Datasets:

scillm

/

scientific_papers-archive

like 4

Follow

scillm_su23 10

Suppose that you have an abstract for a scientific paper: particles crossing repeatedly the surface of a shock wave can be energized by first order fermi acceleration . the linear theory is successful in describing the acceleration process as long as the pressure of the accelerated particles remains negligible compared to the kinetic pressure of the incoming gas ( the so - called test particle approximation ) . when this condition is no longer fulfilled , the shock is modified by the pressure of the accelerated particles in a nonlinear way , namely the spectrum of accelerated particles and the shock structure determine each other . in this paper we present the first description of the nonlinear regime of shock acceleration when the shock propagates in a medium where seed particles are already present . this case may apply for instance to supernova shocks propagating into the interstellar medium , where cosmic rays are in equipartition with the gas pressure . we find that the appearance of multiple solutions , previously found in alternative descriptions of the nonlinear regime , occurs also for the case of reacceleration of seed particles . moreover , for parameters of concern for supernova shocks , the shock is likely to turn nonlinear mainly due to the presence of the pre - existing cosmic rays , rather than due to the acceleration of new particles from the thermal pool . we investigate here the onset of the nonlinear regime for the three following cases : 1 ) seed particles in equipartition with the gas pressure ; 2 ) particles accelerated from the thermal pool ; 3 ) combination of 1 ) and 2 ) . cosmic rays , high energy , acceleration . And you have already written the first three sentences of the full article: diffusive acceleration at newtonian shock fronts is an extensively studied phenomenon . detailed discussions of the current status of the investigations can be found in some recent excellent reviews @xcite . while much is by now well understood , some issues are still subjects of much debate , for the theoretical and phenomenological implications that they may have .. Please generate the next two sentences of the article

the most important of these is the backreaction of the accelerated particles on the shock : the violation of the _ test particle approximation _ occurs when the acceleration process becomes sufficiently efficient to generate pressures of the accelerated particles which are comparable with the incoming gas kinetic pressure . both the spectrum of the particles and the structure of the shock are changed by this phenomenon , which is therefore intrinsically nonlinear . at present

Suppose that you have an abstract for a scientific paper: quintessential inflation is studied using a string modulus as the inflaton quintessence field . it is assumed that the modulus crosses an enhanced symmetry point ( esp ) in field space . particle production at the esp temporarily traps the modulus resulting in a period of inflation . after reheating , the modulus freezes due to cosmological friction at a large value , such that its scalar potential is dominated by contributions due to fluxes in the extra dimensions . the modulus remains frozen until the present , when it can become quintessence . . And you have already written the first three sentences of the full article: a plethora of observations concur that the universe at present enters a phase of accelerated expansion . in fact , most cosmologists accept that over 70% of the universe content at present corresponds to the elusive dark energy ; a substance with pressure negative enough to cause the observed acceleration @xcite . the simplest form of dark energy is a positive cosmological constant @xmath0 , which however , needs to be incredibly fine - tuned to explain the observations @xcite .. Please generate the next two sentences of the article

this is why theorists have looked for alternatives , which could explain the observations while setting , as was originally assumed . a promising idea is to consider that the universe at present is entering a late - time inflationary period @xcite .

Suppose that you have an abstract for a scientific paper: this paper is concerned with the fading multiple - input multiple - output multiple - access channel ( mimo - mac ) with multiple receive antennas at the base station ( bs ) and multiple transmit antennas at each mobile terminal ( mt ) . two multiple - access techniques are considered for scheduling transmissions from each mt to the bs at the same frequency , which are _ space - division multiple - access _ ( sdma ) and _ time - division multiple - access _ ( tdma ) . for sdma , all mts transmit simultaneously to the bs and their individual signals are resolved at the bs via multiple receive antennas while for tdma , each mt transmits independently to the bs during mutually orthogonal time slots . it is assumed that the channel - state information ( csi ) of the fading channel from each mt to the bs is _ unknown _ at each mt transmitter , but is perfectly _ known _ at the bs receiver . thereby , the bs can acquire the long - term channel - distribution information ( cdi ) for each mt . this paper extends the well - known _ transmit - covariance feedback _ scheme for the point - to - point fading mimo channel to the fading mimo - mac , whereby the bs jointly optimizes the transmit signal covariance matrices for all mts based on their cdi , and then sends each transmit covariance matrix back to the corresponding mt via a feedback channel . the main goal of this paper is to characterize the so - called _ multiuser power region _ under the multiuser transmit - covariance feedback scheme for both sdma and tdma . the power region is defined as the constitution of all user transmit power - tuples that can achieve reliable transmissions for a given set of user target rates . simulation results show that sdma can achieve substantial power savings over tdma for the fading mimo - mac , even when the number of antennas at the bs is equal to that at each mt . moreover , this paper demonstrates the usefulness of the multiuser power region for maintaining _ proportionally - fair _ power consumption among.... And you have already written the first three sentences of the full article: transmission through multiple transmit and multiple receive antennas , or the so - called multiple - input multiple - output ( mimo ) technology , is known as an efficient means for providing enormous information rates in rich - scattering mobile environments @xcite-@xcite . characterization of the fading mimo channel capacity limits , under various assumptions on the transmitter - side and receiver - side channel - state information ( csi ) and channel - distribution information ( cdi ) , has motivated a great deal of valuable scholarly work ( e.g. , @xcite and references therein ) . in particular , the case where the csi is perfectly _ known _ at the receiver but _ unknown _ at the transmitter has drawn much interest due to its validity in many practical situations .. Please generate the next two sentences of the article

this is because the presumption of perfect receiver - side csi is usually reasonable for wireless channels where the receiver can locally estimate the fading channel , while the complete csi feedback from the receiver to the transmitter is difficult or even impossible . consequently , many schemes that exploit various forms of _ partial _ channel feedback have been proposed in literature . among others , the _ transmit - covariance feedback _ scheme is known to be capable of achieving data rates close to the fading mimo channel ergodic capacity when the channel cdi exhibits some long - term consistent statistical properties , e.g. , constant channel mean and/or constant channel covariance matrix @xcite-@xcite . in the transmit - covariance feedback scheme ,

Suppose that you have an abstract for a scientific paper: i start by reviewing existing @xmath0 measurements with particular emphasis on the recent 221 mev @xmath0 measurement at triumf which permitted the weak meson - nucleon coupling constants @xmath1 and @xmath2 to be determined separately for the first time . i then review @xmath3 experiments , with specific details of the @xmath4 experiment now under preparation at los alamos national laboratory . this experiment will provide a clean measurement of the weak pion nucleon coupling , @xmath5 . finally , i discuss @xmath6 parity violation experiments , particularly the gzero experiment under way at jefferson lab in virginia . this experiment will measure the weak form factors @xmath7 and @xmath8 , allowing the distribution of strange quarks in the quark sea to be determined . . And you have already written the first three sentences of the full article: in vancouver a popular form of chinese luncheon is `` dim sum '' in which small quantities of a large variety of foods may be tasted . this review is a `` dim sum '' of parity violation experiments . as with a luncheon , my selection is biased by my personal taste and experience .. Please generate the next two sentences of the article

i start with @xmath0 parity violation experiments , concentrating on the the triumf 221 mev @xmath0 experiment , then discuss @xmath3 parity violation experiments with details of the los alamos @xmath4 experiment now being installed at lansce . finally , i discuss @xmath6 parity violation experiments , particularly the gzero experiment at jefferson lab .

Suppose that you have an abstract for a scientific paper: we examine various well known exact solutions available in the literature to investigate the recent criterion obtained in ref . [ 20 ] which should be fulfilled by any static and spherically symmetric solution in the state of hydrostatic equilibrium . it is seen that this criterion is fulfilled only by ( i ) the regular solutions having a vanishing surface density together with the pressure , and ( ii ) the singular solutions corresponding to a non - vanishing density at the surface of the configuration . on the other hand , the regular solutions corresponding to a non - vanishing surface density do not fulfill this criterion . based upon this investigation , we point out that the exterior schwarzschild solution itself provides necessary conditions for the types of the density distributions to be considered inside the mass , in order to obtain exact solutions or equations of state compatible with the structure of general relativity . the regular solutions with finite centre and non - zero surface densities which do not fulfill the criterion [ 20 ] , in fact , can not meet the requirement of the ` actual mass ' set up by exterior schwarzschild solution . the only regular solution which could be possible in this regard is represented by uniform ( homogeneous ) density distribution . the criterion [ 20 ] provides a necessary and sufficient condition for any static and spherical configuration ( including core - envelope models ) to be compatible with the structure of general relativity . thus , it may find application to construct the appropriate core - envelope models of stellar objects like neutron stars and may be used to test various equations of state for dense nuclear matter and the models of relativistic stellar structures like star clusters . _ pacs nos . : 04.20.jd ; 04.40.dg ; 97.60.jd._ * exact solutions of einstein s field equations * + .25 in p. s. negi _ department of physics , kumaun university , nainital 263 002 , india _ . And you have already written the first three sentences of the full article: the first two exact solution of einstein s field equations were obtained by schwarzschild [ 1 ] , soon after einstein introduced general relativity ( gr ) . the first solution describes the geometry of the space - time exterior to a prefect fluid sphere in hydrostatic equilibrium . while the other , known as interior schwarzschild solution , corresponds to the interior geometry of a fluid sphere of constant ( homogeneous ) energy - density , @xmath0 . the importance of these two solutions in gr is well known .. Please generate the next two sentences of the article

the exterior solution at a given point depends only upon the total mass of the gravitating body and the radial distance as measured from the centre of the spherical symmetry , and not upon the ` type ' of the density distribution considered inside the mass . however , we will focus on this point of crucial importance later on in the present paper . on the other hand , the interior schwarzschild solution provides two very important features towards obtaining configurations in hydrostatic equilibrium , compatible with gr , namely - ( i ) it gives an absolute upper limit on compaction parameter , @xmath1 , mass to size ratio of the entire configuration in geometrized units ) @xmath2 for any static and spherical solution ( provided the density decreases monotonically outwards from the centre ) in hydrostatic equilibrium [ 2 ] , and ( ii ) for an assigned value of the compaction parameter , @xmath3 , the minimum central pressure , @xmath4 , corresponds to the homogeneous density solution ( see , e.g. , [ 3 ] ) .

Suppose that you have an abstract for a scientific paper: we investigate feedback control of linear quantum systems subject to feedback - loop time delays . in particular , we examine the relation between the potentially achievable control performance and the time delays , and provide theoretical guidelines for the future experimental setup in two physical systems , which are typical in this research field . the evaluation criterion for the analysis is given by the optimal control performance formula , the derivation of which is from the classical control theoretic results about the input - output delay systems . . And you have already written the first three sentences of the full article: for reliable realization of quantum feedback control , it is indispensable to take into consideration some real - world limitations , such as incomplete knowledge of the physical systems and poor performance of the control devices . various efforts on these issues have been undertaken in these few years , see e.g. , @xcite for the system parameter uncertainty . among such limitations , time delays in the feedback loop , which happen due to the finite computational speed of _ classical _ controller devices , are extremely serious , since their effect may completely lose the benefit of feedback control @xcite . to avoid the time delays. Please generate the next two sentences of the article

, one can think to use the markovian feedback control , in which the measurement results are directly fed back @xcite . however , while these experimental simplification has been extensively studied , theoretical ways to evaluate the effect of the time delays have not been proposed so far . in this paper

Suppose that you have an abstract for a scientific paper: we present a new x - ray analysis of the dwarf seyfert galaxy ngc 4395 , based on two archival _ xmm - newton _ and _ suzaku _ observations . this source is well known for a series of remarkable properties : one of the smallest estimated black hole masses among active galactic nuclei ( of the order of @xmath010@xmath1 ) , intense flux variability on very short time - scales ( a few tens of seconds ) , an unusually flat x - ray continuum ( @xmath2 over the 210 kev energy range ) . ngc 4395 is also characterized by significant variations of the x - ray spectral shape , and here we show that such behaviour can be explained through the partial occultation by circumnuclear cold absorbers with column densities of @xmath010@xmath310@xmath4 @xmath5 . in this scenario , the primary x - ray emission is best reproduced by means of a power law with a standard @xmath6 photon index , consistent with both the spectral slope observed at higher energies and the values typical of local agn . [ firstpage ] galaxies : active galaxies : individual : ngc 4395 x - rays : galaxies . . And you have already written the first three sentences of the full article: the central regions of the dwarf spiral galaxy ngc 4395 show most of the common signatures of nuclear activity . the optical and ultraviolet ( uv ) spectra reveal prominent high - ionization forbidden lines on top of a nearly featureless continuum , and broad wings corresponding to gas velocities in excess of @xmath010@xmath7 km s@xmath8 are detected in the permitted lines ( filippenko & sargent 1989 ) . contrary to the objects of the same kind , the emission - line properties , the optical to x - ray variability pattern and the inferred accretion rate of ngc 4395 are those typical of the seyfert class , of which this source is usually considered to represent the least luminous member .. Please generate the next two sentences of the article

different methods have been employed in the last years to derive the mass of its central black hole : the estimate obtained through reverberation mapping is @xmath9 ( peterson et al . 2005 ) , but the lack in this galaxy of a significant bulge and the stringent upper limit of 30 km s@xmath8 on its velocity dispersion suggest an even lower value , of the order of @xmath010@xmath1010@xmath1 ( filippenko & ho 2003 ) . anyhow , the engine of ngc 4395 falls somewhere between the stellar - mass black holes found in galactic x - ray binaries and the supermassive black holes residing inside active galactic nuclei ( agn ) .

Suppose that you have an abstract for a scientific paper: we propose and study a simplified model for the surface and bulk structures of crosslinked polymer gels , into which voids are introduced through templating by surfactant micelles . such systems were recently studied by atomic force microscopy [ m. chakrapani _ et al . _ , e - print cond - mat/0112255 ] . the gel is represented by a frustrated , triangular network of nodes connected by springs of random equilibrium lengths . the nodes represent crosslinkers , and the springs correspond to polymer chains . the boundaries are fixed at the bottom , free at the top , and periodic in the lateral direction . voids are introduced by deleting a proportion of the nodes and their associated springs . the model is numerically relaxed to a representative local energy minimum , resulting in an inhomogeneous , `` clumpy '' bulk structure . the free top surface is defined at evenly spaced points in the lateral ( @xmath0 ) direction by the height of the topmost spring , measured from the bottom layer , @xmath1 . its scaling properties are studied by calculating the root - mean - square surface width and the generalized increment correlation functions @xmath2 . the surface is found to have a nontrivial scaling behavior on small length scales , with a crossover to scale - independent behavior on large scales . as the vacancy concentration approaches the site - percolation limit , both the crossover length and the saturation value of the surface width diverge in a manner that appears to be proportional to the bulk connectivity length . this suggests that a percolation transition in the bulk also drives a similar divergence observed in surfactant templated polyacrylamide gels at high surfactant concentrations . . And you have already written the first three sentences of the full article: crosslinked polymer hydrogels are completely interconnected polymer networks that combine high water content with high porosity , forming macroscopic molecules that have applications in many fields . their wide range of pore sizes makes such gels ideal for separation of biological macromolecules by electrophoresis or chromatography @xcite . the crosslinking process induces a reorganization of the polymer structure , resulting in inhomogeneities in the spatial density @xcite .. Please generate the next two sentences of the article

these inhomogeneities affect the surface configurations of the gels , but only in recent years have advances in atomic force microscopy ( afm ) made possible the imaging of soft material surfaces in an aqueous environment @xcite . the effects of the crosslinking density , temperature , pressure , and sample thickness on the surface topography have been studied by suzuki _

Suppose that you have an abstract for a scientific paper: the three - gluon vertex is a basic object of interest in nonabelian gauge theory . it contains important structural information , in particular on infrared divergences , and also figures prominently in the schwinger - dyson equations . at the one - loop level , it has been calculated and analyzed by a number of authors . here we use the worldline formalism to unify the calculations of the scalar , spinor and gluon loop contributions to the one - loop vertex , leading to an extremely compact representation . the susy - related sum rule found by binger and brodsky follows from an off - shell extension of the bern - kosower replacement rules . we explain the relation of the structure of our representation to the low - energy effective action . = 11.6pt . And you have already written the first three sentences of the full article: the off - shell three - gluon vertex has been under investigation for more than three decades . by an analysis of the nonabelian gauge ward identities , ball and chiu@xcite in 1980 found a form factor decomposition of this vertex which is valid at any order in perturbation theory , with the only restriction that a covariant gauge be used . at the one - loop level , they also calculated the vertex explicitly for the case of a gluon loop in feynman gauge . later cornwall and papavassiliou@xcite applied the pinch technique to the non - perturbative study of this vertex .. Please generate the next two sentences of the article

davydychev , osland and sax @xcite calculated the massive quark contribution of the one loop three - gluon vertex . binger and brodsky@xcite calculated the one - loop vertex in the pinch technique and found the following susy - related identity between its scalar , spinor and gluon loop contributions , @xmath0 in this talk , i present a recalculation of the scalar , spinor and gluon loop contributions to the three - gluon vertex using the worldline formalism @xcite .

Suppose that you have an abstract for a scientific paper: we have performed very large and high resolution cosmological hydrodynamic simulations in order to investigate detectability of nebular lines in the rest - frame ultraviolet ( uv ) to optical wavelength range from galaxies at @xmath0 . we find that the expected line fluxes are very well correlated with apparent uv magnitudes . the c iv @xmath1 and the c iii ] @xmath2 lines of galaxies brighter than @xmath3 are detectable with current facilities such as the vlt / xshooter and the keck / mosfire . metal lines such as c iv @xmath1 , c iii ] @xmath2 , [ o ii ] @xmath4 and [ o iii ] @xmath5 can be good targets for the spectroscopic observation with thirty meter telescope ( tmt ) , european extremely large telescope ( e - elt ) , giant magellan telescope ( gmt ) and james webb space telescope ( jwst ) . h@xmath6 and h@xmath7 lines are also expected to be detectable with these telescopes . we also predict detectability of the nebular lines for @xmath8 galaxies that will be found with jwst , wide - field infrared survey telescope ( wfirst ) and first light and reionization explorer ( flare ) @xmath9 ) . we conclude that the c iv @xmath1 , c iii ] @xmath2 , [ o iii ] @xmath5 and h@xmath7 lines even from @xmath10 galaxies can be strong targets for tmt , elt and jwst . we also find that the magnification by gravitational lensing is of great help to detect such high-@xmath11 galaxies . according to our model , the c iii ] @xmath2 line in @xmath12 galaxy candidates is detectable even using the current facilities . [ firstpage ] cosmology observations ; galaxies evolution ; galaxies formation ; galaxies high - redshift ; galaxies luminosity function , mass function ; . And you have already written the first three sentences of the full article: understanding physical properties of the high-@xmath11 galaxies beyond @xmath13 is very important , because such galaxies are not only building blocks of lower-@xmath11 galaxies and local galaxies but also the leading candidate of ionizing sources for the cosmic reionization . such galaxies are much fainter objects because they are very distant objects and less massive systems . thus , in order to observe these galaxies , ultra deep surveys are necessary .. Please generate the next two sentences of the article

the wide field camera ( wfc3 ) installed on the hubble space telescope ( hst ) in 2009 have detected many @xmath0 galaxy candidates using the dropout ( lyman break ) technique @xcite . the combination of gravitational lensing by foreground galaxy clusters and the wfc3 camera have also discovered even intrinsically fainter high-@xmath11 galaxy candidates @xcite .

Suppose that you have an abstract for a scientific paper: we introduce a new index of the leptonic cp phase dependence @xmath0 and derive the maximal condition for this index in a simple and general form . @xmath1 may be realized even in the jparc experiment . in the case that the 1 - 3 mixing angle can be observed in the next generation reactor experiments , namely @xmath2 , and nevertheless @xmath3 appearance signal can not be observed in the jparc experiment , we conclude that the cp phase @xmath4 becomes a value around @xmath5 @xmath6 for @xmath7 @xmath8 without depending the uncertainties of solar and atmospheric parameters . . And you have already written the first three sentences of the full article: in future experiments , the determination of the leptonic cp phase @xmath4 is one of the most important aim in elementary particle physics . a lot of effort have been dedicated both from theoretical and experimental point of view in order to attain this aim , see @xcite and the references therein . the cp asymmetry , @xmath9 , is widely used as the index of the cp phase dependence . here ,. Please generate the next two sentences of the article

@xmath10 and @xmath11 are the oscillation probabilities for the transition @xmath12 and @xmath13 respectively . however , this index has to be improved on the following three points . the first one is that the fake cp violation due to matter effect @xcite can not be separated clearly in @xmath14 .

Suppose that you have an abstract for a scientific paper: two methods for the nonperturbative solution of field - theoretic bound - state problems , based on light - front coordinates , are briefly reviewed . one uses pauli villars regularization and the other supersymmetry . applications to yukawa theory and super yang mills theory with fundamental matter are emphasized . . And you have already written the first three sentences of the full article: there have been a number of calculations @xcite using light - front coordinates @xcite as a convenient means of attacking field - theoretic problems nonperturbatively , particularly in 1 + 1 dimensions . efforts in more dimensions have generally been less successful , however , due to the need for regularization and renormalization . here two approaches that include consistent regularization are briefly reviewed in the context of specific model calculations @xcite .. Please generate the next two sentences of the article

one approach is pauli villars ( pv ) regularization @xcite , where massive negative - metric particles are added to a theory to provide the necessary cancellations @xcite . the other is supersymmetry @xcite . these are not the only approaches available on the light front ; in particular , one can find the transverse lattice technique @xcite and similarity transformations @xcite discussed elsewhere in this volume .

Suppose that you have an abstract for a scientific paper: we summarize the contribution of the hatnet project to extrasolar planet science , highlighting published planets ( hat - p-1b through hat - p-26b ) . we also briefly discuss the operations , data analysis , candidate selection and confirmation procedures , and we summarize what hatnet provides to the exoplanet community with each discovery . . And you have already written the first three sentences of the full article: the hungarian - made automated telescope network ( hatnet ; bakos et al . 2004 ) survey , has been one of the main contributors to the discovery of transiting exoplanets ( teps ) , being responsible for approximately a quarter of the @xmath0 confirmed teps discovered to date ( fig . 1 ) . it is a wide - field transit survey , similar to other projects such as super - wasp ( pollaco et al .. Please generate the next two sentences of the article

2006 ) , xo ( mccullough et al . 2005 ) , and tres ( alonso et al .

Suppose that you have an abstract for a scientific paper: a latin bitrade @xmath0 is a pair of partial latin squares that define the difference between two arbitrary latin squares @xmath1 and @xmath2 of the same order . a @xmath3-homogeneous bitrade @xmath0 has three entries in each row , three entries in each column , and each symbol appears three times in @xmath4 . cavenagh @xcite showed that any @xmath3-homogeneous bitrade may be partitioned into three transversals . in this paper we provide an independent proof of cavenagh s result using geometric methods . in doing so we provide a framework for studying bitrades as tessellations in spherical , euclidean or hyperbolic space . additionally , we show how latin bitrades are related to finite representations of certain triangle groups . . And you have already written the first three sentences of the full article: a _ latin bitrade _ @xmath5 is a pair of partial latin squares which are disjoint , occupy the same set of non - empty cells , and whose corresponding rows and columns contain the same set of entries . one of the earliest studies of latin bitrades appeared in @xcite , where they are referred to as _ exchangeable partial groupoids_. latin bitrades are prominent in the study of _ critical sets _ , which are minimal defining sets of latin squares ( @xcite,@xcite,@xcite ) and the intersections between latin squares ( @xcite ) . we write @xmath6 when symbol @xmath7 appears in the cell at the intersection of row @xmath8 and column @xmath9 of the ( partial ) latin square @xmath10 .. Please generate the next two sentences of the article

a @xmath3-homogeneous bitrade has @xmath3 elements in each row , @xmath3 elements in each column , and each symbol appears @xmath3 times . cavenagh @xcite obtained the following theorem , using combinatorial methods , as a corollary to a general classification result on @xmath3-homogeneous bitrades .

Suppose that you have an abstract for a scientific paper: adding small code snippets at key points to existing code fragments is called instrumentation . it is an established technique to debug certain otherwise hard to solve faults , such as memory management issues and data races . dynamic instrumentation can already be used to analyse code which is loaded or even generated at run time . with the advent of environments such as the java virtual machine with optimizing just - in - time compilers , a new obstacle arises : self - modifying code . in order to instrument this kind of code correctly , one must be able to detect modifications and adapt the instrumentation code accordingly , preferably without incurring a high penalty speedwise . in this paper we propose an innovative technique that uses the hardware page protection mechanism of modern processors to detect such modifications . we also show how an instrumentor can adapt the instrumented version depending on the kind of modificiations as well as an experimental evaluation of said techniques . elis , ghent university , sint - pietersnieuwstraat 41 , 9000 gent , belgium @ifundefined . And you have already written the first three sentences of the full article: instrumentation is a technique whereby existing code is modified in order to observe or modify its behaviour . it has a lot of different applications , such as profiling , coverage analysis and cache simulations . one of its most interesting features is however the ability to perform automatic debugging , or at least assist in debugging complex programs .. Please generate the next two sentences of the article

after all , instrumentation code can intervene in the execution at any point and examine the current state , record it , compare it to previously recorded information and even modify it . debugging challenges that are extremely suitable for analysis through instrumentation include data race detection @xcite and memory management checking @xcite .

Suppose that you have an abstract for a scientific paper: this series of papers is devoted to identifying and explaining the properties of strongly correlating liquids , i.e. , liquids with more than 90% correlation between their virial @xmath0 and potential energy @xmath1 fluctuations in the @xmath2 ensemble . paper iv [ n. gnan _ et al . _ , j. chem . phys . * 131 * , 234504 ( 2009 ) ] showed that strongly correlating liquids have `` isomorphs '' , which are curves in the phase diagram along which structure , dynamics , and some thermodynamic properties are invariant in reduced units . in the present paper , using the fact that reduced - unit radial distribution functions are isomorph invariant , we derive an expression for the shapes of isomorphs in the @xmath3 phase diagram of generalized lennard - jones systems of one or more types of particles . the isomorph shape depends only on the lennard - jones exponents ; thus all isomorphs of standard lennard - jones systems ( with exponents 12 and 6 ) can be scaled onto to a single curve . two applications are given . one is testing the prediction that the solid - liquid coexistence curve follows an isomorph by comparing to recent simulations by ahmed and sadus [ j. chem . phys . * 131 * , 174504 ( 2009 ) ] . excellent agreement is found on the liquid side of the coexistence , whereas the agreement is worse on the solid side . a second application is the derivation of an approximate equation of state for generalized lennard - jones systems by combining the isomorph theory with the rosenfeld - tarazona expression for the temperature dependence of potential energy on isochores . it is shown that the new equation of state agrees well with simulations . . And you have already written the first three sentences of the full article: this is the fifth in a series of papers@xcite investigating the properties of strongly correlating liquids,@xcite i.e. , liquids that have strong correlations between their constant - volume equilibrium fluctuations of potential energy , @xmath4 , and virial@xcite @xmath5 where @xmath6 is the position of particle @xmath7 at time @xmath8 . as is well known , the average virial @xmath0 gives the configurational contribution to the pressure : @xmath9 letting @xmath10 denote instantaneous deviations from equilibrium mean values , the @xmath3 correlation is quantified by the correlation coefficient @xmath11 ( with @xmath12 denoting equilibrium average ) : @xmath13 perfect correlation gives @xmath14 . as a pragmatic definition we have chosen `` strongly correlating liquids '' to designate liquids that have @xmath15 in the @xmath2 ensemble ( constant volume , @xmath16 , and temperature , @xmath17 ) . strongly correlating liquids have simpler physics than liquids in general , an observation that has particular significance for the highly viscous phase.@xcite thus it has been shown that strongly correlating viscous liquids to a good approximation have all eight frequency - dependent thermoviscoelastic response functions@xcite given in terms of just one@xcite ( i.e. , are single - parameter liquids in the sense of having dynamic prigogine - defay ratio@xcite close to unity@xcite ) .. Please generate the next two sentences of the article

strongly correlating viscous liquids moreover obey density scaling@xcite to a good approximation , i.e. , their dimensionless relaxation time @xmath18 ( where @xmath19 is the average particle mass ) depends on density @xmath20 and temperature as @xmath21.@xcite paper i@xcite presented computer simulations of 13 different systems , showing that van der waals type liquids are strongly correlating , whereas hydrogen - bonding liquids like methanol or water are not . strongly correlating liquids include@xcite , for instance , the standard lennard - jones ( lj ) liquid , the kob - andersen binary lj ( kablj ) mixture , an asymmetric rigid - bond dumbbell model , a seven - site united - atom toluene model , and the lewis - wahnstrm otp model . paper ii@xcite analyzed the cause of @xmath3 correlations with a focus on the lj potential .

Suppose that you have an abstract for a scientific paper: we report short - time variations in the plasma tail of c/2013 r1(lovejoy ) . a series of short ( two to three minutes ) exposure images with the 8.2-m subaru telescope shows faint details of filaments and their motions over 24 minutes observing duration . we identified rapid movements of two knots in the plasma tail near the nucleus ( @xmath0 3@xmath1 km ) . their speeds are 20 and 25 km s@xmath2 along the tail and 3.8 and 2.2 km s@xmath2 across it , respectively . these measurements set a constraint on an acceleration model of plasma tail and knots as they set the initial speed just after their formation . we also found a rapid narrowing of the tail . after correcting the motion along the tail , the narrowing speed is estimated to be @xmath0 8 km s@xmath2 . these rapid motions suggest the need for high time - resolution studies of comet plasma tails with a large telescope . . And you have already written the first three sentences of the full article: plasma tails of comets and their time variations potentially provide crucial information on solar winds and magnetic fields in the solar system ( e.g. , * ? ? ? * ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

short - time variations in plasma tails , however , are not yet fully understood . indeed , most previous studies observed tails and structures at far distances ( @xmath3 km from the nucleus ) with a time resolution of an order of an hour . regarding the speed of movement along the tail , @xcite studied 72 disconnection events ( des ) of various comet tails and found @xmath4 100 km s@xmath2 at @xmath5 km from the nuclei .

Suppose that you have an abstract for a scientific paper: this paper concerns the problem of the high probability state transfer among @xmath0 symmetrically placed nodes of the @xmath1-nodes spins 1/2 chain with the @xmath2 hamiltonian . we consider examples with @xmath3 , @xmath4 and @xmath5 . , spin dynamics , quantum state transfer , spin chain , ideal state transfer , high - probability state transfer . And you have already written the first three sentences of the full article: this paper concerns the problem of the high probability state transfer ( hpst ) @xcite between different nodes of the spin 1/2 chain , which becomes a popular problem due to the development of the quantum communication systems and quantum computing . by `` state transfer '' we mean the following phenomenon @xcite . consider the chain of spins 1/2 with dipole - dipole interactions in the strong external magnetic field . let all spins be directed along the external magnetic field except the @xmath6th one whose initial state is arbitrary , @xmath7 , where @xmath8 and @xmath9 mean the spin directed along and opposite the external magnetic field respectively .. Please generate the next two sentences of the article

let the energy of the ground state ( all spins are aligned along the magnetic field ) be zero . if the state of @xmath10th node becomes @xmath11 with @xmath12 at time moment @xmath13 then we say that the state has been transfered from the @xmath6th to the @xmath10th node with the phase shift @xmath14 .

Suppose that you have an abstract for a scientific paper: bluein this note , we present a natural proof of a recent and surprising result of gregory berkolaiko interpreting the courant nodal defect as a morse index . this proof is inspired by a nice paper of miroslav fiedler published in 1975 . . And you have already written the first three sentences of the full article: the `` nodal defect '' of an eigenfunction of a schrdinger operator is closely related to the difference between the upper bound on the number of nodal domains given by courant s theorem and the number of nodal domains . in the recent paper @xcite , gregory berkolaiko proves a nice formula for the nodal defect of an eigenfunction of a schrdinger operator on a finite graph in terms of the morse index of the corresponding eigenvalue as a function of a magnetic deformation of the operator . his proof remains mysterious and rather indirect . in order to get a better understanding in view of possible generalizations , it is desirable to have a more direct approach .. Please generate the next two sentences of the article

this is what we do here . after reviewing our notation , we summarize the main result and give an informal description of the proof in section [ sec : statement ] .

Suppose that you have an abstract for a scientific paper: in this paper we investigate the effect of terminal substituents on the dynamics of spin and charge transport in donor - acceptor substituted polyenes ( @xmath0 ) chains , also known as push - pull polyenes . we employ a long - range correlated model hamiltonian for the @xmath0 system , and time - dependent density matrix renormalization group technique for time propagating the wave packet obtained by injecting a hole at a terminal site , in the ground state of the system . our studies reveal that the end groups do not affect spin and charge velocities in any significant way , but change the amount of charge transported . we have compared these push - pull systems with donor - acceptor substituted polymethine imine ( pmi ) , @xmath1 , systems in which besides electron affinities , the nature of @xmath2 orbitals in conjugation also alternate from site to site . we note that spin and charge dynamics in the pmis are very different from that observed in the case of push - pull polyenes , and within the time scale of our studies , transport of spin and charge leads to the formation of a `` quasi - static '' state . . And you have already written the first three sentences of the full article: conjugated organic materials have a variety of applications . they are already being used in organic light emitting diodes ( oleds ) and organic thin - film transistors.@xcite they are also considered to be potential candidates for single - molecule electronic and spintronic devices . the issue of spin and charge transport in @xmath3-conjugated organic systems , therefore , is of prime importance . thus , it is both important and necessary to understand the role of chemical modifications ( substituents ) on the dynamics of spin and charge transport in these systems .. Please generate the next two sentences of the article

electrons in these molecular materials experience strong electron correlations by virtue of reduced dimensionality and these interactions are also long - ranged since the systems are semiconducting . therefore , to study transport of charge and spin in these systems , it is necessary to have appropriate models as well as techniques .

Suppose that you have an abstract for a scientific paper: for the better understanding of the astrophysical @xmath0-process the experimental determination of low energy proton- and @xmath1-capture cross sections on heavy isotopes is required . the existing data for the @xmath2mo(p,@xmath0)@xmath3tc reaction are contradictory and strong fluctuation of the cross section is observed which can not be explained by the statistical model . in this paper a new determination of the @xmath2mo(p,@xmath0)@xmath3tc and @xmath4mo(p,@xmath0)@xmath5tc cross sections based on thick target yield measurements are presented and the results are compared with existing data and model calculations . reaction rates of @xmath2mo(p,@xmath0)@xmath3tc at temperatures relevant for the @xmath0-process are derived directly from the measured thick target yields . the obtained rates are a factor of 2 lower than the ones used in astrophysical network calculations . it is argued that in the case of fluctuating cross sections the thick target yield measurement can be more suited for a reliable reaction rate determination . astrophysical gamma - process , reaction cross section , thick target yield , gamma - spectroscopy 24.60.dr , 25.40.lw , 26.30.-k , 27.60.+j . And you have already written the first three sentences of the full article: the bulk of the chemical elements heavier than iron are thought to be produced by neutron induced reactions in the astrophysical s- and r - processes @xcite . a tiny fraction of the heavy elements , however , can not be synthesized by these processes since some of the most proton rich isotopes ( the so - called p nuclei ) lie outside the path of both the s- and r - processes . it is generally accepted that the main mechanism contributing to the synthesis of the p isotopes is the so - called @xmath0-process @xcite which takes place in high temperature stellar environments .. Please generate the next two sentences of the article

the @xmath0-process converts the isotopes at the bottom of the valley of stability to proton rich species by consecutive ( @xmath0,n ) photodisintegration reactions . charged particle emitting ( @xmath6 ) and ( @xmath0,p ) reactions play also an important role in a @xmath0-process reaction flow model .

Suppose that you have an abstract for a scientific paper: we explore the theory of electrons confined by one dimensional power law potentials . we calculate the density profile in the high density electron gas , the low density wigner crystal , and the intermediate regime . we extract the momentum space wavefunction of the electron at the fermi surface , which can be measured in experiments on tunneling between parallel wires . the onset of localization leads to a dramatic broadening of the momentum space wavefunction together with pronounced sharpening ( in energy ) of the tunneling spectrum . advances in microprocessing have enabled scientists to construct ultra - high mobility one dimensional wires with transverse size @xmath0 nm , which is sufficiently small to freeze out all transverse electronic motion @xcite . by allowing tunneling between two such parallel wires , auslaender et al . @xcite have been able to map out the spectrum of elementary excitations , providing good evidence of spin - charge separation . further experiments have found evidence of electronic localization in these wires when a gate electrode is used to deplete the density of electrons @xcite . this localization is possibly caused by an interaction driven transition into a wigner crystal state @xcite , where each electron is localized by repulsion from its neighbors . here we investigate the theory of such crystallization in one dimensional wires . the wires used in these experiments are not infinitely long . their finite length , which is controlled by electrostatic potentials , leads to striking fringes in the tunneling spectrum @xcite . these fringes can not be explained by particles bounded by ` infinite walls ' , but require a more accurate modeling of the confinement . tserkovnyak et al . @xcite found that the experimental results were consistent with a power - law potential @xmath1 with @xmath2 . in discussing experimental signatures of crystallization in these systems , we must take into account this same physics , and explore the interplay between.... And you have already written the first three sentences of the full article: we consider a gas of electrons with @xmath3 spin states confined to a one dimensional wire , experiencing an external potential @xmath4 , where @xmath5 is the coordinate along the wire . the electrons interact through pairwise three dimensional coulomb interactions , @xmath6 , where @xmath7 is the dielectric constant of the medium and @xmath8 is the electrons effective mass . using parameters for n - doped gaas ( @xmath9 , where @xmath10 is the free - space electron mass ) , the effective bohr radius is quite large , @xmath11 m . in this wire , the electronic wavefunction has a transverse size @xmath12 nm . integrating out these transverse dimensions , the electrons feel a regularized coulomb interaction @xmath13 .. Please generate the next two sentences of the article

two useful regularizations are @xmath14 and @xmath15 , where @xmath16 is the smaller of @xmath5 and @xmath17 . as @xmath18 the exact form of the regularization becomes unimportant .

Suppose that you have an abstract for a scientific paper: hst observations have contributed significantly to our knowledge on the behaviour of isolated neutron stars ( inss ) as optical emitters . first , hst has been instrumental both to discover new optical counterparts ( psr b1055 - 52 , psr b1929 + 10 , psr b0950 + 08 ) and to confirm proposed identifications ( psr b0656 + 14 ) . second , hst multicolor photometry provided useful information to characterize the optical emission mechanism(s ) at work in middle - aged inss like psr b0656 + 14 and geminga . last , but not least , the superior angular resolution of the hst allowed both to perform a very accurate morphological study of the plerionic environments of young pulsars ( e.g. the crab and psr b0540 - 69 ) and to perform very accurate astrometric measurements yielding proper motions ( crab , vela , geminga , psr b0656 + 14 ) and parallaxes ( geminga ) . psfig.sty @xmath0 ifc - cnr , via bassini 15 , i-20133 milan , italy @xmath1 st - ecf , karl schwarzschild str.2 , d8574o garching b. munchen , germany @xmath2 pennsylvania state univ . , 525 davey lab , university park , pa 16802 , usa @xmath3 asi , via liegi 26 , i-00198 rome , italy . And you have already written the first three sentences of the full article: although conspicous inss such as the crab and vela pulsars have been observed from the very beginning of the mission , hst started to play a key role on the study of the optical behaviour of these faint targets after the first refurbishing mission in 1993 . the study did not proceed systematically , e.g. from the brighter to the dimmer , but rather following a random walk dictated by the allocation of observing time . table 1 lists all the inss ( be they bona fide pulsars or radio - silent neutron stars ) observed so far by the hst .. Please generate the next two sentences of the article

ccccc + i d & log(yr ) & log(de / dt ) & d(kpc ) & mag + + crab & 3.1 & 38.6 & 2.0 & 16.6 + b0540 - 69 & 3.2 & 38.2 & 55 & 22.5 + vela & 4.1 & 36.8 & 0.5 & 23.6 + b0656 + 14 & 5.0 & 34.6 & 0.76 & 25.0 + geminga & 5.5 & 34.5 & 0.16 ( ) & 25.5 + b1055 - 52 & 5.7 & 34.5 & 1.5 & 24.9(u ) + b1929 + 10 & 6.5 & 33.6 & 0.17 ( ) & 25.7(u ) + b0950 + 08 & 7.2 & 32.7 & 0.28 ( ) & 27.1(u ) + + rxj 1856 - 3754 & & & @xmath4 & 25.6 + although their number is limited , the objects in table 1 sample 10 magnitude in brightness and 4 decades in age , going from the youngest pulsars , such as the crab and psr b0540 - 69 , to rather old ones , such as psr b0950 + 08 . all inss , but the crab , are faint .

Suppose that you have an abstract for a scientific paper: in the minimal supergravity model ( msugra ) , as the parameter @xmath0 increases , the charged higgs boson and light bottom squark masses decrease , which can potentially increase contributions from @xmath1 , @xmath2 and @xmath3 loops in the decay @xmath4 . we update a previous qcd improved @xmath4 decay calculation to include in addition the effects of gluino and neutralino loops . we find that in the msugra model , loops involving charginos also increase , and dominate over @xmath5 , @xmath1 , @xmath6 and @xmath7 contributions for @xmath8 . we find for large values of @xmath9 that most of the parameter space of the msugra model for @xmath10 is ruled out due to too large a value of branching ratio @xmath11 . for @xmath12 and large @xmath0 , most of parameter space is allowed , although the regions with the least fine - tuning ( low @xmath13 and @xmath14 ) are ruled out due to too _ low _ a value of @xmath11 . we compare the constraints from @xmath4 to constraints from the neutralino relic density , and to expectations for sparticle discovery at lep2 and the fermilab tevatron @xmath15 colliders . finally , we show that non - universal gut scale soft breaking squark mass terms can enhance gluino loop contributions to @xmath4 decay rate even if these are diagonal . . And you have already written the first three sentences of the full article: models of particle physics including weak scale supersymmetry ( susy ) are amongst the most promising candidates@xcite for new physics at the tev scale . of this class of models , the minimal supergravity ( msugra ) model stands out as providing one of the most economic explanations for the diversity of soft supersymmetry breaking terms in the susy lagrangian@xcite . in this model@xcite , supersymmetry is communicated from a hidden sector ( whose dynamics leads to the breaking of supersymmetry ) to the observable sector ( consisting of the fields of the minimal supersymmetric standard model or mssm ) via gravitational interactions . with the assumption of canonical kinetic terms for scalars in the lagrangian , this leads to a universal mass @xmath13 for all scalar particles at some high scale @xmath16 , usually taken to be @xmath17 . at @xmath17 , gaugino masses and trilinear terms. Please generate the next two sentences of the article

are assumed to unify at @xmath14 and @xmath18 , respectively . these parameters , along with the bilinear soft term @xmath19 , provide boundary conditions for the renormalization group evolution of the various soft terms from @xmath17 to @xmath20 .

Suppose that you have an abstract for a scientific paper: we use bbn observational data on primordial abundance of @xmath0 to constrain @xmath1 gravity . the three most studied viable @xmath1 models , namely the power law , the exponential and the square - root exponential are considered , and the bbn bounds are adopted in order to extract constraints on their free parameters . for the power - law model , we find that the constraints are in agreement with those acquired using late - time cosmological data . for the exponential and the square - root exponential models , we show that for realiable regions of parameters space they always satisfy the bbn bounds . we conclude that viable @xmath1 models can successfully satisfy the bbn constraints . . And you have already written the first three sentences of the full article: cosmological observations coming from type ia supernovae @xcite , cosmic microwave background radiation @xcite and the large scale structure @xcite , provide evidences that the universe is currently in an accelerating phase . this result is , in general , ascribed to the existence of a sort of dark energy ( de ) sector in the universe , an exotic energy source characterized by a negative pressure . at late times , the dark - energy sector eventually dominates over the cold dark matter ( cdm ) , and drives the universe to the observed accelerating expansion .. Please generate the next two sentences of the article

the simplest candidate for de is the cosmological constant @xmath2 , which has an equation - of - state parameter @xmath3 . although this model is in agreement with current observations , it is plagued by some difficulties related to the small observational value of de density with respect to the expected one arising from quantum field theories ( the well known cosmological constant problem @xcite ) .

Suppose that you have an abstract for a scientific paper: in this paper , we consider the problem of sum rate maximization in a bidirectional relay network with fading . hereby , user 1 and user 2 communicate with each other only through a relay , i.e. , a direct link between user 1 and user 2 is not present . in this network , there exist six possible transmission modes : four point - to - point modes ( user 1-to - relay , user 2-to - relay , relay - to - user 1 , relay - to - user 2 ) , a multiple access mode ( both users to the relay ) , and a broadcast mode ( the relay to both users ) . most existing protocols assume a fixed schedule of using a subset of the aforementioned transmission modes , as a result , the sum rate is limited by the capacity of the weakest link associated with the relay in each time slot . motivated by this limitation , we develop a protocol which is not restricted to adhere to a predefined schedule for using the transmission modes . therefore , all transmission modes of the bidirectional relay network can be used adaptively based on the instantaneous channel state information ( csi ) of the involved links . to this end , the relay has to be equipped with two buffers for the storage of the information received from users 1 and 2 , respectively . for the considered network , given a total average power budget for all nodes , we jointly optimize the transmission mode selection and power allocation based on the instantaneous csi in each time slot for sum rate maximization . simulation results show that the proposed protocol outperforms existing protocols for all signal - to - noise ratios ( snrs ) . specifically , we obtain a considerable gain at low snrs due to the adaptive power allocation and at high snrs due to the adaptive mode selection . . And you have already written the first three sentences of the full article: in a bidirectional relay network , two users exchange information via a relay node @xcite . several protocols have been proposed for such a network under the practical half - duplex constraint , i.e. , a node can not transmit and receive at the same time and in the same frequency band . the simplest protocol is the traditional two - way relaying protocol in which the transmission is accomplished in four successive point - to - point phases : user 1-to - relay , relay - to - user 2 , user 2-to - relay , and relay - to - user 1 .. Please generate the next two sentences of the article

in contrast , the time division broadcast ( tdbc ) protocol exploits the broadcast capability of the wireless medium and combines the relay - to - user 1 and relay - to - user 2 phases into one phase , the broadcast phase @xcite . thereby , the relay broadcasts a superimposed codeword , carrying information for both user 1 and user 2 , such that each user is able to recover its intended information by self - interference cancellation .

Suppose that you have an abstract for a scientific paper: einstein ( 1936 ) predicted the phenomenon presently known as gravitational lensing ( gl ) . a prime feature of gl is the magnification , because of the gravitational field , of the star visible surface as seen from a distant observer . we show here that nonlinear electrodynamics ( nled ) modifies in a fundamental basis einstein s general relativistic ( gr ) original derivation . the effect becomes apparent by studying the light propagation from a strongly magnetic ( @xmath0 ) pulsar ( smp ) . unlike its gr counterpart , the photon dynamics in nled leads to a new effective gl , which depends also on the @xmath0-field permeating the pulsar . the apparent radius of a smp appears then unexpectedly diminished , by a large factor , as compared to the classical einstein s prediction . this may prove very crucial in determining physical properties of high @xmath0-field stars from their x - ray emission . 0.5 truecm received(07/04/2004 ) revised(16/05/2005 ) . And you have already written the first three sentences of the full article: einstein s general theory of relativity ( gtr ) has proved to be one of the most successful physical theories ever formulated . as a theory of the gravitational interaction , it has a number of predictions definitely corroborated by experiments or astronomical observations , which makes it the correct gravity theory here - to - fore . after readdressing an earlier study , einstein ( 1936 ) @xcite came up with the prediction of the gravitational lensing effect .. Please generate the next two sentences of the article

the idea is that the gravitational field produced by a massive astrophysical object , the sun for instance , can act as a convergent lens able to deviate light rays flying - by . observations of far away quasars and galaxies and more familiar total solar eclipses confirm the reality of this phenomenon .

Suppose that you have an abstract for a scientific paper: paramagnetic impurities in a quantum spin - liquid can result in kondo effects with highly unusual properties . we have studied the effect of locally exchange - coupling a paramagnetic impurity with the spin-@xmath0 honeycomb kitaev model in its gapless spin - liquid phase . the ( impurity ) scaling equations are found to be insensitive to the sign of the coupling . the weak and strong coupling fixed points are stable , with the latter corresponding to a noninteracting vacancy and an interacting , spin-@xmath1 defect for the antiferromagnetic and ferromagnetic cases respectively . the ground state in the strong coupling limit in both cases has a nontrivial topology associated with a finite @xmath2 flux at the impurity site . for the antiferromagnetic case , this result can be obtained straightforwardly owing to the integrability of the kitaev model with a vacancy . the strong - coupling limit of the ferromagnetic case is however nonintegrable , and we address this problem through exact - diagonalization calculations with finite kitaev fragments . our exact diagonalization calculations indicate that that the weak to strong coupling transition and the topological phase transition occur rather close to each other and are possibly coincident . we also find an intriguing similarity between the magnetic response of the defect and the impurity susceptibility in the two - channel kondo problem . . And you have already written the first three sentences of the full article: a study of disorder in condensed matter systems is useful from two perspectives . disorder is inherent in most condensed matter systems and often has profound effects on their properties . incorporation of small amounts of paramagnetic impurities in a metallic host can result in the kondo effect which gives the well - known logarithmic temperature dependence of the resistivity upon cooling , and eventually crosses over to a fermi - liquid regime with a characteristic low energy scale , the kondo temperature .. Please generate the next two sentences of the article

conversely , impurities at low concentrations can act as a probe providing specific signatures of the environment they exist in . from the latter perspective , the kondo effect is a set of signatures of certain low - energy excitations of the host lacking long - range magnetic order . for instance , exotic kondo effects are known to arise in itinerant electron magnets near criticality @xcite and in insulating quantum spin - liquid systems @xcite owing to the paramagnons and spinonic excitations respectively .

Suppose that you have an abstract for a scientific paper: let @xmath0 be a plane graph and @xmath1 an even subset of its vertices . it has been conjectured that if all @xmath1-cuts of @xmath0 have the same parity and the size of every @xmath1-cut is at least @xmath2 , then @xmath0 contains @xmath2 edge - disjoint @xmath1-joins . the case @xmath3 is equivalent to the four color theorem , and the cases @xmath4 , which was conjectured by seymour , and @xmath5 were proved by guenin . we settle the next open case @xmath6 . . And you have already written the first three sentences of the full article: we study packings of @xmath1-joins in plane graphs . let @xmath0 be a graph and @xmath1 an even - size subset @xmath1 of its vertices . @xmath1-join _ is a subgraph @xmath7 of @xmath0 such that the odd - degree vertices of @xmath7 are precisely those in @xmath1 .. Please generate the next two sentences of the article

a _ cut _ is a partition of the vertex set of a graph @xmath0 into two sets @xmath8 and @xmath9 , which we refer to as _ sides _ ; the _ size _ of the cut is the number of edges with one end - vertex in @xmath8 and the other end - vertex in @xmath9 . a cut is _ trivial _ if one its sides consists of a single vertex and a cut is _ odd _ if the size of @xmath8 is odd .

Suppose that you have an abstract for a scientific paper: * we model the spreading of a crisis by constructing a global economic network and applying the susceptible - infected - recovered ( sir ) epidemic model with a variable probability of infection . the probability of infection depends on the strength of economic relations between the pair of countries , and the strength of the target country . it is expected that a crisis which originates in a large country , such as the usa , has the potential to spread globally , like the recent crisis . surprisingly we show that also countries with much lower gdp , such as belgium , are able to initiate a global crisis . using the _ k_-shell decomposition method to quantify the spreading power ( of a node ) , we obtain a measure of `` centrality '' as a spreader of each country in the economic network . we thus rank the different countries according to the shell they belong to , and find the 12 most central countries . these countries are the most likely to spread a crisis globally . of these 12 only six are large economies , while the other six are medium / small ones , a result that could not have been otherwise anticipated . furthermore , we use our model to predict the crisis spreading potential of countries belonging to different shells according to the crisis magnitude . * . And you have already written the first three sentences of the full article: a global economic crisis , such as the recent 2008 - 2009 crisis , is certainly due to a large number of factors . in today s global economy , with strong economic relations between countries , it is important to investigate how a crisis propagates from the country of origin to other countries in the world . indeed , several significant crises in the past few decades have been originated in a single country .. Please generate the next two sentences of the article

however , it is still not clear how and to what extent domestic economies of other countries may be affected by this spreading , due to the inter - dependence of economies @xcite . here , we use a statistical physics approach to deal with the modern economy , as it has been done successfully in the recent years for the case of financial markets and currencies @xcite .

Suppose that you have an abstract for a scientific paper: we present the general properties of the active galactic nuclei ( agns ) and discuss the origin and structure of jets that are associated to a fraction of these objects . we then we address the problems of particle acceleration at highly relativistic energies and set limits on the luminosity of agn jets for being origin of uhecrs . . And you have already written the first three sentences of the full article: most of the galaxies of the local universe shine by effect of stellar and interstellar gas emissions , predominantly in the optical band . typically , the emitted spectra are characterized by stellar absorption lines and emission lines by hii regions . these sources are called _. Please generate the next two sentences of the article

normal galaxies_. a small fraction of galaxies , about @xmath0 , do not follow this behavior . in fact , they show strong and broad emission lines , consistent with velocity dispersion of the emitting gas attaining several thousand of kilometers per second . most remarkably , the non - thermal emission coming from a central nucleus , with size @xmath1 pc , dominates over the thermal one coming from stars and interstellar gas and extends well beyond the optical band , from radio to gamma rays ( fig .

Suppose that you have an abstract for a scientific paper: we perform a many - body investigation of the spin dephasing in @xmath0-typed inas quantum wells under moderate magnetic fields in the voigt configuration by constructing and numerically solving the kinetic bloch equations . we obtain the spin dephasing time due to the rashba effect together with the spin conserving scattering such as the electron - phonon , the electron - nonmagnetic impurity as well as the electron - electron coulomb scattering . by varying the initial spin polarization , temperature , impurity density , applied magnetic field and the interface electric field , we are able to study the spin dephasing time under various conditions . for the electron density and quantum well width we study , the many - body effect dominates the spin dephasing . moreover , we find an anomalous resonance peak in the spin dephasing time for high initial spin polarization under moderate magnetic fields . . And you have already written the first three sentences of the full article: almost all of the current semiconductor devices are based on manipulating electronic charges . the arising field of spintronics proposes to use the spin degree of freedom of electrons in place of / in addition to the charge degree of freedom for device applications in order to add new features and functionalities to semiconductors devices.@xcite the hope of the realization of the proposed spintronic devices is supported by the resent development of ultrafast nonlinear optical experiments where long spin dephasing time ( @xmath1 ns ) is reported . the functionalities of the semiconductor spintronic devices rely on the manipulation of the spin coherence . in order to realize these devices. Please generate the next two sentences of the article

, one needs to thoroughly understand the spin dephasing mechanisms which tend to destroy the spin coherence . historically , three spin dephasing mechanisms have been proposed in semiconductors:@xcite the elliot - yafet ( ey ) mechanism,@xcite the dyakonov - perel ( dp ) mechanism,@xcite and the bir - aronov - pikus ( bap ) mechanism.@xcite all of the three mechanisms are either due to the spin flip ( sf ) scattering or are treated as effective sf scattering .

Suppose that you have an abstract for a scientific paper: we present berkeley illinois maryland association ( bima ) millimeter interferometer observations of giant molecular clouds ( gmcs ) along a spiral arm in m31 . the observations consist of a survey using the compact configuration of the interferometer and follow - up , higher - resolution observations on a subset of the detections in the survey . the data are processed using an analysis algorithm designed to extract gmcs and correct their derived properties for observational biases thereby facilitating comparison with milky way data . the algorithm identifies 67 gmcs of which 19 have sufficient signal - to - noise to accurately measure their properties . the gmcs in this portion of m31 are indistinguishable from those found in the milky way , having a similar size - line width relationship and distribution of virial parameters , confirming the results of previous , smaller studies . the velocity gradients and angular momenta of the gmcs are comparable to the values measured in m33 and the milky way ; and , in all cases , are below expected values based on the local galactic shear . the studied region of m31 has a similar interstellar radiation field , metallicity , toomre @xmath0 parameter , and midplane volume density as the inner milky way , so the similarity of gmc populations between the two systems is not surprising . . And you have already written the first three sentences of the full article: as the instrumentation for millimeter - wave telescopes improves , it becomes progressively more straightforward to study individual molecular clouds in other galaxies . recent studies of local group galaxies have surveyed large numbers of molecular clouds in the large magellanic cloud @xcite , the small magellanic cloud @xcite , m33 @xcite , and a bevy of local group dwarf galaxies ( e.g. * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

these recent studies explore the nature of star formation on galactic scales by studying the properties of giant molecular clouds ( gmcs , @xmath1 ) throughout their host galaxies . such gmcs contain the majority of the molecular mass in the milky way s ism and are responsible for most of the star formation in the galaxy @xcite .

Suppose that you have an abstract for a scientific paper: we show that decaying axino dark matter with r - parity violation can explain the observed excess of the 130gev gamma - ray line from the galactic center in the fermi data . the branching fraction of the axino decay into monochromatic photons can be @xmath0 , and constraints from continuum gamma - rays and the anti - proton flux are ameliorated . the peccei - quinn scale of @xmath1gev and the r - parity violation parameter of @xmath2 are cosmologically favored . .5 in ut-13 - 03 + ipmu 13 - 0024 * axino dark matter with r - parity violation and + 130 gev gamma - ray line * .5 in motoi endo@xmath3 , koichi hamaguchi@xmath3 , seng pei liew@xmath4 , + kyohei mukaida@xmath4 and kazunori nakayama@xmath3 .3 in _ @xmath5department of physics , university of tokyo , bunkyo - ku , tokyo 113 - 0033 , japan + @xmath6kavli institute for the physics and mathematics of the universe , university of tokyo , kashiwa 277 - 8583 , japan + _ .5 in . And you have already written the first three sentences of the full article: recently , there is increasing evidence of the excess of the 130gev gamma - ray line from the galactic center ( gc ) in the four - year fermi data @xcite . this may be interpreted as a signal of the dark matter ( dm ) , which annihilates or decays around the gc . an obstacle to construct a model of the annihilating / decaying dm which explains the observed gamma - ray line excess is that the branching ratio of the monochromatic photon production must be fairly large. Please generate the next two sentences of the article

. it should be larger than around 0.01 @xcite . otherwise , continuum gamma - rays would hide the line gamma , and anti - protons may be overproduced .

Suppose that you have an abstract for a scientific paper: linear state space modeling determines the hidden autoregressive ( ar ) process in a noisy time series ; for an ar process the time series current value is the sum of current stochastic `` noise '' and a linear combination of previous values . we present preliminary results from modeling a sample of 4 channel batse lad lightcurves . we determine the order of the ar process necessary to model the bursts . the comparison of decay constants for different energy bands shows that structure decays more rapidly at high energy . the resulting models can be interpreted physically ; for example , they may reveal the response of the burst emission region to the injection of energy . . And you have already written the first three sentences of the full article: hidden in batse s superb gamma - ray burst lightcurves in different energy bands are temporal and spectral signatures of the fundamental physical processes which produced the observed emission . various techniques have been applied to the batse data to extract these signatures , such as : auto- and crosscorrelations of lightcurves in different energies@xcite ; fourier transforms@xcite ; lightcurve averaging@xcite ; cross - fourier transforms@xcite and pulse fitting@xcite . here we propose to use linear state space models ( lssm ) to study the gamma - ray burst lightcurves .. Please generate the next two sentences of the article

lssm estimates a time series underlying autoregressive ( ar ) process in the presence of observational noise . an ar process assumes that the real time series is a linear function of its past values ( `` autoregression '' ) in addition to `` noise , '' a stochastic component of the process .

Suppose that you have an abstract for a scientific paper: we present results of computing the @xmath0 order low energy constants in the normal part of chiral lagrangian both for two and three flavor pseudo - scalar mesons . this is a generalization of our previous work on calculating the @xmath1 order coefficients of the chiral lagrangian in terms of the quark self energy @xmath2 approximately from qcd . we show that most of our results are consistent with those we can find in the literature . . And you have already written the first three sentences of the full article: chiral lagrangian for low lying pseudoscalar mesons@xcite@xcite as the most successful effective field theory is now widely used in various strong , weak and electromagnetic processes . to match the increasing demand for higher precision in low energy description of qcd , the applications of the low energy expansion of the chiral lagrangian is extended from early time discussions on the leading @xmath3 and next to leading @xmath1 orders to present @xmath0 order . for the latest review , see ref.@xcite . in the chiral lagrangian. Please generate the next two sentences of the article

, there are many unknown phenomenological low energy constants ( lecs ) which appear in front of each goldstone field dependent operators and the number of the lecs increases rapidly when we go to the higher orders of the low energy expansion . for example for the three flavor case , the @xmath3 and @xmath1 order chiral lagrangian have 2 and 10 lecs respectively , while the normal part of @xmath0 order chiral lagrangian have 90 lecs .

Suppose that you have an abstract for a scientific paper: schmidt rank of bipartite pure state serves as a testimony of entanglement . it is a monotone under local operation @xmath0 classical communications ( locc ) and puts restrictions in locc convertibility of quantum states . identifying the schmidt rank of an unknown quantum state therefore seek importance from information theoretic perspective . in this work it is shown that a modified version of hardy s argument , which reveals the contradiction of quantum theory with _ local realism _ , turns out to be useful for inspecting the minimal schmidt rank of the unknown state and hence also the minimal dimension of the system . use of hardy s test in such task provides a practical advantage : the schmidt rank can be determined without knowing the detailed functioning of the experimental devices i.e. , hardy s test suffices to be a device independent schmidt rank witness . among various counterintuitive features of quantum mechanics , certainly , one of the most bizarre property is quantum entanglement @xcite . this holistic property of compound quantum systems , which involves non - classical correlations among subsystems , has potential for many quantum processes , including canonical ones : quantum cryptography @xcite , quantum teleportation @xcite , and dense coding @xcite . according to the quantum formalism , the total hilbert space @xmath1 of the @xmath2 separate systems is a tensor product of the subsystem spaces , i.e. , @xmath3 . when the number of the involved subsystems are two , the pure state @xmath4 of the bipartite system can always be described by its schmidt decomposition , i.e. , the representation of @xmath4 in an orthogonal product basis with minimal number of terms @xcite . a bipartite pure state @xmath5 , with @xmath6 and @xmath7 , has schmidt rank @xmath8 if its schmidt decomposition reads : @xmath9 , where @xmath10 , @xmath11 , @xmath12 and @xmath13 is an orthonormal set of vectors in the hilbert space @xmath14 and @xmath15 is an orthonormal set of vectors in the hilbert.... And you have already written the first three sentences of the full article: consider that alice holds the qubit system and bob holds the qutrit system . like in the @xmath26-qubit scenario here also the following two cases are possible : ( a - i ) all the povm elements are rank one operators ; ( a - ii ) some of the povm elements may have more than one rank . * case(a - i ) * : alice and bob perform three - outcome rank one povms on their respective parts of the shared qubit - qutrit state . like the @xmath105 scenario , consider @xmath70 as basis for the alice s qubit system .. Please generate the next two sentences of the article

for bob s qutrit system consider @xmath106 as basis . then the other vectors on bob s side can be expressed as : @xmath107 forms a basis for the @xmath54 tensor product hilbert space . according to the conditions ( [ h31])-([h33 ] ) the qubit - qutrit state exhibiting hardy s test ( [ h3 ] ) must be orthogonal to the following nine vectors : among the above nine vectors the set @xmath109 are linearly independent.and the rest four vectors ( i.e. @xmath110 )

Suppose that you have an abstract for a scientific paper: let @xmath0 be a hyperbolizable , nontrivial compression body without toroidal boundary components . in this paper , we characterize which discrete and faithful representations of @xmath1 into @xmath2 are separable - stable . the set of separable - stable representations forms a domain of discontinuity for the action of @xmath3 on the @xmath2-character variety of @xmath4 . And you have already written the first three sentences of the full article: recently , the study of the dynamics of @xmath3 on the @xmath2-character variety of @xmath5 for a compact hyperbolizable @xmath6-manifold @xmath0 with nonempty boundary and no toroidal boundary components , has led to the somewhat surprising discovery that often the dynamical and geometric decompositions of the @xmath2-character variety do not coincide . the @xmath2-character variety of @xmath5 denoted @xmath7 is the geometric quotient of @xmath8 by inner automorphisms of @xmath9 sitting inside @xmath10 is @xmath11 the set of discrete and faithful representations , which can equivalently be thought of as the deformation space of hyperbolic @xmath6-manifolds homotopy equivalent to @xmath12 the action of @xmath3 on the interior of @xmath13 is properly discontinuous ( see canary @xcite ) , but if @xmath0 has a primitive essential annulus , the action can not be properly discontinuous on all of @xmath13 ( canary - storm @xcite ) . minsky in @xcite was the first to observe that there exists a domain of discontinuity , called the set of primitive - stable representations , for @xmath3 containing the interior of @xmath13 as well as points on @xmath14 when @xmath0 is a handlebody .. Please generate the next two sentences of the article

in particular , the set of primitive - stable representations contains both discrete and faithful representations and dense representations . jeon - kim - ohshika - lecuire @xcite gave a complete criterion for a discrete and faithful representation to be primitive - stable in terms of disc - busting properties of the ending lamination and parabolic loci of the associated hyperbolic @xmath6-manifold .

Suppose that you have an abstract for a scientific paper: we report on the _ xmm - newton _ observations of the young , 102 ms pulsar psr b1706 - 44 . we have found that both a blackbody plus power - law and a magnetized atmospheric model plus power - law provide an excellent fit to the epic spectra . the two scenarios are therefore indistinguishable on a statistical basis , although we are inclined to prefer the latter on physical grounds . in this case , assuming a source distance of @xmath0 kpc , the size of the region responsible for the thermal emission is @xmath1 km , compatible with the surface of a neutron star . a comparison of the surface temperature of psr b1706 - 44 obtained from this fit with cooling curves favor a medium mass neutron star with @xmath2 or @xmath3 , depending on two different models of proton superfluidity in the interior . the large collecting area of _ xmm - newton _ allows us to resolve a substructure in the broad soft x - ray modulation detected by _ chandra _ , revealing the presence of two separate peaks with pulsed fractions of @xmath4 and @xmath5 , respectively . . And you have already written the first three sentences of the full article: psr b1706 - 44 is a young ( @xmath6 yr ) , energetic 102 ms pulsar originally discovered by @xcite . it is one of several sources with spin down ages 10@xmath710@xmath8 yrs which are referred to as vela - like pulsars , due to their similar emission properties ( @xcite ) . the source is known to display glitches ( @xcite ) and is plausibly associated with the supernova remnant g343.1 - 2.3 ( @xcite ; @xcite ; @xcite ) . according to the new @xcite model. Please generate the next two sentences of the article

, the pulsar is @xmath9 kpc away , which agrees with the kinematic distance in the range 2.43.2 kpc inferred from h i absorption ( @xcite ) . vla images ( @xcite , @xcite ) indicated that the pulsar is located inside a synchrotron plerionic nebula about @xmath10 in size .

Suppose that you have an abstract for a scientific paper: the evolution of magnetic fields frozen to a perfectly conducting plasma fluid around a kerr black hole is investigated . we focus on the plunging region between the black hole horizon and the marginally stable circular orbit in the equatorial plane , where the centrifugal force is unable to stably balance the gravitational force . adopting the kinematic approximation where the dynamical effects of magnetic fields on the fluid motion are ignored , we exactly solve maxwell s equations with the assumptions that the geodesic motion of the fluid is stationary and axisymmetric , the magnetic field has only radial and azimuthal components and depends only on time and radial coordinates . we show that the stationary state of the magnetic field in the plunging region is uniquely determined by the boundary conditions at the marginally stable circular orbit . if the magnetic field at the marginally stable circular orbit is in a stationary state , the magnetic field in the plunging region will quickly settle into a stationary state if it is not so initially , in a time determined by the dynamical time scale in the plunging region . the radial component of the magnetic field at the marginally stable circular orbit is more important than the toroidal component in determining the structure and evolution of the magnetic field in the plunging region . even if at the marginally stable circular orbit the toroidal component is zero , in the plunging region a toroidal component is quickly generated from the radial component by the shear motion of the fluid . finally , we discuss the dynamical effects of magnetic fields on the motion of the fluid in the plunging region . we show that the dynamical effects of magnetic fields are unimportant in the plunging region if they are negligible on the marginally stable circular orbit . this supports the `` no - torque inner boundary condition '' of thin disks , contrary to the claim in the recent literature . . And you have already written the first three sentences of the full article: it is widely believed that accretion disks around kerr black holes exist in many astrophysical environments , ranging from active galactic nuclei to some stellar binary systems @xcite . people usually assume that the inner boundary of a thin keplerian disk around a kerr black hole is located at the marginally stable circular orbit , inside which the centrifugal force is unable to stably balance the gravity of the central black hole @xcite . in the disk region , particles presumably move on nearly circular orbits with a very small inward radial velocity superposed on the circular motion , the gravity of the central black hole is approximately balanced by the centrifugal force .. Please generate the next two sentences of the article

as disk particles reach the marginally stable circular orbit , the gravity of the central black hole becomes to dominate over the centrifugal force and the particles begin to nearly free - fall inwardly . the motion of fluid particles in the plunging region quickly becomes supersonic then the particles loose causal contact with the disk , as a result the torque at the inner boundary of the disk is approximately zero ( * ? ? ? * ; * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: models that seek to unify bl lacs and low - power radio galaxies predict that the two types of object should show similar isotropically emitted x - ray emission . testing this is usually limited by difficulties in separating strong x - ray emission from a bl lac nucleus and surrounding low - surface brightness emission . in this paper we report rosat hri observations of the @xmath0 bl lac object pks 0521@xmath1365 . we are able to separate a luminous extended x - ray component from the bright nucleus . using a new radio map , we show that it is unlikely that the extended emission is due to inverse - compton scattering of photons from the active nucleus , and instead interpret it as thermal emission from dense , rapidly cooling gas . this is a more extreme environment than is found in typical fri radio galaxies , and may pose a problem for unified models . x - rays : galaxies galaxies : individual : pks 0521@xmath1365 galaxies : active . And you have already written the first three sentences of the full article: in unified models for radio sources , bl lac objects are the low - power radio galaxies whose jets are the most highly beamed along our line of sight ( e.g. browne 1983 ; antonucci & ulvestad 1985 ; ulrich 1989 ; urry & padovani 1995 ) . their rapid variability , apparent superluminal motion , strong point - like emission in radio , optical and x - ray , and the detection of some sources in @xmath2-rays , are all explained if we are seeing emission from a relativistic jet closely aligned with our line of sight . low - power radio galaxies then represent the ` parent population ' of unaligned objects whose jets are less favourably aligned .. Please generate the next two sentences of the article

these low - power radio galaxies are likely mostly to be fanaroff & riley ( 1974 ) class i ( fri ) objects , but the parent population may also include some transitional objects and low - excitation frii radio galaxies . an important test of this unified model is the degree to which the isotropic ( alignment - independent ) properties of bl lacs are similar to those of the parent population of radio galaxies .

Suppose that you have an abstract for a scientific paper: we present the results from a multi - epoch survey of two regions of m33 using the 3.5 m wiyn telescope . the inner field is located close to the centre of the galaxy , with the outer region situated about @xmath0 kpc away in the southern spiral arm , allowing us to sample a large metallicity range . we have data for 167 fundamental mode cepheids in the two regions . the reddening - free wesenheit magnitude @xmath1 period - luminosity relations were used to establish the distance modulus of each region , with @xmath2 and @xmath3 . the apparent discrepancy between these two results can be explained by the significant metallicity gradient of the galaxy . we determine a value for the metallicity parameter of the period luminosity relation @xmath4 = @xmath5 , consistent with previous measurements . this leads to a metallicity corrected distance modulus to m33 of @xmath6 mag . catalogues cepheids galaxies : individual : m33 galaxies : distances and redshifts . And you have already written the first three sentences of the full article: cepheid variables have been used to determine galactic distances for many decades ( e.g. @xcite , @xcite and references therein ) . the relationship between their period of pulsation and luminosity has been considered to be well defined at several times during its lifetime . however , the effect of the cepheid s chemical composition on the period - luminosity ( pl ) relation has never been adequately determined , leaving the relation open to systematic uncertainties that have not been fully investigated . proper calibration of this relation is essential not just to explain how metallicity affects the pulsations of cepheids , but to tie down the zero point of the extra - galactic distance scale and thus properly measure the hubble constant . metallicity and differential absorption will both change stellar colours @xcite .. Please generate the next two sentences of the article

theoretical models ( e.g. ) show that the metal content of a cepheid will affect the derived distance modulus . if a star of an unknown metallicity is at an undetermined distance then it is difficult to untangle these two effects on the stars colours .

Suppose that you have an abstract for a scientific paper: low - complexity near - optimal detection of large - mimo signals has attracted recent research . recently , we proposed a local neighborhood search algorithm , namely _ reactive tabu search _ ( rts ) algorithm , as well as a factor - graph based _ belief propagation _ ( bp ) algorithm for low - complexity large - mimo detection . the motivation for the present work arises from the following two observations on the above two algorithms : @xmath0 rts works for general @xmath1-qam . although rts was shown to achieve close to optimal performance for 4-qam in large dimensions , significant performance improvement was still possible for higher - order qam ( e.g. , 16- and 64-qam ) . @xmath2 bp also was shown to achieve near - optimal performance for large dimensions , but only for @xmath3 alphabet . in this paper , we improve the large - mimo detection performance of higher - order qam signals by using a hybrid algorithm that employs rts and bp . in particular , motivated by the observation that when a detection error occurs at the rts output , the least significant bits ( lsb ) of the symbols are mostly in error , we propose to first reconstruct and cancel the interference due to bits other than lsbs at the rts output and feed the interference cancelled received signal to the bp algorithm to improve the reliability of the lsbs . the output of the bp is then fed back to rts for the next iteration . our simulation results show that in a @xmath4 v - blast system , the proposed rts - bp algorithm performs better than rts by about 3.5 db at @xmath5 uncoded ber and by about 2.5 db at @xmath6 rate-3/4 turbo coded ber with 64-qam at the same order of complexity as rts . we also illustrate the performance of large - mimo detection in frequency - selective fading channels . . And you have already written the first three sentences of the full article: multiple - input multiple - output ( mimo ) systems with large number ( e.g. , tens ) of transmit and receive antennas , referred to as ` large - mimo systems , ' are of interest because of the high capacities / spectral efficiencies theoretically predicted in these systems @xcite,@xcite . research in low - complexity receive processing ( e.g. , mimo detection ) techniques that can lead to practical realization of large - mimo systems is both nascent as well as promising . for e.g. , ntt docomo has already field demonstrated a @xmath7 v - blast system operating at 5 gbps data rate and 50 bps / hz spectral efficiency in 5 ghz band at a mobile speed of 10 km / hr @xcite .. Please generate the next two sentences of the article

evolution of wifi standards ( evolution from ieee 802.11n to ieee 802.11ac to achieve multi - gigabit rate transmissions in 5 ghz band ) now considers @xmath8 mimo operation ; see @xmath8 mimo indoor channel sounding measurements at 5 ghz reported in @xcite for consideration in wifi standards . also , @xmath9 mimo channel sounding measurements at 5 ghz in indoor environments have been reported in @xcite .

Suppose that you have an abstract for a scientific paper: disk galaxies contain a large amount of interstellar dust , which affects the projection of kinematic quantities . we investigate in detail the effects of dust extinction on the mean projected velocity and the projected velocity dispersion . we use our results to construct a general strategy to determine the dynamical structure of disk galaxies , with the aim to constrain their mass distribution and dynamical history . . And you have already written the first three sentences of the full article: the knowledge of the dynamics of disk galaxies is essential in order to understand their structure and history . unfortunately , disk galaxies are difficult systems to model dynamically , for several reasons . one of them is the presence of a large amount of interstellar dust , which obscures the light along the lines - of - sight . using extended radiative transfer models. Please generate the next two sentences of the article

it is nowadays possible to recover quite accurately the three - dimensional light and dust distribution in disk galaxies ( kylafis & bahcall 1987 , xilouris et al . 1999 ) . but also the observed kinematics are affected by dust obscuration

Suppose that you have an abstract for a scientific paper: a new path - integral theory is developed to calculate the photoemission spectra ( pes ) of correlated many - electron systems . the application to the study on bi@xmath0sr@xmath0cacu@xmath0o@xmath1 ( bi2212 ) and boron - doped diamond ( bdd ) is discussed in details . it is found that the isotopic shift in the angle - resolved photoemission spectra of bi2212 is due to the off - diagonal quadratic electron - phonon ( @xmath2-ph ) coupling , whereas the presence of electron - electron repulsion partially suppresses this effect . for the bdd , a semiconductor - metal phase transition , which is induced by increasing the @xmath2-ph coupling and dopant concentration , is reproduced by our theory . additionally , the presence of fermi edge and phonon step - like structure in pes is found to be due to a co - existence of itinerant and localized electronic states in bdd . . And you have already written the first three sentences of the full article: the role of electron - phonon ( @xmath2-ph ) interaction in the high-@xmath3 superconductivity has received considerable attention since the discovery of oxygen isotope effect of bi@xmath0sr@xmath0cacu@xmath0o@xmath1 ( bi2212 ) in the angle - resolved photoemission spectra ( arpes)@xcite . the experimental data show that electronic band is shifted slightly with the @xmath4o/@xmath5o substitution , signifying the existence of @xmath2-ph interplay in cuprates . besides , theoretically clarifying this effect is of great significance , for the energy scale of shifts reported by the two groups in refs . @xcite and @xcite seem quite inconsistent with each other , and many questions still remain up to now . in order to have an insight into the isotope effect , in this work , we develop a new path - integral theory to calculate the photoemission spectra ( pes ) of cuprate superconductors , in which the electron - electron ( @xmath2-@xmath2 ) and @xmath2-ph correlations are treated on an equal footing . this theory is also applicable to other kind correlated materials . as an example , here , we also study the pes of boron - doped diamond ( bdd ) , which undertakes a semiconductor - metal phase transition on doping , and becomes a superconductor with the temperature decreases@xcite .. Please generate the next two sentences of the article

the details of our theory will be presented in the next section , in connection with the study on isotope effect . calculation and discussion on pes of bdd are included in section 3 .

Suppose that you have an abstract for a scientific paper: we calculate the phase , the temperature and the junction length dependence of the supercurrent for ballistic graphene josephson - junctions . for low temperatures we find non - sinusoidal dependence of the supercurrent on the superconductor phase difference for both short and long junctions . the skewness , which characterizes the deviation of the current - phase relation from a simple sinusoidal one , shows a linear dependence on the critical current for small currents . we discuss the similarities and differences with respect to the classical theory of josephson junctions , where the weak link is formed by a diffusive or ballistic metal . the relation to other recent theoretical results on graphene josephson junctions is pointed out and the possible experimental relevance of our work is considered as well . . And you have already written the first three sentences of the full article: the peculiar electronic properties of graphene first observed experimentally by geim et al . @xcite and zhang et al . @xcite can accurately be described by massless two dimensional dirac fermion excitations ( for reviews on the physics of graphene see , e.g , refs . ) . owing to the proximity effect a superconductor can induce non - zero pair - potential in the graphene as well@xcite .. Please generate the next two sentences of the article

such graphene - superconductor hybrid structures and in particular the andreev - reflection taking place at the graphene - superconductor interface was first studied theoretically by beenakker @xcite ( for a review on andreev reflection in graphene see ref . ) . soon after beenakker s pioneering work , supercurrent between two superconducting electrodes on top of a graphene monolayer has been observed experimentally by heersche _ et al _ , and later in refs . .

Suppose that you have an abstract for a scientific paper: several interesting correlations among gamma ray bursts ( grb ) prompt and afterglow properties have been found in the recent years . some of these correlations have been proposed also to standardize grb energetics to use them as standard candles in constraining the expansion history of the universe up to @xmath0 . however , given the still unexplained nature of most of these correlations , only the less scattered correlations can be used for constraining the cosmological parameters . the updated correlation is presented . caveats of alternative methods of standardizing grb energetics are discussed . address = inaf - osservatorio astronomico di brera . via e. bianchi 46 , i-23807 merate ( lc ) , italy . And you have already written the first three sentences of the full article: different cosmological probes seem to point toward a consensus scenario characterized by a universe which is experiencing an accelerated expansion . standard candles ( snia , e.g. @xcite ) , standard rulers ( clusters , cmb and bao , e.g. @xcite ) and the angular power spectrum of the cmb ( e.g. @xcite ) are used to probe the hubble expansion flow up to redshifts 1 - 2 ( by means of snia or clusters ) or up to the epoch of recombination ( through the cmb anisotropies ) . gamma ray bursts are observed up to very high redshifts : the farthest is grb080913c at z=6.7 @xcite . among grbs with known redshifts , 45% are at @xmath1 and 8% at @xmath2 .. Please generate the next two sentences of the article

the high grb luminosity ( 10@xmath3 erg ) and their detection in the @xmath4ray band makes them attractive as a potential and complementary cosmological tool to constrain the cosmological models at @xmath1 . however , the problem is that grbs are all but standard candles @xcite : their isotropic equivalent energetics and luminosities span 3 - 4 orders of magnitudes . similarly to snia , it has been proposed to use correlations between various properties of the prompt emission @xcite and also of the afterglow emission @xcite to standardize grb energetics .

Suppose that you have an abstract for a scientific paper: using fors2 , mounted on kueyen ( ut2 of the vlt ) , we have obtained the redshift of the lensing galaxy in the gravitational lens system . we measure @xmath0 , in good agreement with previous estimates based on the time delay and the position of the lens on the fundamental plane . it also coincides with one of the metal line absorption systems that are seen in high resolution spectra of . . And you have already written the first three sentences of the full article: was discovered as part of the hamburg / eso quasar survey and was first identified as a gravitational lens candidate by wisotzki et al . ( @xcite ) . it consists of two lensed images of a radio - quiet quasar at @xmath1= 2.319 that are separated by @xmath23.2 .. Please generate the next two sentences of the article

the lensing galaxy was discovered from ground based near - ir ( courbin , lidman & magain , @xcite ) and hst optical observations ( remy et al . @xcite ; hereafter r98 ) and is 1 from the brighter quasar image ( component a ) . from a spectrophotometric monitoring program that lasted several years , wisotzki et al . ( @xcite ; hereafter w98 ) measured a time delay of 0.73 years between the two components . to convert this into an estimate of the hubble constant

Suppose that you have an abstract for a scientific paper: we present a new analysis of the properties of star - forming cores in the perseus molecular cloud , identified in scuba 850data originally presented by @xcite . our goal is to determine which core properties can be robustly identified and which depend on the extraction technique . four regions in the cloud are examined : ngc 1333 , ic348/hh211 , l1448 and l1455 . we identify clumps of dust emission using two popular automated algorithms , clfind and gaussclumps , finding 85 and 122 clumps in total respectively . using the catalogues of @xcite , we separate these clumps into starless , class 0 and class i cores . some trends are true for both populations : clumps become increasingly elongated over time ; clumps are consistent with constant surface brightness objects ( i.e. @xmath0 ) , with an average brightness @xmath110 times larger than the surrounding molecular cloud ; the clump mass distribution ( cmd ) resembles the stellar intial mass function , with a slope @xmath2 for clfind and @xmath3 for gaussclumps , which straddle the salpeter value ( @xmath4 ) . the mass at which the slope shallows ( similar for both algorithms at @xmath5m@xmath6 ) implies a star - forming efficiency of between 10 and 20per cent . other trends reported elsewhere depend critically on the clump - finding technique : we find protostellar clumps are both smaller ( for gaussclumps ) and larger ( for clfind ) than their starless counterparts ; the functional form , best - fitting to the cmd , is different for the two algorithms . the gaussclumps cmd is best - fitted with a log - normal distribution , whereas a broken power law is best for clfind ; the reported lack of massive starless cores in previous studies ( e.g.@xcite ) can be seen in the clfind but not the gaussclumps data . our approach , exploiting two extraction techniques , highlights similarities and differences between the clump populations , illustrating the caution that must be exercised when comparing results from different studies and.... And you have already written the first three sentences of the full article: stars form out of gas in the densest areas of molecular clouds . early studies of molecular cloud structure ( e.g. @xcite ) concluded that a division into discrete clumps of emission was the best description . within such clumps , star formation occurs inside denser cores @xcite .. Please generate the next two sentences of the article

a growing consensus now maintains that molecular clouds have a scale - free structure governed by turbulence ( e.g.@xcite ) , with clumps only an arbitrary categorization . we may reconcile these viewpoints to some extent ; the clump population has a power - law spectrum of mass implying the overall cloud has a similar distribution ( e.g. @xcite ) .

Suppose that you have an abstract for a scientific paper: combining insights from the study of type refinement systems and of monoidal closed chiralities , we show how to reconstruct lawvere s hyperdoctrine of presheaves using a full and faithful embedding into a monoidal closed bifibration living now over the compact closed category of small categories and distributors . besides revealing dualities which are not immediately apparent in the traditional presentation of the presheaf hyperdoctrine , this reconstruction leads us to an axiomatic treatment of directed equality predicates ( modelled by @xmath0 presheaves ) , realizing a vision initially set out by lawvere ( 1970 ) . it also leads to a simple calculus of string diagrams ( representing presheaves ) that is highly reminiscent of c. s. peirce s existential graphs for predicate logic , refining an earlier interpretation of existential graphs in terms of boolean hyperdoctrines by brady and trimble . finally , we illustrate how this work extends to a bifibrational setting a number of fundamental ideas of linear logic . . And you have already written the first three sentences of the full article: [ [ an - intriguing - discrepancy . ] ] an intriguing discrepancy . + + + + + + + + + + + + + + + + + + + + + + + + + + there is an intriguing and longrunning discrepancy in categorical logic between the way conjunction is coupled to implication in cartesian closed categories , and the way existential quantification is coupled to universal quantification in hyperdoctrines . in a cartesian closed category @xmath1 , every object @xmath2 induces an adjunction @xmath3 where the implication functor @xmath4 is right adjoint to the conjunction functor @xmath5 this categorical situation should be compared with the way quantification is handled in a hyperdoctrine . recall that a hyperdoctrine in the sense of lawvere is first of all a ( pseudo ) functor @xmath6 from a base category @xmath7 to the category @xmath8 of small categories and functors .. Please generate the next two sentences of the article

the intuition behind this definition is that every object @xmath2 of the category @xmath7 is assigned a `` category of predicates '' noted @xmath9 , and every morphism @xmath10 of @xmath7 induces a functor @xmath11 called `` substitution '' along @xmath12 . the leading example of a hyperdoctrine is the `` subset hyperdoctrine '' with basis the category @xmath13 of sets and functions , equipped with the powerset functor @xmath14 which transports every set @xmath2 to the set @xmath15 of subsets of @xmath2 ordered by inclusion .

Suppose that you have an abstract for a scientific paper: in human societies , people s willingness to compete and strive for better social status as well as being envious of those perceived in some way superior lead to social structures that are intrinsically hierarchical . here we propose an agent - based , network model to mimic the ranking behaviour of individuals and its possible repercussions in human society . the main ingredient of the model is the assumption that the relevant feature of social interactions is each individual s keenness to maximise his or her status relative to others . the social networks produced by the model are homophilous and assortative , as frequently observed in human communities and most of the network properties seem quite independent of its size . however , it is seen that for small number of agents the resulting network consists of disjoint weakly connected communities while being highly assortative and homophilic . on the other hand larger networks turn out to be more cohesive with larger communities but less homophilic . we find that the reason for these changes is that larger network size allows agents to use new strategies for maximizing their social status allowing for more diverse links between them . community formation , opinion formation , social hierarchy . And you have already written the first three sentences of the full article: one of the most pervasive tendencies of humans is putting things in ranking order . in human societies these tendencies are reflected in their social interactions and networks being hierarchical in many respects . hierarchies and ranks emerge due to individuals subjective perceptions that some other individuals are in some respect better . then a relevant research question is whether or not the formation and structure of hierarchies in human societies can be understood by making the assumption that the dominant driving force of people in social interactions is to enhance their own `` value '' or `` status '' relative to others .. Please generate the next two sentences of the article

we call this assumption `` better than - hypothesis '' ( bth ) and note that it is closely related to the thinking of the school of individual psychology founded by adler in the early 1900s @xcite , which , while starting with the assumption that human individuals universally strive for `` superiority '' over others , emphasizes inferiority avoidance as a motive for many human actions . further studies of this kind of individuals status - seeking behaviour , especially concerning consumer behaviour and economics , include the canonical references by veblen @xcite , duesenberry @xcite and packard @xcite ( see also refs @xcite ) . in addition there is a closely related sociological model called social dominance theory @xcite , which proposes that the construction and preservation of social hierarchies is one of the main motivations of humans in their social interactions and networks .

Suppose that you have an abstract for a scientific paper: at low temperatures , phonon scattering can become so weak that phonon transport becomes ballistic . we calculate the ballistic phonon conductance @xmath0 for membranes using elasticity theory , considering the transition from three to two dimensions . we discuss the temperature and thickness dependence and especially concentrate on the issue of material parameters . for all membrane thicknesses , the best conductors have , counter - intuitively , the _ lowest _ speed of sound . . And you have already written the first three sentences of the full article: recent advances in nanoscience are expanding the limits of phononic thermal transport , both in the low conductance and high conductance side @xcite . the highest thermal conductance of a particular material is achieved , when the phonons do not scatter at all ; this is the ballistic transport limit . at room temperature the ballistic limit is quite hard to achieve , but at low temperatures ( a few k and below ) phonon - phonon and phonon - impurity scattering become so weak that ballistic transport can be observed @xcite , and the emitted power has the typical stefan - boltzmann form @xcite @xmath1 summing over the different phonon modes with speeds of sound @xmath2 and radiator emissivities @xmath3 .. Please generate the next two sentences of the article

in addition to bulk samples , ballistic phonon transport was also observed for thin amorphous sin@xmath4 membranes recently @xcite . at low temperatures , the dominant thermal phonon wavelength becomes comparable to the membrane thickness ( for a 1 m @xmath5 membrane this happens at @xmath6100mk ) leading to an effectively 2d phonon gas .

Suppose that you have an abstract for a scientific paper: polarization properties of turbulent stochastically inhomogeneous ultrarelativistic qed plasma are studied . it is shown that the sign of nonlinear turbulent landau damping corresponds to an instability of the spacelike modes and , for sufficiently large turbulent fields , to an actual instability of a system . . And you have already written the first three sentences of the full article: working out a quantitative description of the properties of dense strongly interacting matter produced in ultrarelativistic heavy ion collisions presents one of the most fascinating problems in high energy physics . the simplest ( albeit not unique ) way of putting the experimental data from rhic @xcite and lhc @xcite into a coherent framework is to describe the essential physics of these collisions as a hydrodynamical expansion of primordial quark - gluon matter that , after a short transient period , reaches sufficient level of local equilibration allowing the usage of hydrodynamics . the features of the experimentally observed energy flow , in particular the presence of a strong elliptic flow , suggest early equilibration of the initially produced matter and small shear viscosity of the expanding fluid , see e.g. the discussion in @xcite and @xcite devoted to rhic and lhc results respectively . can stylized features of primordial quark - gluon matter , in particular its anomalously low viscosity , be described within a weakly coupled theory , i.e. as a plasma composed of quasiparticles with the quantum numbers of quarks and gluons ? to address this question let us recall that extensive experimental studies of `` ordinary '' electromagnetic plasma has demonstrated , see e.g. @xcite , that it is practically never observed in the state of textbook thermal equilibrium .. Please generate the next two sentences of the article

realistic description of the properties of experimentally observed qed plasma is possible only through taking into account the presence , in addition to thermal excitations , of randomly excited fields . the resulting state was termed _

Suppose that you have an abstract for a scientific paper: electrons and holes in clean , charge - neutral graphene behave like a strongly coupled relativistic liquid . the thermo - electric transport properties of the interacting dirac quasiparticles are rather special , being constrained by an emergent lorentz covariance at hydrodynamic frequency scales . at small carrier density and high temperatures , graphene exhibits signatures of a quantum critical system with an inelastic scattering rate set only by temperature , a conductivity with a nearly universal value , solely due to electron - hole friction , and a very low viscosity . in this regime one finds pronounced deviations from standard fermi liquid behavior . these results , obtained by boltzmann transport theory at weak electron - electron coupling , are fully consistent with the predictions of relativistic hydrodynamics . interestingly , very analogous behavior is found in certain strongly coupled relativistic liquids , which can be analyzed exactly via the ads - cft correspondence , and which had helped identifying and establishing the peculiar properties of graphene . . And you have already written the first three sentences of the full article: single layer graphene is a zero - gap semiconductor whose low energy quasiparticles obey the massless dirac equation @xcite . at charge neutrality , the fermi surface reduces to two inequivalent fermi points , forming a non - analyticity in the density of states , which can be viewed as a rather simple quantum critical point @xcite . on top of that , however , as a consequence of the linear dispersion of the 2d quasiparticles coulomb interactions are unusually strong . they are only marginally irrelevant under renormalization , flowing only logarithmically to zero with decreasing temperature @xmath0 , see @xcite .. Please generate the next two sentences of the article

this is reflected , e.g. , in the inelastic scattering rate being proportional to @xmath1 ( @xmath2 ) , where @xmath3 is the ( slowly running ) dimensionless `` fine structure constant '' characterizing the strength of coulomb interactions , where @xmath4 is the dielectric constant of the adjacent medium and @xmath5 is the fermi velocity of the linearly dispersing quasiparticles . this large scattering rate nearly saturates a heisenberg uncertainty principle for quasiparticles @xcite , according to which the scattering rate is conjectured never to exceed significantly the thermal energy scale .

Suppose that you have an abstract for a scientific paper: we present results from a study of light meson spectra and structure obtained within the framework of light - front qcd formulated on a transverse lattice . we discuss how imposing lorentz covariance conditions on meson dispersion relations allows determination of parameters in the transverse lattice hamiltonian . the pion distribution amplitude obtained in this framework is rather close to its asymptotic shape . # . And you have already written the first three sentences of the full article: many high energy scattering experiments probe hadron structure very close to the light - cone . hence correlation functions probed in such experiments have a particularly simple physical interpretation in the light - front ( lf ) framework ( or infinite momentum frame ) , i.e. in a hamiltonian framework where @xmath1 is ` time ' . for example , parton distribution functions measured in deep - inelastic scattering experiments provide information about the lf momentum distribution of quarks in the target hadron .. Please generate the next two sentences of the article

off - forward parton distributions , probed in deeply virtual compton scattering , have the interpretation of matrix elements of the lf momentum density operator between states of unequal momenta . furthermore , the pion distribution amplitude , relevant for example for the asymptotic pion form factor , can be related to the lf wavefunction for the pion in the @xmath2 fock component when @xmath3 and @xmath4 have the same @xmath5 position .

Suppose that you have an abstract for a scientific paper: this paper discusses the quantum mechanics of closed timelike curves ( ctcs ) and of other potential methods for time travel . we analyze a specific proposal for such quantum time travel , the quantum description of ctcs based on post - selected teleportation ( p - ctcs ) . we compare the theory of p - ctcs to previously proposed quantum theories of time travel : the theory is physically inequivalent to deutsch s theory of ctcs , but it is consistent with path - integral approaches ( which are the best suited for analyzing quantum field theory in curved spacetime ) . we derive the dynamical equations that a chronology - respecting system interacting with a ctc will experience . we discuss the possibility of time travel in the absence of general relativistic closed timelike curves , and investigate the implications of p - ctcs for enhancing the power of computation . einstein s theory of general relativity allows the existence of closed timelike curves , paths through spacetime that , if followed , allow a time traveler whether human being or elementary particle to interact with her former self . the possibility of such closed timelike curves ( ctcs ) was pointed out by kurt gdel @xcite , and a variety of spacetimes containing closed timelike curves have been proposed @xcite . reconciling closed timelike curves with quantum mechanics is a difficult problem that has been addressed repeatedly , for example , using path integral techniques @xcite . this paper explores a particular version of closed timelike curves based on combining quantum teleportation with post - selection . the resulting post - selected closed timelike curves ( p - ctcs ) provide a self - consistent picture of the quantum mechanics of time - travel . p - ctcs offer a theory of closed timelike curves that is physically inequivalent to other hilbert - space based theories , e.g. , that of deutsch @xcite . as in all versions of time travel , closed timelike curves embody apparent paradoxes , such as the grandfather.... And you have already written the first three sentences of the full article: any quantum theory of gravity will have to propose a prescription to deal with the unavoidable @xcite nonlinearities that plague ctcs . this requires some sort of modification of the dynamical equations of motions of quantum mechanics that are always linear . deutsch in his seminal paper @xcite proposed one such prescription , based on a self - consistency condition referred to the state of the systems inside the ctc .. Please generate the next two sentences of the article

deutsch s theory has recently been critiqued by several authors as exhibiting self - contradictory features @xcite . by contrast , although any quantum theory of time travel quantum mechanics is likely to yield strange and counter - intuitive results , p - ctcs appear to be less pathological @xcite . they are based on a different self - consistent condition that states that self - contradictory events do not happen ( novikov principle @xcite ) .

Suppose that you have an abstract for a scientific paper: we fitted the @xmath0-kev spectrum of all the observations of the neutron - star low - mass x - ray binary 4u 1636@xmath153 taken with the _ rossi x - ray timing explorer _ using a model that includes a thermal comptonisation component . we found that in the low - hard state the power - law index of this component , @xmath2 , gradually increases as the source moves in the colour - colour diagram . when the source undergoes a transition from the hard to the soft state @xmath2 drops abruptly ; once the source is in the soft state @xmath2 increases again and then decreases gradually as the source spectrum softens further . the changes in @xmath2 , together with changes of the electron temperature , reflect changes of the optical depth in the corona . the lower kilohertz quasi - periodic oscillation ( khz qpo ) in this source appears only in observations during the transition from the hard to the soft state , when the optical depth of the corona is high and changes depends strongly upon the position of the source in the colour - colour diagram . our results are consistent with a scenario in which the lower khz qpo reflects a global mode in the system that results from the resonance between , the disc and/or the neutron - star surface , and the comptonising corona . [ firstpage ] accretion , accretion discs stars : neutron x - rays : binaries stars : individual : 4u 163653 . And you have already written the first three sentences of the full article: energy spectra and colour - colour diagrams ( cd ) are often used to study neutron - star low - mass x - ray binaries ( ns - lmxbs ; e.g. , * ? ? ? the evolution of the energy spectrum and the tracks on the cd are thought to be driven by variations of mass accretion rate , and reflect changes in the configuration of the accretion flow ( e.g. , * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

* ; * ? ? ? * ) . in the low - hard state

Suppose that you have an abstract for a scientific paper: in our recent paper @xcite we described a fast cubic ( bispectrum ) estimator of the amplitude of primordial non - gaussianity of local type , @xmath0 , from a combined analysis of the cosmic microwave background ( cmb ) temperature and e - polarization observations . in this paper we generalize the estimator to deal with a partial sky coverage as well as inhomogeneous noise . our generalized estimator is still computationally efficient , scaling as @xmath1 compared to the @xmath2 scaling of the brute force bispectrum calculation for sky maps with @xmath3 pixels . upcoming cmb experiments are expected to yield high - sensitivity temperature and e - polarization data . our generalized estimator will allow us to optimally utilize the combined cmb temperature and e - polarization information from these realistic experiments , and to constrain primordial non - gaussianity . . And you have already written the first three sentences of the full article: non - gaussianity from the simplest inflation models , that are based on a slowly rolling scalar field , is very small @xcite ; however , a very large class of more general models , e.g. , models with multiple scalar fields , features in inflation potential , non - adiabatic fluctuations , non - canonical kinetic terms , deviations from the bunch - davies vacuum , among others , predict substantially higher level of primordial non - gaussianity ( * ? ? ? * for a review and references therein ) . primordial non - gaussianity can be described in terms of the 3-point correlation function of bardeen s curvature perturbations , @xmath4 , in fourier space : @xmath5 depending on the shape of the 3-point function , i.e. , @xmath6 , non - gaussianity can be broadly classified into two classes @xcite .. Please generate the next two sentences of the article

first , the local , `` squeezed , '' non - gaussianity where @xmath7 is large for the configurations in which @xmath8 . second , the non - local , `` equilateral , '' non - gaussianity where @xmath7 is large for the configuration when @xmath9 .

Suppose that you have an abstract for a scientific paper: the @xmath0superconformal algebra is a @xmath1 algebra with two free parameters . it consists of 3 superconformal currents of spins @xmath2 , @xmath2 and 2 . the algebra is proved to be the symmetry algebra of the coset @xmath3 . at the central charge @xmath4 the algebra coincides with the superconformal algebra associated to manifolds of @xmath5 holonomy . the unitary minimal models of the @xmath0algebra and their fusion structure are found . the spectrum of unitary representations of the @xmath5 holonomy algebra is obtained . * unitary minimal models of @xmath6 + superconformal algebra and + manifolds of @xmath5 holonomy + * . And you have already written the first three sentences of the full article: recently the manifolds of exceptional holonomy attracted much attention . these are 7dimensional manifolds of @xmath5 holonomy and 8dimensional manifolds of @xmath7 holonomy . they are considered in the context of the string theory compactifications . the supersymmetric nonlinear sigma models on the manifolds of exceptional holonomy are described by conformal field theories , their superconformal chiral algebras were constructed in @xcite .. Please generate the next two sentences of the article

we will call them the @xmath5 and @xmath7 superconformal algebras . these are nonlinear @xmath8algebras ( @xcite , for review see @xcite ) of central charge @xmath9 and @xmath10 respectively .

Suppose that you have an abstract for a scientific paper: we present a model for cosmological inflation which has a natural turn on " and a natural turn off " mechanism . in our model inflation is driven by the hawking - like radiation that occurs in friedman - robertson - walker ( frw ) space - time . this hawking - like radiation results in an effective negative pressure fluid " which leads to a rapid period of expansion in the very early universe . as the universe expands the frw hawking temperature decreases and the inflationary expansion turns off and makes a natural transition to the power law expansion of a radiation dominated universe . the turn on " mechanism is more speculative , but is based on the common hypothesis that in a quantum theory of gravity at very high temperatures / high densities hawking radiation will stop . applying this speculation to the very early universe implies that the hawking - like radiation of the frw space - time will be turned off and therefore the inflation driven by this radiation will turn off . . And you have already written the first three sentences of the full article: cosmological inflation @xcite @xcite @xcite @xcite was proposed to address the horizon problem , flatness problem and monopole problem in the context of big bang cosmology . by postulating that in the early universe there was a brief period of rapid , exponential expansion one can explain , without fine - tuning , the observed facts that the universe is the same in different regions which are causally disconnected ( the horizon problem ) , the universe appears to be spatially flat ( the flatness problem ) and that there appears to be a much lower density of grand unified monopoles than one would naively expect . however , the inflation hypothesis itself has several unanswered questions : ( i ) what is the detailed mechanism for inflation ?. Please generate the next two sentences of the article

( ii ) what precedes the inflationary phase or how does inflation turn on " ? ( iii ) how does the universe make a graceful exit from this early , inflationary phase to standard friedman - robertson - walker ( frw ) radiation dominated expansion i.e. how does inflation turn off " . in many of the original models @xcite @xcite @xcite inflationary expansion

Suppose that you have an abstract for a scientific paper: the alice experiment at the cern large hadron collider ( lhc ) will allow the study of resonance production in nucleus - nucleus and proton - proton collisions . this paper presents results based on physics performance studies to discuss prospects in alice for @xmath0(1020 ) meson production in pp interactions during the lhc startup . . And you have already written the first three sentences of the full article: alice is a general - purpose heavy ion experiment designed to study the physics of strongly interacting matter and the quark gluon plasma ( qgp ) in nucleus - nucleus collisions at the lhc @xcite . resonances , in particular the @xmath0 meson , are useful probes to study the high density medium created in ultrarelativistic heavy ion collisions . the hadronic cross section associated with the @xmath0 meson is small , which makes this particle rather insensitive to the presence of other hadrons in the late stage of the collision .. Please generate the next two sentences of the article

therefore , the production of @xmath0 mesons has been suggested as a signature for strangeness production mechanisms owing to an early partonic phase @xcite . preliminary results from the star collaboration suggest that such mechanisms might have been observed at rhic energies when comparing the @xmath0 yields obtained in au - au collisions , and more recently in cu - cu collisions , with those obtained in pp collisions @xcite .

Suppose that you have an abstract for a scientific paper: a method to calculate the statistics of energy exchange between quantum systems is presented . the generating function of this statistics is expressed through a keldysh path integral . the method is first applied to the problem of heat dissipation from a biased mesoscopic conductor into the adjacent reservoirs . we then consider energy dissipation in an electrical circuit around a mesoscopic conductor . we derive the conditions under which measurements of the fluctuations of heat dissipation can be used to investigate higher order cumulants of the charge counting statistics of a mesoscopic conductor . during the second decade of mesoscopic physics there has been an increasing interest in thermal phenomena . several experiments succeeded in measuring properties of heat transport in mesoscopic samples : experimental tools based on the coulomb blockade to measure accurately local temperatures in mesoscopic samples have been established @xcite . it has been demonstrated that the heat conductance through one - dimensional phonon modes of a micro bridge is quantized at low temperatures @xcite . the universal heat conductance per mode is given by @xmath0 . the same universal heat quantum is also found for carriers other than bosons ( see @xcite and refs . therein ) . thermopower was experimentally investigated for a quantum dot in the coulomb blockade regime @xcite and for multiwalled carbon nanotubes @xcite . the andreev reflection process is ineffective for heat transport and has been employed to measure thermopower in andreev interferometers . the thermopower depends on the magnetic flux and shows geometry dependent time inversion properties @xcite . all these experiments have in common that they investigate mean properties averaged over time . in electrical transport , however , noise measurements have become a very useful tool to study properties of non - equilibrium systems which are hidden in measurements of the mean current ( for a review see @xcite ) . a recent milestone.... And you have already written the first three sentences of the full article: we study the statistics of the exchange of energy between two subvolumes @xmath1 and @xmath2 of a quantum system . we assume that no degrees of freedom leave or enter @xmath1 and that @xmath1 is coupled to @xmath2 only through one degree of freedom @xmath3 . @xmath3 shall be coupled to the variable @xmath4 in @xmath2 , see fig .. Please generate the next two sentences of the article

[ vbarv ] . a generalization of our approach to more than one coupling variable is straightforward .

Suppose that you have an abstract for a scientific paper: we discuss the systematic uncertainties in the recovery of dark energy properties from the use of baryon acoustic oscillations as a standard ruler . we demonstrate that while unknown relativistic components in the universe prior to recombination would alter the sound speed , the inferences for dark energy from low - redshift surveys are unchanged so long as the microwave background anisotropies can measure the redshift of matter - radiation equality , which they can do to sufficient accuracy . the mismeasurement of the radiation and matter densities themselves ( as opposed to their ratio ) would manifest as an incorrect prediction for the hubble constant at low redshift . in addition , these anomalies do produce subtle but detectable features in the microwave anisotropies . . And you have already written the first three sentences of the full article: in standard cosmology , the acoustic oscillations imprinted in the matter power spectrum at recombination have a length scale that can be accurately calculated based on measurements of the cmb anisotropy power spectrum @xcite . it should then be possible to measure this `` standard ruler '' scale at low redshifts , for example in large galaxy redshift surveys , and thereby constrain the matter and energy content of the universe @xcite . however , if the cmb measurements were misled by some new physics , e.g. a new undetected relativistic particle , then the misinterpretation could potentially spread to the low - redshift application and bias the inferences . here. Please generate the next two sentences of the article

, we show that the interpretation of the low - redshift acoustic oscillations are robust if the cmb correctly tells us the baryon - to - photon ratio and the epoch of matter - radiation equality . these quantities are robustly measured in the cmb . the actual densities of matter and radiation drop out of the calculation ; only their ratio matters .

Suppose that you have an abstract for a scientific paper: in this paper , we prove some bmo end - point estimates for some vector - valued multilinear operators related to certain singular integral operators . [ theore]_proof of theorem _ [ theoree]_proof of theorem _ . And you have already written the first three sentences of the full article: let @xmath0 and @xmath1 be the caldern zygmund singular integral operator . the commutator @xmath2 $ ] generated by @xmath3 and @xmath1 is defined as @xmath2(f)(x)=b(x)t(f)(x)-t(bf)(x)$ ] . by using a classical result of coifman _ et al _ @xcite , we know that the commutator @xmath4 $ ] is bounded on @xmath5 for @xmath6 .. Please generate the next two sentences of the article

chanillo @xcite proves a similar result when @xmath1 is replaced by the fractional integral operator . however , it was observed that the commutator is not bounded , in general , from @xmath7 to @xmath5 for @xmath8 @xcite . in @xcite ,

Suppose that you have an abstract for a scientific paper: nanoscale materials display enhanced strength and toughness but also larger fluctuations and more pronounced size effects with respect to their macroscopic counterparts . here we study the system size - dependence of the failure strength distribution of a monolayer graphene sheet with a small concentration of vacancies by molecular dynamics simulations . we simulate sheets of varying size encompassing more than three decades and systematically study their deformation as a function of disorder , temperature and loading rate . we generalize the weakest - link theory of fracture size effects to rate and temperature dependent failure and find quantitative agreement with the simulations . our numerical and theoretical results explain the crossover of the fracture strength distribution between a thermal and rate - dependent regime and a disorder - dominated regime described by extreme value theory . nanomaterials have remarkable mechanical properties , such as enhanced strength and toughness @xcite , but display considerable size effects and sample - to - sample fluctuations , which represent an issue for engineering applications . our current understanding of fracture size - effects in macroscopic disordered media relies on extreme value theory which relates the strength to the statistics of the weakest region in the sample @xcite . while the theory does not consider the effect of stress concentrations and crack interactions , numerical models for the failure of elastic networks with disorder show that an extreme value distribution describes failure at large enough scales , although the form usually deviates from the standard weibull distribution @xcite . understanding size effects in nanomaterials is still an intriguing open issue also because of the presence of rate - dependent thermal effects that would invalidate the weakest - link hypothesis @xcite . yet , the weibull distribution is commonly used to fit experimental data in carbon based nanomaterials @xcite , although the tensile.... And you have already written the first three sentences of the full article: we perform numerical simulations of the deformation and failure of defected monolayer graphene using the lammps molecular dynamics simulator package @xcite . the carbon - carbon atom interaction is modeled with the `` adaptive intermolecular reactive bond order '' ( airebo ) potential @xcite . in order to simulate a realistic bond failure behavior , the shortest - scale adaptive cutoff of the airebo potential has to be fine - tuned @xcite , as detailed in appendix [ sec : potential ] .. Please generate the next two sentences of the article

the simulated system consists of single layer , monocrystalline graphene sheets , composed of a variable number @xmath0 of atoms : @xmath0 varies from approximately @xmath1 to @xmath2 atoms . the sheets are prepared by placing the atoms on a hexagonal lattice ; the characteristic lattice length scale @xmath3 is chosen so that the system is initially in an equilibrium configuration .

Suppose that you have an abstract for a scientific paper: the cohesive energies of solids calculated using mglj eos proposed by sun jiuxun ( sun jiuxun , j. phys . : condens . matter 17 , l103 ( 2005 ) ) are seen to be erroneous . also we observed that the thermodynamic properties calculated using the mglj potential diverge for materials whose pressure derivative of bulk modulus at equilibrium is less than @xmath0 . thus the mglj potential can not be used in liquid state theories and molecular simulations to obtain thermodynamic properties . sun jiuxun @xcite recently suggested an equation of state(eos ) based on modified generalized lennard - jones ( mglj ) potential . the mglj eos is obtained by modifying the generalized lennard - jones potential in such a way that the eos obtained is volume analytic and satisfies spinodal condition . the mglj eos has three parameters and are related to lattice parameter , bulk modulus and derivative of the bulk modulus at equilibrium . in the paper@xcite it was shown that the pressure ( p ) vs compression ratio curve obtained using the mglj eos is quite accurate . the idea of generating an eos starting from a potential is interesting and has the advantage that the potential of the material also can be known in addition to the eos . however , we found some problems with the mglj eos and the potential so obtained from it . they are , ( a ) the cohesive energy calculated from the mglj eos is quite erroneous and ( b ) the thermodynamic properties calculated using the mglj potential with parameters of sun diverge for most of the materials . details about each problem are as follows : . And you have already written the first three sentences of the full article: the total energy formula obtained by sun is @xmath1 \label{uv}\ ] ] where @xmath2 is the total energy per atom , @xmath3 and @xmath4 are the equilibrium bulk modulus and equilibrium volume respectively . @xmath5 and @xmath6 are parameters and are related by the following relations : @xmath7 , @xmath8 , which are obtained by imposing the volume analyticity condition . since in this case the energy of the free atoms is zero , cohesive energy of the solid at @xmath9 is the energy at which the @xmath2 is minimum which happens to be at @xmath4 . thus the formula for cohesive energy @xmath10 turns out to be @xmath11 also , it turns out that @xmath12 .. Please generate the next two sentences of the article

the values of @xmath3 , @xmath4 and @xmath13 are listed for various materials in the paper@xcite . cohesive energies calculated from the above formula are quite erroneous

Suppose that you have an abstract for a scientific paper: the topological basis associated with birman - wenzl - murakami algebra ( bwma ) is constructed and the three dimensional forms of braiding matrices s have been found for both @xmath0 and @xmath1 . a familiar spin-@xmath2 model related to braiding matrix associated with bwma is discussed . the extreme points @xmath3 and @xmath4 of @xmath5-norm and von neumann entropy are shown to be connected to each other . through the general discussion and examples we then point out that the @xmath5-norm describes quantum entanglement . in the ref.@xcite two types of braiding matrices with two distinct eigenvalues , i , e . those associated with temperely - lieb algebra ( tla)@xcite and their corresponding solutions of yang - baxter equation ( ybe)@xcite had been discussed . based on the topological basis @xcite the @xmath6-dimensional braiding operators were mapped onto 2-dimensional ones @xcite . we had shown that the two types of braiding matrices are related to the extremes of @xmath5-norm of wigner s d - function@xcite . especially the @xmath7-d braiding matrix corresponding the bell basis ( the type - ii ) is connected to the maximum of the @xmath5-norm , whereas the permutation and extensions ( the type - i ) to the minimum . it hints that the @xmath5-norm should relate to the quantum information . it is natural to extend the discussions in the ref.@xcite to the solution of ybe with three distinct eigenvalues . among them , the most important ones belong to birman - wenzl - murakami algebra @xcite(bwma ) . as is well - known that the forms of braiding matrices with three distinct eigenvalues were given by references , say in @xcite , and the connection with bwma was shown in ref.@xcite for both standard and non - standard solutions . in parallel to the ref.@xcite , in this paper we shall firstly set up the topological base @xmath8 , @xmath9 , and @xmath10 associated with bwma , then map the @xmath11-d braiding matrices to @xmath12-d forms . the physical application of bwma is raised through.... And you have already written the first three sentences of the full article: for self - contain the bwma relations have been given in the appendix a through the graphs for three states . denoting the eigenvalues of a braiding matrix @xmath15 with three eigenvalues by @xmath16 , @xmath17 , and @xmath18 , where @xmath15 satisfies braid relation @xmath19 and without loss of generality by setting the eigenvalues of @xmath15 to be @xmath16 , @xmath17 and @xmath18 with @xmath20 we have for @xmath15 with three distinct eigenvalues . @xmath21 defining @xmath22 ( [ eq1.3 ] ) becomes @xmath23 where @xmath15 and @xmath24 occupy @xmath25 and @xmath26 sites and satisfy the relations shown in appendix a , i. e. they form bwm algebra . noting that a loop takes the value @xmath27 following the philosophy for t - l algebra to set up the topological basis @xmath28 and @xmath29 @xcite , we shall find the uni - orthogonal basis @xmath28 , @xmath29 and @xmath30 for @xmath15 and @xmath24 such that @xmath31 with @xmath32{cross}}}\quad\mathrm{and}\quad e_{k , k+1}={\raisebox{-0.4\height}{\includegraphics[height=1cm]{uniil}}},\quad d={\raisebox{-0.4\height}{\includegraphics[height=0.6cm]{nu}}}={\raisebox{-0.33\height}{\includegraphics[height=0.5cm]{loop}}}\quad \label{eq1.8}\ ] ] where the eigenvalues @xmath33 may be complex .. Please generate the next two sentences of the article

the graphic expressions @xcite of bwma are shown in appendix a. to satisfy all the relations for bwma the base takes the forms : @xmath34{tsep}}}\label{eq1.9}\\ |e_i\rangle&=&f_i\left\{{\raisebox{-0.4\height}{\includegraphics[height=0.8cm]{tcross}}}+\alpha_i{\raisebox{-0.4\height}{\includegraphics[height=0.8cm]{uu}}}+\beta_i{\raisebox{-0.4\height}{\includegraphics[height=0.5cm]{tsep}}}\right\}\quad ( i=1,2)\label{eq1.10 } .\end{aligned}\ ] ] in terms of the graphic calculations @xcite it can be proved that the ( [ eq1.7 ] ) together with @xmath35 lead to the constraints to the parameters @xmath36 , @xmath37 and normalization constant @xmath38 : @xmath39 and @xmath40\}^{1/2 } \label{eq1.13}\ ] ] for @xmath41 , i.e. @xmath42 ( hermitian ) , whereas @xmath43 for @xmath44 , i.e. @xmath45 ( unitary ) . the ( [ eq1.12 ] ) takes the same form for @xmath15 being hermitian or unitary .

Suppose that you have an abstract for a scientific paper: we investigate triphoton signals of the randall - sundram model at the large hadron collider . such a signal can be an important probe to the rs model as these are relatively cleaner from the hadronic activity and bear significant rate . the corresponding standard model background has also been studied in detail . we also show that a clear graviton reconstruction is possible in such signal . + + . And you have already written the first three sentences of the full article: phenomenology of models based on extra spatial dimensions @xcite is quite popular now . besides offering a solution to the hierarchy problem of the standard model @xcite these models allow for the low - energy unification of the gauge couplings @xcite , provide a rich tev scale new physics phenomenology , existence of gravity at the tev scale and may even offer candidate(s ) for the cold dark matter of the universe @xcite . in the simplest string theory inspired extension of the standard model ( sm ) based on one extra spatial dimension , originally proposed by randell - sundram ( rs ) @xcite , gravitons are the only propagating particles in the bulk . such gravitons will therefore have kaluza - klein ( kk ) excitations which will appear in experiments as a widely separated resonances .. Please generate the next two sentences of the article

this contrasts with the kk spectrum of models with compact extra dimensions such as add @xcite where there are a very large number of closely spaced graviton modes . the coupling of these graviton excitations to the sm is through the 4-d reduced planck mass @xmath0 , which may be on the tev scale , rather than the inaccessibly large planck mass at @xmath1 gev .

Suppose that you have an abstract for a scientific paper: based on the self - consistent scheme beyond mean - field approximation in the large @xmath0 expansion , including current quark mass explicitly , a general scheme of su(2 ) njl model is developed . to ensure the quark self - energy expanded in the proper order of @xmath0 , an approximate internal meson propagator is deduced , which is in order of @xmath1 . in our scheme , adopting the method of external momentum expansion , all the feynman diagrams are calculated in a unified way by only expanding the quark propagator . our numerical results show , that different from the mean field approximation in which the explicitly chiral symmetry breaking is invisible , the effect of finite pion mass can be seen clearly when beyond mean - field approximation . . And you have already written the first three sentences of the full article: as we all know , chiral symmetry breaking was originally explained quite well by nambu - jona - lasinio ( njl ) model as early as 1961 @xcite . like in superconductivity , the strong attractive force between quark and antiquark in the @xmath2 channel can create non - perturbative ground state with @xmath3 condensation . due to the pair condensation , the original symmetry between massless left and right - handed quarks is broken down to @xmath4 , and then the quarks obtain constituent mass . the remaining residual interactions between the constituent quarks bind them into collective excitations , i.e. , hadrons in the chiral symmetry breaking vacuum . especially in the pseudoscalar channel the residual strong interaction creates massless pions as goldstone bosons in the chiral limit . when a small current quark mass @xmath5 is introduced in the theory , chiral symmetry. Please generate the next two sentences of the article

is explicitly broken , and pion obtains its small physical mass @xmath6 . although the njl model has two serious drawbacks , i.e. , lacks of confinement and renormalizability , it is still regarded as an applicable model at low momentum , especially for dealing with processes of pion , such as pion - pion scattering near threshold .

Suppose that you have an abstract for a scientific paper: a robust thermodynamic argument shows that a small reduction of the effective coupling constant @xmath0 of qed greatly enhances the low energy compton scattering cross section and that the thomson scattering length is connected to a fundamental scale @xmath1 . a discussion provides a possible quantum interpretation of this enormous sensitivity to changes in the effective coupling constant @xmath0 . . And you have already written the first three sentences of the full article: the process of the energy interchange between radiation and matter provided by compton scattering is relevant in many areas of physics . for example , in cosmology it keeps the matter at the same temperature as radiation @xcite . compton scattering is also a unique spectroscopy for condensed matter physics , which has acquired greater importance with the advent of modern synchrotron sources @xcite .. Please generate the next two sentences of the article

for instance , it has been used to extract information about wave functions of valence electrons in a variety of systems ranging from ice @xcite and water @xcite to alloys @xcite and correlated electron systems @xcite . moreover , compton scattering can potentially help delineate confinements @xcite and spin polarization effects @xcite in nanoparticles .

Suppose that you have an abstract for a scientific paper: transfer - ionization in fast collisions between a bare ion and an atom , in which one of the atomic electrons is captured by the ion whereas another one is emitted , crucially depends on dynamic electron - electron correlations . we show that in collisions with a highly charged ion a strong field of the ion has a very profound effect on the correlated channels of transfer - ionization . in particular , this field weakens electron emission into the direction opposite to the motion of the ion and strongly suppresses the emission perpendicular to this motion . instead , electron emission is redirected into those parts of the momentum space which are very weakly populated in fast collisions with low charged ions . . And you have already written the first three sentences of the full article: electron - electron interaction is responsible for very many phenomena studied by the different fields of physics ranging from astrophysics to biophysics . amongst them atomic physics and its part physics of ion - atom collisions often deal with most basic and clear manifestations of this interaction . atomic excitation and ionization @xcite-@xcite , projectile - electron excitation and loss @xcite-@xcite , @xcite , electron transfer ( capture ) @xcite , @xcite and pair production @xcite , @xcite-@xcite belong to the elementary reactions occurring when a projectile - ion collides with a target - atom .. Please generate the next two sentences of the article

a combination of these reactions in a single - collision event is also possible and in such a case the electron - electron interaction during the collision when the external field is rapidly changing ( dynamic electron correlations ) is often crucial . in particular , mutual ionization in which both a target - atom and a ( partially stripped ) projectile - ion eject electrons , and transfer - ionization in which one of the atomic electrons is captured by a projectile - ion whereas another one is emitted , represent processes where dynamic electron correlations play a crucial role @xcite-@xcite , @xcite , @xcite , @xcite-@xcite .

Suppose that you have an abstract for a scientific paper: the diffusive properties in velocity fields whose small scales are parameterized by non @xmath0-correlated noise is investigated using multiscale technique . the analytical expression of the eddy diffusivity tensor is found for a @xmath1d steady shear flow and it is an increasing function of the characteristic noise decorrelation time @xmath2 . in order to study a generic flow @xmath3 , a small-@xmath2 expansion is performed and the first correction @xmath4 to the effective diffusion coefficients is evaluated . this is done using two different approaches and it results that at the order @xmath2 the problem with a colored noise is equivalent to the white - in - time case provided by a renormalization of the velocity field @xmath5 depending on @xmath2 . two examples of @xmath1d closed - streamlines velocity field are considered and in both the cases an enhancement of the diffusion is found . pacs number(s ) : ; + . And you have already written the first three sentences of the full article: the problem of diffusion in a given velocity field has both theoretical and practical relevance in many different fields of science and engineering as , e.g. , transport processes in chemical engineering and combustion studies @xcite . the tracers transport , in particular the evolution of their concentration , plays an important role in many aspects of geophysics . for the oceanic flows , satellite data indicate that the mesoscale features , like eddies and cold filaments , advect temperature and nutrients over spatial and temporal scales longer than those of the geostrophic turbulence .. Please generate the next two sentences of the article

the diffusion enhancement by a given velocity field has attracted a lot of works in the last years . in particular the role of the velocity field properties has been largely investigated while the effects of small scales parameterization are not understood . in this paper

Suppose that you have an abstract for a scientific paper: relativistic models developed for the exclusive and inclusive quasielastic ( qe ) electron scattering have been extended to charged - current ( cc ) and neutral - current ( nc ) @xmath0-nucleus scattering . the results of different descriptions of final - state interactions ( fsi ) are compared . . And you have already written the first three sentences of the full article: several decades of experimental and theoretical work on electron scattering have provided a wealth of information on nuclear structure and dynamics @xcite . in these experiments the electron is the probe , whose properties are clearly specified , and the nucleus the target whose properties are under investigation . additional information on nuclear properties is available from @xmath0-nucleus scattering .. Please generate the next two sentences of the article

neutrinos can excite nuclear modes unaccessible in electron scattering , can give information on the hadronic weak current and on the strange form factors of the nucleon . although of great interest , such studies are not the only aim of many neutrino experiments , which are better devised for a precise determination of neutrino properties . in neutrino oscillation experiments nuclei

Suppose that you have an abstract for a scientific paper: in view of the forthcoming results on @xmath0 pair production at lep 2 , we emphasize that _ direct empirical evidence _ on non - trivial properties of the weak vector bosons can be obtained with relatively limited integrated luminosity . an integrated luminosity of @xmath1 at @xmath2 gev will be sufficient to provide direct experimental evidence for non - vanishing self - couplings of non - abelian type among the weak vector bosons . an integrated luminosity of @xmath3 at @xmath2 gev will provide direct evidence for the existence of an anomalous magnetic dipole moment of the charged vector bosons @xmath0 . bi - tp 96/11 + hep - ph/9603283 * i. kuss , d. schildknecht * + universitt bielefeld + fakultt fr physik + postfach 10 01 31 + d33501 bielefeld , germany + revised version , may 1996 [ [ section ] ] with respect to properties of the electroweak vector bosons , there are two salient predictions of the standard electroweak theory @xcite which lack direct experimental confirmation so far : the non - abelian coupling between the members of the @xmath4 triplet of vector bosons , and , closely connected to it , the anomalous magnetic dipole moment coupling of the charged vector bosons , @xmath0 . from the detailed analysis of the lep 1 precision data there is strong _ indirect _ evidence @xcite that indeed the standard couplings are realized in nature . the production of @xmath5 at lep 2 will nevertheless open up a new domain of investigations by providing _ direct _ tests of the non - abelian structure and the anomalous magnetic dipole moment prediction . limited luminosity will restrict the possibility of precision measurements of the trilinear @xmath6 and the @xmath7 couplings at lep 2 . it is the purpose of the present note to point out that a rather small integrated luminosity at lep 2 , however , will nevertheless be sufficient to provide empirical evidence for the existence of a non - abelian trilinear coupling among the massive vector bosons and for the existence of.... And you have already written the first three sentences of the full article: the authors thank s. dittmaier for useful discussions . 99 s. l. glashow , nucl . * 22 * ( 1961 ) 579 ; s. weinberg , phys .. Please generate the next two sentences of the article

* 19 * ( 1967 ) 1264 ; a. salam , proc . 8th nobel symposium , ed .

Suppose that you have an abstract for a scientific paper: computational kernel of the three - dimensional variational data assimilation ( 3d - var ) problem is a linear system , generally solved by means of an iterative method . the most costly part of each iterative step is a matrix - vector product with a very large covariance matrix having gaussian correlation structure . this operation may be interpreted as a gaussian convolution , that is a very expensive numerical kernel . recursive filters ( rfs ) are a well known way to approximate the gaussian convolution and are intensively applied in the meteorology , in the oceanography and in forecast models . in this paper , we deal with an oceanographic 3d - var data assimilation scheme , named oceanvar , where the linear system is solved by using the conjugate gradient ( gc ) method by replacing , at each step , the gaussian convolution with rfs . here we give theoretical issues on the discrete convolution approximation with a first order ( 1st - rf ) and a third order ( 3rd - rf ) recursive filters . numerical experiments confirm given error bounds and show the benefits , in terms of accuracy and performance , of the 3-rd rf . . And you have already written the first three sentences of the full article: in recent years , gaussian filters have assumed a central role in image filtering and techniques for accurate measurement @xcite . the implementation of the gaussian filter in one or more dimensions has typically been done as a convolution with a gaussian kernel , that leads to a high computational cost in its practical application . computational efforts to reduce the gaussian convolution complexity are discussed in @xcite .. Please generate the next two sentences of the article

more advantages may be gained by employing a _ spatially recursive filter _ , carefully constructed to mimic the gaussian convolution operator . + recursive filters ( rfs ) are an efficient way of achieving a long impulse response , without having to perform a long convolution . initially developed in the context of time series analysis @xcite , they are extensively used as computational kernels for numerical weather analysis , forecasts @xcite , digital image processing @xcite .

Suppose that you have an abstract for a scientific paper: we propose a simple ansatz for the three generation neutrino mass matrix @xmath0 which is motivated from an so(10 ) grand unified theory . the ansatz can be combined with information from neutrino oscillation experiments and bounds on neutrinoless double beta decay to determine the neutrino masses themselves and to reconstruct , with some assumptions , the matrix @xmath1 . = 17pt # 1=#1pt = by -by -makecaption#1#2 tempboxa tempboxa > = = # 1 # 2 to = 13pt su-4240 - 719 + hep - ph/0004105 + * complementary ansatz for the neutrino mass matrix * = 12pt deirdre black amir h. fariborz + 0.5 cm salah nasri joseph schechter + _ department of physics , syracuse university , syracuse , ny 13244 - 1130 , usa . _ + 0.5 cm * abstract * . And you have already written the first three sentences of the full article: in the last few years there has been another wave of excitement regarding the question of neutrino masses . this is largely due to the many new experiments testing neutrino oscillations , most notably the positive indications obtained by super kamiokande on atmospheric neutrino oscillations @xcite . similar indications come from other experiments @xcite .. Please generate the next two sentences of the article

the solar neutrino experiments have for many years provided independent evidence for neutrino oscillations @xcite . accelerator and reactor experiments have also played an important role . they have furnished strict bounds on neutrino oscillation parameters @xcite . in the case of the lsnd experiment @xcite at los alamos evidence for @xmath2 oscillation has been reported .

Suppose that you have an abstract for a scientific paper: in the conventional quantum mechanics ( i.e. , hermitian qm ) the adiabatic theorem for systems subjected to time periodic fields holds only for bound systems and not for open ones ( where ionization and dissociation take place ) [ d. w. hone , r. ketzmerik , and w. kohn , phys . rev . a * 56 * , 4045 ( 1997 ) ] . here with the help of the ( t , t ) formalism combined with the complex scaling method we derive an adiabatic theorem for open systems and provide an analytical criteria for the validity of the adiabatic limit . the use of the complex scaling transformation plays a key role in our derivation . as a numerical example we apply the adiabatic theorem we derived to a 1d model hamiltonian of xe atom which interacts with strong , monochromatic sine - square laser pulses . we show that the generation of odd - order harmonics and the absence of hyper - raman lines , even when the pulses are extremely short , can be explained with the help of the adiabatic theorem we derived . department of chemistry and minerva center of nonlinear physics in complex systems technion israel institute of technology haifa 32000 , israel . + 03.65.-w , 42.50.hz , 42.65.-ky , 32.80.rm . And you have already written the first three sentences of the full article: when matter is exposed to intense laser fields , high harmonics ( hhs ) of the incident radiation may be produced . usually , only odd harmonics are obtained even when the laser pulses are short ( for theoretical and experimental work which demonstrates this see @xcite and @xcite , respectively ) . since the duration of the pulse in time is inversely proportional to its width in energy space , one may find this result surprising , as one may expect to obtain also a large distribution of frequencies in the scattered field .. Please generate the next two sentences of the article

why are only odd harmonics obtained even when the laser pulses are short ? for cw lasers ( and symmetric field - free potential ) using the non - hermitian floquet theory it was proved that only odd harmonics are obtained when the dynamics is controlled by a single resonance floquet quasienergy ( qe ) state @xcite,@xcite . when laser pulses are used it was argued that this proof holds since usually the populated resonance states are associated with very different lifetimes and the dynamics is controlled by the resonance state which has the longest lifetime . however , this argument may hold only when the duration of the laser pulses is large enough to enable the decay of the short lived resonances .

Suppose that you have an abstract for a scientific paper: we formulate the nonlinear isovector model in a curved background , and calculate the spherically symmetric solutions for weak and strong coupling regimes . the usual belief that gravity does not have appreciable effects on the structure of solitons will be examined , in the framework of the calculated solutions , by comparing the flat - space and curved - space solutions . it turns out that in the strong coupling regime , gravity has essential effects on the solutions . masses of the self - gravitating solitons are calculated numerically using the tolman expression , and its behavior as a function of the coupling constant of the model is studied . . And you have already written the first three sentences of the full article: there has been considerable interest in the localized solutions of the einstein s equations with nonlinear field sources in recent years ( @xcite , @xcite , @xcite , @xcite , @xcite ) . gravitating non - abelian solitons and black holes with yang - mills fields is investigated in @xcite . such problems were not investigated earlier in the history of gr , mainly because of two reasons : 1 .. Please generate the next two sentences of the article

it was widely accepted that the gravitational effects are too weak to affect -in an essential way- the properties of soliton solutions of nonlinear field theories . 2 . the resulting equations are usually formidable such that the ordinary analytical approaches become idle .

Suppose that you have an abstract for a scientific paper: the chemical structure of neutral clouds in low metallicity environments is examined with particular emphasis on the h to and c@xmath0 to co transitions . we observed near - ir , , and lines and the @xmath1co line from 30 doradus and n159/n160 in the large magellanic cloud and from dem s 16 , dem s 37 , and li - smc 36 in the small magellanic cloud . we find that the emission is uv - excited and that ( weak ) emission always exists ( in our surveyed regions ) toward positions where and [ ] emission have been detected . using a pdr code and a radiative transfer code , we simulate the emission of line radiation from spherical clouds and from large planar clouds . because the [ ] emission and emission arise on the surface of the cloud and the lines are optically thin , these lines are not affected by changes in the relative sizes of the neutral cloud and the bearing core , while the optically thick emission can be strongly affected . the sizes of clouds are estimated by measuring the deviation of co emission strength from that predicted by a planar cloud model of a given size . the average cloud column density and therefore size increases as the metallicity decreases . our result agrees with the photoionization regulated star formation theory by mckee ( 1989 ) . . And you have already written the first three sentences of the full article: stars form in dense , cold molecular clouds . measuring the molecular gas content of the clouds is very important if we are to estimate the star formation efficiency and relate it to the properties of the clouds and to their environments . the total mass , however , can not be measured directly because the lowest levels of from which the observable emission can arise have excitation energies ( e.g. , @xmath2 @xmath3 500 k , @xmath4 = @xmath5 ) too high to be thermally excited in the cold ( @xmath6 k ) molecular clouds . in the milky way , the @xmath1co line . ]. Please generate the next two sentences of the article

( hereafter ) traces the molecular gas content . the conversion factor ( @xmath7 ) between the column density and the velocity integrated intensity of co has been measured via the virial theorem ( @xmath7 = @xmath8 / ( ) , solomon et al .

Suppose that you have an abstract for a scientific paper: we study a family of graphs related to the @xmath0-cube . the middle cube graph of parameter @xmath1 is the subgraph of @xmath2 induced by the set of vertices whose binary representation has either @xmath3 or @xmath1 number of ones . the middle cube graphs can be obtained from the well - known odd graphs by doubling their vertex set . here we study some of the properties of the middle cube graphs in the light of the theory of distance - regular graphs . in particular , we completely determine their spectra ( eigenvalues and their multiplicities , and associated eigenvectors ) . . And you have already written the first three sentences of the full article: the _ @xmath0-cube _ @xmath4 , or @xmath0-dimensional hypercube , has been extensively studied . nevertheless , many open questions remain . et al . _ wrote a comprehensive survey on hypercube graphs @xcite .. Please generate the next two sentences of the article

recall that the _ @xmath0-cube _ @xmath4 has vertex set @xmath5 and @xmath0-tuples representing vertices are adjacent if and only if they differ in exactly one coordinate .

Suppose that you have an abstract for a scientific paper: bilayer graphene hosts valley - chiral one dimensional modes at domain walls between regions of different interlayer potential or stacking order . when such a channel is brought into proximity to a superconductor , the two electrons of a cooper pair which tunnel into it move in opposite directions because they belong to different valleys related by the time - reversal symmetry . this is a kinetic variant of cooper pair splitting , which requires neither coulomb repulsion nor energy filtering but is enforced by the robustness of the valley isospin in the absence of atomic - scale defects . we derive an effective model for the guided modes in proximity to an @xmath0-wave superconductor , calculate the conductance carried by split and spin - entangled electron pairs , and interpret it as a result of _ local _ andreev reflection processes , whereas crossed andreev reflection is absent . creating mobile nonlocal spin - entangled electrons in a transport experiment with the help of superconductor normal junctions has attracted a lot of attention in theory @xcite and experiment @xcite because the spin degree of freedom of the electron could serve as a solid - state qubit @xcite . in the existing experiments , the envisaged process where a cooper pair is split over two normal leads is crossed andreev reflection ( car ) @xcite , which is enhanced by the repulsive electron - electron interaction on two quantum dots weakly coupled to the superconductor @xcite or by energy filtering @xcite . the basic mechanism of these entanglers is not very sensitive to the specific material used , i.e. , the underlying band structure . it has been shown that characteristic features of new materials exhibiting dirac - cones like graphene or topological insulators can be useful for splitting cooper pairs @xcite . in these proposals , the efficiency of the splitting process , in the absence of interactions , relies on non - protected resonance conditions or the split cooper pair is not spin - entangled due to spin -.... And you have already written the first three sentences of the full article: here we give the details of the calculation of the proximity induced amplitudes @xmath146 . because the superconductor is only weakly coupled through the tunnel barrier @xmath52 , we can derive an effective 1d model via low - order quasi - degenerate perturbation theory . we split @xmath147 into two parts , where @xmath59 is diagonal in the eigenbasis @xmath37 , and @xmath148 $ ] .. Please generate the next two sentences of the article

since @xmath62 is diagonal in spin and valley , we suppress the indices @xmath149 in the following . to first order in @xmath62 , @xmath150 and to second order , @xmath151 \notag\\&\hspace{.5cm}\times \int dx{\tilde\phi}^{0\dagger}_{p_x , p_y}(x)h_1(x ) \phi^{0,n'}_{p_y}(x ) , \end{aligned}\ ] ] where @xmath152 are the unperturbed free states above the gap @xmath153 with real @xmath154 and @xmath32 at energy @xmath155 . we impose the quantization condition @xmath156 and normalize the extended wavefunctions according to @xmath157 .

Suppose that you have an abstract for a scientific paper: our paper presents new methods for finding and testing of weak periodic variability of stellar objects developed for the purpose of detecting expected regular light variations of magnetic chemically peculiar ( mcp ) candidates in the large magellanic cloud . we introduce two new periodograms of the mcp star , bs cir ( hd 125630 ) , appropriate for rotating spotted variables and compare the results with those obtained by the well - known lomb - scargle periodogram . the usage of periodograms and the testing of the significance of the found period candidates are demonstrated with two examples : the observed and simulated observations of the magnetic field of the mcp star cq uma ( hd 119213 ) and the mcp candidate ogle lmc136.7 16501 . three newly developed tests of the periodic variability the shuffling , bootstrap and subsidiary ones , are presented . we demonstrate that the found periodic variations known with signal - to - noise ratio larger than 6 can be approved as real . . And you have already written the first three sentences of the full article: the chemical peculiar ( cp ) stars of the upper main sequence display abundances that deviate significantly from the standard ( solar ) abundance distribution . the existence of strong global magnetic field specifies a subset of this class , the magnetic chemically peculiar ( mcp ) stars . the periodic variability of mcp stars is explained in terms of the oblique rotator model , according to which , the period of the observed light , spectrum , and magnetic field variations is identical to the rotational period .. Please generate the next two sentences of the article

the photometric changes are due to variations of global flux redistribution caused by the phase - dependent line blanketing and continuum opacity namely in the ultraviolet part of stellar spectra @xcite . the amplitude of the photometric variability is determined by the degree of non - uniformity of the surface brightness ( spots ) , the used passband , and the line of sight .

Suppose that you have an abstract for a scientific paper: it is argued that whereas the shatskiy single rings produced by the gravitational inner field of a spherically symmetric wormhole and the concentric double einstein rings generated by a toroidal ringhole could not be used without some uncertainty to identify the presence of such tunnelings in the universe or the existence of a parallel universe , the image which the inner gravitational field of a non orientable klein - bottle hole tunneling would leave by lensing a single luminous source is that of a truncated double spiral , which is a signature that can not be attributed to any other single or composite astronomical object in whichever universe it may be placed . in this report we argue some more reasons to predict that such a signature would imply the discovery of one such non orientable tunneling in our or other universe . after all , a nonorientable klein - bottle hole is also a perfectly valid solution to the einstein equations and the stuff which would make it feasible is becoming more and more familiar in cosmology . . And you have already written the first three sentences of the full article: considering observable effects from wormholes or ringholes is not new . more than a decade ago some of such effects were already predicted by several author [ 1,2 ] . in particular , it was shown that these tunnelings can induce lensing effects from luminous sources . more precisely , by embedding these tunnelings in friedmann space , it was seen [ 2 ] that , besides the expected lensing , at least ringholes were able to induce other potentially observable effects such as frequency shifting of the emitting sources , discontinuous change of background temperature , broading and intensity enhancement of the spectral lines , as well as a rather dramatic increase in the luminosity of any objects at the tunnel throat .. Please generate the next two sentences of the article

moreover , the precise form of the lensing signature left by wormholes and ringholes has been quite more recently seen to consist of a single ring and a double concentric ring , respectively [ 3,4 ] . in spite of the interest that all of such results may have from a pedagogical standpoint , none of these induced phenomena has by itself any practical usefulness in order to identify the existence of space - time tunnels in the universe because there are other observable objects in the universe able to produce similar effects .

Suppose that you have an abstract for a scientific paper: we describe dynamics of spin and valley transitions driven by alternating electric fields in quantum dots defined electrostatically within semiconducting carbon nanotubes ( cnt ) . we use the tight - binding approach to describe the states localized within a quantum dot taking into account the circumferential spin - orbit interaction due to the s - p hybridization and external fields . the basis of eigenstates localized in the quantum dot is used in the solution of the time - dependent schrdinger equation for description of spin flips and inter - valley transitions that are driven by periodic perturbation in the presence of coupling between the spin , valley and orbital degrees of freedom . besides the first order transitions we find also fractional resonances . we discuss the transition rates with selection rules that are lifted by atomic disorder and the bend of the tube . we demonstrate that the electric field component perpendicular to the axis of the cnt activates spin transitions which are otherwise absent and that the resonant spin - flip time scales with the inverse of the electric field . . And you have already written the first three sentences of the full article: electron spins confined in carbon nanotube@xcite ( cnt ) quantum dots@xcite ( qd ) are considered attractive for quantum information storage and processing due to the absence of the hyperfine interaction@xcite which is the main source of decoherence in iii - v nanostructures . the spin - orbit ( so ) coupling that is intrinsically present in cnts due to s - p hybridization accompanying the curvature of the graphene plane @xcite paves the way for electrical control of the confined carrier spins . in particular the so interaction allows for spin flips induced by ac electric fields @xcite according to the mechanism of the electric - dipole spin resonance as studied earlier for iii - v quantum dots.@xcite in nanotube quantum dots the so coupling splits the four - fold degeneracy of energy levels with respect to the spin and valley into kramers doublets with spin - orbit coupling energy varying from a fraction of mev @xcite to several mev .. Please generate the next two sentences of the article

@xcite in this work we study the states confined in a qd defined electrostatically within the cnt and simulate spin and valley transitions driven by ac electric field between the quadruple of nearly degenerate energy levels in external magnetic field . for clean cnts the coupling between the @xmath0 and @xmath1 valleys is absent which motivates ideas to use the valley degree of freedom as a carrier of the quantum information alternative for the electron spin . in the transport experiments the valley filters and valves were proposed @xcite for clean samples in which the inter - valley scattering can be neglected . for clean cnt double quantum dots

Suppose that you have an abstract for a scientific paper: the bcs - like pairing in ultracold fermionic atomic ( @xmath0 ) gases is studied in the model of `` isotopic - spin '' pairing proposed in 1991 ku - hof - ssc . this model assumes a mismatch ( @xmath1 ) in chemical potentials of pairing fermionic atoms . it is shown that a @xmath2-josephson junction can be realized in @xmath0 systems , where the left and right banks @xmath3 are the @xmath0 superfluids . the weak link @xmath4 consists from the normal @xmath5 with the finite mismatch @xmath1 . if the @xmath2-junction is a part of a closed ring the superfluid mass - current flows spontaneously in the ring , i.e. , the time - reversal symmetry is broken spontaneously . this is realized if the radius of the ring @xmath6 is larger than the critical one @xmath7 . all these effects exist also in the case when @xmath8 , where @xmath9 is the superfluid gap , but with the reduced thickness of the weak link . it is also discussed , that if junctions @xmath10 and trilayers @xmath11 from @xmath0 are realizable this renders a possibility for a novel electronics - _ hypertronics_. . And you have already written the first three sentences of the full article: physics of ultracold atoms is fascinating in many respects . the ways how these systems can be manipulated in magnetic and optical traps open possibilities to an enormous number of physical effects which can be realized and studied in these systems @xcite , hofstetter . thanks to a large variety of experimental techniques one can manipulate atomic gases by magnetic and electromagnetic fields giving rise to realization of various macroscopic quantum effects .. Please generate the next two sentences of the article

first of all , a number of effects known in standard superfluids and superconductors were already realized in ultracold atomic gases @xcite , hofstetter . in that sense a number of already developed theoretical methods and ideas in solid state physics were used in physics of ultracold atoms . on the other hand this fascinating field gives us new possibilities in studying many aspects of the bose - einstein condensation ( bec ) and of the superfluidity of fermi condensates ( bcs ) which are difficult to realize in solid state physics . for instance in an ultracold gas of bosonic atoms , such as @xmath12 or @xmath13 , one can study bose - einstein condensation(bec ) .

Suppose that you have an abstract for a scientific paper: a new two - parametric family of mass distribution for spherical stellar systems is considered . it generalizes families by @xcite and by @xcite . steady velocity dispersions are found for these models by solving an equation of hydrostatic equilibrium . axisymmetric generalizations of the model are discussed . . And you have already written the first three sentences of the full article: in this study we suggest a new family of spherical mass distribution models that generalizes models by an & evans ( 2006 , hereafter ae ) and models by kuzmin et al . @xcite . the family depends on two structural parameters . it includes plummer s spheres @xcite , hnon s isochrones @xcite and the model by hernquist @xcite as special cases .. Please generate the next two sentences of the article

let us consider the dimensionless potential @xmath0 here @xmath1 and @xmath2 are structural parameters . if @xmath3 , @xmath4 we obtain a model by ae , for @xmath5 , @xmath6 we have a model by kuzmin et al . ( 1969 , 1972 ) .

Suppose that you have an abstract for a scientific paper: the transmission dynamics of some infectious diseases is related to the contact structure between individuals in a network . we used five algorithms to generate contact networks with different topological structure but with the same scale - free degree distribution . we simulated the spread of acute and chronic infectious diseases on these networks , using si ( susceptible infected ) and sis ( susceptible infected susceptible ) epidemic models . in the simulations , our objective was to observe the effects of the topological structure of the networks on the dynamics and prevalence of the simulated diseases . we found that the dynamics of spread of an infectious disease on different networks with the same degree distribution may be considerably different . * adv . studies theor . phys . , vol . 7 , 2013 , no . 16 , 759 - 771 * * hikari ltd , www.m-hikari.com * * http://dx.doi.org/10.12988/astp.2013.3674 * * raul ossada , jos h. h. grisi - filho , * * fernando ferreira and marcos amaku * faculdade de medicina veterinria e zootecnia universidade de so paulo so paulo , sp , 05508 - 270 , brazil copyright @xmath0 2013 raul ossada et al . this is an open access article distributed under the creative commons attribution license , which permits unrestricted use , distribution , and reproduction in any medium , provided the original work is properly cited . * keywords : * scale - free network , power - law degree distribution , dynamics of infectious diseases . And you have already written the first three sentences of the full article: the contact pattern among individuals in a population is an essential factor for the spread of infectious diseases . in deterministic models , the transmission is usually modelled using a contact rate function , which depends on the contact pattern among individuals and also on the probability of disease transmission . the contact function among individuals with different ages , for instance , may be modelled using a contact matrix @xcite or a continuous function @xcite .. Please generate the next two sentences of the article

however , using network analysis methods , we can investigate more precisely the contact structure among individuals and analyze the effects of this structure on the spread of a disease . the degree distribution @xmath1 is the fraction of vertices in the network with degree @xmath2 .

Suppose that you have an abstract for a scientific paper: we present results about the effect of the use of a stiffer equation of state , namely the ideal - fluid @xmath0 ones , on the dynamical bar - mode instability in rapidly rotating polytropic models of neutron stars in full general relativity . we determine the change on the critical value of the instability parameter @xmath1 for the emergence of the instability when the adiabatic index @xmath2 is changed from 2 to 2.75 in order to mimic the behavior of a realistic equation of state . in particular , we show that the threshold for the onset of the bar - mode instability is reduced by this change in the stiffness and give a precise quantification of the change in value of the critical parameter @xmath3 . we also extend the analysis to lower values of @xmath1 and show that low - beta shear instabilities are present also in the case of matter described by a simple polytropic equation of state . . And you have already written the first three sentences of the full article: non - axisymmetric deformations of rapidly rotating self - gravitating bodies are a rather generic phenomenon in nature and could appear in a variety of astrophysical scenarios like stellar core collapses @xcite , accretion - induced collapse of white dwarfs @xcite , or the merger of two neutron stars @xcite . over the years , a considerable amount of work has been devoted to the search of unstable deformations that , starting from an axisymmetric configuration , can lead to the formation of highly deformed rapidly rotating massive objects @xcite . such deformations would lead to an intense emission of high - frequency gravitational waves ( i.e. in the khz range ) , potentially detectable on earth by next - generation gravitational - wave detectors such as advanced ligo @xcite , advanced virgo and kagra @xcite in the next decade @xcite . from the observational point of view , it is import to get any insight on the possible astrophysical scenarios where such instabilities ( unstable deformation ) are present . it is well known that rotating neutron stars are subject to non - axisymmetric instabilities for non - radial axial modes with azimuthal dependence @xmath4 ( with @xmath5 ) when the instability parameter @xmath6 ( i.e. the ratio between the kinetic rotational energy @xmath7 and the gravitational potential energy @xmath8 ) exceeds a critical value @xmath3 . the instability parameter plays an important role in the study of the so - called dynamical bar - more instability , i.e. the @xmath9 instability which takes place when @xmath1 is larger than a threshold @xcite .. Please generate the next two sentences of the article

previous results for the onset of the classical bar - mode instability have already showed that the critical value @xmath3 for the onset of the instability is not an universal quantity and it is strongly influenced by the rotational profile @xcite , by relativistic effects @xcite , and , in a quantitative way , by the compactness @xcite . however , up to now , significant evidence of their presence when realistic equation of state ( eos ) are consider is still missing . for example in @xcite , using the unified sly eos @xcite , was shown the presence of shear - instability but no sign of the classical bar - mode instability and of its critical behavior have been found .

Suppose that you have an abstract for a scientific paper: we study the self - gravitational effect on the equation of state ( eos ) of bose and fermi gases in thermal equilibrium at the end of reheating , the period after quark - hadron transition and before big bang nucleosynthesis ( bbn ) . after introducing new grand canonical partition functions based on the work of uhlenbeck and gropper , we notice some interesting features of the newly developed eoss with distinct behaviors of relativistic and non - relativistic gases under self - gravity . the usual negligence of the self - gravitational effect when solving the background expansion of the early universe is justified with numerical results , showing the magnitude of the self - gravitational modification of the state constant to be less than @xmath0 . this helps us to clarify the background thermal evolution of the primordial patch . such clarification is crucial in testing gravity theories , evaluating inflation models and determining element abundances in bbn . . And you have already written the first three sentences of the full article: in most history of our universe , gravity has been the dominant force in determining cosmological evolutions . due to the onset of gravitational instability , primordial fluctuations generated in cosmic inflation start growing by attracting dark matter and gases nearby after the matter radiation equilibrium at a temperature approximately @xmath1 @xcite . consequently , structures of the first generation galaxies are seeded . shortly after the forming of proto - galaxies , the hydrogen and helium gases within them begin to condensate and make the first stars . in the formation of any astrophysical body ,. Please generate the next two sentences of the article

self - gravity is beyond question one of the key factors in determining the specific destinies of stars , quasars , black holes , and neutron stars . for example , the self - gravity of neutron stars is considered using the affine model @xcite , where the effective relativistic self - gravitational potential is approximated with tolman - oppenheimer - volkoff ( tov ) stellar structure equations .

Suppose that you have an abstract for a scientific paper: we present nuclear spin - independent and dependent parity non - conservation amplitudes for the @xmath06s\;^2s_{1/2}-[4f^{14}]5d\;^2d_{3/2}$ ] transition of @xmath1yb@xmath2 , calculated using perturbed relativistic coupled - cluster theory . as a proxy to estimate theoretical uncertainty of these results we calculate the excitation energies , hyperfine structure constants and e1 transition amplitudes for the important low lying states . the pnc results presented in paper shall be useful in the propose pnc experiments . . And you have already written the first three sentences of the full article: the theoretical results of atomic parity non - conservation ( pnc ) when combined with the experimental results is an important probe of physics beyond the standard model of particle physics @xcite . there are two sources of pnc in atoms , nuclear spin - independent ( nsi ) and nuclear spin - dependent ( nsd ) . the nsi - pnc is well studied and experimentally observed in several atoms .. Please generate the next two sentences of the article

the most precise measurement till date is in the case of atomic cs @xcite . the same experiment also indicated a signature of nsd - pnc effects . the most dominant source of which is the nuclear anapole moment ( nam ) , a parity odd nuclear electromagnetic moment arising from parity violating interaction within the nucleus @xcite .

Suppose that you have an abstract for a scientific paper: we calculate the free energy , entropy and pressure of the quark gluon plasma ( qgp ) at finite temperature and density with a given fraction of spin - up and spin - down quarks using a mit bag model with corrections up to @xmath0 . the expressions for the specific heat and the spin susceptibility are derived in terms of fermi momentum and temperature . the effects of interaction between the quarks on the properties of the qgp phase are also investigated . within our phenomenological model , we estimate the transition temperature @xmath1 by constructing the phase boundary between the hadronic phase and the qgp phase . finally , we compute the equation of state of the qgp and its dependence on the temperature and the density . . And you have already written the first three sentences of the full article: one of the active areas of high energy physics research is the study of thermodynamic properties of interacting hadronic matter in the extreme conditions of temperature and/or density for the last few decades . at such high temperature and/or density the hadrons are expected to dissolve into their more fundamental constituents _ viz . _ quarks and gluons , forming a new state of matter called quark gluon plasma ( qgp ) @xcite . the basic theory that describes the strong interaction in terms of quarks and gluons. Please generate the next two sentences of the article

is known as quantum chromodynamics ( qcd ) . it is known that qcd is asymptotically free _

Suppose that you have an abstract for a scientific paper: is it possible to trap a quantum particle in an open geometry ? in this work we deal with the boundary value problem of the stationary schroedinger ( or helmholtz ) equation within a waveguide with straight segments and a rectangular bending . the problem can be reduced to a one dimensional matrix schroedinger equation using two descriptions : oblique modes and conformal coordinates . we use a corner - corrected wkb formalism to find the energies of the one - dimensional problem . it is shown that the presence of bound states is an effect due to the boundary alone , with no classical counterpart for this geometry . the conformal description proves to be simpler , as the coupling of transversal modes is not essential in this case . + * pacs : * 37.10.gh , 42.25.gy , 03.65.ge + * keywords : * bent waveguides , bound states , corners , dirichlet conditions . . And you have already written the first three sentences of the full article: the use of symmetry methods to understand bound states has an ancient origin and has given many of its fruits in atomic and subatomic physics - the work of marcos moshinsky is an excellent example of this @xcite . over the years , however , other approaches to understand more complicated systems have given up symmetry in both classical and quantum mechanics @xcite , @xcite . here we present one of the simplest ways of destroying continuous symmetries with purely quantum - mechanical consequences : a corner . we will show that a sharply bent waveguide supports a finite number of bound states whose nature has no classical counterpart . due to the geometry ,. Please generate the next two sentences of the article

the traditional methods of integrability can not be used to obtain the corresponding solutions . this type of systems has been studied in the past , either with mathematical tools @xcite proving the existence of bound states or by employing numerical methods for computing the corresponding energies and eigenfunctions @xcite .

Suppose that you have an abstract for a scientific paper: for a projective curve @xmath0 and the canonical divisor @xmath1 on @xmath0 , it is classically known that the canonical ring @xmath2 is finitely generated in degree at most three . in this article , we study whether analogous statements hold for finite graphs and tropical curves . for any finite graph @xmath3 , we show that the canonical semi - ring @xmath4 is finitely generated but that the degree of generators are not bounded by a universal constant . for any hyperelliptic tropical curve @xmath5 with integer edge - length , we show that the canonical semi - ring @xmath6 is not finitely generated , and , for tropical curves with integer edge - length in general , we give a sufficient condition for non - finite generation . # 1 . And you have already written the first three sentences of the full article: let @xmath7 be the tropical semifield , where the tropical sum @xmath8 is taking the maximum @xmath9 , and the tropical product @xmath10 is taking the ordinary sum @xmath11 . let @xmath12 be the sub - semifield of @xmath13 . a tropical curve @xmath5 is a metric graph with possibly unbounded edges .. Please generate the next two sentences of the article

equivalently , in a more formal form , a tropical curve is a compact topological space homeomorphic to a one - dimensional simplicial complex equipped with an integral affine structure over @xmath14 ( see @xcite ) . finite graphs are seen as a discrete version of tropical curves . in relation to the classical algebraic curves , tropical curves and finite graphs

Suppose that you have an abstract for a scientific paper: we discuss the propagation of electromagnetic waves on a rectangular lattice of polarizable point dipoles . for wavelengths long compared to the lattice spacing , we obtain the dispersion relation in terms of the lattice spacing and the dipole polarizabilities . we also obtain the dipole polarizabilities required for the lattice to have the same dispersion relation as a continuum medium of given refractive index @xmath0 ; our result differs from previous work by draine & goodman ( 1993 ) . our new prescription can be used to assign dipole polarizabilities when the discrete dipole approximation is used to study scattering by finite targets . results are shown for selected cases . . And you have already written the first three sentences of the full article: the discrete dipole approximation ( dda ) provides a flexible and general method to calculate scattering and absorption of light by objects of arbitrary geometry @xcite . the approximation consists of replacing the continuum target of interest by an array of polarizable points , which acquire oscillating electric dipole moments in response to the electric field due to the incident wave plus all of the other dipoles . broadly speaking , there are two criteria determining the accuracy of the approximation : * the interdipole separation @xmath1 should be small compared to the wavelength of the radiation in the material ( @xmath2 , where @xmath0 is the complex refractive index , and @xmath3 is the wavenumber _ in vacuo _ ) ; * the interdipole separation @xmath1 should be small enough to resolve structural dimensions in the target . with modern workstations , it is now feasible to carry out dda calculations on targets containing up to @xmath4 dipoles @xcite .. Please generate the next two sentences of the article

in addition to calculation of scattering and absorption cross sections , the dda has recently been applied to computation of forces and torques on illuminated particles @xcite if the dipoles are located on a cubic lattice , then in the limit where the interdipole separation @xmath5 , the familiar clausius - mossotti relation ( see , e.g , @xcite ) can be used to determine the choice of dipole polarizabilities required so that the dipole array will approximate a continuum target with dielectric constant @xmath6 . @xcite showed how this estimate for the dipole polarizabilities should be modified to include radiative reaction corrections , and @xcite derived the @xmath7 $ ] corrections required so that an infinite cubic lattice would have the same dispersion relation as a continuum of given dielectric constant .

Suppose that you have an abstract for a scientific paper: necessary and sufficient conditions for bipartite entanglement are derived , which apply to arbitrary hilbert spaces . motivated by the concept of witnesses , optimized entanglement inequalities are formulated solely in terms of arbitrary hermitian operators , which makes them useful for applications in experiments . the needed optimization procedure is based on a separability eigenvalue problem , whose analytical solutions are derived for a special class of projection operators . for general hermitian operators , a numerical implementation of entanglement tests is proposed . it is also shown how to identify bound entangled states with positive partial transposition . . And you have already written the first three sentences of the full article: entanglement is considered to be the key resource of the rapidly developing fields of quantum information processing and quantum computation , for an introduction see e.g. @xcite . among the early proposals concerning the applications of entangled states are those for quantum key distribution @xcite , quantum dense coding @xcite , and quantum teleportation @xcite . despite the resulting great interest in entangled quantum states , their complete characterization is still an unsolved problem .. Please generate the next two sentences of the article

it is known that entanglement can be fully identified by applying all positive but not completely positive ( pncp ) maps to a given state @xcite . the problem of this approach , however , consists in the fact that the general form of the pncp maps is essentially unknown . the presently best studied pncp map is the partial transposition ( pt ) @xcite .

Suppose that you have an abstract for a scientific paper: let @xmath0 be an irreducible shift of finite type ( sft ) of positive entropy , and let @xmath1 be its set of words of length @xmath2 . define a random subset @xmath3 of @xmath1 by independently choosing each word from @xmath1 with some probability @xmath4 . let @xmath5 be the ( random ) sft built from the set @xmath3 . for each @xmath6 and @xmath2 tending to infinity , we compute the limit of the likelihood that @xmath5 is empty , as well as the limiting distribution of entropy for @xmath5 . for @xmath4 near @xmath7 and @xmath2 tending to infinity , we show that the likelihood that @xmath5 contains a unique irreducible component of positive entropy converges exponentially to @xmath7 . these results are obtained by studying certain sequences of random directed graphs . this version of `` random sft '' differs significantly from a previous notion by the same name , which has appeared in the context of random dynamical systems and bundled dynamical systems . . . And you have already written the first three sentences of the full article: a shift of finite type ( sft ) is a dynamical system defined by finitely many local transition rules . these systems have been studied for their own sake @xcite , and they have also served as important tools for understanding other dynamical systems @xcite . each sft can be described as the set of bi - infinite sequences on a finite alphabet that avoid a finite list of words over the alphabet .. Please generate the next two sentences of the article

thus , there are only countably many sfts up to the naming of letters in an alphabet . for the sake of simplicity , we state our results in terms of sfts in the , even though we prove more general results in terms of sequences of directed graphs in the subsequent sections . let @xmath0 be a nonempty sft ( for definitions , see section [ sftpresentations ] ) .

Suppose that you have an abstract for a scientific paper: many molecular theories of nematic liquid crystals consider the constituent molecules as cylindrically symmetric . in many cases , this approximation may be useful . however the molecules of real nematics have lower symmetry . therefore a theory was developed ( mol . phys . 30 ( 1975 ) 1345 ) for an ensemble of such particles based upon a general expansion of the pairwise intermolecular potential together with the molecular field approximation . in this study , we would like to handle this molecular field theory by using tsallis thermostatistics which has been commonly used for a decade to study the physical systems . with this aim , we would like to investigate the dependence of the order parameters on temperature and would like to report the variation of the critical values of the order parameters at the transition temperature with the entropic index . pacs number(s ) : 05.20.-y , 05.70.-a , 61.30.cz , 61.30 . gd . keywords : tsallis thermostatistics , maier - saupe theory , nematic liquid crystals , non - cylindrically symmetrical molecules . . And you have already written the first three sentences of the full article: it is well known that an essential characteristic of compounds forming liquid crystals is the rod - like shape of their constituent molecules , with an high length to breadth ratio . therefore the molecules are supposed to be cylindrically symmetrical . for example , the ordering matrix which is often used to describe the partial alignment in a mesophase , contains only one independent element and this can be determined by some techniques [ 1 ] .. Please generate the next two sentences of the article

the fact that the molecular cylindrical symmetry is assumed is appealing to a statistical mechanician , because the pairwise anisotropic intermolecular potential required in any calculation is simple for such particles [ 2 ] . however the molecules , in fact , are lath - like and thus do not possess the high symmetry .

Suppose that you have an abstract for a scientific paper: we have studied the abundance of oxygen in the igm by analyzing , , , and pixel optical depths derived from a set of high - quality vlt and keck spectra of 17 qsos at @xmath0 . comparing ratios @xmath1 to those in realistic , synthetic spectra drawn from a hydrodynamical simulation and comparing to existing constraints on [ si / c ] places strong constraints on the ultraviolet background ( uvb ) model using weak priors on allowed values of [ si / o ] : for example , a quasar - only background yields [ si / o ] @xmath2 , highly inconsistent with the [ si / o ] @xmath3 expected from nucleosynthetic yields and with observations of metal - poor stars . assuming a fiducial quasar+galaxy uvb consistent with these constraints yields a primary result that [ o / c ] = 0.66 @xmath4 0.06 @xmath4 0.2 ; this result is sensitive to gas with overdensity @xmath5 . consistent results are obtained by similarly comparing @xmath6 and @xmath7 to simulation values , and also by directly ionization - correcting @xmath8 as function of @xmath9 into [ o / h ] as a function of density . subdividing the sample reveals no evidence for evolution , but low- and high-@xmath9 samples are inconsistent , suggesting either density - dependence of [ o / c ] or more likely prevalence of collisionally - ionized gas at high density . . And you have already written the first three sentences of the full article: the enrichment of the intergalactic medium ( igm ) with heavy elements has , over the past decade , become a key tool in understanding star and galaxy formation by providing a fossil record of metal formation and galactic feedback . absorption line spectroscopy has revealed , among other findings , that the low - density ( @xmath10 ) intergalactic medium ( igm ) , as probed by the ly@xmath11 forest and through , , , , , , and other transitions , is at least partly enriched at all redshifts and densities probed . in particular , recent studies indicate that : * when smoothed over large ( @xmath12 kpc ) scales , the abundance of carbon decreases as gas overdensity @xmath13 does and has a scatter of @xmath14dex at fixed density .. Please generate the next two sentences of the article

there is carbon in at least some gas at all densities down to at least the mean cosmic density , with the median carbon metallicity obeying [ c / h ] @xmath15 at @xmath16 ( schaye et al . 2003 , hereafter * ? ? ? * on smaller ( @xmath17 kpc ) scales the distribution of metals is less well known , but observations suggest that the metals may be concentrated in small , high - metallicity patches @xcite .

Suppose that you have an abstract for a scientific paper: this paper establishes the continuity of the path delay operators for _ dynamic network loading _ ( dnl ) problems based on the lighthill - whitham - richards model , which explicitly capture vehicle spillback . the dnl describes and predicts the spatial - temporal evolution of traffic flow and congestion on a network that is consistent with established route and departure time choices of travelers . the lwr - based dnl model is first formulated as a system of _ partial differential algebraic equations _ ( pdaes ) . we then investigate the continuous dependence of merge and diverge junction models with respect to their initial / boundary conditions , which leads to the continuity of the path delay operator through the _ wave - front tracking _ methodology and the _ generalized tangent vector _ technique . as part of our analysis leading up to the main continuity result , we also provide an estimation of the minimum network supply without resort to any numerical computation . in particular , it is shown that gridlock can never occur in a finite time horizon in the dnl model . ( 1,0)469 path delay operator , continuity , dynamic network loading , lwr model , spillback , gridlock . And you have already written the first three sentences of the full article: dynamic traffic assignment ( dta ) is the descriptive modeling of time - varying flows on traffic networks consistent with traffic flow theory and travel choice principles . dta models describe and predict departure rates , departure times and route choices of travelers over a given time horizon . it seeks to describe the dynamic evolution of traffic in networks in a fashion consistent with the fundamental notions of traffic flow and travel demand ; see @xcite for some review on dta models and recent developments . _ dynamic user equilibrium _ ( due ) of the open - loop type , which is one type of dta , remains a major modern perspective on traffic modeling that enjoys wide scholarly support .. Please generate the next two sentences of the article

it captures two aspects of driving behavior quite well : departure time choice and route choice @xcite . within the due model , travel cost for the same trip purpose is identical for all utilized route - and - departure - time choices . the relevant notion of travel cost is _ effective travel delay _ , which is a weighted sum of actual travel time and arrival penalties .

Suppose that you have an abstract for a scientific paper: current theoretical models for the outflows / jets from agn , x - ray binaries and young stellar objects involve large - scale magnetic fields threading an underlying accretion disk . we suggest that such a disk is subjected to warping instability and retrograde precession driven by magnetic torques associated with the outflow . the growth timescale for the disk warp and the precession period are of order the radial infall time of the disk . these effects may be relevant to jet precession and other variabilities observed in many systems . . And you have already written the first three sentences of the full article: collimated outflows / jets are produced from active galactic nuclei , compact stars in x - ray binaries , and young stellar objects ( ysos ) ( e.g. , krolik 1999 ; mirabel & rodriguez 1999 ; fender 2003 ; reipurth & bally 2001 ) . over the last two decades , evidence for jet precession in these systems has steadily increased . the clearest example is the galactic source ss 433 , whose jet direction varies with an approximate 164 day period ( margon 1984 ; eikenberry et al . the black hole binary gro j1655 - 40 shows jet precession with a period of 3 days ( tingay et al . 1995 ; hjellming & rupen 1995 ) .. Please generate the next two sentences of the article

the jets from the super soft source cal83 may be precessing with a period of @xmath0 days ( cowley et al . 1998 ) . in agns ,