to galactic nuclei @xcite .. Please generate the next two sentences of the article

if the black hole mass is not too large ( @xmath1 ) , a star lost into the black hole could produce a tidal disruption flare @xcite , and several candidate events have been observed to date ( e.g. * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: we present the first definitive measurement of the absolute magnitude of rr lyrae c - type variable stars ( rrc ) determined purely from statistical parallax . we use a sample of 247 rrc selected from the all sky automated survey ( asas ) for which high - quality light curves , photometry and proper motions are available . we obtain high - resolution echelle spectra for these objects to determine radial velocities and abundances as part of the carnegie rr lyrae survey ( carrs ) . we find that @xmath0 at a mean metallicity of @xmath1 } = -1.59 $ ] . this is to be compared with previous estimates for rrab stars ( @xmath2 ) and the only _ direct _ measurement of an rrc absolute magnitude ( rz cephei , @xmath3 ) . we find the bulk velocity of the halo to be @xmath4 in the radial , rotational and vertical directions with dispersions @xmath5 . for the disk , we find @xmath6 with dispersions @xmath7 . finally , we suggest that ucac2 proper motion errors may be overestimated by about 25% . . And you have already written the first three sentences of the full article: determining distances by use of multiple methods has a long and distinguished history in astronomy from antiquity to the present day . aristarchus of samos first determined the moon - earth distance from the lunar eclipse . a century later , hipparchus checked aristarchus values using the independent method of terrestrial parallax : the position of the lunar limb during solar eclipse as seen from alexandria and hellespont .. Please generate the next two sentences of the article

more recently , astronomers have demanded that multiple methods be employed for zeroing in on the precise parameters governing the currently observed and mysterious accelerated expansion of the universe @xcite . pulsating variables have enjoyed a privileged role in the local volume . due to their characteristic light curves and relatively bright absolute magnitudes compared to the bulk of main sequence stars ,

Suppose that you have an abstract for a scientific paper: we investigate isometric immersions of disks with constant negative curvature into @xmath0 , and the minimizers for the bending energy , _ i.e. _ the @xmath1 norm of the principal curvatures over the class of @xmath2 isometric immersions . we show the existence of smooth immersions of arbitrarily large geodesic balls in @xmath3 into @xmath0 . in elucidating the connection between these immersions and the non - existence / singularity results of hilbert and amsler , we obtain a lower bound for the @xmath4 norm of the principal curvatures for such smooth isometric immersions . we also construct piecewise smooth isometric immersions that have a periodic profile , are globally @xmath2 , and numerically have lower bending energy than their smooth counterparts . the number of periods in these configurations is set by the condition that the principal curvatures of the surface remain finite and grow approximately exponentially with the radius of the disc . we discuss the implications of our results on recent experiments on the mechanics of non - euclidean plates . nonlinear elasticity of thin objects , geometry of hyperbolic surfaces , pattern formation , morphogenesis in soft tissue . . And you have already written the first three sentences of the full article: the differential growth of thin elastic sheets can generate highly non - trivial configurations such as the multiple generation of waves along the edge of a torn elastic sheet @xcite and the wrinkled patterns on leaves @xcite . recently , environmentally responsive gel disks of uniform thickness have been created in the laboratory that mimic this type of growth by differentially shrinking in the radial direction when thermally activated in a hot water bath @xcite . the rate of shrinkage can be controlled , allowing for the creation of regions in the disk that shrink at different rates upon activation .. Please generate the next two sentences of the article

rippling occurs in regions that shrink slower than the center of the disk while regions that shrink faster obtain a spherical dome like shape . geometrically , these regions have positive and negative gaussian curvature respectively and by tuning the composition of the gel , different curvatures can be selected .

Suppose that you have an abstract for a scientific paper: disk fragmentation resulting from the gravitational instability has been proposed as an efficient mechanism for forming giant planets . we use the planet fomalhaut b , the triple - planetary system hr 8799 , and the potential protoplanet associated with hl tau to test the viability of this mechanism . we choose the above systems since they harbor planets with masses and orbital characteristics favored by the fragmentation mechanism . we do not claim that these planets _ must _ have formed as the result of fragmentation , rather the reverse : if planets can form from disk fragmentation , then these systems are consistent with what we should expect to see . we use the orbital characteristics of these recently discovered planets , along with a new technique to more accurately determine the disk cooling times , to place both lower and upper limits on the disk surface density and thus mass required to form these objects by disk fragmentation . our cooling times are over an order of magnitude shorter than those of @xcite , which makes disk fragmentation more feasible for these objects . we find that the required mass interior to the planet s orbital radius is @xmath0 for fomalhaut b , the protoplanet orbiting hl tau , and the outermost planet of hr 8799 . the two inner planets of hr 8799 probably could not have formed _ in situ _ by disk fragmentation . . And you have already written the first three sentences of the full article: as more extrasolar planets are discovered , we are increasingly pressed to describe how planets can form in such a variety of environments . until just recently , observational selection biases have resulted in the fact that all observed extrasolar planets have been found to orbit within a few au of their star @xcite . since it seems unlikely that these planets could have formed _ in situ _ @xcite , planet migration is usually invoked @xcite . unfortunately , this means that little is known about where and hence how . Please generate the next two sentences of the article

these planets originally formed . in contrast , the technique of direct - imaging has presented us with a new set of extrasolar planets that lie far from their star @xcite , along with a potential protoplanet @xcite . like previous techniques ,

Suppose that you have an abstract for a scientific paper: it has been shown recently that intermittency of the gledzer ohkitani yamada ( goy ) shell model of turbulence has to be related to singular structures whose dynamics in the inertial range includes interactions with a background of fluctuations . in this paper we propose a statistical theory of these objects by modelling the incoherent background as a gaussian white - noise forcing of small strength @xmath0 . a general scheme is developed for constructing instantons in spatially discrete dynamical systems and the cramr function governing the probability distribution of effective singularities of exponent @xmath1 is computed up to first order in a semiclassical expansion in powers of @xmath0 . the resulting predictions are compared with the statistics of coherent structures deduced from full simulations of the goy model at very high reynolds numbers . . And you have already written the first three sentences of the full article: are structures ( sheets or filaments of vorticity ) a vital ingredient of intermittency in 3d - incompressible turbulence ? to date , this important question remains open @xcite , and an answer starting from first principle , i.e. , from a controlled approximation to the navier - stokes equations , seems over the horizon . the new understanding of the anomalous scaling in the kraichnan s model of passive advection @xcite , based on the identification of zero modes in the homogeneous hopf equations for equal - time correlators , has in particular strengthened the belief that field - theoretical methods would eventually be able to capture the full statistics of turbulent flows without an explicit account of structures .. Please generate the next two sentences of the article

interestingly enough , the relative interplay between coherent ordered structures and incoherent turbulent fluctuations turns out to be a subtle matter already in the restricted framework of the so - called shell models of turbulence @xcite . it was noticed very soon @xcite that elementary bricks of intermittency in those deterministic 1d - cascade models could be pulses or bursts of activity growing in an almost self - similar way as they move from large to small scales

Suppose that you have an abstract for a scientific paper: the classic howard s algorithm , a technique of resolution for discrete hamilton - jacobi equations , is of large use in applications for its high efficiency and good performances . a special beneficial characteristic of the method is the superlinear convergence which , in presence of a finite number of controls , is reached in finite time . performances of the method can be significantly improved by using parallel computing ; how to build a parallel version of method is not a trivial point , the difficulties come from the strict relation between various values of the solution , even related to distant points of the domain . in this contribution we propose a parallel version of the howard s algorithm driven by an idea of domain decomposition . this permits to derive some important properties and to prove the convergence under quite standard assumptions . the good features of the algorithm will be shown through some tests and examples . * keywords : * howard s algorithm ( policy iterations ) , parallel computing , domain decomposition + * 2000 msc : * 49m15 , 65y05 , 65n55 . And you have already written the first three sentences of the full article: the _ howard s algorithm _ ( also called _ policy iteration algorithm _ ) is a classical method for solving a discrete hamilton - jacobi equation . this technique , developed by bellman and howard @xcite , is of large use in applications , thanks to its good proprieties of efficiency and simplicity . it was clear from the beginning that in presence of a space of controls with infinite elements , the convergence of the algorithm is comparable to newton s method .. Please generate the next two sentences of the article

this was shown under progressively more general assumptions @xcite until to @xcite , where using the concept of _ slant differentiability _ introduced in @xcite , the technique can be shown to be of semi - smooth newton s type , with all the good qualities in term of superlinear convergence and , in some cases of interest , even quadratic convergence . in this paper , we propose a parallel version of the policy iteration algorithm , discussing the advantages and the weak points of such proposal . in order to build such parallel algorithm

Suppose that you have an abstract for a scientific paper: the idea of applying machine learning(ml ) to solve problems in security domains is almost 3 decades old . as information and communications grow more ubiquitous and more data become available , many security risks arise as well as appetite to manage and mitigate such risks . consequently , research on applying and designing ml algorithms and systems for security has grown fast , ranging from intrusion detection systems(ids ) and malware classification to security policy management(spm ) and information leak checking . in this paper , we systematically study the methods , algorithms , and system designs in academic publications from 2008 - 2015 that applied ml in security domains . 98% of the surveyed papers appeared in the 6 highest - ranked academic security conferences and 1 conference known for pioneering ml applications in security . we examine the generalized system designs , underlying assumptions , measurements , and use cases in active research . our examinations lead to 1 ) a taxonomy on ml paradigms and security domains for future exploration and exploitation , and 2 ) an agenda detailing open and upcoming challenges . based on our survey , we also suggest a point of view that treats security as a game theory problem instead of a batch - trained ml problem . * keywords * : security , machine learning , large - scale applications , game theory , security policy management . And you have already written the first three sentences of the full article: since dorothy denning s seminal 1987 paper on intrusion detection @xcite , ml and data mining(dm ) have steadily gained attention in security applications . darpa s 1998 network intrusion detection evaluation @xcite , and kdd(conference on knowledge discovery and data mining ) cup s 1999 challenge @xcite have raised profile of ml in security contexts . yet , constrained by hardware and system resources@xcite , large - scale ml applications did not receive much attention for many years . in 2008. Please generate the next two sentences of the article

, acm conference on computer and communications security(ccs ) hosted the 1st artificial intelligence in security(aisec ) workshop , which has since been a dedicated venue at a top - level security conference for the intersection of ml and security . from 2008 , the pace of research and publicity of ml in security started to accelerate in academic communities ( section 2.3 ) , and industry venues ( e.g. black hat , rsa ) also shifted interests .

Suppose that you have an abstract for a scientific paper: in recent continuous - variable quantum memory experiment , one quadrature of light pulse is directly uploaded by the light - atom coupling whereas complementary quadrature is obtained by homodyne measurement of the out - coupled light . subsequently , information from homodyne measurement is written into the memory by feed - back electro - optical control of the atomic state . using the same experimental set - up , a deterministic noise excess free record of unknown quantum states to continuous - variable quantum atomic memory is proposed . further , the memory experiment is extended by the pre - squeezing of the recorded state of light and squeezing post - correction of the recorded state . to upload a resource to the memory , as single - photon state or superposition of coherent states , the post - selection of the measurement results from homodyne detection is suggested . then such the probabilistic upload approaches even a lossless transfer of these highly nonclassical states into the quantum memory . a non - classicality of quantum states is extremely fragile to disturbing effects of a noise coupled to the system . this is a real problem for the transmission and operations with the non - classical states . recently , the same problem arises also in a construction of quantum memory . the quantum memories have been recently demonstrated using electromagnetically - induced transparency @xcite and off - resonant faraday effect @xcite . it is useful to distinguish three basic steps : initial record ( or upload ) of the quantum state , its storage for a longer time inside the memory and final read - out from the memory . in addition , quantum state written to the memory can either carry encoded information or it can be a resource for other quantum operations . to distinguish these two cases , the record of quantum states is used for the states carrying information and the upload of quantum state for the resources . in the former case , encoded information makes the state to be at.... And you have already written the first three sentences of the full article: the noise excess free ( phase - insensitive ) quantum record / upload of single - mode light into the atomic memory can be defined by the transformation @xmath1 of the light quadratures @xmath2 and @xmath3 to the atomic quadratures @xmath4 and @xmath5 in the heisenberg picture . here @xmath6 stands for the transmission coefficient of the record / upload . the quadrature noisy operators @xmath7 and @xmath8 describe the added noises in the state transfer .. Please generate the next two sentences of the article

the variance of vacuum noise is considered to be unity . from the heisenberg uncertainty principle , the minimal variance of both @xmath7 and @xmath8 is @xmath9 ( @xmath10 ) . in this case

Suppose that you have an abstract for a scientific paper: electronic transport through a triple quantum dot system , with only a single dot coupled directly to external leads , is considered theoretically . the model includes coulomb correlations in the central dot , while such correlations in the two side - coupled dots are omitted . the infinite-@xmath0 mean - field slave - boson approach is used to obtain basic transport characteristics in the kondo regime . when tuning position of the side - coupled dots levels , transition from _ subradiant _ to _ superradiant _ like mode ( and _ vice versa _ ) has been found in the spectral function , in analogy to the dicke effect in atomic physics . bias dependence of the differential conductance and zero frequency shot noise is also analysed . . And you have already written the first three sentences of the full article: kondo effect in electronic transport through quantum dots ( qds ) strongly coupled to external leads is a many body phenomenon which occurs at temperatures @xmath1 lower than the so - called kondo temperature @xmath2 , @xmath3 . the kondo temperature is characteristic of a particular system and depends on the corresponding parameters ( energy of the dot level , coupling strength to external leads , coulomb parameter ) . spin fluctuations in the dot , generated by coupling of the dot to external leads , give rise to a narrow peak in the dot s density of states ( dos ) at the fermi level .. Please generate the next two sentences of the article

this kondo peak enhances transmission through the dot , and leads to the unitary limit of the linear conductance at zero temperature , where the conductance reaches @xmath4 . the kondo peak in dos also leads to the so - called zero - bias ( kondo ) anomaly in the differential conductance .

Suppose that you have an abstract for a scientific paper: different aspects of probabilistic shaping for a multi - span optical communication system are studied . first , a numerical analysis of the additive white gaussian noise ( awgn ) channel investigates the effect of using a small number of input probability mass functions ( pmfs ) for a range of signal - to - noise ratios ( snrs ) , instead of optimizing the constellation shaping for each snr . it is shown that if a small penalty of at most 0.1 db snr to the full shaping gain is acceptable , just two shaped pmfs are required per quadrature amplitude modulation ( qam ) over a large snr range . for a multi - span wavelength division multiplexing ( wdm ) optical fiber system with 64qam input , it is shown that just one pmf is required to achieve large gains over uniform input for distances from 1,400 km to 3,000 km . using recently developed theoretical models that extend the gaussian noise ( gn ) model and full - field split - step simulations , we illustrate the ramifications of probabilistic shaping on the effective snr after fiber propagation . our results show that , for a fixed average optical launch power , a shaping gain is obtained for the noise contributions from fiber amplifiers and modulation - independent nonlinear interference ( nli ) , whereas shaping simultaneously causes a penalty as it leads to an increased nli . however , this nonlinear shaping loss is found to have a relatively minor impact , and optimizing the shaped pmf with a modulation - dependent gn model confirms that the pmf found for awgn is also a good choice for a multi - span fiber system . achievable information rates , bit - wise decoders , gaussian noise models , mutual information , nonlinear fiber channel , probabilistic shaping , wavelength division multiplexing . . And you have already written the first three sentences of the full article: a series of revolutionary technological advances , optical transmission systems have enabled the growth of internet traffic for decades @xcite . most of the huge bandwidth of fiber systems is in use @xcite and the capacity of the optical core network can not keep up with the traffic growth @xcite . the usable bandwidth of an optical communication system with legacy standard single - mode fiber ( smf ) is effectively limited by the loss profile of the fiber and the erbium - doped fiber amplifiers ( edfas ) placed between every span .. Please generate the next two sentences of the article

it is thus of high practical importance to increase the spectral efficiency ( se ) in optical fiber systems . even with new fibers , the transceiver will eventually become a limiting factor in the pursuit of higher se because the practically achievable signal - to - noise ratio ( snr ) can be limited by transceiver electronics @xcite .

Suppose that you have an abstract for a scientific paper: we study the bulk viscosity taking dust matter in the generalized teleparallel gravity . we consider different dark energy models in this scenario along with a time dependent viscous model to construct the viscous equation of state parameter for these dark energy models . we discuss the graphical representation of this parameter to investigate the viscosity effects on the accelerating expansion of the universe . it is mentioned here that the behavior of the universe depends upon the viscous coefficients showing the transition from decelerating to accelerating phase . it leads to the crossing of phantom divide line and becomes phantom dominated for specific ranges of these coefficients . * keywords : * @xmath0 gravity ; viscosity ; effective equation of state . + * pacs : * 04.50.kd ; 95.36.+x . And you have already written the first three sentences of the full article: dark energy ( de ) seems to play an important role of an agent that drives the present acceleration of the universe with the help of large negative pressure . an effective viscous pressure can also play its role to develop the dynamical history of an expanding universe @xcite-@xcite . it is found @xcite that viscosity effects are viable at low redshifts , which observe negative pressure for the cosmic expansion with suitable viscosity coefficients . in general , the universe inherits dissipative processes @xcite , but perfect fluid is an ideal fluid with zero viscosity .. Please generate the next two sentences of the article

although , perfect fluid is mostly used to model the idealized distribution of matter in the universe . this fluid in equilibrium generates no entropy and no frictional type heat because its dynamics is reversible and without dissipation .

Suppose that you have an abstract for a scientific paper: we consider continuous quantum measurement of a superconducting qubit in the circuit qed setup with a moderate bandwidth of the measurement resonator , i.e. , when the `` bad cavity '' limit is not applicable . the goal is a simple description of the quantum evolution due to measurement , i.e. , the measurement back - action . extending the quantum bayesian approach previously developed for the `` bad cavity '' regime , we show that the evolution equations remain the same , but now they should be applied to the entangled qubit - resonator state , instead of the qubit state alone . the derivation uses only elementary quantum mechanics and basic properties of coherent states , thus being accessible to non - experts . . And you have already written the first three sentences of the full article: the problem of instantaneous wavefunction collapse ( reduction ) due to measurement @xcite has been a stumbling block for many physicists since the creation of quantum mechanics . the unavoidable `` spookiness '' @xcite of the quantum collapse is related to the impossibility to find a traditional physical mechanism responsible for the collapse . mathematically , the `` spookiness '' can be expressed via violation of the bell inequalities @xcite . even though this violation @xcite is common knowledge nowadays ,. Please generate the next two sentences of the article

the mechanism and interpretation of the collapse remain debatable @xcite . a natural approach to understanding the physics of the wavefunction reduction is through analysis of the gradual evolution at a shorter time scale , i.e. , `` inside '' the collapse . a few decades ago there was an idea that such an evolution can be fully described by decoherence .

Suppose that you have an abstract for a scientific paper: for two symmetric quantum states one may be interested in maximizing the overlap under local operations applied to one of them . the question arises whether the maximal overlap can be obtained by applying the same local operation to each party . we show that for two symmetric multiqubit states and local unitary transformations this is the case ; the maximal overlap can be reached by applying the same unitary matrix everywhere . for local invertible operations ( stochastic local operations assisted by classical communication equivalence ) , however , we present counterexamples , demonstrating that considering the same operation everywhere is not enough . . And you have already written the first three sentences of the full article: in many applications and implementations of quantum information processing , one has to compare two different quantum states . in this context , the quantum fidelity @xcite is a very useful tool to measure the `` closeness '' between two states in the hilbert space of a quantum system . for two arbitrary states @xmath0 and @xmath1 , it is defined as @xmath2 for any pair of pure states @xmath3 and @xmath4 , the quantum fidelity reduces to their ( squared ) overlap , @xmath5 . although the fidelity does not define a metric on the state space , it is the core ingredient for several of them , like for instance the bures distance @xmath6^{1/2}$ ] @xcite .. Please generate the next two sentences of the article

the fidelity is also widely used to define various entanglement monotones . the bures distance @xmath7 is itself such an example @xcite . for multipartite pure states , the geometric measure of entanglement

Suppose that you have an abstract for a scientific paper: most models designed to study the bidirectional movement of cargos as they are driven by molecular motors rely on the idea that motors of different polarities can be coordinated by external agents if arranged into a motor - cargo complex to perform the necessary work @xcite . although these models have provided us with important insights into these phenomena , there are still many unanswered questions regarding the mechanisms through which the movement of the complex takes place on crowded microtubules . for example ( i ) how does cargo - binding affect motor motility ? and in connection with that - ( ii ) how does the presence of other motors ( and also other cargos ) on the microtubule affect the motility of the motor - cargo complex ? we discuss these questions from a different perspective . the movement of a cargo is conceived here as a _ hopping process _ resulting from the transference of cargo between neighboring motors . in the light of this , we examine the conditions under which cargo might display bidirectional movement even if directed by motors of a single polarity . the global properties of the model in the long - time regime are obtained by mapping the dynamics of the collection of interacting motors and cargos into an asymmetric simple exclusion process ( asep ) which can be resolved using the matrix _ ansatz _ introduced by derrida @xcite . _ keywords - _ intracellular transport by molecular motors ; bidirectional movement of cargo , traffic jam on microtubules ; asep models . . And you have already written the first three sentences of the full article: research interest in the origins of the long - range bidirectional movement of particles ( organelles , vesicles , nutrients ) driven by molecular motors is motivated by fundamental questions concerning the nature of interactions between motors and their cargos as transport processes take place . a current explanation for the phenomenon relies on the idea that motors of different polarities act coordinately on the same particle at different times . if , however , they act in parallel , the bidirectional movement would reflect dominance of one or another kind of motor achieved by a _ tug - of - war _ mechanism @xcite , @xcite , @xcite , @xcite , @xcite . an important question that remains in this context concerns the mechanisms that would promote such coordination @xcite . alternatives to the coordination or _ tug - of - war _ models in the literature arise from the possibility of attributing the phenomenon to a dynamic role of the microtubules @xcite or to a mechanical coupling between different motors @xcite .. Please generate the next two sentences of the article

a general difficulty encountered within any of these views is related to the presence of other particles ( including other motors ) on the microtubule at a given time that are not directly involved with the transfer process . these other particles are expected to impose restrictions on motility and performance of the motors that are directly interacting with cargo at that time @xcite .

Suppose that you have an abstract for a scientific paper: we analyse a supersymmetric mechanical model derived from @xmath0-dimensional field theory with yukawa interaction , assuming that all physical variables take their values in a grassmann algebra @xmath1 . utilizing the symmetries of the model we demonstrate how for a certain class of potentials the equations of motion can be solved completely for any @xmath1 . in a second approach we suppose that the grassmann algebra is finitely generated , decompose the dynamical variables into real components and devise a layer - by - layer strategy to solve the equations of motion for arbitrary potential . we examine the possible types of motion for both bosonic and fermionic quantities and show how symmetries relate the former to the latter in a geometrical way . in particular , we investigate oscillatory motion , applying results of floquet theory , in order to elucidate the role that energy variations of the lower order quantities play in determining the quantities of higher order in @xmath1 . . And you have already written the first three sentences of the full article: classical supersymmetry sets out to extend the unified treatment of bosonic and fermionic quantities in the usual qft framework to the classical level . normally , in semiclassical treatments the fermionic variables are set to zero as soon as the supersymmetric theory has been constructed . the usual argument goes that since we can not find classical fermions in nature , fermionic quantities should be omitted altogether at the classical level . however , this is far from necessary .. Please generate the next two sentences of the article

in fact , a consistent approach to classical supersymmetry has long been available for a review see e.g. the book by de witt @xcite . fermionic quantities are then treated as anticommuting variables taking values in a grassmann algebra @xmath1 .

Suppose that you have an abstract for a scientific paper: the problem of identifying the dynamical lie algebras of finite - level quantum systems subject to external control is considered , with special emphasis on systems that are not completely controllable . in particular , it is shown that the dynamical lie algebra for an @xmath0-level system with symmetrically coupled transitions , such as a system with equally spaced energy levels and uniform transition dipole moments , is a subalgebra of @xmath1 if @xmath2 , and a subalgebra of @xmath3 if @xmath4 . general criteria for obtaining either @xmath5 or @xmath3 are established . . And you have already written the first three sentences of the full article: in @xcite we studied the problem of complete controllability of finite - level quantum systems with nearest - neighbour interactions . we showed that many quantum systems of physical interest are indeed completely controllable but that there are nevertheless systems with certain symmetries that are not completely controllable . this paper is devoted to identifying the dynamical lie algebras for the latter systems . as in the previous paper. Please generate the next two sentences of the article

, we consider the case of a driven quantum system , for which the interaction with the control field is linear , i.e. , we assume that the total hamiltonian of the system is @xmath6 where @xmath7 is the internal system hamiltonian and @xmath8 represents the interaction of the system with the real control field @xmath9 . we assume that @xmath7 and @xmath8 are hermitian . for a finite - level quantum system

Suppose that you have an abstract for a scientific paper: we study multipartite bell nonlocality in a framework native of multipartite einstein - podolsky - rosen ( epr ) steering scenarios with a single trusted measurement device . we derive a closed - form necessary and sufficient criterion for systems composed of a qubit and @xmath0 untrusted black - box measurement devices to violate under general dichotomic measurements on the qubit a generic bell inequality from a broad family of linear inequalities with arbitrarily many outputs for the @xmath0 untrusted devices and inputs for all @xmath1 parties . the optimal quantum measurements for maximal violation are also obtained . for two users , and two inputs and two outputs per user , our criterion becomes necessary and sufficient for bell nonlocality . furthermore , in that setting , its form generalizes recently obtained steering inequalities , which allows us to provide useful feedback from nonlocality to the detection of steering . our findings constitute a practical tool for the study of the interplay between epr steering and bell nonlocality , with potential applications in multipartite information processing . _ introduction_. composite quantum systems can display exotic forms of non - classical correlations , a phenomenon known under the generic name of _ quantum nonlocality_. quantum nonlocal correlations can appear in three main variants . the first one is _ entanglement _ , which refers to inseparability of quantum states ( described by density matrices ) @xcite . the second one is _ bell nonlocality _ @xcite , the impossibility of explaining measurement statistics ( described by joint probability distributions ) with local hidden - variable ( lhv ) models @xcite . the third variant is called _ einstein - podolsky - rosen ( epr ) steering _ @xcite , after the famous epr paper @xcite . this is an effect by which ensembles of quantum states are remotely prepared by local measurements at distant labs @xcite . the observable data in steering experiments thus consist of the.... And you have already written the first three sentences of the full article: to prove our main theorem , we need to maximize the bell expression @xmath93,\,\boldsymbol{b}\in[\boldsymbol{o}],\,x\in[m],\,\boldsymbol{y}\in[\boldsymbol{m } ] } \beta_{a,\boldsymbol{b},x,\boldsymbol{y } } \ , \operatorname{tr}\left[m^{(a)}_x\,\sigma_{\boldsymbol{b}|\boldsymbol{y}}\right ] \label{eq : bell_ineqexcltriv}\ ] ] over all sets @xmath94}$ ] of generic dichotomic povm measurements @xmath95 by alice . however , it is known that , to test for bell nonlocality of quantum states , it suffices to examine only von neumann ( rank-1 projective ) measurements @xcite . the same happens for bell violations by assemblages , which we formalize with the following lemma . [ lemma : excludingpovms ] let @xmath32 be an arbitrary well - behaved bell inequality with dichotomic outputs for alice and @xmath44 a generic qubit assemblage . then , the maximal violation of @xmath32 by @xmath44 is attained under rank-1 projective measurements . _. Please generate the next two sentences of the article

proof_. our proof strategy consists in showing that , for an arbitrary assemblage @xmath44 and generic dichotomic povm measurements @xmath96 , the distribution @xmath97 , given by eq . , obtained from @xmath44 under @xmath96 , is equivalent to a distribution @xmath98 obtained from @xmath44 under a set @xmath99 of von neumann measurements followed by a local mixing of alice s outputs . since @xmath32 is well behaved , this implies that if @xmath97 violates @xmath32 , i.e. if @xmath53 , then @xmath100 , which implies that the maximal violation is always attained under von neumann measurements . since , for all @xmath101 $ ] , the povm measurement operators @xmath102 and @xmath103 are both non - negative , they can be diagonalized as @xmath104 where @xmath105 and @xmath106 are rank-1 orthonormal projectors i.e. @xmath107 , being @xmath108 the kronecker delta acting on @xmath19 , and where @xmath109 for @xmath110 . hence , @xmath111}$ ] defines a set of von neumann measurements . substituting eq . into eq . ( [ eq : pofsigma ] ) , we find that @xmath112 \ , \end{aligned}\ ] ] where we have introduced @xmath113 now , defining the distribution @xmath98 such that @xmath114 $ ] , we can write @xmath115 } q(a|a',x ) \

Suppose that you have an abstract for a scientific paper: i present a new method to unveil the history of cosmic accretion and the build - up of supermassive black holes ( smbh ) in the nuclei of galaxies , based on observations of the evolving radio and ( hard ) x - ray luminosity functions of agn . the fundamental plane of black hole activity discovered by merloni , heinz & di matteo ( 2003 ) is used as a mass and accretion rate estimator . i adopt the local bh mass function as a boundary condition to integrate backwards in time the continuity equation for the smbh evolution , neglecting the role of mergers . under the most general assumption that accretion proceeds in a radiatively efficient way above a certain rate , and in a radiatively inefficient way below , the redshift evolution of the mass and accretion rate functions are calculated self - consistently . the only tunable parameters are the accretion efficiency and the critical ratio of the x - ray to eddington luminosity at which the transition between accretion modes takes place . the evolution of the bh mass function between @xmath0 and @xmath1 shows clear signs of an anti - hierarchical behaviour : while the majority of the most massive objects ( @xmath2 ) were already in place at @xmath1 , lower mass ones mainly grew at progressively lower redshift . as an example , i will discuss the consequences of these results for the lifetimes of accreting black holes . . And you have already written the first three sentences of the full article: it has been known for the last ten years that the cosmological evolution of massive galaxies shows signs of ` down - sizing ' @xcite , i.e. of a progressive decrease of the typical mass of actively star forming galaxies . many pieces of evidence , brought forward also during this meeting ( see e.g. the contributions of bender , kauffmann and danese to these proceedings ) , suggest that the baryonic physics of star formation processes counterbalance the hierarchical ( bottom - up ) growth of dark matter structures , favouring the early formation and growth of the most massive ( and dense ) stellar aggregates . the ubiquity of smbh in galactic nuclei , and their tight relation with their hosts bulge properties @xcite seem to indicate that the formation and growth of galaxies and of their resident black holes have proceeded in parallel , and probably influenced each other in the early stages of galaxy formation . as a matter of fact , the number of theoretical studies dedicated to agn feedback in galaxy formation has flourished in the last five years ( see e.g. loeb s contribution in this proceedings , and references therein ) .. Please generate the next two sentences of the article

furthermore , a recent comprehensive study of 23 000 local agn carried out by the sloan digital sky survey ( sdss , @xcite ) have demonstrated , in a direct quantitative way , that accretion onto smbh and formation of stars are tightly coupled even in the local universe . is it possible to learn more about the formation and growth of structures by just looking at the evolution of the agn population ?

Suppose that you have an abstract for a scientific paper: recently , cesium atoms in optical lattices subjected to cycles of unequally - spaced pulses have been found to show interesting behavior : they represent the first experimental demonstration of a hamiltonian ratchet mechanism , and they show strong variability of the dynamical localization lengths as a function of initial momentum . the behavior differs qualitatively from corresponding atomic systems pulsed with equal periods , which are a textbook implementation of a well - studied quantum chaos paradigm , the quantum @xmath0-kicked particle ( @xmath0-qkp ) . we investigate here the properties of the corresponding eigenstates ( floquet states ) in the parameter regime of the new experiments and compare them with those of the eigenstates of the @xmath0-qkp at similar kicking strengths . we show that , with the properties of the floquet states , we can shed light on the form of the observed ratchet current as well as variations in the dynamical localization length . . And you have already written the first three sentences of the full article: periodically - kicked quantum systems , such as the @xmath0-kicked particle ( @xmath0-kp ) , have long played a central role in studies of quantum chaos and the correspondence between quantum behavior and the underlying classical dynamics @xcite . advances in the manipulation of cold atoms have permitted the experimental realization of these systems in pulsed optical lattices @xcite . experiments with sodium and cesium atoms have demonstrated the phenomenon of `` dynamical localization '' ( dl ) the quantum suppression of classical chaotic diffusion and established the suitability of these systems as an arena for the study of effects arising from quantum chaos .. Please generate the next two sentences of the article

when treating conservative quantum systems it is frequently useful to study the system s energy - eigenstates , and for periodically driven systems the appropriate generalization of these states is given by the floquet states . this approach has provided extensive insight into the properties of the standard qkp , and has shown , for example , that dl arises directly from the exponential localization of the system s floquet states @xcite . observed momentum oscillations associated with chaos - assisted tunneling , in experiments using periodically - driven cold atoms @xcite and becs @xcite have also been analysed with floquet theory ; it was found that the oscillation period is determined by the splittings of the floquet phases of a pair of symmetry - related eigenstates .

Suppose that you have an abstract for a scientific paper: we construct density dependent class @xmath0 charge symmetry violating ( csv ) potential due to mixing of @xmath1-@xmath2 meson with off - shell corrections . here in addition to the usual vacuum contribution , the matter induced mixing of @xmath1-@xmath2 is also included . it is observed that the contribution of density dependent csv potential is comparable to that of the vacuum contribution . . And you have already written the first three sentences of the full article: the exploration of symmetries and their breaking have always been an active and interesting area of research in nuclear physics . one of the well known examples , that can be cited here , is the nuclear @xmath3 decay which violates parity that led to the discovery of the weak interaction . our present concern , however , is the strong interaction where , in particular , we focus attention to the charge symmetry violation ( csv ) in nucleon - nucleon ( @xmath4 ) interaction .. Please generate the next two sentences of the article

charge symmetry implies invariance of the @xmath4 interaction under rotation in isospin space , which in nature , is violated . the csv , at the fundamental level is caused by the finite mass difference between up @xmath5 and down @xmath6 quarks @xcite . as a consequence , at the hadronic level , charge symmetry ( cs )

Suppose that you have an abstract for a scientific paper: in this paper we present a brief description of a ladder operator formalism applied to orthogonal polynomials with discontinuous weights . the two coefficient functions , @xmath0 and @xmath1 , appearing in the ladder operators satisfy the two fundamental compatibility conditions previously derived for smooth weights . if the weight is a product of an absolutely continuous reference weight @xmath2 and a standard jump function , then @xmath0 and @xmath1 have apparent simple poles at these jumps . we exemplify the approach by taking @xmath2 to be the hermite weight . for this simpler case we derive , without using the compatibility conditions , a pair of difference equations satisfied by the diagonal and off - diagonal recurrence coefficients for a fixed location of the jump . we also derive a pair of toda evolution equations for the recurrence coefficients which , when combined with the difference equations , yields a particular painlev iv . . And you have already written the first three sentences of the full article: we begin this section by fixing the notation . let @xmath3 be monic polynomials of degree @xmath4 in @xmath5 and orthogonal , with respect to a weight , @xmath6 $ ] , @xmath7 where @xmath8 is the square of the weighted @xmath9 norm of @xmath10 also , @xmath11 for convenience we set @xmath12 . the recurrence relation follows from the orthogonality condition : @xmath13 where @xmath14 , the @xmath15 are real and @xmath16 are strictly positive . in this paper. Please generate the next two sentences of the article

we describe a formalism which will facilitate the determination of the recurrence coefficients for polynomials with singular weights . two points of view lead to this problem : on one hand the x - ray problem @xcite of condensed matter theory , on the other hand related problems in random matrix theory which involve the asymptotics of the fredholm determinant of finite convolution operators with discontinuous symbols @xcite .

Suppose that you have an abstract for a scientific paper: manifold matching works to identify embeddings of multiple disparate data spaces into the same low - dimensional space , where joint inference can be pursued . it is an enabling methodology for fusion and inference from multiple and massive disparate data sources . in this paper we focus on a method called canonical correlation analysis ( cca ) and its generalization generalized canonical correlation analysis ( gcca ) , which belong to the more general reduced rank regression ( rrr ) framework . we present an efficiency investigation of cca and gcca under different training conditions for a particular text document classification task . manifold matching , canonical correlation analysis , reduced rank regression , efficiency , classification . . And you have already written the first three sentences of the full article: in the real world , one single object may have different representations in different domains . for example , the declaration of independence has versions translated into different languages . let @xmath0 denote the number of objects @xmath1 , and @xmath2 be the number of domains .. Please generate the next two sentences of the article

then we have @xmath3 where the @xmath4th object @xmath5 has @xmath2 measurements @xmath6 ; @xmath7 is the representation for object @xmath5 in space @xmath8 . the problem explored in this paper is that for @xmath9 new objects @xmath10 , how to classify their representations @xmath11 given the representations @xmath12 with @xmath13 .

Suppose that you have an abstract for a scientific paper: we simulate light propagation in perturbed whispering - gallery mode microcavities using a two - dimensional finite - difference beam propagation method in a cylindrical coordinate system . optical properties of whispering - gallery microcavities perturbed by polystyrene nanobeads are investigated through this formulation . the light perturbation as well as quality factor degradation arising from cavity ellipticity are also studied . 10 m. l. gorodetsky , a. a. savchenkov , and v. s. ilchenko , `` ultimate q of optical microsphere resonators , '' optics letters * 21 * , 453455 ( 1996 ) . d. k. armani , t. j. kippenberg , s. m. spillane , and k. j. vahala , `` ultra - high - q toroid microcavity on a chip , '' nature * 421 * , 925928 ( 2003 ) . f. vollmer , d. braun , a. libchaber , m. khoshsima , i. teraoka , and s. arnold , `` protein detection by optical shift of a resonant microcavity , '' applied physics letters * 80 * , 40574059 ( 2002 ) . f. vollmer and s. arnold , `` whispering - gallery - mode biosensing : labelfree detection down to single molecules , '' nat . methods * 5 * , 591596 ( 2008 ) . t. lu , h. lee , t. chen , s. herchak , j .- h . kim , s. e. fraser , and k. vahala , `` high sensitivity nanoparticle detection using optical microcavities , '' pnas * 108 * , 59765979 ( 2011 ) . j. dominguez - juarez , g. kozyreff , and j. martorell , `` whispering gallery microresonators for second harmonic light generation from a low number of small molecules , '' nautre communications * 2 * , 18 ( 2010 ) . j. knittel , t. g. mcrae , k. h. lee , and w. p. bowen , `` interferometric detection of mode splitting for whispering gallery mode biosensors , '' applied physics letters * 97 * , 13 ( 2010 ) . y. sun and x. fan , `` optical ring resonators for biochemical and chemical sensing , '' anal bioanal chem * 399 * , 205211 ( 2011 ) . s. spillane , t. j. kippenberg , and k. j. vahala , `` ultralow - threshold raman laser.... And you have already written the first three sentences of the full article: whispering - gallery mode ( wgm ) microcavities are at the frontier of research on subjects ranging from biosensing , nonlinear optics , and laser physics , to fundamental physics such as cavity quantum electrodynamics@xcite . contrary to its rapid experimental advances , numerical exploration of wgm s has been largely lagging behind with a limited number of available options@xcite . on the other hand , the beam propagation method ( bpm ) has a long history@xcite in modelling light propagation along both straight and curved waveguides as well as whispering - gallery microcavity eigenmode analyses@xcite . compared to boundary element@xcite , finite element@xcite , finite - difference time - domain@xcite , and free space radiation mode methods@xcite , bpm remains highly efficient without sacrificing substantial accuracy . by adopting a perfectly matched layer ( pml)@xcite to absorb the light which is otherwise reflected at the computation window and following the procedure formulated in @xcite to correct inaccuracies incurred at the refractive index discontinuities in high refractive index contrast waveguide structures , the finite - difference beam propagation method ( fd - bpm ) can achieve high accuracy with a rapid convergence rate .. Please generate the next two sentences of the article

conventional fd - bpm formulations are based on the fresnel approximation , where light is assumed to propagate close to the propagation axis@xcite . to overcome this limitation for bent waveguide modelling , high - order algorithms known as wide - angle bpm@xcite or the conformal mapping approach@xcite are desirable . alternatively , bpm may be reformulated in cylindrical coordinates systems to analyze such structures@xcite . in this work , we simulated the light propagation in a wgm microcavity by implementing fd - bpm in a cylindrical system as shown in fig .

Suppose that you have an abstract for a scientific paper: * abstract : * a gravitational theory of a scalar field non - minimally coupled with torsion and boundary term is considered with the aim to construct lorentzian wormholes . geometrical parameters including shape and redshift functions are obtained for these solutions . we adopt the formalism of noether gauge symmetry approach in order to find symmetries , lie brackets and invariants ( conserved quantities ) . furthermore by imposing specific forms of potential function , we are able to calculate metric coefficients and discuss their geometrical behavior . . And you have already written the first three sentences of the full article: the notion of lorentzian wormholes ( wh ) arose when morris and thorne explored the possibility of time travels for humans using the principles of general relativity ( gr ) @xcite . einstein s theory of gr predicts that the structure and geometry of spacetime in the presence of matter is not rigid but it is elastic and deformable . the more compact the object is , the more strong the curvature of space is , which essentially leads to the idea of black holes .. Please generate the next two sentences of the article

however in the later case , the fabric of spacetime loses its meaning at the curvature singularity . if somehow the formation of singularity is avoided then it would be possible to travel in and out of the horizon .

Suppose that you have an abstract for a scientific paper: within the context of the concordance model of cosmology we test the consistency of the angular power spectrum data from wmap and planck looking for possible systematics . the best fit concordance model to each observation is used as a mean function along with a crossing function with an orthogonal basis to fit the data from the other observation searching for any possible deviation . we report that allowing an overall amplitude shift in the observed angular power spectra of the two observations , the best fit mean function from planck data is consistent with wmap 9 year data but the best fit mean function generated from wmap-9 data is not consistent with planck data at the @xmath0 level . this is an expected result when there is no clear systematic / tension between two observations and one of them has a considerably higher precision . we conclude that there is no clear tension between planck and wmap 9 year angular power spectrum data from a statistical point of view ( allowing the overall amplitude shift ) . our result highlights the fact that while the angular power spectrum from cosmic microwave background observations is a function of various cosmological parameters , comparing individual parameters might be misleading in the presence of cosmographic degeneracies . another main result of our analysis is the importance of the overall amplitudes of the observed spectra from planck and wmap observations . fixing the amplitudes at their reported values results in an unresolvable tension between the two observations at more than @xmath0 level which can be a hint towards a serious systematic . @xmath1 and @xmath2 + _ @xmath1asia pacific center for theoretical physics , pohang , gyeongbuk 790 - 784 , korea + @xmath3department of physics , postech , pohang , gyeongbuk 790 - 784 , korea _ + . And you have already written the first three sentences of the full article: cosmological observations , in particular the data from cosmic microwave background ( cmb ) , have been providing us knowledge of the history and constituents of the universe since the cosmic background explorer survey . over time we have been able to constrain our knowledge of the early universe with increasing precision . two full sky satellite surveys of cmb , the wilkinson microwave anisotropy probe ( wmap ) @xcite and planck @xcite , have released their data very recently ( last release of wmap data and first release of planck data ) . as the most precise cmb observation. Please generate the next two sentences of the article

, planck has modified the derived cosmological parameters that we had obtained from the wmap and other cmb surveys including the atacama cosmology telescope @xcite and the south pole telescope @xcite . surprisingly , within the same framework of the standard concordance @xmath4cdm model , we find that the values of some of the key cosmological parameters derived from planck data are significantly different than the derived values from earlier cmb observations .

Suppose that you have an abstract for a scientific paper: the electron - positron annihilation spectrum observed by spi / integral during deep galactic center region exposure is reported . the line energy ( 510.954@xmath00.075 kev ) is consistent with the unshifted annihilation line . the width of the annihilation line is 2.37@xmath00.25 kev ( fwhm ) , while the strength of the ortho - positronium continuum suggests that the dominant fraction of positrons ( 94@xmath06% ) form positronium before annihilation . compared to the previous missions these deep integral observations provide the most stringent constraints on the line energy and width . under the assumption of an annihilation in a single - phase medium these spectral parameters can be explained by a warm @xmath1 k gas with the degree of ionization larger than a few @xmath2 . one of the wide - spread ism phases - warm ( @xmath3 k ) and weakly ionized ( degree of ionization @xmath4 0.1 ) medium satisfies these criteria . other single - phase solutions are also formally allowed by the data ( e.g. cold , but substantially ionized ism ) , but such solutions are believed to be astrophysically unimportant . the observed spectrum can also be explained by the annihilation in a multi - phase ism . the fraction of positrons annihilating in a very hot ( @xmath5 k ) phase is constrained to be less than @xmath48% . neither a moderately hot ( @xmath6 k ) ionized medium nor a very cold ( @xmath7 k ) neutral medium can make a dominant contribution to the observed annihilation spectrum . however , a combination of cold / neutral , warm / neutral and warm / ionized phases in comparable proportions could also be consistent with the data . epsf # 1= # 1=1.98 # 1#2=.99 = .99 # 1#2#3=.31 = .31 = .31 [ firstpage ] galaxy : center gamma rays : observations ism : general . And you have already written the first three sentences of the full article: the annihilation line of positrons at 511 kev is the brightest gamma - ray line in the galaxy . first observed with a nai scintillator as a @xmath4 476 kev line coming from the galactic center ( gc ) region ( johnson , harnden & haymes , 1972 ; johnston & haymes , 1973 ) , it was subsequently unambiguously identified with a narrow ( @xmath8 kev ) @xmath9 annihilation line using germanium detectors ( leventhal , maccallum , stang , 1978 ) . since then many balloon flights and several space missions have measured the spatial distribution and spectral properties of the line .. Please generate the next two sentences of the article

a summary of the high energy resolution observations of the 511 kev line prior to integral and the first spi / integral results can be found in jean et al . ( 2003 ) and teegarden et al .

Suppose that you have an abstract for a scientific paper: the quotient complexity , also known as state complexity , of a regular language is the number of distinct left quotients of the language . the quotient complexity of an operation is the maximal quotient complexity of the language resulting from the operation , as a function of the quotient complexities of the operands . the class of star - free languages is the smallest class containing the finite languages and closed under boolean operations and concatenation . we prove that the tight bounds on the quotient complexities of union , intersection , difference , symmetric difference , concatenation , and star for star - free languages are the same as those for regular languages , with some small exceptions , whereas the bound for reversal is @xmath0 . * keywords : * aperiodic , automaton , complexity , language , operation , quotient , regular , star - free , state complexity . And you have already written the first three sentences of the full article: the class of regular languages can be defined as the smallest class containing the finite languages and closed under union , concatenation and star . since regular languages are also closed under complementation , one can redefine them as the smallest class containing the finite languages and closed under boolean operations , concatenation and star . in this new formulation , a natural question is that of the _ generalized star height _ of a regular language , which is the minimum number of nested stars required to define the language when boolean operations are allowed .. Please generate the next two sentences of the article

it is not clear who first considered the problem of generalized star height , but mcnaughton and papert reported in their 1971 monograph @xcite that this problem had been open `` for many years '' . there exist regular languages of star height 0 and 1 , but it is not even known whether there exists a language of star height 2 .

Suppose that you have an abstract for a scientific paper: we measure the logarithmic scatter in mass at fixed richness for clusters in the maxbcg cluster catalog , an optically selected cluster sample drawn from sdss imaging data . our measurement is achieved by demanding consistency between available weak lensing and x - ray measurements of the maxbcg clusters , and the x - ray luminosity mass relation inferred from the 400d x - ray cluster survey , a flux limited x - ray cluster survey . we find @xmath0 ( @xmath1 cl ) at @xmath2 , where @xmath3 is the number of red sequence galaxies in a cluster . as a byproduct of our analysis , we also obtain a constraint on the correlation coefficient between @xmath4 and @xmath5 at fixed richness , which is best expressed as a lower limit , @xmath6 . this is the first observational constraint placed on a correlation coefficient involving two different cluster mass tracers . we use our results to produce a state of the art estimate of the halo mass function at @xmath7 the median redshift of the maxbcg cluster sample and find that it is consistent with the wmap5 cosmology . both the mass function data and its covariance matrix are presented . . And you have already written the first three sentences of the full article: the space density of galaxy clusters as a function of cluster mass is a well - known cosmological probe ( see e.g. * ? ? ? * ; * ? ? ? * ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

* ) , and ranks among the best observational tools for constraining @xmath8 , the normalization of the matter power spectrum in the low redshift universe ( see e.g. * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: we present the results of a study of differential rotation on the k2 iv primary of the rs cvn binary ii pegasi ( hd 224085 ) performed by inverting light curves to produce images of the dark starspots on its surface . the data were obtained in the standard johnson @xmath0 and @xmath1 filter passbands via the tennessee state university t3 0.4-m automated photometric telescope from jd 2447115.8086 to 2454136.6221 ( 1987 november 16 to 2007 february 5 ) . the observations were subdivided into 68 data sets consisting of pairs of @xmath0 and @xmath1 light curves , which were then inverted using a constrained non - linear inversion algorithm that makes no _ a priori _ assumptions regarding the number of spots or their shapes . the resulting surface images were then assigned to 21 groups corresponding to time intervals over which we could observe the evolution of a given group of spots ( except for three groups consisting of single data sets ) . of these 21 groups , six showed convincing evidence of differential rotation over time intervals of several months . for the others , the spot configuration was such that differential rotation was neither exhibited nor contraindicated . the differential rotation we infer is in the same sense as that on the sun : lower latitudes have shorter rotation periods . from plots of the range in longitude spanned by the spotted regions vs. time , we obtain estimates of the differential rotation coefficient @xmath2 defined in earlier work by henry et al . , and show that our results for its value are consistent with the value obtained therein . . And you have already written the first three sentences of the full article: ii pegasi is an sb1 binary system for which the primary component was determined to be of spectral class k2 - 3 iv - v by @xcite . it was classified as an rs cvn system by @xcite . the first photometric light curves were obtained by @xcite , who found variability with a period of approximately 6.75 d and interpreted the asymmetric light curve in terms of rotational modulation due to large , cool starspots . in 1986 september. Please generate the next two sentences of the article

, the difference between maximum and minimum light for the @xmath1 filter reached 0.5 mag , implying a projected spot area coverage of the visible hemisphere at minimum light on the order of 50% @xcite . on the basis of high - quality radial velocity measurements , @xcite determined the revolution period of the binary to be @xmath3 d. the same authors performed a detailed model atmosphere analysis of high - resolution and high signal - to - noise ccd spectra , obtaining values for the photospheric temperature and surface gravity of the primary star of @xmath4 k and @xmath5 , with @xmath6 expressed in cgs units .

Suppose that you have an abstract for a scientific paper: recently , riolo et al . [ r. l. riolo et al . , nature * 414 * , 441 ( 2001 ) ] showed by computer simulations that cooperation can arise without reciprocity when agents donate only to partners who are sufficiently similar to themselves . one striking outcome of their simulations was the observation that the number of tolerant agents that support a wide range of players was not constant in time , but showed characteristic fluctuations . the cause and robustness of these tides of tolerance remained to be explored . here we clarify the situation by solving a minimal version of the model of riolo et al . it allows us to identify a net surplus of random changes from intolerant to tolerant agents as a necessary mechanism that produces these oscillations of tolerance which segregate different agents in time . this provides a new mechanism for maintaining different agents , i.e. for creating biodiversity . in our model the transition to the oscillating state is caused by a saddle node bifurcation . the frequency of the oscillations increases linearly with the transition rate from tolerant to intolerant agents . . And you have already written the first three sentences of the full article: the emergence of cooperation in evolving populations with exploitative individuals is still a challenging problem in biological and social sciences . most theories that explain cooperation are based on direct reciprocity , as the famous iterated prisoner s dilemma @xcite . cooperation can also arise from indirect reciprocity when agents help others only if these are known as sufficiently altruistic @xcite . in most of these models. Please generate the next two sentences of the article

a finite population of agents is simulated , pairs of agents meet randomly as potential donator and receiver . a donation involves some cost to the donor while it provides a larger benefit to the receiver .

Suppose that you have an abstract for a scientific paper: in order to investigate the relationship between superconductivity and magnetism in bilayer - hydrate cobaltate na@xmath0(h@xmath1o)@xmath2coo@xmath3h@xmath4o co nuclear magnetic resonance ( nmr ) and nuclear quadrupole resonance ( nqr ) measurements were performed on three different samples , which demonstrate various ground states at low temperatures . the appearance of small internal fields is observed in the nqr spectra below approximately 6 k on one of the samples that possesses the largest @xmath5-axis length and the highest nqr frequency . the other two samples exhibit superconducting transition in zero magnetic field , while these two samples show different ground states in the magnetic fields greater than 5 t. the comparison of the nmr spectra of these two samples obtained in high magnetic fields reveals the appearance of static internal magnetic fields at the co site below 4 k in the sample that possesses the intermediate @xmath5-axis length and the nqr frequency . . And you have already written the first three sentences of the full article: superconductivity was found in the sufficiently water - intercalated cobaltate compound , na@xmath0(h@xmath1o)@xmath2coo@xmath3h@xmath4o with the bilayer - hydrate ( blh ) structure@xcite . it is amazing that superconductivity is observed only in the hydrous phase with the blh structure . superconductivity has not been observed neither in the monolayer - hydrate nor in the anhydrous compounds . the superconductivity is realized on the two - dimensional coo@xmath4 layers , which consist of a triangular lattice . the superconducting pairing state in the blh compounds has been considered to be unconventional on the basis of the results of the power - law temperature dependence of the specific heat @xcite and the nuclear spin - lattice relaxation rate @xcite in the superconducting state . despite the intriguing physical properties both in the superconducting and normal state , the details still remain to be solved due to the difficulty in the reproducible sample preparation . in the blh compounds ,. Please generate the next two sentences of the article

the ground state strongly depends on the chemical compositions , na ion ( @xmath6 ) , oxonium ion h@xmath1o@xmath7 ( @xmath8 ) and water molecule ( @xmath9 ) contents . it is difficult to control these parameters precisely during the water intercalation .

Suppose that you have an abstract for a scientific paper: tidal downsizing ( td ) is a recently developed planet formation theory that supplements the classical gravitational disc instability ( gi ) model with planet migration inward and tidal disruptions of gi fragments in the inner regions of the disc . numerical methods for a detailed population synthesis of td planets are presented here . as an example application , the conditions under which gi fragments collapse faster than they migrate into the inner @xmath0 a few au are considered . it is found that most gas fragments are tidally or thermally disrupted unless ( a ) their opacity is @xmath1 orders of magnitude less than the interstellar dust opacity at metallicities typical of the observed giant planets , or ( b ) the opacity is high but the fragments accrete large dust grains ( pebbles ) from the disc . case ( a ) models produce very low mass solid cores ( @xmath2 ) and follow a negative correlation of giant planet frequency with host star metallicity . in contrast , case ( b ) models produce massive solid cores , correlate positively with host metallicity and explain naturally while giant gas planets are over - abundant in metals . [ firstpage ] accretion , accretion discs quasars : general black hole physics galaxies : evolution stars : formation . And you have already written the first three sentences of the full article: a most general description of a planet is that it is a self - gravitating object composed of a heavy element core and an envelope of gas . terrestrial like planets are dominated by solid cores whereas giant gas planets are mainly hydrogen gas . given these observational facts , it should come as no surprise that there are two competing scenarios for planet formation that take opposite views on what comes first ( for a recent review see * ? ? ? * ) . in the top - down scenario hydrogen gas cloud. Please generate the next two sentences of the article

comes first and the solid element core is assembled later . in the bottom - up picture the solid core must be made first before a bound gas envelope appears . in the former scenario planets

Suppose that you have an abstract for a scientific paper: it is shown that the dynamics of a two - dimensional crystal with a finite concentration of dislocations , as well as vacancy and interstitial defects , is governed by the hydrodynamic equations of a viscoelastic medium . at the longest length scales the viscoelasticity is described by the simplest _ maxwell _ model , whose shear and compressional relaxation times are obtained in terms of microscopic quantities , including the density of free dislocations . at short length scales , bond orientational order effects become important and lead to wavevector dependent corrections to the relaxation times . = 10000 2 . And you have already written the first three sentences of the full article: experimental @xcite and numerical @xcite studies of the dynamics of driven disordered media , such as vortex arrays in type - ii superconductors and charge density waves in metals , have clearly indicated that when the disorder is strong these systems exhibit a spatially inhomogeneous plastic response upon depinning , without long wavelength elastic restoring forces @xcite . in this plastic regime dislocations proliferate due to the interplay of drive , disorder and interactions , and the system is broken up in fluid - like regions flowing around solid regions @xcite . it was proposed recently @xcite that a description of shear deformations in this plastic regime may be obtained by focusing on the dynamics of coarse - grained degrees of freedom ( the solid - like regions ) and replacing the elastic couplings of local displacements with viscoelastic couplings of local velocities .. Please generate the next two sentences of the article

it was found that the simplest , maxwell , model of viscoelasticity yields interesting features , such hysteretic depinning and switching , which have also been observed in experiments . the local viscoelastic couplings were introduced as an ad hoc way of mimicking the presence in the system at any given time of unbound dislocations , whose motion is in turn responsible for plastic slip . in this paper

Suppose that you have an abstract for a scientific paper: here , we report on our results where self - consistent calculations are performed to investigate the interference conditions , numerically . we employ the successful 4@xmath0 order grid technique to obtain the actual electrostatic quantities of the samples used at the quantum hall based aharonov - bohm interferometers . by knowing the electron density distribution we calculate the spatial distribution of the edge - states , which are considered as mono - energetic current channels . our results are in accord with the experimental findings concerning the electron density distribution . finally , we also comment on the `` optimized '' sample design in which highest visibility oscillations can be measured . . And you have already written the first three sentences of the full article: recent low - temperature transport experiments , utilizes the quantum hall based interferometers to investigate the quantum nature of particles . particularly , the aharonov - bohm ( ab ) interference experiments became a paradigm @xcite , which infers the ab phases of both the electrons and the quasi- particles . the single particle edge - state picture is used to describe transport , meanwhile electrostatics is enriched by interactions and both are used to explain the observed ab oscillations @xcite . however , the actual spatial distribution of the edge - states is still under debate for real samples , since handling the full electrostatics is a formidable task , although , several powerful techniques are used @xcite . by full electrostatics we mean both handing the crystal growth parameters and the edge " definition of the interferometer , _ i.e. _ gate , etched or trench - gated . in this work ,. Please generate the next two sentences of the article

we provide a semi - analytical scheme to model ab interferometers induced on a two dimensional electron gas ( 2deg ) by solving the 3d poisson for the given hetero - structure @xcite . our calculation scheme also takes into account the lithographically defined surface patterns to obtain the electron and potential distributions under quantized hall conditions @xcite .

Suppose that you have an abstract for a scientific paper: a quasi - particle model is presented which describes qcd lattice results for the 0 , 2 and 4 quark - flavor equation of state . the results are mapped to finite baryo - chemical potentials . as an application of the model we make a prediction of deconfined matter with appropriate inclusion of strange quarks and consider pure quark stars . . And you have already written the first three sentences of the full article: the qcd lattice calculations of the equation of state ( eos ) of deconfined matter have advanced to such a level that reliable results for the pure gluon plasma are available @xcite . for the two - flavor case an estimate of the continuum extrapolation is at disposal @xcite . the eos of four light flavors @xcite are not yet continuum extrapolated .. Please generate the next two sentences of the article

the physically interesting case of two light flavors and a medium - heavy strange quark is still in progress @xcite . all of these _ ab initio _ calculations of the eos of deconfined matter , however , are yet constrained to finite temperatures @xmath0 ( here @xmath1 is the deconfinement temperature ) and vanishing baryo - chemical potential , @xmath2 . while first attempts to calculate the eos at @xmath3 are under way @xcite , the final results can probably be expected only in a few years .

Suppose that you have an abstract for a scientific paper: we have studied the effect of thermal annealing on electron dephasing times @xmath0 in three - dimensional polycrystalline metals . measurements are performed on as - sputtered and annealed aupd and sb thick films , using weak - localization method . in all samples , we find that @xmath0 possesses an extremely weak temperature dependence as @xmath1 . our results show that the effect of annealing is non - universal , and it depends strongly on the amount of disorder quenched in the microstructures during deposition . the observed saturation " behavior of @xmath0 can not be easily explained by magnetic scattering . we suggest that the issue of saturation can be better addressed in three - dimensional , rather than lower - dimensional , structures . . And you have already written the first three sentences of the full article: the electron dephasing time @xmath0 is a very important quantity that governs the mesoscopic phenomena at low temperatures . particularly , the behavior of the dephasing time near zero temperature , @xmath2 , has recently attracted vigorous experimental @xcite and theoretical @xcite attention . one of the central themes of this renewed interest is concerned with whether @xmath3 should reach a finite or an infinite value as @xmath4 0 .. Please generate the next two sentences of the article

the connection of the zero - temperature dephasing behavior with the very fundamental condensed matter physics problems such as the validity of the fermi - liquid picture , the possibility of the occurrence of a quantum phase transition , and the persistent currents in metals , etc . , has been addressed .

Suppose that you have an abstract for a scientific paper: lenticular galaxies remain remarkably mysterious as a class . observations to date have not led to any broad consensus about their origins , properties and evolution , though they are often thought to have formed in one big burst of star formation early in the history of the universe , and to have evolved relatively passively since then . in that picture , current theory predicts that stellar evolution returns substantial quantities of gas to the interstellar medium ; most is ejected from the galaxy , but significant amounts of cool gas might be retained . past searches for that material , though , have provided unclear results . we present results from a survey of molecular gas in a volume - limited sample of field s0 galaxies , selected from the nearby galaxies catalog . co emission is detected from 78 percent of the sample galaxies . we find that the molecular gas is almost always located inside the central few kiloparsecs of a lenticular galaxy , meaning that in general it is more centrally concentrated than in spirals . we combine our data with hi observations from the literature to determine the total masses of cool and cold gas . curiously , we find that , across a wide range of luminosity , the most gas rich galaxies have @xmath010 percent of the total amount of gas ever returned by their stars . that result is difficult to understand within the context of either monolithic or hierarchical models of evolution of the interstellar medium . . And you have already written the first three sentences of the full article: in broad terms , there are two very different ways in which galaxies could have formed . the first , which we shall refer to as the monolithic formation idea , is that a large cloud of primordial gas collapsed rapidly to produce either an elliptical or lenticular galaxy , or perhaps the spheroidal bulge of a spiral galaxy @xcite . the main advantage of monolithic formation is that it seems consistent with the observational facts that most such systems have relatively little angular momentum and that they contain mostly old stars .. Please generate the next two sentences of the article

the second way galaxies might have formed is through the hierarchical accumulation of smaller clumps of gas and stars into larger structures that became the galaxies we see today @xcite . within that view , there would be a continuum of mergers between clumps of varying masses and angular momenta .

Suppose that you have an abstract for a scientific paper: in this paper we show global existence of lipschitz continuous solution for the stable muskat problem with finite depth ( confined ) and initial data satisfying some smallness conditions relating the amplitude , the slope and the depth . the cornerstone of the argument is that , for these _ small _ initial data , both the amplitude and the slope remain uniformly bounded for all positive times . we notice that , for some of these solutions , the slope can grow but it remains bounded . this is very different from the infinite deep case , where the slope of the solutions satisfy a maximum principle . our work generalizes a previous result where the depth is infinite . * keywords * : darcy s law , inhomogeneus muskat problem , well - posedness . * acknowledgments * : the author is supported by the grant mtm2011 - 26696 from ministerio de economa y competitividad ( mineco ) . the author thanks david paredes and professors diego crdoba and rafael orive for comments that greatly improved the manuscript . the author is grateful to reviewers for their helpful suggestions . . And you have already written the first three sentences of the full article: in this paper we study the dynamics of two different incompressible fluids with the same viscosity in a bounded porous medium . this is known as the confined muskat problem . for this problem we show that there are global in time lipschitz continuous solutions corresponding to initial data that fulfills some conditions related to the amplitude , slope and depth .. Please generate the next two sentences of the article

this problem is of practical importance because it is used as a model for a geothermal reservoir ( see @xcite and references therein ) or a model of an aquifer or an oil well ( see @xcite ) . the velocity of a fluid flowing in a porous medium satisfies darcy s law ( see @xcite ) @xmath0 where @xmath1 is the dynamic viscosity , @xmath2 is the permeability of the medium , @xmath3 is the acceleration due to gravity , @xmath4 is the density of the fluid , @xmath5 is the pressure of the fluid and @xmath6 is the incompressible velocity field . to simplify the notation we assume @xmath7 the motion of a fluid in a two - dimensional porous medium is analogous to the hele - shaw cell problem ( see @xcite and the references therein ) .

Suppose that you have an abstract for a scientific paper: the equilibrium thermodynamics of the two dimensional su - schrieffer - heeger model is derived by means of a path integral method which accounts for the variable range of the electronic hopping processes . while the lattice degrees of freedom are classical functions of time and are integrated out exactly , the electron particle paths are treated quantum mechanically . the free energy of the system and its temperature derivatives are computed by summing at any @xmath0 over the ensemble of relevant particle paths which mainly contribute to the total partition function . in the low @xmath0 regime , the _ heat capacity over t _ ratio shows an upturn peculiar of a glassy like behavior . this feature is more sizeable in the square lattice than in the linear chain as the overall hopping potential contribution to the total action is larger in higher dimensionality . # . And you have already written the first three sentences of the full article: the lattice dimensionality is a key parameter in materials science . one dimensional ( 1d ) systems with half filled band undergo a structural distortion @xcite which increases the elastic energy and opens a gap at the fermi surface thus lowering the electronic energy . the competition between lattice and electronic subsystems stabilizes the 1d structure which accordingly acquires semiconducting properties whereas the behavior of the 3d system would be metallic like .. Please generate the next two sentences of the article

conjugated polymers , take polyacetylene as prototype , show anisotropic electrical and optical properties @xcite due to intrinsic delocalization of @xmath2 electrons along the chain of ch units . as the intrachain bonding between adjacent ch monomers is much stronger than the interchain coupling the lattice is quasi-1d . hence , as a result of the peierls instability , polyacetylene shows an alternation of short and long neighboring carbon bonds , a dimerization , accompanied by a two fold degenerate ground state energy . the su - schrieffer - heeger ( ssh ) model hamiltonian @xcite has become a successful tool in polymer physics as it hosts the peculiar ground state excitations of the 1d conjugated structure and it accounts for a broad range of polymer properties @xcite . as a fundamental feature of the ssh hamiltonian the electronic hopping integral linearly depends on the relative displacement between adjacent atomic sites thus leading to a nonlocal _ e - ph _ coupling with vertex function depending both on the electronic and the phononic wave vector .

Suppose that you have an abstract for a scientific paper: we present results from multi - epoch neutral hydrogen ( hi ) absorption observations of six bright pulsars with the arecibo telescope . moving through the interstellar medium ( ism ) with transverse velocities of 10150 au yr@xmath0 , these pulsars have swept across 1200 au over the course of our experiment , allowing us to probe the existence and properties of the tiny scale atomic structure ( tsas ) in the cold neutral medium ( cnm ) . while most of the observed pulsars show no significant change in their hi absorption spectra , we have identified at least two clear tsas - induced opacity variations in the direction of b1929 + 10 . these observations require strong spatial inhomogeneities in either the tsas clouds physical properties themselves or else in the clouds galactic distribution . while tsas is occasionally detected on spatial scales down to 10 au , it is too rare to be characterized by a spectrum of turbulent cnm fluctuations on scales of @xmath1 au , as previously suggested by some work . in the direction of b1929 + 10 , an apparent correlation between tsas and interstellar clouds inside the warm local bubble ( lb ) indicates that tsas may be tracing the fragmentation of the lb wall via hydrodynamic instabilities . while similar fragmentation events occur frequently throughout the ism , the warm medium surrounding these cold cloudlets induces a natural selection effect wherein small tsas clouds evaporate quickly and are rare , while large clouds survive longer and become a general property of the ism . . And you have already written the first three sentences of the full article: for many years , observations of the diffuse interstellar medium ( ism ) have traced a whole hierarchy of structures on spatial scales @xmath2 pc ( cf . @xcite ) , often attributed to the ism turbulence . however , the extremely small - scale end of this spectrum , reaching down to scales of tens to hundreds of aus , has been largely unexplored . as the kinetic energy cascades from larger to smaller scales , it is expected that the turbulent spectrum will reach its end at so - called `` dissipation scales . ''. Please generate the next two sentences of the article

understanding of the dissipative properties of turbulence , such as its scale , efficiency , dissipation rate , and ubiquity , are important since the delicate balance between energy injection and dissipation has a profound impact on the stellar ism recycling chain .

Suppose that you have an abstract for a scientific paper: we analyse the connections between structure and dynamics in two model glass - formers , using the mutual information between an initial configuration and the ensuing dynamics to compare the predictive value of different structural observables . we consider the predictive power of normal modes , locally favoured structures , and coarse - grained measurements of local energy and density . the mutual information allows the influence of the liquid structure on the dynamics to be analysed quantitatively as a function of time , showing that normal modes give the most useful predictions on short time scales while local energy and density are most strongly predictive at long times . as supercooled liquids approach their glass transitions , structural relaxation slows down dramatically , but molecular configurations remain disordered and apparently random @xcite . however , computer simulations @xcite and experiments @xcite show that liquid structure and dynamical relaxation are correlated in these systems , as predicted ( or assumed ) in several theories @xcite . however , correlations between structure and dynamics do not by themselves imply a causal relationship @xcite : other theories @xcite assume that local structure plays only a peripheral role in dynamical relaxation . correlations between structure and dynamics can be demonstrated at a microscopic level @xcite , by exploiting the dynamically heterogeneous nature of glassy relaxation @xcite . that is , individual particles have different propensities for motion @xcite , depending on local structure . here , we use _ information theory _ @xcite to analyze the strength of these correlations , by measuring the extent to which structural measurements can be used to _ predict _ particle dynamics at subsequent times . this quantitative analysis provides a stringent test of proposed causal links between structural features and slow dynamics , in contrast to previous analyses based on restricted subsets of particles or snapshots of the.... And you have already written the first three sentences of the full article: this supporting information contains : * details of the models described in the main text , and the methods used to identify locally - favored structures . * illustrative results of mutual information between propensity and particle type * discussion of the @xmath40-dependence of the results shown in fig . 1(b , c ) * analysis of the numerical method that we use when estimating mutual information .. Please generate the next two sentences of the article

the ka mixture is defined as in [ 25 ] . the system consists of @xmath79 particles of which @xmath25 are of type a and @xmath80 of type b. the particles interact by lennard - jones potentials with parameters @xmath81 and @xmath82 .

Suppose that you have an abstract for a scientific paper: we present what we argue is the generic generalization of conway s `` game of life '' to a continuous domain . we describe the theoretical model and the explicit implementation on a computer . . And you have already written the first three sentences of the full article: there have been many generalizations of conway s `` game of life '' ( gol ) since its invention in 1970 @xcite . almost all attributes of the gol can be altered : the number of states , the grid , the number of neighbors , the rules . one feature of the original gol is the glider , a stable structure that moves diagonally on the underlying square grid .. Please generate the next two sentences of the article

there are also `` spaceships '' , similar structures that move horizontally or vertically . attempts to construct gliders ( as we will call all such structures in the following ) , that move neither diagonally nor straight , have led to huge man - made constructions in the original gol .

Suppose that you have an abstract for a scientific paper: the emission of @xmath0 pairs off electrons in a polarized ultra - intense electromagnetic ( e.g. laser ) wave field is analyzed . we elaborate on the significance of non - linear electrodynamics effects ( i.e. , multi - photon processes ) and the peculiarities of neutrino production . special attention is devoted to the convergence of the reaction probabilities as a function of the number of absorbed photons . expressions for large field intensities are provided . the asymmetry between the probabilities of electron and @xmath1 neutrino production depends on initial conditions such as energy of the wave field photons and the field intensity . these findings differ from the lowest order perturbative calculation of the reaction @xmath2 . . And you have already written the first three sentences of the full article: the exact solution of dirac s equation for an electron moving in the field of a plane electromagnetic wave was found by d. m. volkov in 1935 @xcite . the electron wave function , compared to the field - free case , changes due to a modification of its spinor structure and the appearance of an additional phase factor . the electron momentum changes to an effective quasi - momentum , and the electron mass becomes an effective `` dressed '' mass .. Please generate the next two sentences of the article

these modifications depend on the dimensionless variable @xmath3 related to the amplitude of the electromagnetic four - potential @xmath4 @xcite @xmath5 where @xmath6 is the absolute value of electron charge ( @xmath7 with @xmath8 ) and @xmath9 is the electron mass . ( for a manifestly gauge invariant formulation cf . @xcite . )

Suppose that you have an abstract for a scientific paper: we present the complete next - to - leading order calculation of isolated prompt photon production in association with a jet in deep - inelastic scattering . the calculation involves , direct , resolved and fragmentation contributions . it is shown that defining the transverse momenta in the proton virtual - photon frame ( cm@xmath0 ) , as usually done , or in the laboratory frame ( lab ) , as done in some experiments , is not equivalent and leads to important differences concerning the perturbative approach . in fact , using the latter frame may preclude , under certain conditions , the calculation of the next - to - leading order correction to the important resolved component . a comparaison with the latest zeus data is performed and good agreement is found in the perturbatively stable regions . + lpt - orsay-14 - 85 + lapth-229/14 + to 1 truecm * photon - jet cross sections in deep - inelastic scattering * 2 truecm * p. aurenche@xmath1 and m. fontannaz@xmath2 * 3 truemm _ @xmath3 lapth , universit de savoie , cnrs + bp 110 , chemin de bellevue , 74941 annecy - le - vieux cedex , france _ 3 truemm _ @xmath4 laboratoire de physique thorique , umr 8627 du cnrs , + universit paris - sud , btiment 210 , 91405 orsay cedex , france _ 2 truecm @xmath5 e - mail : patrick.aurenche@lapth.cnrs.fr @xmath6 e - mail : michel.fontannaz@th.u-psud.fr . And you have already written the first three sentences of the full article: large transverse momentum phenomena in deep inelastic scattering reactions have been extensively studied by the h1 and zeus collaborations at hera . large-@xmath7 particle and jet spectra have been measured and compared to next - to - leading order ( nlo ) qcd calculations . large-@xmath7 photons have also been observed , in an inclusive way @xcite or in correlation with a hadronic jet @xcite .. Please generate the next two sentences of the article

this latter reaction has been the subject of theoretical studies some ten years ago @xcite . the recent data from zeus @xcite lead us to extend these studies and to compare the complete nlo qcd results with the @xmath8-jet cross sections . in principle , prompt photon production in deep - inelastic scattering ( dis ) is a very simple process : it goes via the compton scattering of a virtual photon on a quark : @xmath9 and requires only the knowledge of the distribution function of a quark in the proton . including higher - order ( ho ) corrections

Suppose that you have an abstract for a scientific paper: the structural , electronic and lattice dielectric properties of multiferroic tbmn@xmath0o@xmath1 are investigated using density functional theory within the generalized gradient approximation ( gga ) . we use collinear spin approximations and ignore the spin - orbit coupling . the calculated structural parameters are in excellent agreement with the experiments . we confirm that the ground state structure of tbmn@xmath0o@xmath1 is of space group @xmath2 , allowing polarizations along the @xmath3-axis . the spontaneous electric polarization is calculated to be @xmath4 @xmath5@xmath6 . the calculated zone - center optical phonons frequencies and the oscillator strengths of ir phonons agree very well with the experimental values . we then derive an effective hamiltonian to explain the magnetically - induced ferroelectricity in this compound . our results strongly suggest that the ferroelectricity in tbmn@xmath0o@xmath1 is driven by the magnetic ordering that breaks the the inversion symmetry , without invoking the spin - orbit coupling . . And you have already written the first three sentences of the full article: recently , a large class of manganese oxides ( rmno@xmath7 , @xcite and rmn@xmath0o@xmath1 , @xcite with r = y , tb , dy , etc . ) has been discovered to be multiferroic , with strong magnetoelectric ( me ) coupling . the me coupling leads to various novel physical effects , such as the `` colossal magnetodielectric '' ( cmd ) effects and magneto - spin - flop effects . @xcite for example , in tbmn@xmath0o@xmath1,@xcite the me coupling is so strong , that the electric polarization can be reversed by applying a magnetic field . @xcite the remarkable me effects revealed in these materials have attracted great attention @xcite because of the fascinating physics and their potential applications in novel multifunctional me devices .. Please generate the next two sentences of the article

the crystal structure of tbmn@xmath0o@xmath1 is orthorhombic , with four chemical formula units per primitive cell ( 32 atoms in total ) , containing mn@xmath8o@xmath9 octahedra and mn@xmath10o@xmath1 pyramids , as shown in fig.[fig : structure ] . tbmn@xmath0o@xmath1 shows several magnetic phase transitions accompanied with the appearance of electric polarizations and dielectric anomalies , when cooling down from the room temperature .

Suppose that you have an abstract for a scientific paper: in this work we show a rational approximation of the dawson integral that can be implemented for high - accuracy computation of the complex error function in a rapid algorithm . specifically , this approach provides accuracy exceeding @xmath0 in the domain of practical importance @xmath1 . a matlab code for computation of the complex error function with entire coverage of the complex plane is presented . + * keywords : * complex error function , faddeeva function , dawsons integral , rational approximation . And you have already written the first three sentences of the full article: the complex error function also widely known as the faddeeva function can be defined as @xcite @xmath2 where @xmath3 is the complex argument . it is a solution of the following differential equation @xcite @xmath4 where the initial condition is given by @xmath5 the complex error function is principal in a family of special functions . the main functions from this family are the dawsons integral , the complex probability function , the error function , the fresnel integral and the normal distribution function .. Please generate the next two sentences of the article

the dawsons integral is defined as @xcite @xmath6 it is not difficult to obtain a relation between the complex error function and the dawson integral . in particular , comparing right sides of equations and immediately yields @xmath7 another closely related function is the complex probability function . in order to emphasize the continuity of the complex probability function at @xmath8 , it may be convenient to define it in form of principal value integral @xcite @xmath9 or @xmath10 the complex probability function has no discontinuity at @xmath11 and @xmath12 since according to the principal value we can write @xmath13 where @xmath14 $ ] .

Suppose that you have an abstract for a scientific paper: we present colour - magnitude diagrams of open clusters , located in the range @xmath0 , manifesting stellar populations in the background of clusters . some of the populations are found to be located beyond the perseus arm and may be the part of norma - cygnus ( outer ) arm . the outer arm seems to be continued from @xmath1 to @xmath2 . the background populations follow the downward warp of the galactic plane around @xmath3 . [ firstpage ] open clusters and association : general , distances - galaxy : structure . And you have already written the first three sentences of the full article: the recently discovered ring - like structure ( the monoceros / canis major ring ) in the anti - center direction of the galaxy ( e.g. newberg et al . 2002 , ibata et al . 2003 ) could be the consequence of accretion of dwarf galaxies by the milky way ( cf .. Please generate the next two sentences of the article

martin et al . 2004 , bellazzini et al .

Suppose that you have an abstract for a scientific paper: the coupled discrete linear and kerr nonlinear schrdinger equations with gain and loss describing transport on dimers with parity - time ( @xmath0 ) symmetric potentials are considered . the model is relevant among others to experiments in optical couplers and proposals on bose - einstein condensates in @xmath0symmetric double - well potentials . it is known that the models are integrable . here , the integrability is exploited further to construct the phase - portraits of the system . a pendulum equation with a linear potential and a constant force for the phase - difference between the fields is obtained , which explains the presence of unbounded solutions above a critical threshold parameter . the behaviour of all solutions of the system , including changes in the topological structure of the phase - plane , is then discussed . . And you have already written the first three sentences of the full article: it is postulated in quantum physics that quantities we observe are eigenvalues of operators representing the dynamics of the quantities . therefore , the energy spectra , i.e. the eigenvalues , are required to be real and bounded from below so that the system has a stable lowest - energy state . to satisfy such requirements , it was conjectured that the operators must be hermitian .. Please generate the next two sentences of the article

non - hermitian hamiltonians have been commonly associated with complex eigenvalues and therefore decay of the quantities . however , it turned out that hermiticity is not necessarily required by a hamiltonian system to satisfy the postulate @xcite . of particular examples have been systems exhibiting the so - called parity - time ( @xmath0 ) symmetry , suggested by bender and co - workers @xcite .

Suppose that you have an abstract for a scientific paper: star clusters open and globulars experience dynamical evolution on time scales shorter than their age . consequently , open and globular clusters provide us with unique dynamical laboratories for learning about two - body relaxation , mass segregation from equipartition of energy , and core collapse . we review briefly , in the framework of star clusters , some elements related to the theoretical expectation of mass segregation , the results from n - body and other computer simulations , as well as the now substantial clear observational evidence . # 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in . And you have already written the first three sentences of the full article: the dynamics of any stellar system may be characterized by the following three dynamical time scales : ( i ) the crossing time @xmath0 , which is the time needed by a star to move across the system ; ( ii ) the two - body relaxation time @xmath1 , which is the time needed by the stellar encounters to redistribute energies , setting up a near - maxwellian velocity distribution ; ( iii ) the evolution time @xmath2 , which is the time during which energy - changing mechanisms operate , stars escape , while the size and profile of the system change . several ( different and precise ) definitions exist for the relaxation time . the most commonly used is the half - mass relaxation time @xmath3 of spitzer ( 1987 , eq . 2 - 62 ) , where the values for the mass - weighted mean square velocity of the stars and the mass density are those evaluated at the half - mass radius of the system ( see meylan & heggie 1997 for a review ) . in the case of globular clusters , @xmath0 @xmath4 , @xmath1 @xmath4 100 , and @xmath2 @xmath4 10 . table 1 displays , for open clusters , globular clusters , and galaxies , some interesting relations between the above three time scales . for open clusters , crossing time @xmath0 and relaxation time @xmath1 are more or less equivalent , both being significantly smaller than the evolution time @xmath2 .. Please generate the next two sentences of the article

this means that most open clusters dissolve within a few gigayears . for galaxies , the relaxation time @xmath1 and the evolution time @xmath2 are more or less equivalent , both being significantly larger than the crossing time @xmath0 .

Suppose that you have an abstract for a scientific paper: * version 1 * * ( results ) * we show that cosmological constant @xmath0 is not optional in gr ( _ general _ relativity ) because it is required by sr ( special relativity ) . this completely unexpected result is obtained by introducing a minimal acceleration @xmath1 ( milgrom ) in einstein boost with lorentz transformation ( lt ) . we prove that hyperbolic rotation ( lt ) is an hyperbolic _ motion _ with a centrifugal acceleration . in cosmological sr with @xmath2 ( csr or cr ) , the universe is not only in expansion ( with the law of hubble ) but even in accelerated expansion ( cosmological parameter @xmath3 . in cr the constant @xmath2 is naturally associated to the bending of light ( ishak and rindler ) . given that the structure of space - time in einstein s gr is determined by the _ presence _ of matter and @xmath2 is associated to the _ absence _ of matter , we associate @xmath2 not to quantum vacuum but to classical vacuum of minkowski s space - time . finally we show that 1917 einstein s cosmological constant @xmath2 corresponds to 1906 poincar s _ non - electromagnetic _ negative pressure and we deduce density of poincar s relativistic fluid . * version 2 ( methodology ) * in * 1 * we switch the scale radius factor @xmath4 of friedman - lematre in the second member of lorentz invariant @xmath5 @xmath6 ( @xmath7 is hubble constant and @xmath8 is milgrom s acceleration ) . in * 2 * we sum up einstein - born - rindler ( ebr ) s model of acceleration in sr . ebr s rigid motion is induced from non - relativistic _ rectilinear _ uniformly accelerated motion . in * 3 * we propose another relativistic theory of acceleration induced from non - relativistic uniformly _ circular _ accelerated motion given that euclidean rotation ( centripetal acceleration ) must be replaced by hyperbolic rotation _ motion _ ( _ centrifugal _ acceleration ) . this new theory of acceleration in lorentz boost involves not a rigid motion but an elastic expanding motion . we introduce a _.... And you have already written the first three sentences of the full article: let us consider fundamental hyperbolas along @xmath13 and @xmath14 in minkowski s space - time ( at one space dimension with the axis , @xmath15 @xmath16 of system k with light velocity @xmath17 . the two hyperbolas determining the units of measure ( @xmath18 are called hyperbolas of scale or calibration ( @xcite ) . we focus the attention on the along @xmath14 hyperbola defined with invariance of _ space interval _ by a _. Please generate the next two sentences of the article

passive _ lorentz transformation ( @xmath19 ) ( 5 ) @xmath20 @xmath21 ( * fig1 * , light asymptotes and standard representation of primed axis @xmath22 @xmath23 in scissors or _ hyperbolic rotation _ of system k ) @xmath24 given that @xmath25 ( the hyperbolic radius of curvature ) can be as large as we wish , the calibration hyperbolas disappear at the infinity and we have only one invariant @xmath26 in standard configuration . let us however note that , only the _ finite _ interval involves , according to minkowski , that _

Suppose that you have an abstract for a scientific paper: stem ( science , technology , engineering , and mathematics ) fields have become increasingly central to u.s . economic competitiveness and growth . the shortage in the stem workforce has brought promoting stem education upfront . the rapid growth of social media usage provides a unique opportunity to predict users real - life identities and interests from online texts and photos . in this paper , we propose an innovative approach by leveraging social media to promote stem education : matching twitter college student users with diverse linkedin stem professionals using a ranking algorithm based on the similarities of their demographics and interests . we share the belief that increasing stem presence in the form of introducing career role models who share similar interests and demographics will inspire students to develop interests in stem related fields and emulate their models . our evaluation on 2,000 real college students demonstrated the accuracy of our ranking algorithm . we also design a novel implementation that recommends matched role models to the students . , recommendation systems , social media , text mining . And you have already written the first three sentences of the full article: the importance of the stem industry to the development of our nation can not be understated . as the world becomes more technology - oriented , there is a necessity for a continued increase in the stem workforce . however , the u.s . has been experiencing the opposite . in the united states ,. Please generate the next two sentences of the article

200,000 engineering positions go unfilled every year , largely due to the fact that only about 60,000 students are graduating with stem degrees in the united states annually [ 17 ] . another obvious indication is the relatively fast growth in wages in most stem - oriented occupations : for computer workers alone , there are around 40,000 computer science bachelor s degree earners each year , but roughly 4 million job vacancies [ 29 ] .

Suppose that you have an abstract for a scientific paper: dusty galaxies at @xmath0 span a wide range of relative brightness between rest - frame mid - infrared ( 8@xmath1 ) and ultraviolet wavelengths . we attempt to determine the physical mechanism responsible for this diversity . dust - obscured galaxies ( dogs ) , which have rest - frame mid - ir to uv flux density ratios @xmath2 , might be abnormally bright in the mid - ir , perhaps due to prominent agn and/or pah emission , or abnormally faint in the uv . we use far - infrared data from the goods-_herschel _ survey to show that most dogs with @xmath3 are not abnormally bright in the mid - ir when compared to other dusty galaxies with similar ir ( 81000@xmath1 ) luminosities . we observe a relation between the median ir to uv luminosity ratios and the median uv continuum power - law indices for these galaxies , and we find that only 24% have specific star formation rates which indicate the dominance of compact star - forming regions . this circumstantial evidence supports the idea that the uv- and ir - emitting regions in these galaxies are spatially coincident , which implies a connection between the abnormal uv faintness of dogs and dust obscuration . we conclude that the range in rest - frame mid - ir to uv flux density ratios spanned by dusty galaxies at @xmath0 is due to differing amounts of uv obscuration . of galaxies with these ir luminosities , dogs are the most obscured . we attribute differences in uv obscuration to either : 1 ) differences in the degree of alignment between the spatial distributions of dust and massive stars , or 2 ) differences in the total dust content . . And you have already written the first three sentences of the full article: at @xmath0 , a large fraction of all high mass stars form in dusty galaxies @xcite . most of the intrinsic uv emission from newly formed stars in these galaxies is obscured , or absorbed by dust grains that subsequently heat up and radiate at ir wavelengths . the ir luminosity resulting from this obscuration is usually much greater than the emergent uv luminosity . for galaxies in which the intrinsic uv emission from newly formed stars is less obscured , the ir luminosity is still greater than the emergent uv luminosity , but to a lesser degree @xcite .. Please generate the next two sentences of the article

the relation between the ir and emergent uv emission from a @xmath0 galaxy depends on the interplay between star formation and dust obscuration . one of the many ways to select dusty galaxies at @xmath0 , without redshift determinations from spectroscopy , is to use the ratio of observed 24 to 0.65@xmath1 ( @xmath4-band ) flux densities @xcite .

Suppose that you have an abstract for a scientific paper: large numbers of ground states of the three - dimensional @xmath0 random - bond ising model are calculated for sizes up to @xmath1 using a combination of a genetic algorithm and cluster - exact approximation . several quantities are calculated as function of the concentration @xmath2 of the antiferromagnetic bonds . the critical concentration where the ferromagnetic order disappears is determined using the binder cumulant of the magnetization . a value of @xmath3 is obtained . from the finite - size behavior of the binder cumulant and the magnetization critical exponents @xmath4 and @xmath5 are calculated . the behavior of the distribution of overlaps @xmath6 is used to investigate how the spin - glass phase evolves with increasing concentration @xmath2 . the spin - glass order is characterized by a broad distribution of overlaps which extends down to @xmath7 . * keywords ( pacs - codes ) * : spin glasses and other random models ( 75.10.nr ) , numerical simulation studies ( 75.40.mg ) , general mathematical systems ( 02.10.jf ) . [ [ introduction ] ] introduction + + + + + + + + + + + + in this work systems of @xmath8 spins @xmath9 , described by the hamiltonian @xmath10 are investigated . the spins are placed on a three - dimensional ( d=3 ) cubic lattice of linear size @xmath11 with periodic boundary conditions in all directions . systems with quenched disorder of the nearest - neighbor interactions ( bonds ) are investigated . their possible values are @xmath12 . the concentration of the antiferromagnetic ( af ) bonds ( @xmath13 ) is denoted with @xmath2 , all other @xmath14 interactions are ferromagnetic . a constrained disorder is used , so that the fraction of the antiferromagnetic bonds is exactly @xmath2 for all realizations of the disorder . the model shows a complex behavior for low temperatures . for large concentrations of the ferromagnetic bonds it is energetically favorable for two interacting spins to have the same orientation . so the system shows.... And you have already written the first three sentences of the full article: the algorithm for the calculation of the ground states bases on a special genetic algorithm @xcite and on _ cluster - exact approximation _ ( cea ) @xcite which is a sophisticated optimization method . next a short sketch of these algorithms is given . the genetic algorithm starts with an initial population of @xmath24 randomly initialized spin configurations (= _ individuals _ ) , which are linearly arranged in a ring . then @xmath25 times two neighbors from the population are taken ( called _ parents _ ) and two offsprings are created using a triadic crossover : a mask is used which is a third randomly chosen ( usually distant ) member of the population with a fraction of @xmath26 of its spins reversed . in a first step the offsprings are created as copies of the parents. Please generate the next two sentences of the article

. then those spins are selected , where the orientations of the first parent and the mask agree @xcite . the values of these spins are swapped between the two offsprings . then a _ mutation _ with a rate of @xmath27

Suppose that you have an abstract for a scientific paper: the mock lisa data challenges are a program to demonstrate lisa data - analysis capabilities and to encourage their development . each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters . participants analyze the datasets and report best - fit solutions for the source parameters . here we present the results of the third challenge , issued in apr 2008 , which demonstrated the positive recovery of signals from chirping galactic binaries , from spinning supermassive black - hole binaries ( with optimal snrs between @xmath0 and @xmath1 ) , from simultaneous extreme mass - ratio inspirals ( snrs of 1050 ) , from cosmic - string cusp bursts ( snrs of 10100 ) , and from a relatively loud isotropic background with @xmath2 , slightly below the lisa instrument noise . . And you have already written the first three sentences of the full article: the laser interferometer space antenna ( lisa ) is a planned nasa esa gravitational - wave ( gw ) observatory sensitive in the @xmath3@xmath4 hz range @xcite . lisa s data will contain superposed signals from millions of sources , including all the binaries in the galaxies with orbital periods below five hours and massive black - hole ( mbh ) binary coalescences out to @xmath5 @xcite .. Please generate the next two sentences of the article

thousands of sources will be resolvable individually . the potential for source confusion and the very complex dynamics and waveforms of sources such as extreme mass - ratio inspirals ( emris ) , suggested the need for a coordinated effort to develop and demonstrate lisa data - analysis capabilities .

Suppose that you have an abstract for a scientific paper: we have studied the time variation of the radial abundance gradients using samples of planetary nebulae , open clusters , cepheids and other young objects . based on the analysis of o / h and s / h abundances for planetary nebulae and metallicities of the remaining objects , we concluded that the gradients have been flattening out in the last 8 gyr with an average rate of the order of 0.005 0.010 dex kpc@xmath0 gyr@xmath0 . we have estimated the errors involved in the determination of the gradients , and concluded that the existence of systematic abundance variations is more likely than a simple statistical dispersion around a mean value . address = iag / usp , so paulo , brazil . And you have already written the first three sentences of the full article: radial abundance gradients in the milky way disk are among the main constraints of models of the chemical evolution of the galaxy . the study of the gradients comprises the determination of their magnitudes along the disk , space variations and their time evolution ( see for example henry & worthey 1999 , maciel & costa 2003 ) . probably the most interesting property of the gradients is their time evolution , which is a distinctive constraint of recent chemical evolution models .. Please generate the next two sentences of the article

maciel et al . ( 2003 ) suggested that the o / h gradient has been flattening during the last few gyr , on the basis of a large sample of planetary nebulae ( pn ) for which accurate abundances are available , and for which the ages of the progenitor stars have been individually estimated . this work has been recently extended ( maciel et al . 2005 ) to include the s / h ratio in planetary nebulae , [ fe / h ] metallicities from open clusters and cepheid variables , as well as some young objects , such as ob associations and hii regions . in this work

Suppose that you have an abstract for a scientific paper: the holstein - primakoff representation for spin systems is used to derive expressions with solutions that are conjectured to be the zeros of hermite polynomials @xmath0 as @xmath1 . this establishes a correspondence between the zeros of the hermite polynomials and the boundaries of the position basis of finite - dimensional hilbert spaces . the hermite polynomials are prevalent in many fields . they can be defined as @xmath2 in the physics community , they are perhaps best recognized as the gaussian - weighted eigenfunctions ( in position representation ) of the quantum harmonic oscillator ( with @xmath3 , a convention that will be used for the rest of the paper ) : @xmath4 as such , they are orthogonal over the gaussian - weighted whole domain , @xmath5 . this last property allows their use in gaussian quadrature , a useful and popular numerical integration technique where @xmath6 is approximated as @xmath7 where @xmath8 are the zeros of @xmath0 and @xmath9 is a well - behaved function . for this and many other reasons , an analytic formula for the asymptotic zeros of hermite and other orthogonal polynomials has been a subject of much interest@xcite , especially in the applied mathematics community and the field of approximation theory . in this paper , i examine the position state representation of the eigenstates of finite dimensional @xmath10-spin systems , as expressed in the holstein - primakoff transformation . as @xmath11 , the system becomes the infinite dimensional harmonic oscillator . this association allows me to derive the simple main results presented in eqs [ eq : evenzeros ] and [ eq : oddzeros ] , with solutions that i conjecture become the asymptotic zeros of the hermite polynomials ( as @xmath1 ) . furthermore , i numerically show that this convergence is rather quick and so the expressions can frequently be used , in many instances of finite - precision application , as the effective zeros of @xmath0 with finite @xmath12 , such as in applications of gaussian.... And you have already written the first three sentences of the full article: the author thanks prof . j. katriel for helpful comments on the manuscript . j. katriel , through correspondence , showed that eqns [ eq : evenzeros ] and [ eq : oddzeros ] agree with the first asymptotic term from dominici for @xmath51 for low @xmath40 ( not for maximal @xmath40 ) .. Please generate the next two sentences of the article

the latter result makes sense from the point of view that the maximal @xmath8 is always close to the edge of the hilbert space where the wavefunction goes to zero for any finite @xmath12 whereas that of the harmonic oscillator decays forever . [ eq : evenzeros ] and [ eq : oddzeros ] do not agree with higher order terms ( w.r.t .

Suppose that you have an abstract for a scientific paper: observing the ckm matrix elements written in different parametrization schemes , one can notice obvious relations among the sine - values of the cp phases in those schemes . using the relations , we establish a few parametrization - independent equations , by which the matrix elements of the ckm matrix can be completely fixed up to a universal parameter . if it is true , we expect that there should exist a hidden symmetry in the nature which determines the relations . moreover , it requires a universal parameter , naturally it would be the famous jarlskog invariant which is also parametrization independent . thus the four parameters ( three mixing angles and one cp phase ) of the ckm matrix are not free , but determined by the symmetry and the universal parameter . as we generalize the rules to the pmns matrix for neutrino mixing , the cp phase of the lepton sector is predicted to be within a range of @xmath0 centered at @xmath1 ( in the p@xmath2 parametrization ) which will be tested in the future experiments . . And you have already written the first three sentences of the full article: since cabibbo first noted the difference between the decays of neutron ( @xmath3 ) and muon ( @xmath4 ) and suggested there is a mixing angle between d and s quarks@xcite , and the mixing perfectly explained the data of the @xmath5decays of @xmath6 and @xmath7 @xcite . later the ckm matrix @xcite has been proposed to mix the three generation quarks . in the @xmath8 matrix there are three mixing angles and a cp phase which seem to be completely independent of each other .. Please generate the next two sentences of the article

the mixing is understood as that the eigen - basis of weak interaction is not the same as that of mass , so matching them , a unitary transformation matrix must be introduced@xcite . from then on , the research field about quark mixing has been thoroughly investigated and exploration of its source has never ceased . in analog to the quark sector , the pontecorvo - maki - nakawaga - sakata ( pmns ) matrix @xcite relates the lepton flavor eigenstates with the mass eigenstates . thus it is natural to consider that there might be an underlying symmetry which results in the practical ckm and pmns matrices after symmetry breaking .

Suppose that you have an abstract for a scientific paper: we derive quenched subdiffusive lower bounds for the exit time @xmath0 from a box of size @xmath1 for the simple random walk on the planar invasion percolation cluster . the first part of the paper is devoted to proving an almost sure analog of h. kesten s subdiffusivity theorem for the random walk on the incipient infinite cluster and the invasion percolation cluster using ideas of m. aizenman , a. burchard and a. pisztora . the proof combines lower bounds on the instrinsic distance in these graphs and general inequalities for reversible markov chains . in the second part of the paper , we present a sharpening of kesten s original argument , leading to an explicit almost sure lower bound for @xmath0 in terms of percolation arm exponents . the methods give @xmath2 , where @xmath3 depends on the instrinsic distance and @xmath4 can be taken to be @xmath5 on the hexagonal lattice . [ [ section ] ] h. kesten has proved @xcite that the simple random walk @xmath6 started at @xmath7 on the incipient infinite cluster ( iic ) @xcite in two - dimensional bernoulli bond percolation is subdiffusive in the sense that there exists @xmath8 such that the family @xmath9 is tight . the purpose of the current work is to explain how a `` quenched '' version of this result can be obtained and extended to the random walk in an environment generated by a related two - dimensional model , invasion percolation . ( the model is defined in the next section ) . we present some refinements of kesten s method , which provides a general framework for proving subdiffusivity of random walks in stochastic geometric models . in the case of two - dimensional invasion percolation ( as well as the incipient infinite cluster ) , the ideas in @xcite can be used to give explicit bounds on @xmath10 from in terms of known critical exponents ( see and below ) . our main result is the following : [ main - theorem ] let @xmath11 be a simple random walk on the invasion percolation cluster ( ipc ) , and @xmath0 the.... And you have already written the first three sentences of the full article: in this section , we justify remark 3 above and outline the derivation of a result analogous to theorem [ kesten - ipc-1 ] for the random walk on h. kesten s _ incipient infinite cluster _ ( iic ) . for cylinder events @xmath74 , the iic measure is defined by @xmath716 it was shown in @xcite that the limit ( [ eq : iic - def ] ) exists and that the resulting set function extends to a measure . note that the connected cluster of the origin , @xmath717 , is @xmath718-almost surely unbounded . we will refer to this cluster as the iic .. Please generate the next two sentences of the article

we have the following result : let @xmath719 denote a simple random walk on the incipient infinite cluster started at @xmath7 . let @xmath0 denote the first exit time of @xmath720 from @xmath35 .

Suppose that you have an abstract for a scientific paper: an increasing fraction of today social interactions occur using online social media as communication channels . recent worldwide events , such as social movements in spain or revolts in the middle east , highlight their capacity to boost people coordination . online networks display in general a rich internal structure where users can choose among different types and intensity of interactions . despite of this , there are still open questions regarding the social value of online interactions . for example , the existence of users with millions of online friends sheds doubts on the relevance of these relations . in this work , we focus on twitter , one of the most popular online social networks , and find that the network formed by the basic type of connections is organized in groups . the activity of the users conforms to the landscape determined by such groups . furthermore , twitter s distinction between different types of interactions allows us to establish a parallelism between online and offline social networks : personal interactions are more likely to occur on internal links to the groups ( the weakness of strong ties ) , events transmitting new information go preferentially through links connecting different groups ( the strength of weak ties ) or even more through links connecting to users belonging to several groups that act as brokers ( the strength of intermediary ties ) . . And you have already written the first three sentences of the full article: there exists an open discussion on the validity of online interactions as indicators of real social activity @xcite . most of the online social networks incorporate several types of user - user interactions that satisfy the need for different level of involvement or relation intensity between users @xcite . the cost of establishing the cheapest relation is usually very low , and it requires the acceptation or simply the notification to the targeted user .. Please generate the next two sentences of the article

these connections can accumulate due to the asymmetric social cost of cutting and creating them , and pile up to the astronomic numbers that capture popular imagination @xcite . if the number of connections increases to the thousands or the millions , the amount of effort that a user can invest into the relation that each link represents must fall to near zero . does this mean that online networks are irrelevant for understanding social relations , or for predicting where higher quality activity ( e.g. , personal communications , information transmission events ) is taking place ? by analyzing the clusters of the network formed by the cheapest connections between users of twitter

Suppose that you have an abstract for a scientific paper: we review the normal and superconducting state properties of the unconventional triplet superconductor sr@xmath0ruo@xmath1 with an emphasis on the analysis of the magnetic susceptibility and the role played by strong electronic correlations . in particular , we show that the magnetic activity arises from the itinerant electrons in the ru @xmath2-orbitals and a strong magnetic anisotropy occurs ( @xmath3 ) due to spin - orbit coupling . the latter results mainly from different values of the @xmath4-factor for the transverse and longitudinal components of the spin susceptibility ( i.e. the matrix elements differ ) . most importantly , this anisotropy and the presence of incommensurate antiferromagnetic and ferromagnetic fluctuations have strong consequences for the symmetry of the superconducting order parameter . in particular , reviewing spin fluctuation - induced cooper - pairing scenario in application to sr@xmath0ruo@xmath1 we show how @xmath5-wave cooper - pairing with line nodes between neighboring ruo@xmath0-planes may occur . we also discuss the open issues in sr@xmath0ruo@xmath1 like the influence of magnetic and non - magnetic impurities on the superconducting and normal state of sr@xmath0ruo@xmath1 . it is clear that the physics of triplet superconductivity in sr@xmath0ruo@xmath1 is still far from being understood completely and remains to be analyzed more in more detail . it is of interest to apply the theory also to superconductivity in heavy - fermion systems exhibiting spin fluctuations . . And you have already written the first three sentences of the full article: the phenomenon of superconductivity remains one of the most interesting problems of condensed matter physics . in particular , in recent years the material science development has revealed several interesting systems where high transition temperature superconductivity was found , in particular the families of high-@xmath6 cuprates @xcite with a maximum @xmath6 of about 155 k. soon after their discovery it was realized that the essential physics of cuprates takes place in the cuo@xmath0-planes which is believed to be responsible for the high transition temperature . sr@xmath7cuo@xmath1 and ( b ) layered perovskite structure of the triplet superconductor sr@xmath0ruo@xmath1 .. Please generate the next two sentences of the article

both structures are identical if la ( ba ) is replaced by sr and the cuo@xmath0-plane is replaced by ruo@xmath0-plane.,title="fig:",scaledwidth=40.0% ] sr@xmath7cuo@xmath1 and ( b ) layered perovskite structure of the triplet superconductor sr@xmath0ruo@xmath1 . both structures are identical if la ( ba ) is replaced by sr and the cuo@xmath0-plane is replaced by ruo@xmath0-plane.,title="fig:",scaledwidth=30.0% ] in this connection the discovery of superconductivity in sr@xmath0ruo@xmath1 with @xmath8 k @xcite is of particular interest for several reasons . first , the crystal structure of sr@xmath0ruo@xmath1 is identical to that of the parent compound of the high-@xmath6 superconductor la@xmath0cuo@xmath1 ( see fig .

Suppose that you have an abstract for a scientific paper: in the minimal supersymmetric standard model ( mssm ) , the neutralinos , the spin1/2 majorana superpartners of the neutral gauge and higgs bosons , are expected to be among the light supersymmetric particles that can be produced copiously at future high energy colliders . we analyze two body neutralino decays into a neutralino plus a @xmath0 boson or a lightest neutral higgs boson @xmath1 , allowing the relevant parameters to have complex phases . we show that the two body tree level decays of neutralinos are kinematically allowed in a large region of the mssm parameter space and they can provide us with a powerful probe of the majorana nature and cp properties of the neutralinos through the @xmath0boson polarization measured from @xmath0boson leptonic decays . = 100000 kias p03079 + kupt0304 + hep - ph/0311037 + * analysis of the neutralino system in two body decays of neutralinos * + s. y. choi@xmath2 and y. g. kim@xmath3 0.5 cm 1 . @xmath2 _ department of physics , chonbuk national university , chonju 561 - 756 , korea _ + 2 . @xmath3 _ department of physics , korea university , seoul 136701 , korea _ . And you have already written the first three sentences of the full article: the search for supersymmetry ( susy ) is one of the main goals at present and future colliders @xcite as susy is generally accepted as one of the most promising concepts for physics beyond the standard model ( sm ) @xcite . a special feature of susy theories is the existence of the neutralinos , the spin1/2 majorana superpartners of the neutral gauge bosons and higgs bosons . in the mssm , the neutralinos are expected to be among the light supersymmetric particles that can be produced copiously at future high energy colliders @xcite .. Please generate the next two sentences of the article

once several neutralino candidates are observed at such high energy colliders , it will be crucial to establish the majorana nature and cp properties of the neutralinos . in this light , many extensive studies of the general characteristics of the neutralinos in their production and decays @xcite as well as in the selectron pair production @xcite at @xmath4 and/or @xmath5 linear colliders have been performed .

Suppose that you have an abstract for a scientific paper: we study numerically the thermal emission of @xmath0 pairs from a bare strange star heated by energy input onto its surface ; heating starts at some moment , and is steady afterwards . the thermal luminosity in @xmath0 pairs increases to some constant value . the rise time and the steady thermal luminosity are evaluated . both normal and colour superconducting states of strange quark matter are considered . the results are used to test the magnetar model of soft gamma - ray repeaters where the bursting activity is explained by fast decay of superstrong magnetic fields and heating of the strange star surface . it is shown that the rise times observed in typical bursts may be explained in this model only if strange quark matter is a superconductor with an energy gap of more that 1 mev . . And you have already written the first three sentences of the full article: strange stars are astronomical compact objects which are entirely made of deconfined quarks ( for a review , see glendenning 1996 ; weber 1999 ) . the possible existence of strange stars is a direct consequence of the conjecture that strange quark matter ( sqm ) may be the absolute ground state of the strong interaction , i.e. , absolutely stable with respect to @xmath1fe ( bodmer 1971 ; witten 1984 ) . sqm with a density of @xmath2 g @xmath3 might exist up to the surface of a strange star .. Please generate the next two sentences of the article

recently , the thermal emission from bare sqm surfaces of strange stars was considered ( usov 1998 , 2001a ) . it was shown that the surface emissivity of sqm in both equilibrium photons and @xmath0 pairs created by the coulomb barrier at the sqm surface is @xmath4% of the black body surface emissivity at the surface temperature @xmath5 k. below this temperature , @xmath6 k , the sqm surface emissivity decreases rapidly with decrease of @xmath7 . at the moment of formation of a strange star

Suppose that you have an abstract for a scientific paper: following a previous work [ shen , ma , xie and zhang , phys . rev . lett . 92 , 256603 ( 2004 ) ] on the resonant spin hall effect , we present detailed calculations of the spin hall conductance in two - dimensional quantum wells in a strong perpendicular magnetic field . the rashba coupling , generated by spin - orbit interaction in wells lacking bulk inversion symmetry , introduces a degeneracy of zeeman - split landau levels at certain magnetic fields . this degeneracy , if occuring at the fermi energy , will induce a resonance in the spin hall conductance below a characteristic temperature of order of the zeeman energy . at very low temperatures , the spin hall current is highly non - ohmic . the dresselhaus coupling due to the lack of structure inversion symmetry partially or completely suppresses the spin hall resonance . the condition for the resonant spin hall conductance in the presence of both rashba and dresselhaus couplings is derived using a perturbation method . in the presence of disorder , we argue that the resonant spin hall conductance occurs when the two zeeman split extended states near the fermi level becomes degenerate due to the rashba coupling and that the the quantized charge hall conductance changes by @xmath0 instead of @xmath1 as the magnetic field changes through the resonant field . . And you have already written the first three sentences of the full article: spintronics , which exploits electron spin rather than charge to develop a new generation of electronic devices , has emerged as an active field in condensed matters because of both the underlying fundamental physics and its potential impact on the information industry.prinz98science,wolf01science,awschalom02 one key issue in spintronics is the generation and efficient control of spin current . spin - orbit interaction of electrons exists extensively in metals and semiconductors and mix spin states . it provides an efficient way to control the coherent motion of electron spins .. Please generate the next two sentences of the article

recently it is proposed theoretically that an electric field may generate a spin current in hole - doped semiconductors and in two - dimensional electron gases ( 2deg ) in heterostructures with spin - orbit coupling due to the spin helicity and the noncollinearity of the velocity of the single particle wave function.@xcite studies of this intrinsic spin hall effect has evolved into a subject of intense research . shen03xxx , sinitsyn03xxx , culcer03xxx , schliemann04prb , hu03xxx , rashba03prb , hulb04xxx the spin hall effect in a paramagnetic metal with magnetic impurities has also been discussed , in which a transverse spin imbalance will be generated when a charge current circulates.dyakonov71,hirsch99,zhang00prl,hu03prb we also note that the spin chirality in systems with strong spin - orbit interaction may induce a pure spin current@xcite over the past two decades , remarkable phenomena have been observed in the 2deg , most notably , the discovery of integer and fractional quantum hall effect.@xcite research in spin transports provides a good opportunity to explore spin physics in the 2deg with spin - orbit couplings .

Suppose that you have an abstract for a scientific paper: this paper considers the problem of compact source detection on a gaussian background . we make a one - dimensional treatment ( though a generalization to two or more dimensions is possible ) . two relevant aspects of this problem are considered : the design of the detector and the filtering of the data . our detection scheme is based on local maxima and it takes into account not only the amplitude but also the curvature of the maxima . a neyman - pearson test is used to define the region of acceptance , that is given by a sufficient linear detector that is independent on the amplitude distribution of the sources . we study how detection can be enhanced by means of linear filters with a scaling parameter and compare some of them that have been proposed in the literature ( the mexican hat wavelet , the matched and the scale - adaptive filters ) . we introduce a new filter , that depends on two free parameters ( biparametric scale - adaptive filter ) . the value of these two parameters can be determined , given the a priori _ pdf _ of the amplitudes of the sources , such that the filter optimizes the performance of the detector in the sense that it gives the maximum number of real detections once fixed the number density of spurious sources . the new filter includes as particular cases the standard matched filter and the scale - adaptive filter . then , by construction , the biparametric scale adaptive filter outperforms these filters . the combination of a detection scheme that includes information on the curvature and a flexible filter that incorporates two free parameters ( one of them a scaling ) improves significantly the number of detections in some interesting cases . in particular , for the case of weak sources embedded in white noise the improvement with respect to the standard matched filter is of the order of @xmath0 . finally , an estimation of the amplitude of the source ( most probable value ) is introduced and it is proven that such an estimator is unbiased and it has.... And you have already written the first three sentences of the full article: the detection of compact signals ( sources ) embedded in a background is a recurrent problem in many fields of astronomy . some common examples are the separation of individual stars in a crowded optical image , the identification of local features ( lines ) in noisy one - dimensional spectra or the detection of faint extragalactic objects in microwave frequencies . the detection , identification and removal of the extragalactic point sources ( eps ) is fundamental for the study of the cosmic microwave background radiation ( cmb ) data ( franceschini et al .. Please generate the next two sentences of the article

1989 , toffolatti et al . 1998 , de zotti et al . 1999 ) . in particular

Suppose that you have an abstract for a scientific paper: we prove that the first continuous @xmath0-cohomology of free group factors vanishes . this answers a question by andreas thom regarding continuity properties of free difference quotients and shows that one can not distinguish free group factors by means of first continuous @xmath0-betti number . . And you have already written the first three sentences of the full article: introduced by topologists @xcite , @xmath0-betti numbers have been generalized to various contexts like groups , groupoids etc . alain connes and dimitri shlyakhtenko @xcite introduced @xmath0-betti numbers for subalgebras of finite von neumann algebras , with the purpose to obtain a suitable notion for arbitrary ii@xmath1-factors and in the hope to get a nice homological invariant for them . unfortunately , as of now there are only very few concrete calculations of them . the most advanced computational result so far is due to andreas thom @xcite who proved that the @xmath0-betti numbers vanish for von neumann algebras with diffuse center .. Please generate the next two sentences of the article

to allow more computable examples , he also introduced a continuous version of the first @xmath0-betti number @xcite which turns out to be much more manageable than its algebraic counterpart . the first continuous @xmath0-betti number is defined as the von neumann dimension of the first continuous hochschild cohomology of the von neumann algebra @xmath2 with values in the algebra of operators affiliated with @xmath3 .

Suppose that you have an abstract for a scientific paper: we present a michelson - morley type experiment for testing the isotropy of the speed of light in vacuum and matter . the experiment compares the resonance frequency of a monolithic optical sapphire resonator with the resonance frequency of an orthogonal evacuated optical cavity made of fused silica while the whole setup is rotated on an air bearing turntable once every 45 s. preliminary results yield an upper limit for the anisotropy of the speed of light in matter ( sapphire ) of @xmath0 , limited by the frequency stability of the sapphire resonator operated at room temperature . work to increase the measurement sensitivity by more than one order of magnitude by cooling down the sapphire resonator to liquid helium temperatures ( lhe ) is currently under way . . And you have already written the first three sentences of the full article: testing the isotropy of the speed of light serves as a sensitive test of special relativity and lorentz invariance . the classic experiment to test the isotropy of the speed of light uses a michelson interferometer and was first performed by a.a . michelson in berlin ( 1880 ) and potsdam ( 1881 ) , germany .. Please generate the next two sentences of the article

he was later joined by e.w . morley to perform an improved experiment in cleveland , ohio ( 1887 ) @xcite .

Suppose that you have an abstract for a scientific paper: the myads - arxiv service provides the scientific community with a one stop shop for staying up - to - date with a researcher s field of interest . the service provides a powerful and unique filter on the enormous amount of bibliographic information added to the ads on a daily basis . it also provides a complete view with the most relevant papers available in the subscriber s field of interest . with this service , the subscriber will get to know the lastest developments , popular trends and the most important papers . this makes the service not only unique from a technical point of view , but also from a content point of view . on this poster we will argue why myads - arxiv is a tailor - made , open access , virtual journal and we will illustrate its unique character . the ads is funded by nasa grant nng06gg68 g . . And you have already written the first three sentences of the full article: searching and staying up - to - date with scholarly literature is an essential part of scientific research . with the advent of the world - wide web ( www ) and the evolution of electronic publishing , a powerful environment was created to open the vast universe of scientific literature on a world - wide scale . in early 1994 the www had become sophisticated enough to allow the search of electronic resources via `` web forms '' . over the past decade , this environment matured into an unavoidable and indispensable fact of life and tools have emerged in it that have become a crucial ingredient in scientific research .. Please generate the next two sentences of the article

being able to search vast amounts of data electronically obviously facilitates the review process , but applying advanced technologies such as pattern recognition to the electronic data or by allowing nested searches , one is able to produce results that are unattainable in conventional , non - electronic ways . in that sense one can argue that the available electronic search tools on the www even further scientific research . using a straight - forward search engine ( google , yahoo , msn , altavista , ... ) results in thousands of documents , ranked by some sophisticated algorithm .

Suppose that you have an abstract for a scientific paper: we search the complete hubble frontier field dataset of abell 2744 and its parallel field for @xmath0 sources to further refine the evolution of the cosmic star - formation rate density ( sfrd ) between @xmath1 and @xmath2 . we independently confirm two images of the recently discovered triply - imaged @xmath3 source by zitrin et al . ( 2014 ) and set an upper limit for similar @xmath0 galaxies with red colors of @xmath4 in the parallel field of abell 2744 . we utilize extensive simulations to derive the effective selection volume of lyman - break galaxies at @xmath2 , both in the lensed cluster field and in the adjacent parallel field . particular care is taken to include position - dependent lensing shear to accurately account for the expected sizes and morphologies of highly - magnified sources . we show that both source blending and shear reduce the completeness at a given observed magnitude in the cluster , particularly near the critical curves . these effects have a significant , but largely overlooked , impact on the detectability of high - redshift sources behind clusters , and substantially reduce the expected number of highly - magnified sources . the detections and limits from both pointings result in a sfrd which is consistent within the uncertainties with previous estimates at @xmath2 from blank fields . the combination of these new results with all other estimates are also consistent with a rapidly declining sfrd in the 170 myr from @xmath1 to @xmath2 as predicted by cosmological simulations and dark - matter halo evolution in @xmath5cdm . once biases introduced by magnification - dependent completeness are accounted for , the full six cluster and parallel frontier field program will be an extremely powerful new dataset to probe the evolution of the galaxy population at @xmath6 before the advent of the jwst . . And you have already written the first three sentences of the full article: the first 500 myr after the big bang mark the current frontier in our exploration of cosmic history . understanding when and how the first galaxies started to form , how they grew their stellar mass and eventually turned into the diverse population of galaxies we see today is one of the most intriguing and challenging questions of modern observational astronomy . this is the main science driver for the director s discretionary time @xmath7 frontier field program ( hff ; e.g. * ? ? ?. Please generate the next two sentences of the article

the hff will make use of lensing magnification of 4 - 6 foreground clusters to probe the ultra - faint galaxy population as early as 400 - 500 myr after the big bang . furthermore , the hff additionally creates six deep parallel blank field pointings in order to mitigate the uncertainties of lensing magnification and cosmic variance . while great progress has been made recently in probing galaxy build - up out to @xmath8 ( e.g. * ? ? ?

Suppose that you have an abstract for a scientific paper: extending the results of s. y. cheng and s .- t . yau it is shown that a strictly pseudoconvex domain @xmath0 in a complex manifold carries a complete khler - einstein metric if and only if its canonical bundle is positive , i.e. admits an hermitian connection with positive curvature . we consider the restricted case in which the cr structure on @xmath1 is normal . in this case @xmath2 must be a domain in a resolution of the sasaki cone over @xmath1 . we give a condition on a normal cr manifold which it can not satisfy if it is a cr infinity of a khler - einstein manifold . we are able to mostly determine those normal cr 3-manifolds which can be cr infinities . we give many examples of khler - einstein strictly pseudoconvex manifolds on bundles and resolutions . in particular , the tubular neighborhood of the zero section of every negative holomorphic vector bundle on a compact complex manifold whose total space satisfies @xmath3 admits a complete khler - einstein metric . . And you have already written the first three sentences of the full article: s. y. cheng and s .- t . yau proved in @xcite that a bounded strictly pseudoconvex domain in @xmath4 admits a complete negative scalar curvature khler - einstein metric . their arguments also extended to other types of domains , such as a pseudoconvex domain which is the intersection of pseudoconvex domains with @xmath5 boundary .. Please generate the next two sentences of the article

many cases of domains in arbitrary complex manifolds are already dealt with in @xcite , and in @xcite . in @xcite n. mok and s .- t . yau proved the existence of a khler - einstein metric on strictly pseudoconvex domains under some hypotheses .

Suppose that you have an abstract for a scientific paper: we present the self - consistent treatment of the simplest , nontrivial , self - gravitating system of degenerate neutrons , protons and electrons in @xmath0-equilibrium within relativistic quantum statistics and the einstein - maxwell equations . the impossibility of imposing the condition of local charge neutrality on such systems is proved , consequently overcoming the traditional tolman - oppenheimer - volkoff treatment . we emphasize the crucial role of imposing the constancy of the generalized fermi energies . a new approach based on the coupled system of the general relativistic thomas - fermi - einstein - maxwell equations is presented and solved . we obtain an explicit solution fulfilling global and not local charge neutrality by solving a sophisticated eigenvalue problem of the general relativistic thomas - fermi equation . the value of the coulomb potential at the center of the configuration is @xmath1 and the system is intrinsically stable against coulomb repulsion in the proton component . this approach is necessary , but not sufficient , when strong interactions are introduced . neutron star electrodynamics , general relativistic thomas - fermi treatment . . And you have already written the first three sentences of the full article: the insurgence of critical electric fields in the process of gravitational collapse leading to vacuum polarization process @xcite has convinced us of the necessity of critically reexamining the gravitational and electrodynamical properties in neutron stars . in this light we have recently generalized the feynman , metropolis and teller treatment of compressed atoms to the relativistic regimes @xcite . we have so enforced , self - consistently in a relativistic thomas - fermi equation , the condition of @xmath0-equilibrium extending the works of v. s. popov @xcite , ya .. Please generate the next two sentences of the article

b. zeldovich and v. s. popov @xcite , a. b. migdal et al . @xcite , j. ferreirinho et al .

Suppose that you have an abstract for a scientific paper: battery electrode surfaces are generally coated with electronically insulating solid films of thickness 1 - 50 nm . both electrons and li@xmath0 can move at the electrode - surface film interface in response to the voltage , which adds complexity to the `` electric double layer '' ( edl ) . we apply density functional theory ( dft ) to investigate how the applied voltage is manifested as changes in the edl at atomic lengthscales , including charge separation and interfacial dipole moments . illustrating examples include li@xmath1po@xmath2 , li@xmath3co@xmath1 , and li@xmath4mn@xmath3o@xmath2 thin - films on au(111 ) surfaces under ultrahigh vacuum conditions . adsorbed organic solvent molecules can strongly reduce voltages predicted in vacuum . we propose that manipulating surface dipoles , seldom discussed in battery studies , may be a viable strategy to improve electrode passivation . we also distinguish the computed potential governing electrons , which is the actual or instantaneous voltage , and the `` lithium cohesive energy''-based voltage governing li content widely reported in dft calculations , which is a slower - responding self - consistency criterion at interfaces . this distinction is critical for a comprehensive description of electrochemical activities on electrode surfaces , including li@xmath0 insertion dynamics , parasitic electrolyte decomposition , and electrodeposition at overpotentials . keywords : lithium ion batteries ; voltage prediction ; density functional theory ; computational electrochemistry epsf . And you have already written the first three sentences of the full article: unlike pristine noble metal or graphite basal - plane electrodes used in classical electric double layer ( edl ) studies,@xcite lithium ion battery ( lib ) electrodes generally exhibit complex interfaces.@xcite both electron ( @xmath5 ) and li@xmath0 transport can occur inside lib electrodes . in addition , solid thin films , on the order 1 - 50 nm thick , are ubiquitous on lib electrode surfaces and can become part of the edl ( fig . [ fig1]a - h ) .. Please generate the next two sentences of the article

the edl is critical because key battery processes like li@xmath0 incorporation kinetics ( including li@xmath0 desolvation ) , parasitic reactions , li - plating , and degradation - inducing phase transformations on electrode surfaces most likely initiate within it . indeed , `` solid electrolyte interphase '' ( sei ) films@xcite covering anodes are relied upon as kinetic barriers that prevent thermodynamic equilibrium in batteries ; they are critical for lib which operate outside the redox stability window of the organic solvent electrolytes used . as discussed below , the edl is also crucial in computational work because it effectively determines the electrode potential ( henceforth `` applied voltage '' or simply `` voltage '' ) in the simulation cell .

Suppose that you have an abstract for a scientific paper: the group @xmath0 consists of @xmath1-by-@xmath1 monomial matrices whose entries are @xmath2th roots of unity . it is generated by @xmath1 complex reflections acting on @xmath3 . the reflecting hyperplanes give rise to a ( hyperplane ) arrangement @xmath4 . the internal zonotopal algebra of an arrangement is a finite dimensional algebra first studied by holtz and ron . its dimension is the number of bases of the associated matroid with zero internal activity . in this paper we study the structure of the internal zonotopal algebra of the gale dual of the reflection arrangement of @xmath0 , as a representation of this group . our main result is a formula for the top degree component as an induced character from the cyclic group generated by a coxeter element . we also provide results on representation stability , a connection to the whitehouse representation in type @xmath5 , and an analog of decreasing trees in type @xmath6 . . And you have already written the first three sentences of the full article: a meta - problem in the theory of hyperplane arrangements starts with an algebraic object @xmath7 derived from an arrangement @xmath8 and determines the extent to which the intersection lattice @xmath9 determines @xmath7 up to isomorphism . the prototypical example of this associates to an arrangement @xmath10 the cohomology ring of the complement @xmath11 . the structure of this ring was determined by orlik and solomon @xcite it is determined by the combinatorics of no - broken - circuit subsets of the associated matroid .. Please generate the next two sentences of the article

there is an equivariant version of the meta - problem where the arrangement @xmath8 is fixed by the action of a group @xmath12 acting linearly on @xmath13 . when this happens one wants to determine the structure of @xmath7 as a representation of @xmath12 .

Suppose that you have an abstract for a scientific paper: we propose a cavity qed setup which implements a dissipative lipkin - meshkov - glick model an interacting collective spin system . by varying the external model parameters the system can be made to undergo both first - and second - order quantum phase transitions , which are signified by dramatic changes in cavity output field properties , such as the probe laser transmission spectrum . the steady - state entanglement between pairs of atoms is shown to peak at the critical points and can be experimentally determined by suitable measurements on the cavity output field . the entanglement dynamics also exhibits pronounced variations in the vicinities of the phase transitions . . And you have already written the first three sentences of the full article: the branch of atomic physics associated with ultracold atoms , ions , and molecules now provides a rich and exciting arena for investigations of strongly interacting , many - body quantum systems . trapping and cooling techniques , coherent laser or microwave interactions , and applied magnetic fields enable exquisite control of both external ( motional ) and internal ( electronic ) degrees of freedom of the particles , allowing one to `` tailor '' particle - particle interactions and thereby implement a broad range of systems that can be described accurately and transparently by idealized ( but nontrivial ) many - body hamiltonians . an important example is the hubbard model , realized with ultracold atoms in periodic optical lattices @xcite , while realizations of other novel and significant lattice - spin models have been proposed , for example , with dipolar molecules in optical lattices @xcite and with chains of trapped atomic ions @xcite . the common , defining feature of these systems is the possibility for quantum critical phenomena , i.e. , transitions between distinct quantum phases , in response to variations of an effective field or particle - particle interaction strength around some critical value .. Please generate the next two sentences of the article

the above - mentioned schemes generally provide many - body quantum systems that are subject to short - range ( e.g. , nearest - neighbor ) interactions . another interesting and commonly studied class of many - body systems are those possessing long - range , or even infinite - range , interactions , for which theoretical models typically allow exact solutions in the thermodynamic limit , or at least enable efficient numerical solution for large numbers of particles . a standard and classic example is the lipkin - meshkov - glick ( lmg ) model @xcite , which was originally introduced in nuclear physics and is described by a hamiltonian of the form @xmath0 where @xmath1 are collective angular momentum operators for @xmath2 spin-1/2 particles , @xmath3 and @xmath4 are parameters giving the effective magnetic field and spin - spin interaction strengths , respectively , and @xmath5 $ ] is an anisotropy parameter . in this model

Suppose that you have an abstract for a scientific paper: statistical properties of the temporal distribution of polarity reversals of the geomagnetic field are commonly assumed to be a realization of a renewal poisson process with a variable rate . however , it has been recently shown that the polarity reversals strongly depart from a local poisson statistics , because of temporal clustering . such clustering arises from the presence of long - range correlations in the underlying dynamo process . recently achieved laboratory dynamo also shows reversals . it is shown here that laboratory and paleomagnetic data are both characterized by the presence of long - range correlations . . And you have already written the first three sentences of the full article: the observation of the paleomagnetic data @xcite have shown that , unlike the solar magnetic field , where the polarity reversals are strictly periodic , geomagnetic measurements of the last @xmath0 million years present rather sudden and occasional polarity reversals . the reversal process is normally very rapid with respect to the typical time interval between successive reversals , which may range from @xmath1 up to @xmath2 years @xcite . recent works on data analysis , experimental dynamo and theoretical modeling have inproved the knowledge of the earth dynamo. Please generate the next two sentences of the article

. however , the main fundamental questions concerning the polarity reversals still remain unanswered @xcite . the nature of the triggers ( external or internal to earth ) and the physical mechanisms giving rise to the reversals , the reason for the long time variations in the average reversal rate ( cf . e.g. @xcite ) , are still open problems . the sequence of geomagnetic reversals ( see the example from the ck95 database @xcite shown in fig . [ fig1 ] ) seems to result from a of a stochastic process .

Suppose that you have an abstract for a scientific paper: we study unstable epitaxy on singular surfaces using continuum equations with a prescribed slope - dependent surface current . we derive scaling relations for the late stage of growth , where power law coarsening of the mound morphology is observed . for the lateral size of mounds we obtain @xmath0 with @xmath1 . an analytic treatment within a self consistent mean field approximation predicts multiscaling of the height height correlation function , while the direct numerical solution of the continuum equation shows conventional scaling with @xmath2 , independent of the shape of the surface current . . And you have already written the first three sentences of the full article: on many crystal surfaces step edge barriers are observed which prevent interlayer ( downward ) hopping of diffusing adatoms @xcite . in homoepitaxy from a molecular beam this leads to a growth instability which can be understood on a basic level : adatoms form islands on the initial substrate and matter deposited on top of them is caught there by the step edge barrier . thus a pyramid structure of islands on top of islands develops . at late stages of growth pyramids coalesce and form large `` mounds '' .. Please generate the next two sentences of the article

their lateral size @xmath3 is found experimentally to increase according to a power law in time , @xmath0 with @xmath4 6 depending on the material and , possibly , deposition conditions used . a second characteristic is the slope of the mounds hillsides @xmath5 , which is observed to either approach a constant ( often referred to as a `` magic slope '' since it does not necessarily coincide with a high symmetry plane ) or to increase with time as @xmath6 @xcite .

Suppose that you have an abstract for a scientific paper: we present imaging observations at 1.3 millimeters of the debris disk surrounding the nearby m - type flare star au mic with beam size @xmath0 ( 30 au ) from the submillimeter array . these data reveal a belt of thermal dust emission surrounding the star with the same edge - on geometry as the more extended scattered light disk detected at optical wavelengths . simple modeling indicates a central radius of @xmath1 au for the emission belt . this location is consistent with the reservoir of planetesimals previously invoked to explain the shape of the scattered light surface brightness profile through size - dependent dust dynamics . the identification of this belt further strengthens the kinship between the debris disks around au mic and its more massive sister star @xmath2 pic , members of the same @xmath3 myr - old moving group . . And you have already written the first three sentences of the full article: au mic is a nearby ( @xmath4 pc , * ? ? ? * ) m1ve flare star @xcite with the young age of @xmath5 myr @xcite , a key epoch in the formation of planetary systems . the star is surrounded by a nearly edge - on circumstellar disk discovered in coronographic images of scattered starlight that extends to a radius of at least 210 au @xcite .. Please generate the next two sentences of the article

since the small grains responsible for scattering should be removed rapidly by stellar pressure forces , the disk is thought to consist of the collisional debris of unseen planetesimals experiencing ongoing impacts ( for recent reviews of the debris disk phenomenon , see * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: we present a new scenario for the cooling of compact stars considering the central source of cassiopeia a ( cas a ) . the cas a observation shows that the central source is a compact star that has high effective temperature , and it is consistent with the cooling without exotic phases . the observation also gives the mass range of @xmath0 , which may conflict with the current plausible cooling scenario of compact stars . there are some cooled compact stars such as vela or 3c58 , which can be barely explained by the minimal cooling scenario , which includes the neutrino emission by nucleon superfluidity ( pbf ) . therefore , we invoke the exotic cooling processes , where a heavier star cools faster than lighter one . however , the scenario seems to be inconsistent with the observation of cas a. therefore , we present a new cooling scenario to explain the observation of cas a by constructing models that include a quark color superconducting ( csc ) phase with a large energy gap ; this phase appears at ultrahigh density region and reduces neutrino emissivity . in our model , a compact star has csc quark core with a low neutrino emissivity surrounded by high emissivity region made by normal quarks . we present cooling curves obtained from the evolutionary calculations of compact stars : while heavier stars cool slowly , and lighter ones indicate the opposite tendency without considering nucleon superfluidity . furthermore , we show that our scenario is consistent with the recent observations of the effective temperature of cas a during the last 10 years , including nucleon superfluidity . . And you have already written the first three sentences of the full article: the cooling of compact stars has been discussed mainly in the context of neutron stars for decades @xcite . it has been believed that some stars require exotic cooling to explain the observed effective temperature and others can be explained by the modified urca and bremsstrahlung processes , where the central density of the star determines which cooling process works : an exotic cooling phase appears at higher density above a threshold density ( e.g. , * ? ? ? * ; * ? ? ? as a consequence , the heavier star which has higher central density cools faster than lighter one @xcite .. Please generate the next two sentences of the article

however , as described below this scenario becomes inconsistent when we consider the recent observation of the effective temperature of cas a whose mass has been found to be unexpectedly large . cas a is the youngest - known supernova remnant in the milky way and it is located @xmath1 from the solar system @xcite .

Suppose that you have an abstract for a scientific paper: a simple , yet reasonably accurate , analytical technique is proposed for multi - factor structural credit portfolio models . the accuracy of the technique is demonstrated by benchmarking against monte carlo simulations . the approach presented here may be of high interest to practitioners looking for transparent , intuitive , easy to implement and high performance credit portfolio model . . And you have already written the first three sentences of the full article: structural multi - factor _ economic capital _ ( ec ) models derived from the creditmetrics framework @xcite have become the most widely adopted tools for risk quantification in credit portfolios . an outcome of these models , a portfolio ec and its allocation down to individual facilities , is used by financial institutions for any or all of the following : internal capital adequacy assessment , external reporting , risk - based pricing , performance management , acquisition / divestiture analyses , stress - testing and scenario analysis , etc . while in most cases monte carlo simulations are used due to limited analytical tractability of the multi - factor models , the recently reported advanced analytical techniques @xcite may be viewed as an alternative . unfortunately , neither the industry standard simulation - based approach nor the existing analytical techniques can fully address the needs of the financial institutions . in particular , the risk - based real - time pricing remains the ultimate challenge : none of the existing models is capable of providing sufficiently accurate , stable and time - efficient input . yet another practical aspect which has not received enough attention in the literature. Please generate the next two sentences of the article

is the sometimes overly complex structure of the models as perceived by end users . very often the complexity of the models makes them hard to be understood and , hence , affects their acceptance within an organization .

Suppose that you have an abstract for a scientific paper: the maximum weight independent set ( mwis ) problem is a well - known np - hard problem . a popular way to study mwis is to detect graph classes for which mwis can be solved in polynomial time , with particular reference to hereditary graph classes , i.e. , defined by a hereditary graph property or equivalently by forbidding one or more induced subgraphs . for graphs @xmath0 , @xmath1 denotes the disjoint union of @xmath2 and @xmath3 , and for a constant @xmath4 , @xmath5 denotes the disjoint union of @xmath6 copies of @xmath7 . a _ claw _ has vertices @xmath8 , and edges @xmath9 . mwis can be solved for claw - free graphs in polynomial time ; the first two polynomial time algorithms were introduced in 1980 by @xcite , then revisited by @xcite , and recently improved by @xcite , and by @xcite with the best known time bound in @xcite . furthermore mwis can be solved for the following extensions of claw - free graphs in polynomial time : fork - free graphs @xcite , @xmath10+claw - free graphs @xcite , and apple - free graphs @xcite . this manuscript shows that for any constant @xmath6 , mwis can be solved for @xmath6claw - free graphs in polynomial time . our approach is based on farber s approach showing that every @xmath11-free graph has @xmath12 maximal independent sets @xcite , which directly leads to a polynomial time algorithm for mwis on @xmath11-free graphs by dynamic programming . solving mwis for @xmath6claw - free graphs in polynomial time extends known results for claw - free graphs , for @xmath13-free graphs for any constant @xmath6 @xcite , for @xmath10+claw - free graphs , for @xmath14-free graphs @xcite , and solves the open questions for @xmath15-free graphs and for @xmath16+claw - free graphs being two of the minimal graph classes , defined by forbidding one induced subgraph , for which the complexity of mwis was an open problem . institut fr informatik , universitt rostock , d-18051 rostock , germany . + ` ab@informatik.uni-rostock.de ` dipartimento di.... And you have already written the first three sentences of the full article: for any missing notation or reference let us refer to @xcite . for a graph @xmath7 , let @xmath17 ( @xmath18 , respectively ) denote its vertex set ( edge set , respectively ) . for a subset @xmath19 , let @xmath20 @xmath21 is adjacent to some @xmath22 be the _ neighborhood of u in g _ , and @xmath23 be the _ anti - neighborhood of u in g_. if @xmath24 , then let us simply write @xmath25 instead of @xmath26 , and @xmath27 instead of @xmath28 .. Please generate the next two sentences of the article

for @xmath19 let @xmath29 $ ] denote the subgraph of @xmath7 induced by @xmath30 . for a vertex @xmath31 and for a subset @xmath32 ( with @xmath33 ) , let us say that _ @xmath21 contacts @xmath30 _ if @xmath21 is adjacent to some vertex of @xmath30 , and _

Suppose that you have an abstract for a scientific paper: renormalization group ( rg ) methods used to soften hamiltonians for nuclear many - body calculations change the effective resolution of the interaction . for nucleon knock - out processes , these rg transformations leave cross sections invariant , but initial - state wave functions , interaction currents , and final - state interactions are individually altered . this has implications for the factorization of nuclear structure and reactions . we use deuteron electrodisintegration as a controlled laboratory for studying how structure and reaction components are modified under rg evolution , without the complication of three - body forces or currents . the dependence of these changes on kinematics is explored . . And you have already written the first three sentences of the full article: softened or `` low momentum '' interactions are widely used in contemporary nuclear structure calculations because they exhibit faster convergence for methods using basis expansions ( this includes coupled cluster , configuration interaction , in - medium similarity renormalization group , and self - consistent green s function methods ) @xcite . such interactions are derived using unitary transformations starting from chiral effective field theory or phenomenological interactions that exhibit significant coupling of high- and low - momentum physics . when done in small steps , these unitary transformations are a type of renormalization group ( rg ) transformation .. Please generate the next two sentences of the article

the rg decoupling scale can be associated with the resolution of the interaction @xcite . but how do we handle observables involving external probes when using such interactions ?

Suppose that you have an abstract for a scientific paper: we explain a naive approach towards the problem of finding genus 3 curves @xmath0 over any given finite field @xmath1 of odd characteristic , with a number of rational points close to the hasse - weil - serre upper bound @xmath2 $ ] . the method turns out to be successful at least in characteristic @xmath3 . . And you have already written the first three sentences of the full article: [ [ section ] ] the maximal number of rational points that a ( smooth , geometrically irreducible ) curve of genus @xmath4 over a finite field @xmath5 can have , is denoted by @xmath6 . one has the estimate ( see @xcite ) @xmath7\ ] ] in which the notation @xmath8 $ ] for @xmath9 means the largest integer @xmath10 . the upper bound here is called the hasse - weil - serre bound . for @xmath11 ,. Please generate the next two sentences of the article

it is a classical result of deuring @xcite , @xcite that @xmath12 $ ] , except when @xmath13 with @xmath14 prime and @xmath15 odd and @xmath14 divides @xmath16 $ ] , in which case @xmath17 $ ] . for @xmath18 an explicit formula is due to j - p . he stated and proved the result during a course @xcite he gave at harvard university in 1985 ; a nice survey including some modifications of the original proof can be found in chapter 5 of the thesis @xcite .