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Suppose that you have an abstract for a scientific paper: many statistical data are imprecise due to factors such as measurement errors , computation errors , and lack of information . in such cases , data are better represented by intervals rather than by single numbers . existing methods for analyzing interval - valued data include regressions in the metric space of intervals and symbolic data analysis , the latter being proposed in a more general setting . however , there has been a lack of literature on the parametric modeling and distribution - based inferences for interval - valued data . in an attempt to fill this gap , we extend the concept of normality for random sets by lyashenko and propose a normal hierarchical model for random intervals . in addition , we develop a minimum contrast estimator ( mce ) for the model parameters , which we show is both consistent and asymptotically normal . simulation studies support our theoretical findings , and show very promising results . finally , we successfully apply our model and mce to a real dataset . . And you have already written the first three sentences of the full article: in classical statistics , it is often assumed that the outcome of an experiment is precise and the uncertainty of observations is solely due to randomness . under this assumption , numerical data are represented as collections of real numbers . in recent years , however , there has been increased interest in situations when exact outcomes of the experiment are very difficult or impossible to obtain , or to measure . the imprecise nature of the data thus collected is caused by various factors such as measurement errors , computational errors , loss or lack of information . under such circumstances and , in general , any other circumstances such as grouping and censoring ,. Please generate the next two sentences of the article

when observations can not be pinned down to single numbers , data are better represented by intervals . practical examples include interval - valued stock prices , oil prices , temperature data , medical records , mechanical measurements , among many others . in the statistical literature ,

Suppose that you have an abstract for a scientific paper: we have developed a quantitative , empirical method for estimating the age of type ia supernovae ( sne ia ) from a single spectral epoch . the technique examines the goodness of fit of spectral features as a function of the temporal evolution of a large database of sne ia spectral features . when a sn ia spectrum with good signal - to - noise ratio over the rest frame range 3800 to 6800 @xmath0 is available , the precision of a spectral feature age ( sfa ) is ( 1-@xmath1 ) @xmath2 1.4 days . sfa estimates are made for two spectral epochs of sn 1996bj ( z=0.574 ) to measure the _ rate _ of aging at high redshift . in the 10.05 days which elapsed between spectral observations , sn 1996bj aged 3.35 @xmath3 3.2 days , consistent with the 6.38 days of aging expected in an expanding universe and inconsistent with no time dilation at the 96.4% confidence level . the precision to which individual features constrain the supernova age has implications for the source of inhomogeneities among sne ia . . And you have already written the first three sentences of the full article: a beguiling prediction of an expanding universe is that distant objects will appear to age at a slower rate than nearby ones . type ia supernovae ( sne ia ) provide extragalactic clocks of unparalleled precision which are sufficiently luminous to reveal this remarkable phenomenon . while a few doubt that expansion alone causes cosmological redshifts ( e.g. , arp 1987 , 1994 ; arp et al . 1990 ; narlikar & arp 1993 ) , the conventional interpretation has only modest experimental verification ( sandage & perelmuter 1991 ) .. Please generate the next two sentences of the article

initial suggestions that time dilation might be seen in the photometric history of sne ia ( wilson 1939 ; rust 1974 ) have been confirmed with recent observations of high redshift sn ia light curves ( leibundgut et al . 1996 ; goldhaber et al . . specifically , leibundgut et al . (

Suppose that you have an abstract for a scientific paper: lipshitz , ozsvth and thurston defined a bordered heegaard floer invariant @xmath0 for 3-manifolds with two boundary components , including mapping cylinders for surface diffeomorphisms . we define a related invariant for certain 4-dimensional cobordisms with corners , by associating a morphism @xmath1 to each such cobordism between two mapping cylinders @xmath2 and @xmath3 . like the osvth - szab invariants of cobordisms between closed 3-manifolds , this morphism arises from counting holomorphic triangles on heegaard triples . we demonstrate that the homotopy class of the morphism @xmath4 only depends on the symplectic structure of the cobordism in question . . And you have already written the first three sentences of the full article: heegaard floer theory is a set of invariants for closed , connected 3-manifolds and cobordisms between them , with a related invariant for closed 4-manifolds @xcite . together these invariants form a @xmath5 dimensional topological quantum field theory ( tqft ) , meaning a functor from the cobordism category of 3-manifolds to , in this case , the category of graded abelian groups . + the construction of heegaard floer homology involves counting holomorphic curves associated to heegaard diagrams of 3-manifolds . specifically , given a 3-manifold @xmath6 with a genus @xmath7 heegaard diagram @xmath8 , the invariant @xmath9 is defined as the homology of a chain complex generated by g - tuples of intersection points between the @xmath10 and @xmath11 curves . in lipshitz reformulation @xcite , the differential arises from counts of rigid holomorphic curves in the symplectic manifold @xmath12 \times \mathbb{r}$ ] , with boundaries mapping to the lagrangian submanifolds @xmath13 and @xmath14 .. Please generate the next two sentences of the article

the maps associated to cobordisms arise from a similar construction , which uses heegaard triples to represent certain elementary cobordisms @xcite . + in 2008 , lipshitz , ozsvth and thurston @xcite developed bordered heegaard floer homology , which generalizes @xmath15 to parametrized riemann surfaces and to bordered 3-manifolds , meaning 3-manifolds with parametrized boundary . given two such 3-manifolds @xmath16 and @xmath17 , if the surfaces @xmath18 and @xmath19 have compatible parametrizations , then the bordered heegaard floer invariants for @xmath16 and @xmath17 may be combined to obtain @xmath9 , where @xmath6 is the 3-manifold defined by identifying the boundaries of @xmath16 and @xmath17 .

Suppose that you have an abstract for a scientific paper: we investigate electron transport across a complex oxide heterointerface of la@xmath0sr@xmath1mno@xmath2 ( lsmo ) on nb : srtio@xmath2 ( nb : sto ) at different temperatures . for this , we employ the conventional current - voltage method as well as the technique of ballistic electron emission microscopy ( beem ) , which can probe lateral inhomogeneities in transport at the nanometer scale . from current - voltage measurements , we find that the schottky barrier height ( sbh ) at the lsmo / nb : sto interface decreases at low temperatures accompanied by a larger than unity ideality factor . this is ascribed to the tunneling dominated transport caused by the narrowing of the depletion width at the interface . however , beem studies of such unbiased interfaces , do not exhibit sbh lowering at low temperatures , implying that this is triggered by the modification of the interface due to an applied bias and is not an intrinsic property of the interface . interestingly , the sbh at the nanoscale , as extracted from beem studies , at different locations in the device is found to be spatially homogeneous and similar both at room temperature and at low temperatures . our results highlight the application of beem in characterizing electron transport and their homogeneity at such unbiased complex oxide interfaces and yields new insights into the origin of the temperature dependence of the sbh at biased interfaces . . And you have already written the first three sentences of the full article: interfaces between complex oxides often exhibit unconventional transport properties normally unattainable in their individual constituents.@xcite epitaxial schottky interfaces involving oxide semiconductors have been investigated for their electrical transport both as a function of temperature and doping concentration of the semiconductor and are relevant for device applications.@xcite reliable methods employed to study transport properties are current - voltage ( i - v ) and capacitance - voltage ( c - v ) measurements and more recently the internal photoemission ( ipe ) @xcite technique . these studies have yielded new insights , that necessitate consideration of transport mechanisms beyond that commonly employed to describe electron transport in conventional ( non - oxide based ) schottky interfaces.@xcite the influence of interface states and interface dipoles @xcite , temperature and electric field dependence of the dielectric permittivity in complex oxides have to be incorporated for a complete description of the transport characteristics across such schottky interfaces.@xcite however , studies related to the homogeneity of the transport properties at such complex oxide interfaces , where competing electronic phases might coexist , are absent , primarily due to the limitations of the techniques used thus far . here , using the technique of ballistic electron emission microscopy , we investigate transport properties at different regions in a la@xmath0sr@xmath1mno@xmath2 ( lsmo)/nb doped srtio@xmath2 ( nb : sto ) heterostructure at the nanoscale and at different temperatures . we compare this with the current - voltage measurements performed on the same device at identical temperatures and find this to be significantly influenced by thermally activated tunneling across the interface .. Please generate the next two sentences of the article

this is associated with a narrowing of the depletion width , due to the applied electric field , which , otherwise broadens with decreasing temperature . this enhances the probability of tunneling dominated transport in current - voltage measurements , leading to an apparent decrease in the schottky barrier height at low temperatures and a greater than unity ideality factor in such schottky diodes . in beem ,

Suppose that you have an abstract for a scientific paper: we present sources selected from their wide - field infrared survey explorer ( wise ) colors that merit future observations to image for disks and possible exoplanet companions . introducing a weighted detection method , we eliminated the enormous number of specious excess seen in low signal to noise objects by requiring greater excess for fainter stars . this is achieved by sorting through the 747 million sources of the allwise database . in examining these dim stars , it can be shown that a non - gaussian distribution best describes the spread around the main - sequence polynomial fit function . using a gamma probability density function ( pdf ) , we can best mimic the main sequence distribution and exclude natural fluctuations in ir excess . with this new methodology we re - discover 25 ir excesses and present 14 new candidates . one source ( j053010.20 - 010140.9 ) , suggests a 8.40 @xmath0 0.73 au disk , a likely candidate for possible direct imagining of planets that are likely fully formed . although all of these sources are well within the current flux ratio limit of @xmath110@xmath2 ( wyatt 2008 ) , j223423.85 + 403515.8 shows the highest bolometric flux ratio ( @xmath3=0.0694 ) between disk and host star , providing a very good candidate for direct imaging of the circumstellar disk itself . in re - examining the kepler candidate catalog ( original study preformed by kennedy and wyatt 2012 ) , we found one new candidate that indicates disk like characteristics ( tyc 3143 - 322 - 1 ) . method : data analysis , protoplanetary disks , techniques : photometric , methods : statictial . And you have already written the first three sentences of the full article: circumstellar disks are created from the remnant material of stellar formation . young protostellar disks provide a method for distinguishing the age of its stellar host and help models converge in determining the exact mechanisms of planet formation . current models suggest most protoplanetary disks will photoevaporate within @xmath1 1 - 5 myr ( alexander et al 2006a , b ; owen et al .. Please generate the next two sentences of the article

this infancy in which the star has just begun fusion , but not yet shed its disk , is the key time in which planet formation occurs . finding stars within this narrow window of the stars lifetime , provides a further glimpse into the mysterious cause of planet formation . additional clues to planet formation have resulted from the many planetary systems with large dust disks ( kalas et al .

Suppose that you have an abstract for a scientific paper: cooling flows galaxies : nuclei galaxies : formation galaxies : jets galaxies : luminosity function in cuspy atmospheres , jets driven by supermassive black holes ( bhs ) offset radiative cooling . the jets fire episodically , but often enough that the cuspy atmosphere does not move very far towards a cooling catastrophe in the intervals of jet inactivity . the ability of energy released on the sub - parsec scale of the bh to balance cooling on scales of several tens of kiloparsecs arises through a combination of the temperature sensitivity of the accretion rate and the way in which the radius of jet disruption varies with ambient density . accretion of hot gas does not significantly increase bh masses , which are determined by periods of rapid bh growth and star formation when cold gas is briefly abundant at the galactic centre . hot gas does not accumulate in shallow potential wells . as the universe ages , deeper wells form , and eventually hot gas accumulates . this gas soon prevents the formation of further stars , since jets powered by the bh prevent it from cooling , and it mops up most cold infalling gas before many stars can form . thus bhs set the upper limit to the masses of galaxies . the formation of low - mass galaxies is inhibited by a combination of photo - heating and supernova - driven galactic winds . working in tandem these mechanisms can probably explain the profound difference between the galaxy luminosity function and the mass function of dark halos expected in the cold dark matter cosmology . [ firstpage ] . And you have already written the first three sentences of the full article: gravitational potential wells that are deep enough to trap gas hotter than @xmath0 can generally be detected in the thermal x - ray emission of the trapped gas . these potential wells range in size from those of massive elliptical galaxies through groups of galaxies to clusters of galaxies . as one proceeds down this sequence , the fraction of the system s baryons that are contained in the virial - temperature gas rises from @xmath1 to @xmath2 . the central cooling time @xmath3 is defined to be the ratio of the central energy density to the central luminosity density due to radiative cooling . in many ,. Please generate the next two sentences of the article

perhaps most , systems , @xmath3 is shorter than the hubble time . in the case of an elliptical galaxy such as ngc 4472 , @xmath4 , while in a cluster of galaxies such as hydra @xmath5 . hence , we must ask how these systems endure for times that greatly exceed @xmath3 . in the absence of heating , radiative losses cause the central density to rise inexorably as the central temperature falls .

Suppose that you have an abstract for a scientific paper: we report the discovery of a population of deeply embedded protostellar candidates in the 20 kms@xmath0 cloud , one of the massive molecular clouds in the central molecular zone ( cmz ) of the milky way , using interferometric submillimeter continuum and h@xmath1o maser observations . the submillimeter continuum emission shows five 1-pc scale clumps , each of which further fragments into several 0.1-pc scale cores . we identify 17 dense cores , among which 12 are gravitationally bound . among the 18 h@xmath1o masers detected , 13 coincide with the cores and probably trace outflows emanating from the protostars . there are also 5 gravitationally bound dense cores without h@xmath1o maser detection . in total the 13 masers and 5 cores may represent 18 protostars with spectral types later than b1 or potential growing more massive stars at earlier evolutionary stage , given the non - detection in the centimeter radio continuum . in combination with previous studies of ch@xmath2oh masers , we conclude that the star formation in this cloud is at an early evolutionary phase , before the presence of any significant ionizing or heating sources . our findings indicate that star formation in this cloud may be triggered by a tidal compression as it approaches pericenter , similar to the case of g0.253 + 0.016 but with a higher star formation rate , and demonstrate that high angular resolution , high sensitivity maser and submillimeter observations are a promising technique to unveil deeply embedded star formation in the cmz . . And you have already written the first three sentences of the full article: the inner 500-pc region of the galaxy , known as the central molecular zone ( cmz ) , is rich in dense molecular gas , but the current star formation is unusually inactive . other than the few star forming regions such as sgr b2 @xcite , sgr a complex @xcite , and sgr c @xcite , most cmz clouds appear to be inactive in star formation ( e.g. , g0.253 + 0.016 ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

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Suppose that you have an abstract for a scientific paper: the package cosmolib is a combination of a cosmological boltzmann code and a simulation toolkit to forecast the constraints on cosmological parameters from future observations . in this paper we describe the released linear - order part of the package . we discuss the stability and performance of the boltzmann code . this is written in newtonian gauge and including dark energy perturbations . in cosmolib the integrator that computes the cmb angular power spectrum is optimized for a @xmath0-by-@xmath0 brute - force integration , which is useful for studying inflationary models predicting sharp features in the primordial power spectrum of metric fluctuations . as an application , cosmolib is used to study the axion monodromy inflation model that predicts cosine oscillations in the primordial power spectrum . in contrast to the previous studies by aich _ et al _ and meerburg _ et al _ , we found no detection or hint of the osicllations . we pointed out that the camb code modified by aich _ et al _ does not have sufficient numerical accuracy . cosmolib and its documentation are available at http://www.cita.utoronto.ca/~zqhuang/cosmolib . . And you have already written the first three sentences of the full article: the hot big bang model and the cosmological perturbation theory , where the physical metric is perturbed around the spatially homogeneous and isotropic friedmann - robertson - walker ( frw ) metric @xcite , have led to a remarkable success in interpreting the plethora of observational data of the last two decades @xcite . observations of the temperature anisotropy in the cosmic microwave background ( cmb ) have been playing an essential role in building the standard cosmological model and measuring its parameters @xcite . in order to maximize the usage of the observational data , one would like to compute the theoretical prediction on the cmb anisotropy for a given model as accurately as possible , with tolerable time consumption .. Please generate the next two sentences of the article

computation tools developed over the years such as cmbfast @xcite , camb @xcite , cmbeasy @xcite and class @xcite are capable of computing a cmb angular power spectrum to percent - level accuracy within a few seconds on a modern desktop personal computer . the crucial technique used in all the fast cmb codes to date is the line - of - sight integration approach @xcite and an assumption that the primordial power spectrum of metric perturbations is smooth .

Suppose that you have an abstract for a scientific paper: we implement the elliptical gauss - laguerre ( egl ) galaxy - shape measurement method proposed by bernstein & jarvis ( 2002 ) [ @xcite ] and quantify the shear recovery accuracy in weak lensing analysis . this method uses a deconvolution fitting scheme to remove the effects of the point - spread function ( psf ) . the test simulates @xmath0 noisy galaxy images convolved with anisotropic psfs , and attempts to recover an input shear . the tests are designed to be immune to shape noise , selection biases , and crowding . the systematic error in shear recovery is divided into two classes , calibration ( multiplicative ) and additive , with the latter arising from psf anisotropy . at s / n @xmath1 , the deconvolution method measures the galaxy shape and input shear to @xmath2 multiplicative accuracy , and suppresses @xmath3 of the psf anisotropy . these systematic errors increase to @xmath4 for the worst conditions , with poorly resolved galaxies at s / n @xmath5 . the egl weak lensing analysis has the best demonstrated accuracy to date , sufficient for the next generation of weak lensing surveys . . And you have already written the first three sentences of the full article: weak gravitational lensing , the shearing of galaxy images by gravitational bending of light , is an effective tool to probe the large - scale matter distribution of the universe . it is also a means to measure the cosmological parameters by comparing observation to numerical simulations of large scale structure growth @xcite . there are many weak lensing ( wl ) surveys underway to obtain the cosmological parameters to higher precision , and in particular to probe the evolution of the dark energy by observing its effects on the evolution of matter distribution ( dls , cfhtls ) .. Please generate the next two sentences of the article

the wl signal is very subtle , however ; it is necessary to measure these small distortions ( typical shear @xmath6 ) in the presence of optical distortions and the asymmetric point - spread - function ( psf ) of real - life imaging . the level of systematic error in the wl measurement methods are currently above the statistical accuracy expected from future wide and deep wl surveys ( pan - starrs , snap , lsst , ska ) .

Suppose that you have an abstract for a scientific paper: we present a new derivation of the proof for the tcp / cpt theorem using the dynamical principle and variation of action methods first defined by schwinger in 1951 @xcite . this new proof will significantly extend the tcp theorem beyond the original proofs by pauli - lders and jost , which were significantly constrained by limits of free quantum fields and the asymptotic condition . this paper gives a more fundamental proof based on invariance of the variation of action with interactions included and no free field or asymptotic condition on the quantum fields . this new proof for tcp / cpt can now be applied to more complicated quantum field systems that include n - particle bound states and unstable states . . And you have already written the first three sentences of the full article: we present a new derivation of a proof of the tcp / cpt theorem using schwinger s extended action principle and green s function methods . sixty years ago , schwinger reformulated quantum field theory in terms of a generalized variation of action principle ( first defined in detail in @xcite ) , and showed how propagators and multiparticle green s functions can be derived from this action principle in @xcite , @xcite , and @xcite . schwinger first described the concept of `` strong reflection '' for tcp in relativistic quantum fields in @xcite .. Please generate the next two sentences of the article

he also described the critical connection between t inversion and c ( complex / charge ) conjugation in @xcite . t inversion reverses the sign in front of the action integral and c conjugation is required to counterbalance .

Suppose that you have an abstract for a scientific paper: gaia spectroscopic and radial velocity performancies are reviewed on the base of ground - based test observations and simulations . the prospects for accurate analysis of stellar atmospheres ( temperature , gravity , chemical abundances , rotation , peculiarities ) and precise radial velocities ( single stars , binaries , pulsating stars ) are colorful provided the spectral dispersion is high enough . a higher dispersions also favors a given precision of radial velocities to be reached at fainter magnitudes : for example , with current parameters for gaia spectrograph , a 1 km sec@xmath0 accuracy on epoch rvs of a k0 star is reached at @xmath113.0 mag with 0.25 / pix dispersion spectra , at @xmath110.3 mag for 0.5 / pix , and @xmath16.7 mag for 1 / pix . gaia radial velocities for single stars can match the @xmath20.5 km sec@xmath0 mean accuracy of tangential motions at @xmath3 mag , provided the observations are performed at a dispersion not less than 0.5 / pix . . And you have already written the first three sentences of the full article: the giant leap that gaia spectroscopy will lead us through can be sized by four basic considerations : ( @xmath4 ) gaia will record multi - epoch spectra for a magnitude complete sample of stars @xmath5 larger than any whole - sky existing database ( e.g. hd survey , progressing michigan project , etc . ) ; ( @xmath6 ) for each target , an average of 67 epoch spectra will be recorded over the five year mission lifetime ; ( @xmath7 ) the wavelength and flux calibrated spectra will be available in digital format to the community ; ( @xmath8 ) the foreseeable spectral dispersion ( 0.75 / pix are currently baselined ) is significantly higher that those of other whole - sky surveys . a review of gaia spectroscopy has already been presented by munari ( 1999a , hereafter m99a ) . we will consider here mainly updates to the content of m99a reflecting advancements in some areas over the last couple of years . therefore , to cope with the generous but limited amount of space available to this review in its printed format , basic physics and overall considerations developed in m99a will not be discussed here again .. Please generate the next two sentences of the article

technical aspects connected to spacecraft optical and mechanical assembly , telemetry budgets , modus operandi , limiting magnitudes etc . , are covered in the esa s _ gaia concept and technology study report _ ( esa - sci-2000 - 4 ) and in abridged format in perryman et al .

Suppose that you have an abstract for a scientific paper: we propose a new type of radiative neutrino model with a local dark @xmath0 symmetry where neutrino masses are induced at the three - loop level , and discuss the muon anomalous magnetic moment , and dark matter candidates therein . by allowing the hypercharges larger than 3/2 for new fields that contribute to the neutrino masses and making them decay into the standard model fields appropriately , we introduce a lot of new particles with multiple electrical charges in a natural manner . as a by - product , we can accommodate the 750 gev diphoton excess depending on the hypercharge quantum numbers of new fields responsible for the neutrino masses at the three - loop level . kias - p16018 . And you have already written the first three sentences of the full article: recently , the atlas and cms collaborations reported some excess around 750 gev in the observation of the diphoton invariant mass spectrum from the run - ii data at 13 tev @xcite . if confirmed , this could be a new particle @xmath1 with spin-0 or -2 and zero electric charge . these data also indicate that @xmath2 fb can explain the excess of diphoton events . therefore , @xmath1 should have sizable interaction with charged particles in order to have a sufficiently large branching fraction in the diphoton mode .. Please generate the next two sentences of the article

it implies that we have to improve the standard model ( sm ) by adding two types of particles at least : @xmath1 , and a new charged particle that interacts with @xmath1 , and producing @xmath3 through one loop diagram . along this line of thought , a large number of papers have recently been published ; see refs.@xcite .

Suppose that you have an abstract for a scientific paper: we show that expanding or contracting kasner universes are unstable due to the amplification of gravitational waves ( gw ) . as an application of this general relativity effect , we consider a pre - inflationary anisotropic geometry characterized by a kasner - like expansion , which is driven dynamically towards inflation by a scalar field . we investigate the evolution of linear metric fluctuations around this background , and calculate the amplification of the long - wavelength gw of a certain polarization during the anisotropic expansion ( this effect is absent for another gw polarization , and for scalar fluctuations ) . these gw are superimposed to the usual tensor modes of quantum origin from inflation , and are potentially observable if the total number of inflationary e - folds exceeds the minimum required to homogenize the observable universe only by a small margin . their contribution to the temperature anisotropy angular power spectrum decreases with the multipole @xmath0 as @xmath1 , where @xmath2 depends on the slope of the initial gw power - spectrum . constraints on the long - wavelength gw can be translated into limits on the total duration of inflation and the initial gw amplitude . the instability of classical gw ( and zero - vacuum fluctuations of gravitons ) during kasner - like expansion ( or contraction ) may have other interesting applications . in particular , if gw become non - linear , they can significantly alter the geometry before the onset of inflation . . And you have already written the first three sentences of the full article: the inflationary stage of the very early universe explains the dynamical origin of the observed isotropic and homogeneous frw geometry . the patch of the frw geometry covers the cosmological horizon and beyond if inflation lasted @xmath3 e - folds or longer . here @xmath4 is the potential energy of the inflation , and @xmath5 is a correction from the ( p)reheating stage after inflation , which is not essential for our discussion .. Please generate the next two sentences of the article

chaotic inflationary models , associated with a large energy ( @xmath6 gut scale ) of @xmath7gev , predict a very large number of inflationary e - folds , @xmath8 . long - lasting inflation erases all classical anisotropies and inhomogeneities of the pre - inflationary stage

Suppose that you have an abstract for a scientific paper: we present high resolution observations of the giant extragalactic regions ngc 604 , ngc 2363 , ngc 5461 and ngc 5471 , based on observations taken with the isis spectrograph on the william herschel telescope . we have detected -by the first time- c ii and o ii recombination lines in these objects . we find that recombination lines give larger c@xmath0 and o@xmath0 abundances than collisionallly excited lines , suggesting that temperature variations can be present in the objects . we detect [ ] lines in ngc 2363 and ngc 5471 , the most confident detection of optical lines of this kind in regions . considering the temperature structure we derive their h , he , c , n , o , ne , s , ar , and fe abundances . from the recombination lines of ngc 5461 and ngc 5471 we determine the presence of c / h and o / h gradients in m101 . we calculate the @xmath1/@xmath2 and @xmath1/@xmath3 values considering the presence of temperature variations and under the assumption of constant temperature . we obtain a better agreement with models of galactic chemical evolution by considering the presence of temperature variations than by assuming that the temperature is constant in these nebulae . . And you have already written the first three sentences of the full article: the analysis of the spectra of regions allows to determine the abundances of he , c , n , o , ne , s , ar and fe in the ionized phase of the interstellar medium . this is useful to trace the chemical evolution of the interstellar gas , to compute the radial abundance gradients in spiral galaxies and even to estimate the primordial helium abundance . due to the surface brightness of distant extragalactic regions it is possible to measure their line intensities with reasonable accuracy .. Please generate the next two sentences of the article

therefore , it is essential and feasible to have confident determinations of their chemical composition . the possibility to obtain deep spectra of regions with large telescopes allows us to detect and measure important faint emission lines . among these , recombination lines ( hereafter rls ) of heavy element ions are of special interest .

Suppose that you have an abstract for a scientific paper: following the idea of galois - type extensions and entwining structures , we define the notion of a principal extension of noncommutative algebras . we show that modules associated to such extensions via finite - dimensional corepresentations are finitely generated projective , and determine an explicit formula for the chern character applied to the thus obtained modules . 0.5 * rsum * 0.5nous nous inspirons des extensions de type galois et des structures enlaces pour dfinir la notion dextension principale dalgbres non commutatives . nous montrons que les modules associs de telles extensions au travers de coreprsentations de dimension finie sont projectifs et de type fini , et nous dterminons une formule explicite pour le caractre de chern appliqu aux modules ainsi obtenus . , . And you have already written the first three sentences of the full article: the aim of this paper is twofold . first we need to determine a class of galois - type extensions that are sufficiently general to accommodate interesting examples and sufficiently specific to derive a number of desired properties . this leads to the concept of principal extensions .. Please generate the next two sentences of the article

they play the role of algebraic analogues of principal bundles . to any such extension one can associate modules much as vector bundles are associated to principal bundles . for finite - dimensional corepresentations these modules

Suppose that you have an abstract for a scientific paper: metal - insulator transition in ca@xmath0li@xmath1pd@xmath2o@xmath3 has been studied through charge transport measurements . the resistivity , the seebeck coefficient , and the hall coefficient are consistently explained in terms of a simple one - band picture , where a hole with a moderately enhanced mass is itinerant three - dimensionally . contrary to the theoretical preditcion [ phys . rev . b62 , 13426 ( 2000 ) ] , capd@xmath2o@xmath3 is unlikely to be an excitonic insulator , and holds a finite carrier concentration down to 4.2 k. thus the metal - insulator transition in this system is basically driven by localization effects . . And you have already written the first three sentences of the full article: a metal - insulator transition is one of the most important topics in solid - state physics @xcite . in case of a conventional semiconductor , donors ( acceptors ) supply electrons ( holes ) in a band insulator . a metal - insulator transition takes place at a critical carrier density , where the average carrier - carrier distance is comparable with the effective bohr radius of the doped impurity atom . the critical carrier density has been quantitatively discussed for various semiconductors @xcite .. Please generate the next two sentences of the article

metal - insulator transitions in strongly correlated systems are completely different from that in a band insulator @xcite . the most remarkable example is that in high - temperature superconductors , where the metallic state is accompanied by high temperature superconductivity .

Suppose that you have an abstract for a scientific paper: we investigate the distributions of the link overlap , @xmath0 , in 3-dimensional ising spin glasses . we use clustering methodology to identify a set of pairs of states from different gibbs states , and calculate its contribution to @xmath0 . we find that the distribution over this set does not become trivial as the system size increases . . And you have already written the first three sentences of the full article: while equilibrium properties of infinite range spin glasses @xcite are completely understood within the framework of replica symmetry breaking ( rsb ) @xcite , spin glasses with short range interactions are the subject of considerable current debate and controversy . open questions address the nature of the low temperature phases @xcite and their theoretical description . resolution of these issues by experiments or simulations is hindered by the extremely long relaxation time required for equilibration .. Please generate the next two sentences of the article

the the edwards - anderson model is the most widely studied type of short - range ising spin glass @xmath1 where the sum is over nearest neighbor sites , @xmath2 , of a simple ( hyper ) cubic lattice with periodic boundary conditions , @xmath3 , and the couplings , @xmath4 , are independent random variables taken from a normal distribution with zero average and standard deviation @xmath5 . for the infinite range sherington kirkpatrick ( sk ) model the sum in eq .

Suppose that you have an abstract for a scientific paper: we present infrared photometry of the episodic dust - making wolf - rayet system wr19 ( ls3 ) , tracking its fading from a third observed dust - formation episode in 2007 and strengthening the view that these episodes are periodic ( @xmath0 ) . radial velocities of the o9 component observed between 2001 and 2008 show rv variations consistent with wc19 being a spectroscopic binary of high eccentricity ( @xmath1 ) , having periastron passage in 2007.14 , shortly before the phase of dust formation . in this respect , wr19 resembles the archetypical episodic dust - making colliding - wind binary system wr140 . [ firstpage ] stars : wolf - rayet binaries : spectroscopic stars : circumstellar matter infrared : stars stars : individual : wr19 . . And you have already written the first three sentences of the full article: the dense , supersonic winds that give wr stars their characteristic emission - line spectra carry significant mass loss ( @xmath2 m@xmath3y@xmath4 ) and kinetic energy ( @xmath5 l@xmath6 ) . the release of some of this energy from the collision of such a wind with that of a massive companion in a colliding - wind binary ( cwb ) system gives rise to a range of theoretically predicted ( x - ray emission ) and unpredicted ( non - thermal radio emission and dust formation ) phenomena . the association of dust formation with colliding winds began with the demonstration that the 2900-d periodic dust formation episodes by the archetypal wolf - rayet colliding - wind binary wr140 occurred during periastron passages of its highly eccentric orbit ( williams et al .. Please generate the next two sentences of the article

the high densities ( 10@xmath7 10@xmath8 times that of the undisturbed wolf - rayet wind ) required for dust formation to occur can be produced in colliding - wind shocks if they cool efficiently ( usov 1991 ) . the link between the dust - formation episodes and binary orbit in wr140 is provided by periodic increases of the _ pre - shock _ wind density by a factor of @xmath9 40 for a brief time during periastron passage when the separation of the wc7 and o5 stars is at a minimum ( williams 1999 ) .

Suppose that you have an abstract for a scientific paper: first principles calculations are used to investigate the effects of epitaxial strain on the structure of the perovskite oxide catio@xmath0 , with particular focus on the stabilization of a ferroelectric phase related to a polar instability hidden in the orthorhombic equilibrium bulk @xmath1 structure but found in previous first - principles studies of the ideal cubic perovskite high - symmetry reference structure . at 1.5% strain , we find an epitaxial orientation transition between the @xmath2-@xmath3 phase , favored for compressive strains , and the @xmath4-@xmath3 phase . for larger tensile strains , a polar instability develops in the @xmath4-@xmath3 phase and an epitaxial - strain - induced ferroelectric phase is obtained with polarization along a @xmath5110@xmath6 direction with respect to the primitive perovskite lattice vectors of the square substrate . with the recent dramatic advances in the synthesis of coherent epitaxial films of complex oxides @xcite , it is possible to maintain extremely high strains in thin film materials , often as much as 23% . in some materials , such high strains can drive the system through a structural phase boundary to a novel phase with structure and properties distinct from those of the bulk equilibrium phase . first principles calculations can provide quantitative predictions about these novel phases and phase boundaries ; in particular , such phases can be identified from examination of the lattice instabilities of the high - symmetry reference structure of the bulk phase @xcite , and their structure and properties predicted . a prototypical example is strain - induced ferroelectricity in srtio@xmath0 . starting from the bulk equilibrium paraelectric phase , strain - polarization coupling results in a polar instability beyond critical values of both tensile and compressive ( 001 ) epitaxial strain . this behavior was predicted by landau theory @xcite and further analyzed in first principles investigations @xcite . experimental observation of.... And you have already written the first three sentences of the full article: we would like to thank m. h. cohen , v. gopalan , d. r. hamann , d. g. schlom , and d. vanderbilt for useful discussions . this work was supported by nsf mrsec dmr-0820404 and onr n00014 - 09 - 1 - 0302 . k. m. r. would also like to thank the aspen center for physics , where part of this work was carried out .. Please generate the next two sentences of the article

99 d. g. schlom , l. q. chen , c. b. eom , k. m. rabe , s. k. streiffer and j. m. triscone , ann . rev . mat .

Suppose that you have an abstract for a scientific paper: kalman filters and observers are two main classes of dynamic state estimation ( dse ) routines . power system dse has been implemented by various kalman filters , such as the extended kalman filter ( ekf ) and the unscented kalman filter ( ukf ) . in this paper , we discuss two challenges for an effective power system dse : ( a ) model uncertainty and ( b ) potential cyber attacks . to address this , the cubature kalman filter ( ckf ) and a nonlinear observer are introduced and implemented . various kalman filters and the observer are then tested on the 16-machine , 68-bus system given realistic scenarios under model uncertainty and different types of cyber attacks against synchrophasor measurements . it is shown that ckf and the observer are more robust to model uncertainty and cyber attacks than their counterparts . based on the tests , a thorough qualitative comparison is also performed for kalman filter routines and observers . cubature kalman filter , cyber attack , dynamic state estimation , extended kalman filter , model uncertainty , observer , phasor measurement unit ( pmu ) , unscented kalman filter . . And you have already written the first three sentences of the full article: estimation is a crucial application in the energy management system ( ems ) . the well - known static state estimation ( sse ) methods @xcite assume that the power system is operating in quasi - steady state , based on which the static states the voltage magnitude and phase angles of the buses are estimated by using scada and/or synchrophasor measurements . sse is critical for power system monitoring as it provides inputs for other ems applications such as automatic generation control and optimal power flow .. Please generate the next two sentences of the article

however , sse may not be sufficient for desirable situational awareness as the system states evolve more rapidly due to an increasing penetration of renewable generation and distributed energy resources . therefore , dynamic state estimation ( dse ) processes estimating the dynamic states ( i.e. , the internal states of generators ) by using highly synchronized pmu measurements with high sampling rates will be critical for the wide - area monitoring , protection , and control of power systems . for both sse and dse

Suppose that you have an abstract for a scientific paper: a commercially available calorimeter has been used to investigate the specific heat of a high - quality k@xmath0na@xmath1fe@xmath2as@xmath2 single crystal . the addenda heat capacity of the calorimeter is determined in the temperature range @xmath3 . the data of the k@xmath0na@xmath1fe@xmath2as@xmath2 crystal imply the presence of a large @xmath4 contribution to the specific heat which gives evidence of @xmath5-wave order parameter symmetry in the superconducting state . to improve the measurements , a novel design for a calorimeter with a paramagnetic temperature sensor is presented . it promises a temperature resolution of @xmath6 and an addenda heat capacity less than @xmath7 at @xmath8 . . And you have already written the first three sentences of the full article: specific - heat studies down to very low temperatures provide insight into low - energy excitations of the electronic , phononic , or magnetic subsystems of solids @xcite . being directly linked to the entropy changes , i.e. @xmath9 , the specific heat @xmath10 is a valuable tool to study such excitations as well as phase transitions . one example is the onset of superconductivity in bcs superconductors where a specific heat jump @xmath11@xmath12 appears at @xmath12 ( @xmath13 is the sommerfeld coefficient ) .. Please generate the next two sentences of the article

well below @xmath12 , the specific heat gives direct access to the entropy of cooper - pair breaking and in bcs superconductors it exponentially depends on the isotropic gap @xmath14 . to be more general , the specific heat measures the gap magnitude and structure and provides information on the pairing mechanism . noteworthy , being a thermodynamic quantity the specific heat is sensitive to bulk properties which is in contrast to rather surface - sensitive methods such as arpes or stm . in this work

Suppose that you have an abstract for a scientific paper: a simple multipole pomeron and odderon model for elastic hadron scattering , reproducing the structure of the first and second diffraction cones is used to analyze @xmath0 and @xmath1 scattering . the main emphasis is on the delicate and non - trivial dynamics in the dip - bump region , at @xmath2 gev@xmath3 and at the second cone . the simplicity of the model and the expected smallness of the absorption corrections enables one the control of various contributions to the scattering amplitude , in particular the interplay between the c - even and c - odd components of the amplitude , as well as their relative contribution , changing with @xmath4 and @xmath5 . the role of the non - linearity of the regge trajectories is verified . a detailed analysis of the lhc energy region , where most of the exiting models may be either confirmed or ruled out , is presented . = 0.3 cm 0.5 cm * indirect evidence of the odderon from the lhc data on elastic proton - proton scattering * 0.3 cm a.i . lengyel @xmath6 , z.z . tarics @xmath7 _ institute of electron physics , nat . ac . sc . of ukraine , _ 0.1 cm @xmath8 0.1 cm . And you have already written the first three sentences of the full article: the long - standing debate about the existence of the odderon ( @xmath9-odd partner of the pomeron ) can be resolved definitely only by a high - energy experiment involving particle and anti - particle scattering , e.g. @xmath0 and @xmath10 scattering , in the same kinematical region . there was a single experiment of that kind , at the isr @xcite , where the two cross sections were found to differ . the unique observation , however relies on a few data points only , and isr was shut down shortly after that experiment , leaving some doubts on the validity of the effect .. Please generate the next two sentences of the article

moreover , the isr energies were not high enough to exclude the alternative explanation of the difference , namely due to @xmath11 exchange still noticeable at the isr in the region of the dip . this is not the case at the lhc , where the contribution from secondary trajectories can be practically excluded within the diffraction cone region . waiting for a possible future upgrade of the lhc energy down to that of the tevatron , which will enable a direct confrontation of @xmath0 and @xmath10 data ,

Suppose that you have an abstract for a scientific paper: we model the normal state of ferromagnetic superconductors with two general ellipsoidal fermi surfaces ( fss ) , one for each spin projection @xmath0 , each with its ferromagnetically split chemical potential @xmath1 and its three distinct single particle effective masses , @xmath2 , the geometric mean of which is @xmath3 . we study this model in the presence of an arbitrarily oriented magnetic induction , @xmath4 , where @xmath5 includes the ising - like spontaneous ferromagnetic order , which for urhge is in the @xmath6-axis direction above the superconducting transition temperature @xmath7 . in analogy to the sommerfeld low - temperature @xmath8 expansion with @xmath9 , we assume the low-@xmath8 total particle density @xmath10 to be independent of @xmath11 , and obtain a self - consistent asymptotic expansion for @xmath12 in even powers of @xmath11 , where @xmath13 . we assume that the @xmath14 are linear in @xmath11 for both spins due to the zeeman interaction and that the remaining even @xmath11 dependence in the @xmath15 arises only from @xmath16 . an analogous procedure leads to an asymptotic expansion in even powers of @xmath11 for the linear @xmath8-coefficient , @xmath17 , of the low-@xmath8 specific heat @xmath18 . our expression for @xmath17 leads to good fits to the @xmath19 data of aoki and flouquet [ j. phys . . jpn . * 81 * , 011003 ( 2012 ) ] obtained for the ferromagnetic superconductor urhge in the ferromagnetic , non - superconducting phase , with the applied magnetic field @xmath20 along each of the three crystallographic directions . we discuss this model in terms of the reentrant superconducting properties of urhge and ucoge . this model can be generalized to an arbitrary number of ellipsoidal fss . recent discoveries of heavy fermion superconducting materials such as uge@xmath21 @xcite , ucoge @xcite , and urhge @xcite in which there is simultaneous ferromagnetic and superconducting order , have sparked renewed interest in the field of @xmath22-wave superconductivity.... And you have already written the first three sentences of the full article: we developed a model of the normal state of ferromagnetic superconductors consisting of two general ellipsoidal fermi surfaces for the @xmath145 spin states that are ferromagnetically split in the presence of an arbitrarily oriented magnetic induction @xmath75 , which includes the spontaneous magnetization @xmath76 . by applying the klemm - clem transformations on each fermi surface separately , the problem was mapped onto one with two spherical fermi surfaces with @xmath146 on each fs pointing along the crystal @xmath147-axis direction . we calculated the linear @xmath8-coefficient of the specific heat , @xmath148 , and obtained good fits to the experimental data of aoki and flouquet for urhge .. Please generate the next two sentences of the article

this model can be generalized to any number of ellipsoidal fermi surfaces . our results are expected to provide information crucial for the investigation of the high - field reentrant phase of the very strong candidate parallel - spin ferromagnetic superconductor urhge . in particular

Suppose that you have an abstract for a scientific paper: using a full implementation of resummed perturbation theory ( pt ) from a multi - point propagator expansion , we put forward new theoretical predictions for the two - point statistics of matter fluctuations in redshift space . the predictions consistently include pt corrections up to the two - loop order and are based on an improved prescription of the redshift - space distortions ( rsd ) that properly takes into account their non - gaussian impact from a systematic low-@xmath0 expansion . in contrast to the previous studies that partly used standard pt calculations , the present treatment is able to provide a consistent prediction for both power spectra and correlation functions . these results are compared with @xmath1-body simulations with which a very good agreement is found up to the quadrupole moment . the theoretical predictions for the hexadecapole moment of the power spectra are however found to significantly departs from the numerical results at low redshift . we examine this issue and found it to be likely related to an improper modeling of the rsd damping effects on which this moment shows large dependence . . And you have already written the first three sentences of the full article: the large - scale structure of the universe observed via galaxy redshift surveys appears distorted due to the peculiar velocity of galaxies , known as the redshift - space distortions ( rsd ) ( e.g. , @xcite ) . the rsd breaks the statistical isotropy , and the resultant galaxy clustering exhibits characteristic anisotropies along observer s line - of - sight direction by the two competitive effects , i.e. , kaiser and finger - of - god effects @xcite . while the latter effect mostly comes from the virialized random motion of the mass ( or galaxy ) in halos , the kaiser effect apparently enhances the clustering amplitude along a line - of - sight direction , and the effect is dominated by the large - scale coherent motion . in particular , the strength of the kaiser effect is simply described by the linear theory , and is characterized by the growth - rate parameter , @xmath2 , defined as @xmath3 , where the quantities @xmath4 and @xmath5 are the linear growth factor and scale factor of the universe , respectively ( e.g. , @xcite ) .. Please generate the next two sentences of the article

thus , the kaiser effect can be used as a useful tool to measure the growth of cosmological structure , and combining the distance measurements , the measurement of rsd offers a unique opportunity to test the gravity theory on cosmological scales ( e.g. , @xcite ) . note that the galaxy redshift surveys also provide a way to measure the cosmological distance , utilizing the so - called alcock - paczynski effect @xcite . with the baryon acoustic oscillations ( baos ) imprinted on the large - scale structure as a robust standard ruler , we can thus measure the angular diameter distance @xmath6 and the hubble parameter @xmath7 of distant galaxies at redshift @xmath8 separately through the alcock - paczynski effect ( e.g. , @xcite ) .

Suppose that you have an abstract for a scientific paper: we study ensembles of globally coupled , nonidentical phase oscillators subject to correlated noise , and we identify several important factors that cause noise and coupling to synchronize or desychronize a system . by introducing noise in various ways , we find a novel estimate for the onset of synchrony of a system in terms of the coupling strength , noise strength , and width of the frequency distribution of its natural oscillations . we also demonstrate that noise alone is sufficient to synchronize nonidentical oscillators . however , this synchrony depends on the first fourier mode of a phase - sensitivity function , through which we introduce common noise into the system . we show that higher fourier modes can cause desychronization due to clustering effects , and that this can reinforce clustering caused by different forms of coupling . finally , we discuss the effects of noise on an ensemble in which antiferromagnetic coupling causes oscillators to form two clusters in the absence of noise . . And you have already written the first three sentences of the full article: synchronization describes the adjustment of rhythms of self - sustained oscillators due to their interaction @xcite . such collective behavior has important ramifications in myriad natural and laboratory systems ranging from conservation and pathogen control in ecology @xcite to applications throughout physics , chemistry , and engineering @xcite . numerous studies have considered the effects of coupling on synchrony using model systems such as kuramoto oscillators @xcite . in a variety of real - world systems , including sets of neurons @xcite and ecological populations @xcite , it is also possible for synchronization to be induced by noise . in many such applications. Please generate the next two sentences of the article

, one needs to distinguish between extrinsic noise common to all oscillators ( which is the subject of this paper ) and intrinsic noise , which affects each oscillator separately . consequently , studying oscillator synchrony can also give information about the sources of system noise @xcite .

Suppose that you have an abstract for a scientific paper: we present hst / wfpc2 high - spatial resolution images in the @xmath0 and @xmath1 bands of the close environment of the sightlines to seven quasars which spectra show either a damped absorption line , 21 cm absorption , or a very strong / absorption system at intermediate redshifts ( @xmath2 ) . objects down to about 0.3 , or 2.0 kpc at @xmath3 ( @xmath4 kms s@xmath5 mpc@xmath5 , @xmath6 ) , and to a limiting magnitude @xmath7 could be detected for seven fields comprising eight absorbers ( one at higher redshift @xmath8 = 1.78 towards mc 1331 + 170 ) with high column densities of at least @xmath9 @xmath10 . in each case , a candidate absorber with absolute magnitude @xmath11 or much brighter has been detected . this small sample of gas - rich galaxies at intermediate redshifts covers a wide range in morphological types . there are three spiral galaxies of various sizes and luminosities ( towards 3c 196 , q 1209 + 107 and mc 1331 + 170 ) , three compact objects ( towards ex 0302@xmath12223 , pks 0454 + 039 and , at high redshift , mc 1331 + 170 ) , and two amorphous , low surface brightness galaxies ( towards pks 1229@xmath12021 and 3c 286 ) . in the fields around 3c 196 , pks 1229@xmath12021 and q 1209 + 107 , there is an excess of galaxies in the pc2 images , suggestive of the presence of a group of galaxies associated with the damped absorber , or maybe with the quasar itself for the two @xmath13 1.0 cases . for 3c 196 and 3c 286 , the quasar host galaxies have also tentatively been discovered . we do not detect any quasar multiple images , implying no large amount of dark matter around the damped absorbers . this survey also led to the discovery of the first @xmath14 1.0 optical counterpart of a quasar radio jet ( pks 1229@xmath12021 ) . as will be reported elsewhere ( boiss et al . 1996 ) , spectroscopy with the hst - fos of the strong / absorption systems confirms the validity of our selection criterion in predicting the existence of damped systems.... And you have already written the first three sentences of the full article: metal - rich absorption line systems ( and , damped and 21 cm systems ) are a very powerful tool for studying the statistical properties of high - redshift young galaxies , otherwise very difficult to detect directly , but it must be ascertained which kind of population does indeed probe each type of system . the large column density absorbers giving rise to high - redshift damped absorption lines in quasar spectra are generally assumed to trace proto - galactic disks ( wolfe et al . 1986 ) , whereas absorptions at intermediate redshifts trace the gaseous halos of luminous field galaxies ( bergeron & boiss 1991 , thereafter bb91 ; steidel 1993 ) with typically radii of the order of @xmath15 kpc ( where @xmath16 is the hubble constant in units of 50 mpc@xmath5 , and using @xmath6 ) .. Please generate the next two sentences of the article

the main arguments that have led to associate the damped systems ( dlas ) with the progenitors of present - day gas - rich galaxies are related to their mass density ( wolfe 1987 ) and to their metal content ( pettini et al . 1994 ) . nevertheless , the population producing the damped absorption lines is not yet unambiguously identified since the systems detected in the optical range are at too high redshifts ( @xmath17 ) to easily detect the absorber by its emission , both because of its apparent faintness and its proximity to the quasar image .

Suppose that you have an abstract for a scientific paper: results are presented of the spin - parity analysis on a sample of centrally produced mesons in the reaction @xmath0 with 800 gev protons on liquid hydrogen . the spin - parity analysis in the mass region between threshold and 1.58 gev/@xmath1 shows that the @xmath2 system is produced mainly in @xmath3 wave . the @xmath4 is clearly observed in this region . above 1.58 gev/@xmath1 two solution are possible , one with mainly @xmath3 wave and another with mainly @xmath5 wave . this ambiguity prevents a unique determination of the spin of the @xmath6 meson . . And you have already written the first three sentences of the full article: the first evidence of the central production of @xmath4 in the reaction @xmath7 is presented here . the @xmath4 was first observed in @xmath8 @xcite interactions and beautifully confirmed in low energy @xmath9 annihilations by the crystal barrel collaboration @xcite . its properties are of current interest because it is considered a candidate to be the lowest lying glueball state @xcite .. Please generate the next two sentences of the article

one of the advantages of the final state selected is that only states with quantum numbers @xmath10 are allowed to decay into @xmath2 . this not only greatly simplifies the analysis but eliminates confusion coming from all the other states .

Suppose that you have an abstract for a scientific paper: we discuss production of two pairs of @xmath0 within a simple formalism of double - parton scattering ( dps ) . surprisingly very large cross sections , comparable to single - parton scattering ( sps ) contribution , are predicted for lhc energies . both total inclusive cross section as a function of energy and differential distributions for @xmath1 are shown . we discuss a perspective how to identify the double scattering contribution . . And you have already written the first three sentences of the full article: it is commonly believed that gluon - gluon fusion is the dominant mechanism of @xmath2 or @xmath3 production at high energies . then in leading - order ( lo ) approximation the differential cross section for the single - parton scattering ( sps ) production of heavy quark and heavy antiquark pair reads : @xmath4 where longitudinal momentum fractions can be calculated from kinematical variables of final quark and antiquark as : @xmath5 , @xmath6 with @xmath7 s being quark ( antiquark ) rapidities and @xmath8 being a quark ( antiquark ) transverse mass . we have limited here to gluon - gluon fusion only which is the dominant mechanism at high energies .. Please generate the next two sentences of the article

the quark - antiquark annihilation plays some role only close to the kinematical threshold and/or large rapidities . in general , the higher - order corrections do not change most of observables leading to a rough renormalization of the cross section by the so - called @xmath9 factor . in the present paper we wish to estimate the contribution of double - parton scatterings ( dps ) .

Suppose that you have an abstract for a scientific paper: we compute q - holonomic formulas for the homfly polynomials of 2-bridge links colored with one - column ( or one - row ) young diagrams . = 1 . And you have already written the first three sentences of the full article: the colored homfly polynomial is an invariant of framed , oriented links @xmath0 in @xmath1 whose components are colored with young diagrams ( or alternatively partitions of integers ) . it takes values in the ring @xmath2(q)$ ] . in this note we mostly consider colorings by one - column young diagrams , i.e. partitions of the form @xmath3 and refer to them as @xmath4-colorings .. Please generate the next two sentences of the article

let @xmath0 be a framed , oriented link with components numbered @xmath5 . let @xmath6 be the colored homfly polynomial of @xmath0 with coloring @xmath7 on the @xmath8 component .

Suppose that you have an abstract for a scientific paper: we introduce the statistical asynchronous regression ( sar ) method : a technique for determining a relationship between two time varying quantities without simultaneous measurements of both quantities . we require that there is a time invariant , monotonic function y = u(x ) relating the two quantities , y and x. in order to determine u(x ) , we only need to know the statistical distributions of x and y. we show that u(x ) is the change of variables that converts the distribution of x into the distribution of y , while conserving probability . we describe an algorithm for implementing this method and apply it to several example distributions . we also demonstrate how the method can separate spatial and temporal variations from a time series of energetic electron flux measurements made by a spacecraft in geosynchronous orbit . we expect this method will be useful to the general problem of spacecraft instrument calibration . we also suggest some applications of the sar method outside of space physics . igpp publication no . . And you have already written the first three sentences of the full article: we developed the statistical asynchronous regression ( sar ) technique described in this paper as part of a study of relativistic electron conditions at geosynchronous orbit . this part of the earth s radiation belts can evolve on a timescale of hours or even minutes . unfortunately , while individual satellites may make measurements every few seconds , it is difficult to separate the temporal changes from consequences of orbital motion . the easiest way to do. Please generate the next two sentences of the article

this would be to have continuous measurements at a fixed location , or local time , such as local noon . instead , we have continuous measurements on board moving spacecraft .

Suppose that you have an abstract for a scientific paper: we present @xmath0-band scattered light imaging of a bright debris disk around the a0 star hd 36546 obtained from the subaru coronagraphic extreme adaptive optics ( scexao ) system with data recorded by the hiciao camera using the vector vortex coronagraph . scexao traces the disk from @xmath1 @xmath2 03 to @xmath1 @xmath2 1 ( 34114 au ) . the disk is oriented in a near east - west direction ( pa @xmath2 75@xmath3 ) , is inclined by @xmath4 @xmath2 7075@xmath3 and is strongly forward - scattering ( @xmath5 @xmath6 0.5 ) . it is an extended disk rather than a sharp ring ; a second , diffuse dust population extends from the disk s eastern side . while hd 36546 intrinsic properties are consistent with a wide age range ( @xmath7 @xmath2 1250 @xmath8 ) , its kinematics and analysis of coeval stars suggest a young age ( 310 @xmath8 ) and a possible connection to taurus - auriga s star formation history . scexao s planet - to - star contrast ratios are comparable to the first - light _ gemini planet imager _ contrasts ; for an age of 10 @xmath8 , we rule out planets with masses comparable to hr 8799 b beyond a projected separation of 23 au . a massive icy planetesimal disk or an unseen superjovian planet at @xmath1 @xmath6 20 au may explain the disk s visibility . the hd 36546 debris disk may be the youngest debris disk yet imaged , is the first newly - identified object from the now - operational scexao extreme ao system , is ideally suited for spectroscopic follow up with scexao / charis in 2017 , and may be a key probe of icy planet formation and planet - disk interactions . . And you have already written the first three sentences of the full article: cold debris disks around nearby , young stars offer a reference point for the formation and evolution of the kuiper belt and provide evidence for unseen planets @xcite . debris disk luminosities are highest at the youngest ages ( 530 @xmath8 ) around stars more massive than the sun ; the luminosity of these debris disks may trace debris production from collisions between boulder - sized planetsimals as a byproduct of icy planet formation . unseen massive planets may also dynamically stir icy planetesimals to make debris disks visible and sculpt debris disks .. Please generate the next two sentences of the article

resolved images of debris disks probe icy planet formation and reveal evidence for hidden planets @xcite . in some cases , planets stirring debris disks were subsequently imaged ; the properties of the debris disks help constrain the masses of planets ( e.g. * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: we present a map and an angular power spectrum of the anisotropy of the cosmic microwave background ( cmb ) from the first flight of maxima . maxima is a balloon - borne experiment with an array of 16 bolometric photometers operated at 100 mk . maxima observed a 124 deg@xmath0 region of the sky with 10 resolution at frequencies of 150 , 240 and 410 ghz . the data were calibrated using in - flight measurements of the cmb dipole anisotropy . a map of the cmb anisotropy was produced from three 150 and one 240 ghz photometer without need for foreground subtractions . analysis of this cmb map yields a power spectrum for the cmb anisotropy over the range @xmath1 . the spectrum shows a peak with an amplitude of @xmath2 @xmath3 at @xmath4 and an amplitude varying between @xmath5 @xmath3 and @xmath6 @xmath3 for @xmath7 . . And you have already written the first three sentences of the full article: measurements of the anisotropy of the cosmic microwave background ( cmb ) can discriminate between cosmological models and determine cosmological parameters with high accuracy ( * ? ? ? * and references therein ) . inflationary dark matter models , for example , predict a series of peaks in the angular power spectrum of the anisotropy . the collected results from many experiments show the existence of a first peak at angular scales corresponding to the spherical harmonic multipole number @xmath8 .. Please generate the next two sentences of the article

these results have been interpreted as evidence for a flat universe @xcite . additional observations probing a broad range of angular scales would greatly increase confidence in these results and further constrain cosmological parameters .

Suppose that you have an abstract for a scientific paper: nighttime visible - light sky brightness and transparency are reported for the polar environment research laboratory ( pearl ) , located on a 610-m high ridge near the eureka research station , on ellesmere island , canada . photometry of polaris obtained in @xmath0 band with the pearl all sky imager ( pasi ) over two winters is supported by standard meteorological measurements and visual estimates of sky conditions from sea level . these data show that during the period of the study , october through march of 2008/09 and 2009/10 , the sky near zenith had a mean surface brightness of @xmath1 when the sun was more than @xmath2 below the horizon , reaching @xmath3 during astronomical darkness with no moon . skies were without thick cloud and potentially usable for astronomy 86% of the time ( extinction @xmath4 mag ) . up to 68% of the time was spectroscopic ( @xmath5 mag ) , attenuated by ice crystals , or clear with stable atmospheric transparency . those conditions can persist for over 100 hours at a time . further analysis suggests the sky was entirely free of ice crystals ( truly photometric ) @xmath6% of the time at pearl in winter , and that a higher elevation location nearby may be better . . And you have already written the first three sentences of the full article: winters in the high arctic are cold , dry , and dark . in northern canada , within the territory of nunavut , the coasts of the ice - locked eastern arctic archipelago combine these conditions with high terrain , providing locations potentially above much of the surface cloud and turbulence , and leading to the prospect of good observing sites for optical / near - infrared astronomy ( see * ? ? ? one such site under study is the location of the polar environment atmospheric research laboratory ( pearl ) at @xmath7 north latitude , on ellesmere island . the pearl facility is at an elevation 610 m on a ridge at the tip of the fosheim peninsula .. Please generate the next two sentences of the article

it is accessible via a 15 km long road from the sea - level research base at eureka , providing reliable logistical support : power , broadband satellite communications , an all - weather airstrip , and sea access in summer . eureka is operated by the civilian weather service of the canadian government , environment canada ( ec ) , providing hourly meteorological data ( air temperature , barometric pressure , relative humidity , wind speed and direction ) and visual cloud - cover estimates . with the onset of continuous polar night in early october ,

Suppose that you have an abstract for a scientific paper: presymmetry , the hidden symmetry underlying the charge and generational patterns of quarks and leptons , is utilized for repairing the left right asymmetry of the standard model with dirac neutrinos . it is shown that the restoration of parity is consequent with an indispensable left right symmetric residual presymmetry . thus , presymmetry substantiates left right symmetry and the experimental search for the latter is the test of the former , with the nature of neutrinos as a crucial feature that can distinguish the left right symmetry alone and its combination with presymmetry . this phenomenological implication is in accordance with the fact that majorana neutrinos are usually demanded in the first case , but forbidden in the second . . And you have already written the first three sentences of the full article: the phenomenological success of the standard model ( sm ) of particle physics based on the gauge group su(3)@xmath0 @xmath1 su(2)@xmath2 @xmath1 u(1)@xmath3 is moderated by a number of problems . there is no logical sense for the complete asymmetry between left and right in the weak sector and no explanation for the charge symmetry between quarks and leptons . it also offers no reason for the existence of fermion family copies and no prediction for their numbers .. Please generate the next two sentences of the article

faced with these troubles , many theoretical ideas have been advanced beyond the sm . the minimal extension of the sm which repairs its left right ( lr ) asymmetry is in the lr symmetric models ( lrsm ) with gauge group @xmath4 , where an interchange symmetry between the left and right sectors is assumed.@xcite the other popular choice to rectify the lr asymmetry of the sm is held by the mirror matter models based on the gauge group @xmath5 , where @xmath6 , with equal gauge coupling constants for the symmetric sectors.@xcite@xmath7@xcite however , none of these extended chiral models with lr symmetry finds the solutions to the quark

Suppose that you have an abstract for a scientific paper: a deep mid- and far - infrared survey in the extended groth strip ( egs ) area gives 3.6 to 8 flux densities or upper limits for 253 lyman break galaxies ( lbgs ) . the lbgs are a diverse population but with properties correlated with luminosity . the lbgs show a factor of 30 range in indicated stellar mass and a factor of 10 in apparent dust content relative to stellar mass . about 5% of lbgs are luminous at all wavelengths with powerful emission at rest 6 . in the rest 0.9 to 2 spectral range these galaxies have stellar spectral slopes with no sign of an agn power law component , suggesting that their emission is mainly powered by intensive star formation . galaxies in this luminous population share the infrared properties of cold scuba sources : both are massive and dusty starburst galaxies at @xmath0 ; their stellar mass is larger than @xmath1 . we suggest that these galaxies are the progenitors of present - day giant elliptical galaxies , with a substantial fraction of their stars already formed at @xmath2 . . And you have already written the first three sentences of the full article: the two most efficient ways of identifying galaxies at high redshifts are first , the lyman break broadband - droput technique , and second , observations at submillimeter wavelengths . for example , surveys with the submillimeter common - user bolometer array ( scuba ) on the james clerk maxwell telescope reveal high - redshift objects via emission from the cold dust they contain @xcite . conventional wisdom is that the submillimeter observations preferentially select starburst galaxies at @xmath3 because the far - infrared luminosity peak shifts into the submillimeter band @xcite .. Please generate the next two sentences of the article

most scuba sources are too faint in the optical and near - infrared bands for spectroscopic identification , but @xcite and @xcite have confirmed that most scuba sources in their sample are at @xmath3 . despite all the effort that has gone into scuba searches , lyman break galaxies ( lbgs ) still constitute by far the largest well - studied rest - frame - uv selected galaxy samples at high redshift @xcite . the relation between lbgs and scuba galaxies remains unclear , but recently @xcite have confirmed that some scuba galaxies have the typical rest - frame uv colors as lbgs at @xmath4@xcite . understanding both populations requires a direct comparison of properties , such as stellar mass and dust emission .

Suppose that you have an abstract for a scientific paper: it is usually considered that the spectrum of an optical cavity coupled to an atomic medium does not exhibit a normal - mode splitting unless the system satisfies the strong coupling " condition , meaning the rabi frequency of the coherent coupling exceeds the decay rates of atom and cavity excitations . we show that this need not be the case , but depends on the way in which the coupled system is probed . measurements of the reflection of a probe laser from the input mirror of an overdamped cavity reveal an avoided crossing in the spectrum which is not observed when driving the atoms directly and measuring the purcell - enhanced cavity emission . we understand these observations by noting a formal correspondence with electromagnetically - induced transparency of a three - level atom in free space , where our cavity acts as the absorbing medium and the coupled atoms play the role of the control field . the oscillatory dynamics intrinsic to quantum systems can be harnessed in a number of ways for advanced applications in metrology and sensing . coherent oscillations among quantum states are at the heart of existing time - frequency standards @xcite , atom interferometers @xcite , and quantum information processors @xcite . coherence in these systems is ultimately limited by dephasing which arises from the coupling of the isolated quantum system to the vast reservoir of states representing the environment . in some cases the system is _ open _ by design , for example to allow communication of information into and out of the system ; in other cases it is unavoidable , due to losses or the influence of uncontrolled fluctuations in the reservoir . the exact role of decoherence in the transition from microscopic quantum to macroscopic classical behaviour remains an active field of study @xcite . here we study a system comprising cold atoms coupled to a high finesse optical microcavity . the relatively small cavity mode volume results in a large electric dipole coupling between a single.... And you have already written the first three sentences of the full article: a single two - level atom coupled to a single mode of an ideal optical cavity is described in the dipole and rotating wave approximations by the jaynes - cummings hamiltonian @xcite ( @xmath0 ) , @xmath1 here the operator @xmath2 annihilates a photon from the cavity field and @xmath3 is the pauli isospin operator lowering the atom from the excited state @xmath4 to the ground state @xmath5 , @xmath6 ( @xmath7 ) is the angular frequency of the uncoupled cavity resonance ( atomic transition ) , and the atom - field coupling constant , @xmath8 , is proportional to the atomic dipole moment and inversely proportional to the square root of the cavity mode volume . the hamiltonian ( [ eq : h ] ) conserves the total excitation number @xmath9 , and the simultaneous eigenstates of @xmath10 and @xmath11 consist of a dark ground state , @xmath12 obeying @xmath13 , and a ladder of doublets consisting of superpositions of @xmath14 and @xmath15 with @xmath16 , etc . figure [ fig : eigenfreqs](a ) shows the eigenvalues for the lowest doublet ( @xmath17 ) of the coupled system : @xmath18 the interaction lifts the degeneracy at @xmath19 , splitting the two levels in the eigenspectrum by @xmath20 at this point . in the time domain ,. Please generate the next two sentences of the article

this splitting corresponds to the rabi oscillation between the states @xmath21 and @xmath22 . of the undamped hamiltonian @xmath10 . dashed lines : uncoupled atom ( blue ) , and cavity ( red ) .

Suppose that you have an abstract for a scientific paper: we discuss some 3d numerical simulations of accretion discs using the sph method and a polytropic equation of state . we show that discs exist even for as large value of the polytropic index as 1.2 , and that these discs are always in hydrostatic balance . we also show that even without any inflow , spiral shocks appear in the discs . . And you have already written the first three sentences of the full article: numerical studies of accretion discs have been mostly restricted to 2d cases , due to computing time limitations . among many things , these 2d simulations have shown that spiral shocks appear in inviscid discs ( e.g. sawada et al . recently some 3d simulations have been carried out ( see yukawa , boffin & matsuda , 1997 for an uncomplete list ) , mostly using particles methods . these simulations were apparently unable to generate spiral shocks in the accretion disc , but this could be related to the fact that they used either an isothermal or pseudo - isothermal equation of state , either neglected pressure effects or used too low resolution .. Please generate the next two sentences of the article

we have run three - dimensional smoothed particle hydrodynamics ( sph ; see e.g. monaghan 1992 for a review ) simulations with a polytropic equation of state . this method includes self - consistently the effect of pressure forces and we checked that we could always resolve the disc in the vertical dimension . concerning this last point , we therefore used a variable smoothing length ( which , in sph , decides the resolution ) and checked that at each point in space , the smoothing length , @xmath0 , was smaller than the disc scale height , @xmath1 .

Suppose that you have an abstract for a scientific paper: low- and intermediate mass higgs bosons decay preferably into fermion pairs . the one - loop electroweak corrections to the respective decay rates are dominated by a flavour - independent term of @xmath0 . we calculate the two - loop gluon correction to this term . it turns out that this correction screens the leading high-@xmath1 behaviour of the one - loop result by roughly 10% . we also present the two - loop qcd correction to the contribution induced by a pair of fourth - generation quarks with arbitrary masses . as expected , the inclusion of the qcd correction considerably reduces the renormalization - scheme dependence of the prediction . 16.5 cm 23.cm @=11 tempcntc citex[#1]#2@fileswauxout tempcnta@tempcntb@neciteaciteforciteb:=#2citeo#1 citeotempcnta > tempcntbciteacitea , tempcnta = tempcntbtempcnta @=12 . And you have already written the first three sentences of the full article: one of the great puzzles of elementary particle physics today is whether nature makes use of the higgs mechanism of spontaneous symmetry breaking to generate the observed particle masses . the higgs boson , @xmath2 , is the missing link sought to verify this concept in the standard model . many of the properties of the higgs boson are fixed , e.g. , its couplings to the gauge bosons , @xmath3 , and fermions , @xmath4 , and the vacuum expectation value , @xmath5 . however , its mass , @xmath6 , and its self - couplings , which depend on @xmath6 , are essentially unspecified .. Please generate the next two sentences of the article

the failure of experiments at lep 1 and slc to detect the decay @xmath7 has ruled out the mass range @xmath8 gev at the 95% confidence level @xcite . at the other extreme , unitarity arguments in intermediate - boson scattering at high energies @xcite and considerations concerning the range of validity of perturbation theory @xcite establish an upper bound on @xmath6 at @xmath9 tev in a weakly interacting standard model . the higgs - boson discovery potential of lep 1 and slc is almost exhausted @xcite . prior to the advent of the lhc , the higgs - boson search will be restricted to the lower mass range . with lep 2

Suppose that you have an abstract for a scientific paper: for any given @xmath0 immersion @xmath1 such that the set @xmath2 is not empty , a simple geometric model of crystal growth is constructed . it is shown that our geometric model of crystal growth never formulates a polygon while it is growing . moreover , it is shown also that our model always dissolves to a point . . And you have already written the first three sentences of the full article: let @xmath1 be a @xmath0 immersion such that the set @xmath3 is not the empty set , where @xmath4 is identified with @xmath5 . the perspective projection of the given plane curve @xmath6 from any point of ( 1.1 ) does not give the silhouette of @xmath6 because it is non - singular . by this reason , the set ( 1.1 ) is called the _ no - silhouette _ of @xmath7 and is denoted by @xmath8 ( see figure 1 ) .. Please generate the next two sentences of the article

.,width=151 ] the notion of no - silhouette was first defined and studied from the viewpoint of perspective projection in @xcite . in @xcite it has been shown that the topological closure of no - silhouette is a wulff shape , which is the well - known geometric model of crystal at equilibrium introduced by g. wulff in @xcite . in this paper , we show that by rotating all tangent lines about their tangent points simultaneously with the same angle , we always obtain a geometric model of crystal growth ( proposition [ proposition 4 ] ) , our model never formulates a polygon while it is growing ( theorem [ theorem 1 ] ) , our model always dissolves to a point ( theorems [ theorem 2 ] ) , and our model is growing in a relatively simple way when the given @xmath7 has no inflection points ( theorem 3 ) . for any @xmath0 immersion @xmath1 and any real number @xmath9 , define the new set @xmath10 where @xmath11 is the rotation defined by @xmath12 ( see figure 2 ) .

Suppose that you have an abstract for a scientific paper: we propose a new thermodynamic equality and several inequalities concerning the relationship between work and information for an isothermal process with maxwell s demon . our approach is based on the formulation la jarzynski of the thermodynamic engine and on the quantum information - theoretic characterization of the demon . the lower bound of each inequality , which is expressed in terms of the information gain by the demon and the accuracy of the demon s measurement , gives the minimum work that can be performed on a single heat bath in an isothermal process . these results are independent of the state of the demon , be it in thermodynamic equilibrium or not . . And you have already written the first three sentences of the full article: ever since the proposition of the `` demon '' by maxwell @xcite , numerous studies have been conducted on the consistency between the role of the demon and the second law of thermodynamics @xcite . bennett resolved the apparent contradiction by considering the logically irreversible initialization of the demon @xcite . the key observation here is the so - called landauer principle @xcite which states that , in erasing one bit of information from the demon s memory , at least @xmath0 of heat should , on average , be dissipated into the environment with the same amount of work being performed on the demon .. Please generate the next two sentences of the article

piechocinska has proved this principle without invoking the second law in an isothermal process @xcite . the essence of consistency between the role of the demon and the second law of thermodynamics can be illustrated by the setup of the szilard engine @xcite .

Suppose that you have an abstract for a scientific paper: we have obtained _ spitzer _ irs 5.535 @xmath0 m spectroscopy of the debris disk around @xmath1 pictoris . in addition to the 10@xmath2 silicate emission feature originally observed from the ground , we also detect the crystalline silicate emission bands at 28@xmath2 and 33.5@xmath2 . this is the first time that the silicate bands at wavelengths longer than 10@xmath2 have ever been seen in the @xmath1 pictoris disk . the observed dust emission is well reproduced by a dust model consisting of fluffy cometary and crystalline olivine aggregates . we searched for line emission from molecular hydrogen and atomic [ ] , , and gas but detected none . we place a 3@xmath3 upper limit of @xmath417@xmath5 on the h@xmath6 s(1 ) gas mass , assuming an excitation temperature of @xmath7=100@xmath8 . this suggests that there is less gas in this system than is required to form the envelope of jupiter . we hypothesize that some of the atomic gas observed in keplerian rotation around @xmath1 pictoris may be produced by photon - stimulated desorption from circumstellar dust grains . . And you have already written the first three sentences of the full article: the a5v star @xmath1 pictoris ( hd 39060 = hr 2020 ) at a distance @xmath9 possesses a spectacular edge - on debris disk imaged in scattered light and thermal emission that extends to radii @xmath101400@xmath11 @xcite . an age of @xmath1212 myr has been estimated for for the central star based on the properties of late - type members of the @xmath1 pic moving group @xcite . the dust in this system is believed to be replenished from a reservoir , such as collisions between parent bodies or sublimation of comets because the estimated lifetime for the dust under radiation pressure , poynting - robertson drag , and grain - grain collisions is a few orders of magnitude shorter than the age of the system @xcite. Please generate the next two sentences of the article

. there may be evidence for the presence of large bodies in the @xmath1 pictoris disk that perturb dust grains and parent bodies and instigate collisional cascades between them . a 5@xmath13 warp at radii @xmath480 au has been observed in scattered light using stis on _ hst _ and may be generated by either a brown dwarf close to the star ( at distances @xmath43 au ) or a 0.17@xmath14 planet at larger distances from the star ( 50@xmath11 ) @xcite .

Suppose that you have an abstract for a scientific paper: recent experimental results on the formation of molecular hydrogen on astrophysically relevant surfaces under conditions similar to those encountered in the interstellar medium provided useful quantitative information about these processes . rate equation analysis of experiments on olivine and amorphous carbon surfaces provided the activation energy barriers for the diffusion and desorption processes relevant to hydrogen recombination on these surfaces . however , the suitability of rate equations for the simulation of hydrogen recombination on interstellar grains , where there might be very few atoms on a grain at any given time , has been questioned . to resolve this problem , we introduce a master equation that takes into account both the discrete nature of the h atoms and the fluctuations in the number of atoms on a grain . the hydrogen recombination rate on microscopic grains , as a function of grain size and temperature , is then calculated using the master equation . the results are compared to those obtained from the rate equations and the conditions under which the master equation is required are identified . . And you have already written the first three sentences of the full article: the formation of molecular hydrogen in the interstellar medium ( ism ) is a process of fundamental importance @xcite . it was recognized long ago @xcite that @xmath0 can not form in the gas phase efficiently enough to account for its abundance . it was thus proposed that dust grains act as catalysts , where an h atom approaching the surface of a grain has a probability @xmath1 to become adsorbed .. Please generate the next two sentences of the article

the adsorbed h atom ( adatom ) spends an average time @xmath2 ( residence time ) before leaving the surface . if during the residence time the h adatom encounters another h adatom , an @xmath0 molecule will form with a certain probability .

Suppose that you have an abstract for a scientific paper: the metallic surface states of a topological insulator support helical dirac fermions protected by topology with their spin locked perpendicular to their momentum . they can acquire mass through magnetic doping or through hybridization of states on opposite faces of a thin sample . in this case there can be a component of electron spin oriented perpendicular to the surface plane . the electron - phonon interaction renormalizes the dynamics of the charge carriers through their spectral density . it also modifies the gap channel and a second spectral function enters which , not only determines the out of plane spin component , but also comes into in - plane properties . while the out of plane spin component is decreased below the fermi momentum ( @xmath0 ) , the in plane component increases . there are also correlation tails extending well beyond @xmath0 . the angular resolved photo - emission line shapes aquire holstein side bands . the effective gap in the density of states is reduced and the optical conductivity aquires distinct measurable phonon structure even for modest value of the electron - phonon coupling . . And you have already written the first three sentences of the full article: helical dirac fermions protected by topology and found at the surface of topological insulators ( ti)@xcite exhibit spin locked perpendicular to their momentum.@xcite doping with magnetic impurities can break time reversal symmetry and create massive dirac fermions as has been experimentally demonstrated@xcite in @xmath1 . a gap can also be introduced in thin films when the distance between top and bottom surfaces is of the order of the extend in space of the surface states . @xcite gapped dirac fermions arise in many other systems , for example in two dimensional membranes such as the dichalcoginide @xmath2 @xciteand silicene@xcite with buckled honeycomb lattice . in both these cases. Please generate the next two sentences of the article

pseudospin plays the analogous role to the real spin of topological insulators . the electron - phonon interaction renormalizes quasiparticle dynamics and leads to important observable changes in electronic properties @xcite which illustrate the effects of many body renormalizations not captured in single particle theories . for the dirac electrons in graphene as an example ,

Suppose that you have an abstract for a scientific paper: a novel class of einstein vacua is presented , which possess non - vanishing cosmological constant and accelerating horizon with the topology of @xmath0 fibration over @xmath1 . after euclideanization , the solution describes a conformally distorted @xmath2 fibration over @xmath3 , which is smooth , compact and inhomogeneous , and can be regarded as analogue of don page s gravitational instanton . . And you have already written the first three sentences of the full article: despite its nearly a hundred - year - old age , einstein gravity continues to be a source of inspirations and surprises . besides the great success in describing physics in solar system , einstein gravity also predicts existence of various black holes and even extended objects like black strings @xcite and black rings @xcite in higher dimensions . not all aspects of these nontrivial solutions have been fully understood . even in the pure vacuum sector. Please generate the next two sentences of the article

, einstein gravity has been shown to possess an unexpected richness in addition to the well known maximally symmetric vacua ( ds , ads , minkowski etc ) , einstein gravity also admits inhomogeneous vacua such as the anisotropic accelerating vacua @xcite and the massless topological black hole vacua @xcite and so on . in this article , we shall present a novel class of einstein vacua which possess accelerating horizons of nontrivial topology . concretely

Suppose that you have an abstract for a scientific paper: the topology of configuration space may be responsible in part for the existence of sphalerons . here , sphalerons are defined to be static but unstable finite - energy solutions of the classical field equations . another manifestation of the nontrivial topology of configuration space is the phenomenon of spectral flow for the eigenvalues of the dirac hamiltonian . the spectral flow , in turn , is related to the possible existence of anomalies . in this review , the interconnection of these topics is illustrated for three particular sphalerons of @xmath0 yang mills higgs theory . invited paper for the special issue of the journal of mathematical physics on _ `` integrability , topological solitons and beyond '' _ edited by t. fokas and n.s . manton . j. math . phys . , vol . 44 , no . 8 , august 2003 ka tp012003 hep - th/0304167 . And you have already written the first three sentences of the full article: one of the main themes of the present special issue concerns the so - called topological solitons . the field configurations of these classical solutions are characterized by a topologically nontrivial map of the space manifold ( or part of it ) into some internal space of the model considered . a well - known example is the skyrme soliton @xcite , for which the space manifold @xmath1. Please generate the next two sentences of the article

( i.e. , the compactified euclidean space @xmath2 ) is mapped into the internal space @xmath0 . another example is the magnetic monopole @xcite , for which the `` sphere at infinity '' @xmath3 is mapped into the higgs vacuum manifold @xmath4 .

Suppose that you have an abstract for a scientific paper: the recent detection of gamma radiation from mkn 501 at energies as high as @xmath0 tev suggests stringent upper bounds on the diffuse , far infrared , extragalactic radiation density . the production of electron - positron pairs through photon - photon collisions would prevent gamma photons of substantially higher energies from reaching us across distances of order 100mpc . however , coherently arriving tev or sub - tev gammas bose - einstein condensations of photons at these energies could mimic the cherenkov shower signatures of extremely energetic gammas . to better understand such events , we describe their observational traits and discuss how they might be generated . . And you have already written the first three sentences of the full article: high energy gamma rays are readily absorbed in the intergalactic medium through pair production in a sufficiently dense , diffuse , microwave or infrared radiation field ( gould & schrder,1966 ; stecker , de jager , & salamon 1992 ) . for this reason , a great deal of attention has be paid to gamma rays at energies apparently reaching @xmath1tev , recently detected from the galaxy mkn 501 ( hayashida et al . , 1998 , pian et al . , 1998 , aharonian et al . , 1999 , krennrich , et al . , 1999 ) . mkn 501 is a bl lac object at a distance of @xmath2mpc , for a hubble constant , h@xmath3 = 50 kms@xmath4mpc@xmath4 .. Please generate the next two sentences of the article

unattenuated transmission of @xmath1tev photons across distances of this order would place severe constraints on the diffuse extragalactic infrared background radiation ( coppi & aharonian,1997 , stanev & franceschini , 1998 ) placing upper limits to the radiation density that are close to values derived from cobe detections and iras source counts alone ( hauser , et al . , 1998 ; hacking & soifer , 1991 ; gregorich , et al . , 1995 )

Suppose that you have an abstract for a scientific paper: we reanalyze oklo @xmath0sm data using realistic models of the natural nuclear reactors . disagreements among recent oklo determinations of the time evolution of @xmath1 , the electromagnetic fine structure constant , are shown to be due to different reactor models , which led to different neutron spectra used in the calculations . we use known oklo reactor epithermal spectral indices as criteria for selecting realistic reactor models . two oklo reactors , rz2 and rz10 , were modeled with mcnp . the resulting neutron spectra were used to calculate the change in the @xmath0sm effective neutron capture cross section as a function of a possible shift in the energy of the 97.3-mev resonance . we independently deduce ancient @xmath0sm effective cross sections , and use these values to set limits on the time - variation of @xmath1 . our study resolves a contradictory situation with previous oklo @xmath1-results . our suggested @xmath2 bound on a possible time variation of @xmath1 over two billion years is stringent : @xmath3 , but model dependent in that it assumes only @xmath1 has varied over time . . And you have already written the first three sentences of the full article: two papers @xcite and @xcite on the determination of the time evolution of @xmath1 the electromagnetic fine structure constant from oklo reactor data recently appeared , adding contradictory results to earlier investigations @xcite . the fractional change of @xmath1 over a two billion year period has been found from oklo data to be : @xmath4 @xcite , @xmath5 @xcite , @xmath6 @xcite , and either @xmath7 or @xmath8 in @xcite . by comparison , astrophysics determinations from data on the shifts of the absorption lines in the spectra of quasar light have yielded @xmath9 @xcite and @xmath10 @xcite over an approximately ten billon year period . the sign of @xmath11 is defined by the relationship @xmath12 , so that a negative sign , for example , means that 2 - 10 billion years ago the value of @xmath1 was smaller than at present . for more results and references on the time variation of fundamental constants. Please generate the next two sentences of the article

@xcite . as the results indicate , the situation is not entirely satisfactory : some analyses give only upper limits , while those showing a definite effect disagree even in sign . while theoretical models have been proposed which can accommodate time dependent rates of change of @xmath1 , clarifying the disagreements among the oklo analyses is important , particular since there are also questions about just how model - dependent these very precise limits actually are @xcite . in this paper

Suppose that you have an abstract for a scientific paper: motivated by the properties of the iron chalcogenides , we study the phase diagram of a generalized heisenberg model with frustrated bilinear - biquadratic interactions on a square lattice . we identify zero - temperature phases with antiferroquadrupolar and ising - nematic orders . the effects of quantum fluctuations and interlayer couplings are analyzed . we propose the ising - nematic order as underlying the structural phase transition observed in the normal state of fese , and discuss the role of the goldstone modes of the antiferroquadrupolar order for the dipolar magnetic fluctuations in this system . our results provide a considerably broadened perspective on the overall magnetic phase diagram of the iron chalcogenides and pnictides , and are amenable to tests by new experiments . _ introduction . _ because superconductivity develops near magnetic order in most of the iron pnictides and chalcogenides , it is important to understand the nature of their magnetism . the iron pnictide families typically have parent compounds that show a collinear @xmath0 antiferromagnetic order @xcite . lowering the temperature in the parent compounds gives rise to a tetragonal - to - orthorhombic distortion , and the temperature @xmath1 for this structural transition is either equal to or larger than the nel transition temperature @xmath2 . a likely explanation for @xmath1 is an ising - nematic transition at the electronic level . it was recognized from the beginning that models with quasi - local moments and their frustrated heisenberg @xmath3 interactions @xcite feature such an ising - nematic transition @xcite . similar conclusions have subsequently been reached in models that are based on fermi - surface instabilities @xcite . the magnetic origin for the nematicity fits well with the experimental observations of the spin excitation spectrum observed in the iron pnictides . inelastic neutron scattering experiments @xcite in the parent iron pnictides have revealed a low - energy spin.... And you have already written the first three sentences of the full article: exactly at @xmath48 , the classical @xmath97 spins are always ordered . therefore , the afq order is accompanied by magnetic dipolar orders . because the @xmath0 afq order doubles the unit cell , the structure factor @xmath98 of the compatible magnetic dipolar order must show a two-@xmath51 structure as the consequence of brillion zone folding , _ i.e. _ , @xmath99 where @xmath76 . the ordering wavevector @xmath100 depends on model parameters . and @xmath41 . in each case , the dashed box shows the magnetic unit cell .. Please generate the next two sentences of the article

the corresponding ordering wavevectors are as follows : @xmath101 and @xmath102 in ( a ) ; @xmath103 in ( b ) and ( c ) ; @xmath104 and @xmath105 in ( d).,width=302 ] we find that in the @xmath21 afq ground state the spins are ordered at a wavevector @xmath50 with infinite degeneracies for @xmath40 . assuming a @xmath0 afq order , the spin variable at site @xmath12 is @xmath106\gamma(i_y)$ ] , where @xmath107 and @xmath108 are coordinates of site @xmath12 , @xmath109 , and @xmath110 is a random variable defined on each column of the lattice . the randomness in the real - space spin configuration leads to infinite number of degenerate ground - state spin patterns . transforming to the momentum space

Suppose that you have an abstract for a scientific paper: recently , there has been an explosion of work on network routing in hostile environments . hostile environments tend to be dynamic , and the motivation for this work stems from the scenario of ied placements by insurgents in a logistical network . for discussion , we consider here a sub - network abstracted from a real network , and propose a framework for route selection . what distinguishes our work from related work is its decision theoretic foundation , and statistical considerations pertaining to probability assessments . the latter entails the fusion of data from diverse sources , modeling the socio - psychological behavior of adversaries , and likelihood functions that are induced by simulation . this paper demonstrates the role of statistical inference and data analysis on problems that have traditionally belonged in the domain of computer science , communications , transportation science , and operations research . . . And you have already written the first three sentences of the full article: network routing problems involve the selection of a pathway from a source to a sink in a network . network routing is encountered in logistics , communications , the internet , mission planning for unmanned aerial vehicles , telecommunications , and transportation , wherein the cost effective and safe movement of goods , personnel , or information is the driving consideration . in transportation science and operations research , network routing goes under the label _ vehicle routing problem _ ( vrp ) ; see bertsimas and simchi - levi ( @xcite ) for a survey .. Please generate the next two sentences of the article

the flow of any commodity within a network is hampered by the failure of one or more pathways that connect any two nodes . pathway failures could be due to natural and physical causes , or due to the capricious actions of an adversary .

Suppose that you have an abstract for a scientific paper: we revisit the anomaly of rotation curve in the nearly face - on galaxy m51 that shows an apparently faster decrease of rotation velocity than the keplerian law in the outer disk , further showing apparent counter rotation in the outermost hi disk . we interpret this anomaly as due to warping of the galactic disk , and determined the warping structure of m51 s disk using the tilted - ring method , assuming that the intrinsic rotation curve is normal . it is shown that the disk is nearly flat in the inner disk at a constant inclination angle , but the disk suddenly bends at radius 7.5 kpc by about 27@xmath0 . the inclination angle , then , decreases monotonically outward reaching a perfect face - on ring at 18 kpc , beyond which the disk is warped in the opposite sense to the inner disk , resulting in apparent counter rotation . ministry of defence , shibata , 957 - 8530 niigata ; @xmath1 the university of tokyo . ] . And you have already written the first three sentences of the full article: spiral galaxies have universally flat rotation curves ( rubin et al . 1980 ; persic and salucci 1996 ; salucci et al . 2001 ; sofue and rubin 2001 ) . however , two exceptional cases of anomalously rapid decrease in rotation velocity have been known : one in the edge - on peculiar galaxy m82 ( ngc 3032 ) and the other in the face - on sc spiral m51 ( ngc 5194 ) .. Please generate the next two sentences of the article

it was shown that the rotation curve of m82 is fitted by the keplerian law at radii beyond @xmath2 kpc . the kepler rotation was interpreted as due to absence of dark halo by tidal truncation during the past gravitational encounter with the parent galaxy m81 ( sofue 1998 ) . for an edge - on galaxy like m82

Suppose that you have an abstract for a scientific paper: effective conductivity of a 2d random composite is expressed in the form of long series in the volume fraction of ideally conducting disks . the problem of a _ direct _ reconstruction of the critical index for superconductivity from the series is solved with good accuracy , for the first time . general analytical expressions for conductivity in the whole range of concentrations are derived and compared with the regular composite and existing models . . And you have already written the first three sentences of the full article: it is frequently declared that only lower order formulae can be deduced for the effective conductivity problem which can not be analytically solved in general case because of the complicated random geometrical structures . after such an announce hard numerical computations are applied to solve such a problem . of course , advanced computational approaches can be useful in mechanical engineering . but an exact or approximate analytical formula is always better because it can exactly show asymptotic behavior near singular points when numerics usually fails . in the present paper ,. Please generate the next two sentences of the article

we deduce such a formula for a 2d , two - component composite made from a collection of non - overlapping , identical , circular discs , embedded randomly in an otherwise uniform locally isotropic host ( see fig.[figdisksrandom ] ) . the conductivity of the host is normalized to unity .

Suppose that you have an abstract for a scientific paper: we present a multiwavelength study of the ngc 281 complex which contains the young cluster ic 1590 at the center , using deep wide - field optical @xmath0 photometry , slitless spectroscopy along with archival data sets in the near - infrared ( nir ) and x - ray . the extent of ic 1590 is estimated to be @xmath16.5 pc . the cluster region shows a relatively small amount of differential reddening . the majority of the identified young stellar objects ( ysos ) are low mass pms stars having age @xmath2 myr and mass 0.5 - 3.5 m@xmath3 . the slope ( @xmath4 ) of the mass function for ic 1590 , in the mass range @xmath5 , is found to be @xmath6 . the slope of the @xmath7-band luminosity function ( @xmath8 ) is similar to the average value ( @xmath10.4 ) reported for young clusters . the distribution of gas and dust obtained from the iras , co and radio maps indicates clumpy structures around the central cluster . the radial distribution of the young stellar objects , their ages , @xmath9(@xmath10 ) nir - excess , and the fraction of classical t tauri stars suggest triggered star formation at the periphery of the cluster region . however , deeper optical , nir and mir observations are needed to have a conclusive view of star formation scenario in the region . the properties of the class 0/i and class ii sources detected by using the _ spitzer _ mid - infrared observations indicate that a majority of the class ii sources are x - ray emitting stars , whereas x - ray emission is absent from the class 0/i sources . the spatial distribution of class 0/i and class ii sources reveals the presence of three sub - clusters in the ngc 281 west region . . And you have already written the first three sentences of the full article: h ii regions have been studied quite extensively in recent years on account of their close association with star formation . there seems to be two modes of star formation associated with h ii regions depending on the initial density distribution of the natal molecular cloud . one is the cluster mode which gives birth to a rich open clusters and the other is the dispersed mode which forms only loose clusters or aggregates of stars .. Please generate the next two sentences of the article

presumably , the former takes place in centrally condensed , massive clouds , whereas the latter occurs in clumpy , dispersed clouds ( see e.g. , ogura 2006 ) . these clusters / aggregates of stars emerging from their natal clouds can be the laboratories to address some of the fundamental questions of star formation .

Suppose that you have an abstract for a scientific paper: linear paul traps have been used recently to simulate the transverse field ising model with long - range spin - spin couplings . we study the intrinsic effects of phonon creation ( from the initial phonon ground state ) on the spin - state probability and spin entanglement for such quantum spin simulators . while it has often been assumed that phonon effects are benign because they play no role in the pure ising model , they can play a significant role when a transverse field is added to the model . we use a many - body factorization of the quantum time - evolution operator of the system , adiabatic perturbation theory and exact numerical integration of the schrdinger equation in a truncated spin - phonon hilbert space followed by a tracing out of the phonon degrees of freedom to study this problem . we find that moderate phonon creation often makes the probabilities of different spin states behave differently from the static spin hamiltonian . in circumstances in which phonon creation is minor , the spin dynamics state probabilities converge to the static spin hamiltonian prediction at the cost of reducing the spin entanglement . we show how phonon creation can severely impede the observation of kink transitions in frustrated spin systems when the number of ions increases . many of our results also have implications for quantum simulation in a penning trap . = 1 . And you have already written the first three sentences of the full article: complex states of matter like spin liquids are suspected to exist in quantum spin models with frustration due to geometry or due to the nature of the spin - spin interaction @xcite . spin liquids are complicated quantum many - body states that exhibit significant entanglement of their wave functions without symmetry breaking , and could also exhibit emergent quantum phenomena within their low - energy excitation spectra . classical computation , such as exact diagonization and quantum monte carlo simulation , or conventional theories based on local order parameters fail to describe these systems without bias . for example. Please generate the next two sentences of the article

, exact diagonalization studies are limited to small size lattices and hence usually have strong finite - size effects , while quantum monte carlo simulations can suffer from the sign problem or have a large computational expense to describe long - range interactions and hence can not reach the low temperatures needed to see the predicted exotic phases . feynman proposed that one could use controlled quantum - mechanical systems with few quantum gates to simulate many - body problems @xcite as an useful quantum computation before achieving universal quantum computation . in recent years

Suppose that you have an abstract for a scientific paper: in this paper , a topological superfluid phase with chern number @xmath0 , possessing gapless edge states and non - abelian anyons is designed in a @xmath0 topological insulator proximity to an @xmath1-wave superfluid on an optical lattice with the effective gauge field and layer - dependent zeeman field coupled to ultracold fermionic atoms pseudo spin . we also study its topological properties and calculate the phase stiffness by using the random - phase - approximation approach . finally we derive the temperature of the kosterlitz - thouless transition by means of renormalized group theory . owning to the existence of non - abelian anyons , this @xmath0 topological superfluid may be a possible candidate for topological quantum computation . . And you have already written the first three sentences of the full article: topological quantum computation , based on the manipulation of non - abelian anyons@xcite , is considered as an effective method to deal with decoherence in realizing quantum computation . the first proposed candidate is the fractional quantum hall state at filling factor @xmath2 in ultra high - mobility samples @xcite . other proposals are based on two dimensional ( 2d ) chiral @xmath3 superconductors with @xmath0(the chern - number ) topological invariable@xcite and then the s - wave - superconductor - topological - insulator systems@xcite . among these approaches , accurate manipulations of single quasi - particles. Please generate the next two sentences of the article

remains a major difficulty and new techniques are to be expected to overcome this drawback . on the other hand , cold atoms in optical lattices are an extensively developing research field@xcite . because one can precisely controls over the system parameters and defect - free properties , ultracold atoms in optical lattices

Suppose that you have an abstract for a scientific paper: we calculate the nonequilibrium dynamic evolution of a one - dimensional system of two - component fermionic atoms after a strong local quench by using a time - dependent spin - density - functional theory . the interaction quench is also considered to see its influence on the spin - charge separation . it is shown that the charge velocity is larger than the spin velocity for the system of on - site repulsive interaction ( luttinger liquid ) , and vise versa for the system of on - site attractive interaction ( luther - emery liquid ) . we find that both the interaction quench and polarization suppress the spin - charge separation . . And you have already written the first three sentences of the full article: while the nonequilibrium dynamic evolution of quantum systems has long been extensively studied , @xcite progress is hindered by the tremendous difficulties in solving the nonequilibrium quantum many - body schrdinger equation . this situation is going to be changed due to the progress in experiments and the development in numerical methods . on the experimental side , the development in manipulating ultracold atomic gases makes it feasible to study strongly correlated systems with time - varying interactions and external potentials and in out - of - equilibrium situations .. Please generate the next two sentences of the article

the high controllability in ultracold atomic - gases systems provides an ideal testbed to observe the long - time evolution of strongly correlated quantum many - body systems , and to test theoretical predictions , such as the bloch oscillation , @xcite the absence of thermalization in nearly integrable one - dimensional ( 1d ) bose gases , @xcite and the expansion of bec in a random disorder after switching off the trapping potential . @xcite these efforts allow us to study the nonequilibrium dynamics of strongly correlated systems from a new perspective .

Suppose that you have an abstract for a scientific paper: we propose the subwavelength localization via adiabatic passage ( slap ) technique to coherently achieve state - selective patterning of matter waves well beyond the diffraction limit . the slap technique consists in coupling two partially overlapping and spatially structured laser fields to three internal levels of the matter wave yielding state - selective localization at those positions where the adiabatic passage process does not occur . we show that by means of this technique matter wave localization down to the single nanometer scale can be achieved . we analyze in detail the potential implementation of the slap technique for nano - lithography with an atomic beam of metastable ne@xmath0 and for coherent patterning of a two - component @xmath1rb bose - einstein condensate . . And you have already written the first three sentences of the full article: the highly controlled manipulation of atomic matter waves has proven to be an exciting field of research in recent years . specially , research in bose - einstein condensation ( bec ) , fermi quantum degeneracy , and quantum information processing with ultracold atoms has achieved tremendous advances @xcite . future progress in this field will strongly profit from optical addressability , localization , and patterning of atomic systems with a resolution not limited by the wavelength of the radiation involved .. Please generate the next two sentences of the article

some important examples are site - specific addressing of ultracold atoms in optical lattices @xcite , patterning of becs @xcite , and atom lithography @xcite based on light forces @xcite , optical quenching @xcite , or multi - photon processes @xcite . recently , there have been several proposals for subwavelength atom localization based on the interaction of three - level atoms with light having a space - dependent amplitude distribution , mainly standing wave ( sw ) fields @xcite . in all these proposals

Suppose that you have an abstract for a scientific paper: we extend the theory of the universal @xmath0-invariant to the case of bordism groups of manifolds with boundaries . this allows the construction of secondary descendants of the universal @xmath0-invariant . we obtain an interpretation of laures @xmath1-invariant as an example of this general construction . . And you have already written the first three sentences of the full article: in this paper we investigate the question how elements in bordism groups of manifolds with boundary can be detected using spectral invariants of dirac operators , namely the @xmath0-invariant of atiyah - patodi - singer @xcite . the corresponding problem for bordism groups of closed manifolds has been thouroughly studied in @xcite and led to the introduction of the universal @xmath0-invariant . the purpose of the present paper is to extend this theory from closed manifolds to manifolds with boundary .. Please generate the next two sentences of the article

one motivation for this generalization is to prove theorem [ thm1000 ] which refines a recent result in ( * ? ? ? * thm 1.1 ) .

Suppose that you have an abstract for a scientific paper: we examine the non - ergodic properties of scaled brownian motion , a non - stationary stochastic process with a time dependent diffusivity of the form @xmath0 . we compute the ergodicity breaking parameter eb in the entire range of scaling exponents @xmath1 , both analytically and via extensive computer simulations of the stochastic langevin equation . we demonstrate that in the limit of long trajectory lengths @xmath2 and short lag times @xmath3 the eb parameter as function of the scaling exponent @xmath1 has no divergence at @xmath4 and present the asymptotes for eb in different limits . we generalise the analytical and simulations results for the time averaged and ergodic properties of scaled brownian motion in the presence of ageing , that is , when the observation of the system starts only a finite time span after its initiation . the approach developed here for the calculation of the higher time averaged moments of the particle displacement can be applied to derive the ergodic properties of other stochastic processes such as fractional brownian motion . . And you have already written the first three sentences of the full article: the non - brownian scaling of the mean squared displacement ( msd ) of a diffusing particle of the power - law form @xcite @xmath5 is a hallmark of a wide range of anomalous diffusion processes @xcite . equation ( [ msd ] ) features the anomalous diffusion coefficient @xmath6 of physical dimension @xmath7 and the anomalous diffusion exponent @xmath1 . depending on its magnitude we distinguish subdiffusion ( @xmath8 ) and superdiffusion ( @xmath9 ) . interest in anomalous diffusion processes was rekindled with the advance of modern spectroscopic methods , in particular , advanced single particle tracking methods @xcite .. Please generate the next two sentences of the article

thus , subdiffusion was observed for the motion of biopolymers and submicron tracer particles in living biological cells @xcite , in complex fluids @xcite , as well as in extensive computer simulations of membranes @xcite or structured systems @xcite , among others @xcite . superdiffusion of tracer particles was observed in living cells due to active motion @xcite .

Suppose that you have an abstract for a scientific paper: a photometric _ ubv _ survey is presented for 610 stars in a region surrounding the cepheid aq puppis and centered southwest of the variable , based upon photoelectric measures for 14 stars and calibrated iris photometry of photographic plates of the field for 596 stars . an analysis of reddening and distance for program stars indicates that the major dust complex in this direction is @xmath0 kpc distant , producing differential extinction described by a ratio of total - to - selective extinction of @xmath1 . zero - age main - sequence fitting for the main group of b - type stars along the line of sight yields a distance of @xmath2 kpc ( @xmath3 s.e . ) . the 29@xmath4.97 cepheid aq pup , of field reddening @xmath5 ( @xmath6 ) , appears to be associated with b - type stars lying within @xmath7 of it as well as with a sparse group of stars , designated turner 14 , centered south of it at j2000.0 = 07:58:37 , 29:25:00 , with a mean reddening of @xmath8 . aq pup has an inferred luminosity as a cluster member of @xmath9 and an evolutionary age of @xmath10 yr . its observed rate of period increase of @xmath11 s yr@xmath12 is an order of magnitude larger than what is observed for cepheids of comparable period in the third crossing of the instability strip , and may be indicative of a high rate of mass loss or a putative fifth crossing . another sparse cluster , designated turner 13 , surrounds the newly - recognized 2@xmath4.59 cepheid v620 pup , of space reddening @xmath13 ( @xmath14 ) , distance @xmath15 kpc ( @xmath16 s.e . ) , evolutionary age @xmath17 yr , and an inferred luminosity as a likely cluster member of @xmath18 . v620 pup is tentatively identified as a first crosser , pending additional observations . . And you have already written the first three sentences of the full article: the most important galactic calibrators for the cepheid period - luminosity ( pl ) relation are long - period pulsators , which are less frequently found in open clusters than their short - period cousins ( e.g. , * ? ? ? * ; * ? ? ? such objects are massive and young enough , however , to belong to older portions of ob associations , which can often be delineated by photometric or spectroscopic methods .. Please generate the next two sentences of the article

that philosophy initiated a program by sidney van den bergh thirty years ago to identify associated young b - type stars in the vicinity of bright southern hemisphere long - period cepheids @xcite , with offshoots involving studies of potential coincidences of long - period cepheids with open clusters @xcite . the present study involves the 29@xmath4.97 cepheid aq puppis ( @xmath19 , @xmath20 ) , which presents unique complications arising from the high degree of differential reddening by interstellar dust along its line of sight .

Suppose that you have an abstract for a scientific paper: we present hi 21 cm line observations , obtained with the australia telescope compact array , of two dwarf elliptical galaxies ( des ) in the fornax cluster : fcc032 and fcc336 . the optical positions and velocities of these galaxies place them well within the fornax cluster . fcc032 was detected at the 3@xmath0 significance level with a total hi flux density of 0.66@xmath10.22 jy km s@xmath2 or an hi mass of 5.0@xmath11.7@xmath3 . based on our deep h@xmath4 $ ] narrow - band images , obtained with fors2 mounted on the vlt , this de was already known to contain 600 - 1800 @xmath5 of ionised hydrogen ( depending on the relative strengths of the h@xmath6 and [ nii ] emission lines ) . hence , this is the first study of the complex , multi - phase interstellar medium of a de outside the local group . fcc336 was detected at the same significance level : 0.37@xmath10.10 jy km s@xmath2 or a total hi mass of 2.8@xmath10.7@xmath7 . using a compilation of hi data of dwarf galaxies , we find that the observed high hi - mass boundary of the distribution of dirrs , bcds , and des in a @xmath8 versus @xmath9 diagram is in good agreement with a simple chemical evolution model with continuous star formation . the existence of many gas - poor des ( undetected at 21 cm ) suggest that the environment ( or more particularly , a galaxy s orbit within a cluster ) also plays a crucial role in determining the amount of gas in present - day des . e.g. , fcc032 and fcc336 are located in the sparsely populated outskirts of the fornax cluster . this is in agreement with hi surveys of des in the virgo cluster and an h@xmath6 survey of the fornax cluster , which also tend to place gas - rich dwarf galaxies in the cluster periphery . = = = = = = = = # 1 # 1 # 1 # 1 @mathgroup@group @mathgroup@normal@groupeurmn @mathgroup@bold@groupeurbn @mathgroup@group @mathgroup@normal@groupmsamn @mathgroup@bold@groupmsamn = `` 019 = ' ' 016 = `` 040 = ' ' 336 = " 33e = = = = = = = = # 1 # 1 # 1 # 1 = = = = = = = = .... And you have already written the first three sentences of the full article: one would not expect that dwarf elliptical galaxies ( des ) in dense environments contain a significant interstellar medium ( ism ) . several arguments support this statement . supernova - explosions are able to transfer enough energy to the ism to heat it above the escape velocity in the least massive dwarfs @xcite .. Please generate the next two sentences of the article

alternatively , the frequent high - speed interactions with giant cluster - members to which a small late - type disk galaxy is subjected can transform it into a gasless spheroidal de - like object . this `` galaxy harassment '' process @xcite induces a dramatic morphological evolution on a time - span of about 3 gyr .

Suppose that you have an abstract for a scientific paper: starting off with two distinct initially static stellar cores ( i ) florides interior ( constant density , vanishing radial pressure ) and ( ii ) wyman interior ( constant density , nonvanishing radial pressure ) , we explore the dynamics of these two models once hydrostatic equilibrium is lost . we show that although the time of formation of horizon , evolution of the mass and proper radius are independent of the chosen initially static configurations _ _ _ _ , there is a significant difference in the temperature profiles of the radiating bodies as the collapse proceeds . . And you have already written the first three sentences of the full article: one of the most interesting areas in the study of general relativity and astrophysics is the end states of gravitational collapse of massive stars . once a massive star has exhausted its thermonuclear source of energy , it begins its endless gravitational collapse . interest in the outcome of this collapse started in 1939 , when oppenheimer and snyder @xcite considered a spherically symmetric dust cloud which underwent continued collapse .. Please generate the next two sentences of the article

the first exact solution to the einstein field equations was presented by karl schwarzschild in 1916 @xcite which described the exterior gravitational field of a static sphere . schwarzschild then presented the solution describing the gravitational field for the interior of a static spherically symmetric star , where the matter was assumed to be a perfect fluid with constant density . in 1951

Suppose that you have an abstract for a scientific paper: we consider a general multiple antenna network with multiple sources , multiple destinations and multiple relays in terms of the diversity - multiplexing tradeoff ( dmt ) . we examine several subcases of this most general problem taking into account the processing capability of the relays ( half - duplex or full - duplex ) , and the network geometry ( clustered or non - clustered ) . we first study the multiple antenna relay channel with a full - duplex relay to understand the effect of increased degrees of freedom in the direct link . we find dmt upper bounds and investigate the achievable performance of decode - and - forward ( df ) , and compress - and - forward ( cf ) protocols . our results suggest that while df is dmtoptimal when all terminals have one antenna each , it may not maintain its good performance when the degrees of freedom in the direct link is increased , whereas cf continues to perform optimally . we also study the multiple antenna relay channel with a half - duplex relay . we show that the half - duplex dmt behavior can significantly be different from the full - duplex case . we find that cf is dmt optimal for half - duplex relaying as well , and is the first protocol known to achieve the half - duplex relay dmt . we next study the multiple - access relay channel ( marc ) dmt . finally , we investigate a system with a single source - destination pair and multiple relays , each node with a single antenna , and show that even under the idealistic assumption of full - duplex relays and a clustered network , this virtual multi - input multi - output ( mimo ) system can never fully mimic a real mimo dmt . for cooperative systems with multiple sources and multiple destinations the same limitation remains to be in effect . cooperation , diversity - multiplexing tradeoff , fading channels , multiple - input multiple - output ( mimo ) , relay channel , wireless networks . . And you have already written the first three sentences of the full article: next - generation wireless communication systems demand both high transmission rates and a quality - of - service guarantee . this demand directly conflicts with the properties of the wireless medium . as a result of the scatterers in the environment and mobile terminals , signal components received over different propagation paths may add destructively or constructively and cause random fluctuations in the received signal strength @xcite . this phenomena , which is called fading , degrades the system performance .. Please generate the next two sentences of the article

multi - input multi - output ( mimo ) systems introduce spatial diversity to combat fading . additionally , taking advantage of the rich scattering environment , mimo increases spatial multiplexing @xcite . user cooperation / relaying is a practical alternative to mimo when the size of the wireless device is limited .

Suppose that you have an abstract for a scientific paper: a microscopic model for the @xmath0 process is presented in the meson exchange framework , which in the pseudophysical region agrees with available quasiempirical information . the scalar ( @xmath1 ) and vector ( @xmath2 ) piece of correlated two pion exchange in the pion nucleon interaction is then derived via dispersion integrals over the unitarity cut . inherent ambiguities in the method and implications for the description of pion nucleon scattering data are discussed . . And you have already written the first three sentences of the full article: the interaction between a pion and a nucleon plays a prominent role in low and medium energy physics since it is an important ingredient in many other hadronic reactions , _ e.g. _ pion production in nucleon - nucleon collisions or scattering of a pion by a nucleus . recently we have presented a meson exchange model for @xmath3scattering @xcite which contains conventional direct and exchange pole diagrams ( fig .. Please generate the next two sentences of the article

[ fig : diags](a) ... [fig : diags](d ) ) plus @xmath1 and @xmath2exchange terms ( fig .

Suppose that you have an abstract for a scientific paper: narrow - line seyfert 1 galaxies ( nls1s ) are arguably one of the key agn subclasses in investigating the origin of the black hole mass - stellar velocity dispersion ( @xmath0 ) relation because of their high accretion rate and significantly low @xmath1 . currently , it is under discussion whether present - day nls1s offset from the @xmath0 relation . using the directly measured stellar velocity dispersion of 93 nls1s at z@xmath20.1 , and @xmath1 estimates based on the updated mass estimators , we investigate the @xmath0 relation of nls1s in comparison with broad - line agns . we find no strong evidence that the nls1s deviates from the @xmath0 relation , which is defined by reverberation - mapped type 1 agns and quiescent galaxies . however , there is a clear trend of the offset with the host galaxy morphology , i.e. , more inclined galaxies toward the line - of - sight have higher stellar velocity dispersion , suggesting that the rotational broadening plays a role in measuring stellar velocity dispersion based on the single - aperture spectra from the sloan digital sky survey . in addition , we provide the virial factor @xmath3 ( f = 1.12 ) , for @xmath1 estimators based on the fwhm of h@xmath4 , by jointly fitting the @xmath0 relation using quiescent galaxies and reverberation - mapped agns . . And you have already written the first three sentences of the full article: the scaling relation between black hole mass and host - galaxy properties , e.g. , the black hole mass@xmath5stellar velocity dispersion relation ( @xmath0 ) , suggests a coevolution of black holes and galaxies ( e.g. , * ? ? ? * ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

* ; * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: existence of self - similar , superposed pulse - train solutions of the nonlinear , coupled maxwell - schrdinger equations , with the frequencies controlled by the oscillator strengths of the transitions , is established . some of these excitations are specific to the resonant media , with energy levels in the configurations of @xmath0 and @xmath1 and arise because of the interference effects of cnoidal waves , as evidenced from some recently discovered identities involving the jacobian elliptic functions . interestingly , these excitations also admit a dual interpretation as single pulse - trains , with widely different amplitudes , which can lead to substantially different field intensities and population densities in different atomic levels . pacs number(s ) : 42.50.md , 42.50.hz , 42.65.tg . And you have already written the first three sentences of the full article: the generation of shape preserving excitations in nonlinear media has been the subject of extensive research in diverse areas of physics , ranging from hydrodynamics @xcite , particle physics @xcite to quantum optics @xcite and optical communications@xcite . starting from the explanation of the solitary waves in shallow water@xcite , these solutions of the nonlinear wave equations have found ample experimental verifications . in optical context , the nonlinear nature of the coupled maxwell- schrdinger equations @xcite , describing the interaction of classical radiation with matter in a resonant media , has naturally generated tremendous interest in the study of the pulse @xcite and pulse - train solutions@xcite . recently the continuous pulse - train soliton solutions have been observed experimentally for the two - level system @xcite . for a detailed overview ,. Please generate the next two sentences of the article

the interested readers are referred to refs.(@xcite ) , apart from the above references . + the common factor that governs the existence of the self - similar excitations in various nonlinear systems is the critical balance between nonlinearity and dispersion @xcite .

Suppose that you have an abstract for a scientific paper: we explore the physical properties of a unified microscopic theory for the coexistence of superconductivity and charge density waves in two - dimensional transition metal dichalcogenides . in the case of particle - hole symmetry the elementary particles are dirac fermions at the nodes of the charge density wave gap . when particle - hole symmetry is broken electron ( hole ) pockets are formed around the fermi surface . the superconducting ground state emerges from the pairing of nodal quasi - particles mediated by acoustic phonons via a piezoelectric coupling . we calculate several properties in the @xmath0-wave superconducting phase , including specific heat , ultra - sound absorption , nuclear magnetic relaxation , thermal , and optical conductivities . in the case with particle - hole symmetry , the specific heat jump at the transition deviates strongly from ordinary superconductors . the nmr response shows an anomalous anisotropy due to the broken time - reversal symmetry of the superconducting gap , induced by the triple cdw state . the loss of lattice inversion symmetry in the charge density wave phase leads to anomalous coherence factors in the optical conductivity and to the appearance of an absorption edge at the optical gap energy . furthermore , optical and thermal conductivities display anomalous peaks in the infrared when particle - hole symmetry is broken . . And you have already written the first three sentences of the full article: the quasi two - dimensional ( 2d ) transition metal dichalcogenides ( tmd ) 2h - tase@xmath1 , 2h - tas@xmath1 and 2h - nbse@xmath1 are layered compounds where @xmath0-wave superconductivity coexists with a charge density wave ( cdw ) @xcite at low temperatures , and whose transport properties are highly anisotropic in the high temperature cdw phase @xcite . there is a vast literature reporting anomalous effects in the cdw phase , including , non - linear hall effect , anomalous impurity effects in the superconducting ( sc ) phase @xcite , stripe phases @xcite , and different regimes of commensurability @xcite . recent angle resolved photoemission experiments ( arpes ) reveal that the quasi - particles of tase@xmath1 have a marginal fermi liquid ( mfl ) lifetime @xcite .. Please generate the next two sentences of the article

this scenario becomes more exciting by the verification that some of the physical properties of tmd , such as the linear growth of the normal resistivity with temperature @xcite , and the strong anisotropy in the in - plane and out - of - plane transport are similar to the same properties in the high temperature superconductors ( htc ) . htc do not show a cdw gap but a @xmath2wave _ pseudo - gap _ coexisting with the superconducting phase .

Suppose that you have an abstract for a scientific paper: molybdenum supported thin films of scn , mgo and naf with a cu adatom have been studied in the framework of density functional theory . we have observed a charge transfer from the metal / film interface to the cu atom and investigated its relation to surface and interface deformations . we find that a weak interaction between the metal and the film is a promising prerequisite for adatom charging . the detailed study of cu / naf / mo and naf / mo indicates that the distortion of the naf film caused by the cu adsorption has essentially anharmonic character , as it is coupled to a strong charge redistribution in the system . . And you have already written the first three sentences of the full article: modern experimental techniques made it possible to grow epitaxial films with atomic precision creating a whole new class of complex materials with unique properties where interfaces often play the decisive role @xcite . ultrathin films of insulating materials grown on a metal support are one example of such materials @xcite . in particular , due to the proximity of the insulator / metal interface to the vacuum / insulator interface the adsorption properties of such complex substrates can be completely different from those of the surfaces of the corresponding insulating materials @xcite . this makes complex substrates very interesting for applications in the field of heterogeneous catalysis @xcite . in this regard ,. Please generate the next two sentences of the article

one of the intriguing properties of metal supported thin films is a charging of neutral atoms adsorbed on them . this phenomenon was first found when the charge of an au atom adsorbed on nacl supported by cu was manipulated with scanning tunneling microscope ( stm ) @xcite .

Suppose that you have an abstract for a scientific paper: we present new radio observations of the recently identified , young galactic supernova remnant ( snr ) rx j0852.04622 ( g266.201.2 ) made at 1.40 ghz with a resolution of @xmath0 . these results , along with other radio observations from the literature , are used to derive the extent , morphology and radio spectrum of the remnant . the possible age and distance to this remnant are discussed , along with the consequences of its properties especially its low radio surface brightness for statistical studies of galactic snrs . the extended features identified by combi et al . ( @xcite ) are considered , and we conclude that these are probably unrelated to the new remnant . if rx j0852.04622 is nearby , as is suggested by the available @xmath1-ray data , then the range of intrinsic radio luminosities for snrs of the same diameter may be much larger than was previously thought . . And you have already written the first three sentences of the full article: recently , aschenbach ( @xcite ) reported the discovery of a young supernova remnant ( snr ) designated rx j0852.04622 from high - energy x - ray data from the rosat all - sky survey . this new snr appears near the southeastern boundary of the vela remnant ( e.g. milne @xcite ; aschenbach et al . @xcite ; duncan et al .. Please generate the next two sentences of the article

@xcite ) , appearing in x - rays ( with @xmath2 1.3 kev ) as a nearly circular `` ring '' approximately @xmath3 in angular diameter . around the circumference of this ring are a number of enhancements in the x - ray emission , the most prominent of which appears near the northwestern perimeter .

Suppose that you have an abstract for a scientific paper: we demonstrate a new tool for filtering technical and electronic noises from pulses of light , especially relevant for signal processing methods in quantum optics experiments as a means to achieve the shot - noise level and reduce strong technical noise by means of a pattern function . we provide the theory of this pattern - function filtering based on balance detection . moreover , we implement an experimental demonstration where 10 db of technical noise is filtered after balance detection . such filter can readily be used for probing magnetic atomic ensembles in environments with strong technical noise . . And you have already written the first three sentences of the full article: balanced detection provides a unique tool for many physical , biological and chemical applications . in particular , it has proven useful for improving the coherent detection in telecommunication systems @xcite , in the measurement of polarization squeezing @xcite , for the detection of polarization states of weak signals via homodyne detection @xcite , and in the study of light - atom interactions @xcite . interestingly , balanced detection has proved to be useful when performing highly sensitive magnetometry @xcite , even at the shot - noise level , in the continuous - wave @xcite and pulsed regimes @xcite . the detection of light pulses at the shot - noise level with low or negligible noise contributions , namely from detection electronics ( electronic noise ) and from intensity fluctuations ( technical noise ) , is of paramount importance in many quantum optics experiments .. Please generate the next two sentences of the article

while electronic noise can be overcome by making use of better electronic equipment , technical noise requires special techniques to filter it , such as balanced detection and spectral filtering . even though several schemes have been implemented to overcome these noise sources @xcite , an optimal shot - noise signal recovery technique that can deal with both technical and electronic noises , has not been presented yet . in this paper

Suppose that you have an abstract for a scientific paper: starting from the central density slope anisotropy theorem of an & evans @xcite , recent investigations have shown that the involved density slope anisotropy inequality holds not only at the center , but at all radii ( i.e. globally ) in a very large class of spherical systems with positive phase space distribution function . here we present some additional analytical cases that further extend the validity of the global density slope anisotropy inequality . these new results , several numerical evidences , and the absence of known counter examples , lead us to conjecture that the global density slope anisotropy inequality could actually be a universal property of spherical systems with positive distribution function . address = dept . of astronomy , univ . of bologna , + via ranzani 1 , 40127 bologna , italy address = dept . of astronomy , univ . of bologna , + via ranzani 1 , 40127 bologna , italy , , altaddress = max - planck - institut fr ex . physik , garching , germany . And you have already written the first three sentences of the full article: in the study of stellar systems based on the `` @xmath0to@xmath1 '' approach ( where @xmath0 is the material density and @xmath1 is the associated phase space distribution function , hereafter df ) , @xmath0 is given , and specific assumptions on the internal dynamics of the model are made ( e.g. see @xcite , @xcite ) . in some special cases inversion formulae exist and the df can be obtained in integral form or as series expansion ( see , e.g. , @xcite@xcite ) . once the df of the system is derived , a non negativity check should be performed , and in case of failure the model must be discarded as unphysical , even if it provides a satisfactory description of data .. Please generate the next two sentences of the article

indeed , a minimal but essential requirement to be met by the df ( of each component ) of a stellar dynamical model is positivity over the accessible phase space . this requirement ( also known as phase

Suppose that you have an abstract for a scientific paper: in type iii seesaw model the heavy neutrinos are contained in leptonic triplet representations . the yukawa couplings of the triplet fermion and the left - handed neutrinos with the doublet higgs field produce the dirac mass terms . together with the majorana masses for the leptonic triplets , the light neutrinos obtain non - zero seesaw masses . we point out that it is also possible to have a quadruplet higgs field to produce the dirac mass terms to facilitate the seesaw mechanism . the vacuum expectation value of the quadruplet higgs is constrained to be small by electroweak precision data . therefore the yukawa couplings of a quadruplet can be much larger than those for a doublet . we also find that unlike the usual type iii seesaw model where at least two copies of leptonic triplets are needed , with both doublet and quadruplet higgs representations , just one leptonic triplet is possible to have a phenomenologically acceptable model because light neutrino masses can receive sizable contributions at both tree and one loop levels . large yukawa couplings of the quadruplet can induce observable effects for lepton flavor violating processes @xmath0 and @xmath1 conversion . implications of the recent @xmath2 limit from meg and also limit on @xmath3 conversion on au are also given . some interesting collider signatures for the doubly charged higgs boson in the quadruplet are discussed . . And you have already written the first three sentences of the full article: the type iii seesaw contains leptonic triplets @xmath4 under the standard model ( sm ) gauge group @xmath5 as @xmath6 , @xmath7@xcite . in tensor notation , the triplet can be written as @xmath8 symmetric in @xmath9 and @xmath10 , where @xmath9 and @xmath10 take the values @xmath11 and @xmath12 . @xmath13 , @xmath14 and @xmath15 .. Please generate the next two sentences of the article

the yukawa couplings related to neutrino and charged lepton masses come from the following terms @xmath16 where the super - script `` c '' indicates the charge conjugation . the lepton doublet @xmath17 , @xmath18 , and higgs doublet @xmath19 ( @xmath20 ) have the components given by @xmath21 , @xmath22 , and @xmath23 , @xmath24 . with just one higgs doublet , @xmath25 and @xmath26

Suppose that you have an abstract for a scientific paper: the differential event rate for direct detection of dark matter , both the time averaged and the modulated one due to the motion of the earth , are discussed . the calculations focus on relatively light cold dark matter candidates ( wimp ) and low energy transfers . it is shown that for some wimp masses the modulation amplitude may change sign . this effect can be exploited to yield information about the mass of the dark matter candidate . . And you have already written the first three sentences of the full article: the combined maxima-1 @xcite , boomerang @xcite , dasi @xcite and cobe / dmr cosmic microwave background ( cmb ) observations @xcite imply that the universe is flat @xcite and that most of the matter in the universe is dark @xcite , i.e. exotic . combining the data of these quite precise experiments one finds : @xmath0 since any `` invisible '' non exotic component can not possibly exceed @xmath1 of the above @xmath2 @xcite , exotic ( non baryonic ) matter is required and there is room for cold dark matter candidates or wimps ( weakly interacting massive particles ) . even though there exists firm indirect evidence for a halo of dark matter in galaxies from the observed rotational curves , see e.g the review @xcite , it is essential to directly detect such matter . the possibility of such detection , however , depends on the nature of the dark matter constituents and their interactions . since the wimp s are expected to be extremely non relativistic , with average kinetic energy @xmath3 , they are not likely to excite the nucleus .. Please generate the next two sentences of the article

so they can be directly detected mainly via the recoiling of a nucleus ( a , z ) in elastic scattering . the event rate for such a process can be computed from the following ingredients@xcite : i ) the elementary nucleon cross section .

Suppose that you have an abstract for a scientific paper: we study the probability distribution function ( pdf ) of mass surface densities , @xmath0 , of infrared dark cloud ( irdc ) g028.37 + 00.07 and its surrounding giant molecular cloud . this pdf constrains the physical processes , such as turbulence , magnetic fields and self - gravity , that are expected to be controlling cloud structure and star formation activity . the chosen irdc is of particular interest since it has almost 100,000 solar masses within a radius of 8 parsecs , making it one of the most massive , dense molecular structures known and is thus a potential site for the formation of a `` super star cluster . '' we study @xmath0 in two ways . first , we use a combination of nir and mir extinction maps that are able to probe the bulk of the cloud structure up to @xmath1(@xmath2 mag ) . second , we study the fir and sub - mm dust continuum emission from the cloud utilizing herschel pacs and spire images and paying careful attention to the effects of foreground and background contamination . we find that the pdfs from both methods , applied over a @xmath3(30 pc)-sized region that contains @xmath4 and encloses a minimum closed contour with @xmath5(@xmath6 mag ) , shows a log - normal shape with the peak measured at @xmath7(@xmath8 mag ) . there is tentative evidence for the presence of a high-@xmath0 power law tail that contains from @xmath9 to 8% of the mass of the cloud material . we discuss the implications of these results for the physical processes occurring in this cloud . . And you have already written the first three sentences of the full article: the probability distribution function ( pdf ) of mass surface density , @xmath0 , is one of the simplest metrics of interstellar cloud structure . this @xmath0-pdf is , in principle , much easier to observe than other distributions , such as volume density , thus making it a convenient metric with which to compare observed and simulated clouds . the @xmath0-pdf shape should be sensitive to physical processes occurring in the clouds .. Please generate the next two sentences of the article

for example , simulations of driven supersonic hydrodynamic ( and if including magnetic fields , super - alfvnic ) turbulence of non - self - gravitating gas in periodic boxes yield lognormal @xmath0-pdfs ( e.g. , federrath 2013 ; padoan et al . 2014 ) , i.e. , the area - weighted pdf , @xmath10 , can be well - fit by a lognormal : @xmath11 , \label{eq : lognormal}\ ] ] where @xmath12 is mean - normalized @xmath0 .

Suppose that you have an abstract for a scientific paper: we present time series photometry of the m dwarf transiting exoplanet system gj 436 obtained with the epoch ( extrasolar planet observation and characterization ) component of the nasa _ epoxi _ mission . we conduct a search of the high - precision time series for additional planets around gj 436 , which could be revealed either directly through their photometric transits , or indirectly through the variations these second planets induce on the transits of the previously known planet . in the case of gj 436 , the presence of a second planet is perhaps indicated by the residual orbital eccentricity of the known hot neptune companion . we find no candidate transits with significance higher than our detection limit . from monte carlo tests of the time series , we rule out transiting planets larger than 1.5 @xmath0 interior to gj 436b with 95% confidence , and larger than 1.25 @xmath0 with 80% confidence . assuming coplanarity of additional planets with the orbit of gj 436b , we can not expect that putative planets with orbital periods longer than about 3.4 days will transit . however , if such a planet were to transit , we rule out planets larger than 2.0 @xmath0 with orbital periods less than 8.5 days with 95% confidence . we also place dynamical constraints on additional bodies in the gj 436 system , independent of radial velocity measurements . our analysis should serve as a useful guide for similar analyses of transiting exoplanets for which radial velocity measurements are not available , such as those discovered by the _ kepler _ mission . from the lack of observed secular perturbations , we set upper limits on the mass of a second planet as small as 10 @xmath1 in coplanar orbits and 1 @xmath1 in non - coplanar orbits close to gj 436b . we present refined estimates of the system parameters for gj 436 . we find @xmath2 = @xmath3 @xmath4 , @xmath5 = @xmath6 @xmath7 , and @xmath8 = @xmath9 @xmath0 . we also report a sinusoidal modulation in the gj 436 light curve that.... And you have already written the first three sentences of the full article: _ epoxi _ ( epoch + dixi ) is a nasa discovery program mission of opportunity using the deep impact flyby spacecraft @xcite . from january through august 2008 , the epoch ( extrasolar planet observation and characterization ) science investigation used the hri camera @xcite with a broad visible bandpass to gather precise , rapid cadence photometric time series of known transiting exoplanet systems . the majority of these targets were each observed nearly continuously for several weeks at a time . in table 1 we give basic information about the seven epoch targets and the number of transits of each that epoch observed .. Please generate the next two sentences of the article

one of the epoch science goals is a search for additional planets in these systems . such planets would be revealed either through the variations they induce on the transits of the known exoplanet , or directly through the transit of the second planet itself .

Suppose that you have an abstract for a scientific paper: understanding the physical origin of creep in calcium silicate hydrate ( c s h ) is of primary importance , both for fundamental and practical interest . here , we present a new method , based on molecular dynamics simulation , allowing us to simulate the long - term visco - elastic deformations of c s h . under a given shear stress , c s h features a gradually increasing shear strain , which follows a logarithmic law . the computed creep modulus is found to be independent of the shear stress applied and is in excellent agreement with nanoindentation measurements , as extrapolated to zero porosity . . And you have already written the first three sentences of the full article: creep is a major limitation of concrete . indeed , it has been suggested that creep deformations are logarithmic , that is , virtually infinite and without asymptotic bound , which raises safety issues @xcite . the creep of concrete is generally thought to be mainly caused by the viscoelastic and viscoplastic behavior of the cement hydrates @xcite . while secondary cementitious phases can show viscoelastic behavior @xcite , the rate and extent of viscoelastic deformations of such phases is far less significant than that calcium silicate . Please generate the next two sentences of the article

hydrate ( c s h ) , the binding phase of the cement paste @xcite . as such , understanding the physical mechanism of the creep of c s h is of primary importance . despite the prevalence of concrete in the built environment , the molecular structure of c s h has just recently been proposed @xcite , which makes it possible to investigate its mechanical properties at the atomic scale . here , relying on the newly available model , we present a new methodology allowing us to simulate the long - term creep deformation of bulk c s h ( at zero porosity , i.e. , at the scale of the grains ) . results show an excellent agreement with nanoindentation measurements @xcite .

Suppose that you have an abstract for a scientific paper: we perform high - resolution hydrodynamic simulations of a milky way - mass galaxy in a fully cosmological setting using the adaptive mesh refinement code , _ enzo _ , and study the kinematics of gas in the simulated galactic halo . we find that the gas inflow occurs mostly along filamentary structures in the halo . the warm - hot ( @xmath0 k @xmath1 @xmath2 k ) and hot ( @xmath3 k ) ionized gases are found to dominate the overall mass accretion in the system ( with @xmath45 m@xmath5 yr@xmath6 ) over a large range of distances , extending from the virial radius to the vicinity of the disk . most of the inflowing gas ( by mass ) does not cool , and the small fraction that manages to cool does so primarily close to the galaxy ( @xmath7 kpc ) , perhaps comprising the neutral gas that may be detectable as , e.g. , high - velocity clouds . the neutral clouds are embedded within larger , accreting filamentary flows , and represent only a small fraction of the total mass inflow rate . the inflowing gas has relatively low metallicity ( @xmath8 ) . the outer layers of the filamentary inflows are heated due to compression as they approach the disk . in addition to the inflow , we find high - velocity , metal - enriched outflows of hot gas driven by supernova feedback . our results are consistent with observations of halo gas at low @xmath9 . . And you have already written the first three sentences of the full article: chemical evolution models and analysis of the color magnitude diagram of the hipparcos dataset indicate the milky way has been forming stars at a nearly constant , yet slowly declining , rate of 13 @xmath10 yr@xmath6 over the past several gigayears @xcite . in addition , a continuous supply of low metallicity gas coming in at a slightly lower rate is needed to account for the metallicity of the long - lived galactic stars ( the g - dwarf problem ; see * ? ? ? * for a review ) . the source of this fuel has been the subject of decades of research ( see * ? ? ? * for a review ) .. Please generate the next two sentences of the article

high - velocity clouds ( hvcs ) detected in h i surveys have long been suspected as the source of the star formation fuel @xcite . now that distances to most large complexes are known , the mass accretion rate from hvc complexes can be estimated @xcite .

Suppose that you have an abstract for a scientific paper: a new method for the localization of crystalline orbitals for entangled energy bands is proposed . it is an extension of the wannier - boys algorithm [ c.m . zicovich - wilson , r. dovesi , and v.r . saunders , j. chem . phys . * 115 * , 9708 ( 2001 ) ] which is particularly well - suited for linear combination of atomic orbital representations of the bloch waves . it allows the inclusion of additional bands during the optimization of the unitary hybridization matrix used in the multi - band wannier transformation . by a projection technique , the proper chemical character is extracted from the bloch waves and compact localized orbitals are obtained even for entangled bands . the performance of the new projective wannier - boys localization is demonstrated on the low - lying unoccupied bands of _ trans_-polyacetylene , diamond and silicon . . And you have already written the first three sentences of the full article: localization of wannier functions ( wf ) has attracted great attention of scientists in the recent years . despite the success of describing most of the physical phenomena in crystals in terms of bloch waves ( bw ) , wannier functions have obvious advantages . to mention a few : wfs provide a chemically intuitive picture of the electronic structure in crystals , using localized wfs , physical quantities such as effective born charges and spontaneous polarization can be evaluated in a very simple way , @xcite and they play a central role in many post hartree - fock electron correlation methods .. Please generate the next two sentences of the article

@xcite several rigorous schemes for the localization of wfs have been proposed so far . they fall into two categories , those which are based on the variational principle , @xcite and those which are an extension of the foster - boys localization criterion @xcite for periodic systems .

Suppose that you have an abstract for a scientific paper: we consider possible new physics contributions to @xmath0 assuming the new physics modifies ( chromo)magnetic and electric form factors in @xmath1 and @xmath2 with the same chirality structure as in the standard model . parametrizing the new physics effects on @xmath1 and @xmath2 in terms of four real parameters , one finds that there are enough region of parameter space in which the measured branching ratio for @xmath3 can be accomodated , and the predicted cp violation effect could be as large as @xmath4 . moreover , the branching ratio and the forward - backward asymmetry of a lepton in @xmath5 and the tau polarization asymmetry in @xmath6 can be deviated from the sm predictions by a factor of @xmath7 , which can be accessible at b factories . we also discuss these observables in a specific class of supersymmetric models with gluino - mediated flavor changing neutral current ( fcnc ) . . And you have already written the first three sentences of the full article: the missions of @xmath8factories under constructions are ( i ) to test the cp violation in the standard model ( sm ) _ la _ kobayashi - maskawa scheme @xcite , and ( ii ) to find out any new flavor violation and especially new source of cp violation beyond the km phase in the sm with three generations . the latter is well motivated by the fact that the km phase in the sm may not be enough to generate the baryon number asymmetry in the universe . in terms of physics view point , the second mission seems more exciting one , since it could uncover a veil beyond the sm and provide an ingredient that is necessary to explain baryon number asymmetry of the universe . then , one has to seek for a possible signal of new physics in rare decays of @xmath8mesons and cp violation therein .. Please generate the next two sentences of the article

one could choose his / her own favorite models to work out the consequences of such model to the physics issues that could be investigated at b factories . or one could work in the effective field theory framework , in a manner as much as model - independent as possible .

Suppose that you have an abstract for a scientific paper: a great deal of research work has been undertaken in @xmath0-clustering study since the pioneering discovery of @xmath1c+@xmath1c molecular resonances half a century ago . our knowledge on physics of nuclear molecules has increased considerably and nuclear clustering remains one of the most fruitful domains of nuclear physics , facing some of the greatest challenges and opportunities in the years ahead . the occurrence of exotic " shapes in light @xmath2=@xmath3 @xmath0-like nuclei is investigated . various approaches of the superdeformed and hyperdeformed bands associated with quasimolecular resonant structures are presented . evolution of clustering from stability to the drip - lines is examined : clustering aspects are , in particular , discussed for light exotic nuclei with large neutron excess such as neutron - rich oxygen isotopes with their complete spectrocopy . . And you have already written the first three sentences of the full article: one of the greatest challenges in nuclear science is the understanding of the structure of light nuclei from both the experimental and theoretical perspectives . starting in the 1960s the search for resonant structures in the excitation functions for various combinations of light @xmath0-cluster ( @xmath2=@xmath3 ) nuclei in the energy regime from the coulomb barrier up to regions with excitation energies of @xmath4=20@xmath550 mev remains a subject of contemporary debate @xcite . these resonances @xcite have been interpreted in terms of nuclear molecules @xcite .. Please generate the next two sentences of the article

the question of how quasimolecular resonances may reflect continuous transitions from scattering states in the ion - ion potential to true cluster states in the compound systems was still unresolved in the 1990s @xcite . in many cases , these resonant structures have been associated with strongly - deformed shapes and with @xmath0-clustering phenomena @xcite , predicted from the nilsson - strutinsky approach , the cranked @xmath0-cluster model @xcite , or other mean - field calculations @xcite . in light

Suppose that you have an abstract for a scientific paper: we obtain general formulae for the plus- and cross- polarized waveforms of gravitational radiation emitted by a cosmic string loop in transverse , traceless ( synchronous , harmonic ) gauge . these equations are then specialized to the case of piecewise linear loops , and it is shown that the general waveform for such a loop is a piecewise linear function . we give several simple examples of the waveforms from such loops . we also discuss the relation between the gravitational radiation by a smooth loop and by a piecewise linear approximation to it . . And you have already written the first three sentences of the full article: cosmic strings are one dimensional topological defects that may have formed if the vacuum underwent a phase transition at very early times breaking a local @xmath0 symmetry @xcite . the resulting network of strings is of cosmological interest if the strings have a large enough mass per unit length , @xmath1 . if @xmath2 , where @xmath3 is newton s constant and @xmath4 is the speed of light ( i.e. @xmath5g / cm ) then cosmic strings may be massive enough to have provided the density perturbations necessary to produce the large scale structure we observe in the universe today and could explain the pattern of anisotropies observed in the cosmic microwave background @xcite . the main constraints on @xmath1 come from observational bounds on the amount of gravitational background radiation emitted by cosmic string loops ( @xmath6@xcite and references therein ) .. Please generate the next two sentences of the article

a loop of cosmic string is formed when two sections of a long string ( a string with length greater than the horizon length ) meet and intercommute . once formed , loops begin to oscillate under their own tension , undergoing a process of self - intersection ( fragmentation ) and eventually creating a family of non - self - intersecting oscillating loops . the gravitational radiation emitted by each loop as it oscillates contributes to the total background gravitational radiation . in a pair of papers

Suppose that you have an abstract for a scientific paper: we study gravitationally collapsing models of pressureless dust , fluids with pressure , and the generalized chaplygin gas ( gcg ) shell in ( 2 + 1)-dimensional spacetimes . various collapse scenarios are investigated under a variety of the background configurations such as anti - de sitter(ads ) black hole , de sitter ( ds ) space , flat and ads space with a conical deficit . as with the case of a disk of dust , we find that the collapse of a dust shell coincides with the oppenheimer - snyder type collapse to a black hole provided the initial density is sufficiently large . we also find for all types of shell that collapse to a naked singularity is possible under a broad variety of initial conditions . for shells with pressure this singularity can occur for a finite radius of the shell . we also find that gcg shells exhibit diverse collapse scenarios , which can be easily demonstrated by an effective potential analysis . gr - qc/0609094 * gravitationally collapsing shells in ( 2 + 1 ) dimensions * + robert b. mann and john j. oh + department of physics , university of waterloo , + waterloo , ontario , n2l 3g1 , canada + pacs numbers : 04.20.jb , 04.50.+h , 97.60.lf . And you have already written the first three sentences of the full article: over the last few decades , general relativity in ( 2 + 1 ) dimensions has fascinated both field theorists and relativists because of its fertility as a test - bed for ideas about quantum gravity . one particular feature of interest is manifest when a negative cosmological constant is present . despite the fact that the spacetime geometry of this solution is an anti - de sitter ( ads ) spacetime , possessing negative constant curvature , a black hole can be present under a suitable choice of topological identifications @xcite .. Please generate the next two sentences of the article

this solution has drawn much attention since its inception from a wide variety of perspectives @xcite . shortly after the black hole solution was obtained , it was shown that it can be formed from a disk of pressureless dust undergoing gravitational collapse @xcite ( the three - dimensional analogue of oppenheimer - snyder type collapse ) , generalizing earlier results that suggested matter could collapse to form conical singularities @xcite .

Suppose that you have an abstract for a scientific paper: we describe the following new features which significantly enhance the power of the recently developed real - space imaginary - time @xmath0 scheme ( rieger _ et al . _ , comp . . commun . * 117 * , 211 ( 1999 ) ) for the calculation of self - energies and related quantities of solids : ( i ) to fit the smoothly decaying time / energy tails of the dynamically screened coulomb interaction and other quantities to model functions , treating only the remaining time / energy region close to zero numerically and performing the fourier transformation from time to energy and vice versa by a combination of analytic integration of the tails and gauss - legendre quadrature of the remaining part and ( ii ) to accelerate the convergence of the band sum in the calculation of the green s function by replacing higher unoccupied eigenstates by free electron states ( plane waves ) . these improvements make the calculation of larger systems ( surfaces , clusters , defects etc . ) accessible . . And you have already written the first three sentences of the full article: density - functional calculations provide reliable information about the ground state properties of electron systems but give , in principle , no access to the excitation spectrum of the system under study . excitations can be described by many - body perturbation theory which is , however , at present only computationally feasible for real materials in its simplest form , the @xmath0 approximation of hedin.@xcite the latter gives a comparatively simple expression for the self - energy operator , which allows the one - particle green s function of an interacting many - electron system to be described in terms of the green s function of a hypothetical non - interacting system with an effective potential . the green s function contains information not only about the ground - state density and energy but also about the quasiparticle ( qp ) spectrum .. Please generate the next two sentences of the article

the @xmath0 approximation has been successfully applied to the calculation of qp bandstructures of semiconductors and other materials,@xcite for a recent review see ref . . the real - space imaginary - time @xmath0 method , first proposed by rojas _

Suppose that you have an abstract for a scientific paper: for the additive white gaussian noise channel with average codeword power constraint , new coding methods are devised in which the codewords are sparse superpositions , that is , linear combinations of subsets of vectors from a given design , with the possible messages indexed by the choice of subset . decoding is by least squares , tailored to the assumed form of linear combination . communication is shown to be reliable with error probability exponentially small for all rates up to the shannon capacity . . And you have already written the first three sentences of the full article: the additive white gaussian noise channel is basic to shannon theory and underlies practical communication models . we introduce classes of superposition codes for this channel and analyze their properties . we link theory and practice by showing superposition codes from polynomial size dictionaries with least squares decoding achieve exponentially small error probability for any communication rate less than the shannon capacity .. Please generate the next two sentences of the article

a companion paper @xcite,@xcite provides a fast decoding method and its analysis . the developments involve a merging of modern perspectives on statistical linear model selection and information theory .

Suppose that you have an abstract for a scientific paper: we present a nonparametric approach to reconstruct the interaction between dark energy and dark matter directly from snia union 2.1 data using gaussian processes , which is a fully bayesian approach for smoothing data . in this method , once the equation of state ( @xmath0 ) of dark energy is specified , the interaction can be reconstructed as a function of redshift . for the decaying vacuum energy case with @xmath1 , the reconstructed interaction is consistent with the standard @xmath2cdm model , namely , there is no evidence for the interaction . this also holds for the constant @xmath0 cases from @xmath3 to @xmath4 and for the chevallier - polarski - linder ( cpl ) parametrization case . if the equation of state deviates obviously from @xmath5 , the reconstructed interaction exists at @xmath6 confidence level . this shows the degeneracy between the interaction and the equation of state of dark energy when they get constraints from the observational data . . And you have already written the first three sentences of the full article: it has been more than fifteen years since the universe was found in accelerating expansion @xcite . however , it is fair to say that its origin is still not yet clear . a possible explanation of this cosmic acceleration is provided by the introduction of a fluid with negative pressure called dark energy ( de ) . the simplest dark energy candidate is the cosmological constant @xmath2 with the equation of state @xmath7 . the tiny cosmological constant together with the cold dark matter ( cdm ) ( called the @xmath2cdm model ) turned out to be the standard model which fits the current observational data sets consistently . in spite of this success , however , it is faced with the fine - tuning problem @xcite and the coincidence problem .. Please generate the next two sentences of the article

the former arises from the fact that the present - time observed value for the vacuum energy density is more than 120 orders of magnitude smaller than the naive estimate from quantum field theory . the later is the question why we live in such a special moment that the densities of dark energy and dark matter are of the same order .

Suppose that you have an abstract for a scientific paper: magnetised turbulence is ubiquitous in astrophysical systems , where it notoriously spans a broad range of spatial scales . phenomenological theories of mhd turbulence describe the self - similar dynamics of turbulent fluctuations in the inertial range of scales . numerical simulations serve to guide and test these theories . however , the computational power that is currently available restricts the simulations to reynolds numbers that are significantly smaller than those in astrophysical settings . in order to increase computational efficiency and , therefore , probe a larger range of scales , one often takes into account the fundamental anisotropy of field - guided mhd turbulence , with gradients being much slower in the field - parallel direction . the simulations are then optimised by employing the reduced mhd equations and relaxing the field - parallel numerical resolution . in this work we explore a different possibility . we propose that there exist certain quantities that are remarkably stable with respect to the reynolds number . as an illustration , we study the alignment angle between the magnetic and velocity fluctuations in mhd turbulence , measured as the ratio of two specially constructed structure functions . we find that the scaling of this ratio can be extended surprisingly well into the regime of relatively low reynolds number . however , the extended scaling becomes easily spoiled when the dissipation range in the simulations is under - resolved . thus , taking the numerical optimisation methods too far can lead to spurious numerical effects and erroneous representation of the physics of mhd turbulence , which in turn can affect our ability to correctly identify the physical mechanisms that are operating astrophysical systems . . And you have already written the first three sentences of the full article: magnetised turbulence pervades the universe . it is likely to play an important role in the transport of energy , momentum and charged particles in a diverse range of astrophysical plasmas . it is studied with regards to its influence on the generation of magnetic fields in stellar and planetary interiors , small - scale structure and heating of stellar winds , the transport of angular momentum in accretion discs , gravitational collapse and star formation in molecular clouds , the propagation and acceleration of cosmic rays , and interstellar scintillation ( e.g. , * ? ? ?. Please generate the next two sentences of the article

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Suppose that you have an abstract for a scientific paper: we re - examine the possible magnitude of the supersymmetric contribution to @xmath0 in the light of the constraints imposed by the absence of light charginos at lep 1.5 , implementing also other available phenomenological constraints . we find the supersymmetric contribution to be @xmath1 , and discuss the extent to which this upper bound could be strengthened by future constraints on the chargino and top - squark masses . such values of @xmath2 tend to disfavor a supersymmetry explanation of the apparent @xmath3 discrepancy . = 11 # 1#2 # 1#1| # 1| # 1 # 1#1 # 1#1 versim#1#2 # 1@xmath4 # 1@xmath5 11 # 1#2#3nucl . phys . b * # 1 * ( 19#2 ) # 3 # 1#2#3phys . lett . b * # 1 * ( 19#2 ) # 3 # 1#2#3b * # 1 * ( 19#2 ) # 3 # 1#2#3phys . rev . d * # 1 * ( 19#2 ) # 3 # 1#2#3phys . rev . lett . * # 1 * ( 19#2 ) # 3 # 1#2#3phys . rep . * # 1 * ( 19#2 ) # 3 # 1#2#3mod . phys . lett . a * # 1 * ( 19#2 ) # 3 # 1#2#3int . j. mod . phys . a * # 1 * ( 19#2 ) # 3 # 1ctp - tamu-#1 # 1hep - ph/#1 # 1hep - th/#1 6.0 in 8.5 in -0.25truein 0.30truein 0.30truein cern - th/95 - 314 + doe / er/4071722 + ctp - tamu-46/95 + act-17/95 + hep - ph/9512288 0.75 cm john ellis,@xmath6 jorge l. lopez,@xmath7 and d.v . nanopoulos@xmath8 + 0.5 cm @xmath6cern theory division , 1211 geneva 23 , switzerland + @xmath7department of physics , bonner nuclear lab , rice university + 6100 main street , houston , tx 77005 , usa + @xmath9center for theoretical physics , department of physics , texas a&m university + college station , tx 778434242 , usa + @xmath10astroparticle physics group , houston advanced research center ( harc ) + the mitchell campus , the woodlands , tx 77381 , usa + 0.5 cm cern - th/95 - 314 + doe / er/4071722 + ctp - tamu-46/95 + act-17/95 + december 1995 lep 1 has , unfortunately , provided a showcase for the standard model , which has been tested successfully down to the _ per mille _ level . the measurements have proved to be sensitive to quantum corrections.... And you have already written the first three sentences of the full article: we thank carlos wagner and james white for helpful discussions . the work of j. l. has been supported in part by doe grant de - fg05 - 93-er-40717 , and that of d.v.n . has been supported in part by doe grant de - fg05 - 91-er-40633 . 99 j. ellis , g.l .. Please generate the next two sentences of the article

fogli , and e. lisi , cern - th/95 - 202 ( ) , and references therein . p. renton , rapporteur talk at the international symposium on lepton and photon interactions at high energies , high energy physics , beijing ( august 1995 ) , oxford preprint ounp-95 - 20 ( 1995 ) .

Suppose that you have an abstract for a scientific paper: we design an algorithm writing down presentations of graph braid groups . generators are represented in terms of actual motions of robots moving without collisions on a given graph . a key ingredient is a new motion planning algorithm whose complexity is linear in the number of edges and quadratic in the number of robots . the computing algorithm implies that 2-point braid groups of all light planar graphs have presentations where all relators are commutators . . And you have already written the first three sentences of the full article: this is a research on the interface between topology and graph theory with applications to motion planning algorithms in robotics . we consider moving objects as zero - size points travelling without collisions along fixed tracks forming a graph , say on a factory floor or road map . we prefer to call these objects ` robots ' , although the reader may use a more neutral and abstract word like ` token ' . for practical reasons we study discrete analogues of configuration spaces of graphs , where robots can not be very close to each other , roughly one edge apart .. Please generate the next two sentences of the article

this discrete approach reduces the motion planning of real ( not zero - size ) vehicles to combinatorial questions about ideal robots moving on a subdivided graph . first we recall basic notions .

Suppose that you have an abstract for a scientific paper: we discuss the state tomography of a fixed qubit ( a spin-1/2 target particle ) , which is in general in a mixed state , through 1d scattering of a probe qubit off the target . two strategies are presented , by making use of different degrees of freedom of the probe , spin and momentum . remarkably , the spatial degree of freedom of the probe can be useful for the tomography of the qubit . . And you have already written the first three sentences of the full article: the determination of a quantum state is a highly nontrivial problem . a wave function itself , or more generally a density operator , is not an observable and can not be measured directly . one can see the state only through measurable quantities , which are related to the matrix elements of the density operator .. Please generate the next two sentences of the article

it is therefore an interesting and important issue to discuss how to infer a given quantum state from a list of observed quantities . such a problem is called state reconstruction or state tomography @xcite .

Suppose that you have an abstract for a scientific paper: the electromagnetic potential consisting in the coulomb plus the magnetic moment interactions between two nucleons is studied in nucleon - deuteron scattering . for states in which the relative @xmath0 angular momentum @xmath1 has low values the three nucleon problem has been solved using the correlated hyperspherical harmonic expansion basis . for states in which the angular momentum @xmath1 has large values , explicit formulae for the nucleon - deuteron magnetic moment interaction are derived and used to calculate the corresponding @xmath2-matrices in born approximation . then , the transition matrices describing @xmath0 elastic scattering have been derived including an infinite number of partial waves as required by the @xmath3 behavior of the magnetic moment interaction . appreciable effects are observed in the vector analyzing powers at low energies . the evolution of these effects by increasing the collision energy is examined . . And you have already written the first three sentences of the full article: the study of the magnetic moment interaction ( mm ) in the two - nucleon ( @xmath4 ) system has been subject of many investigations ( see refs . @xcite and references there in ) . although the intensity of this interaction is very small compared to the nuclear interaction , its long range behavior produces significant effects in nucleon . Please generate the next two sentences of the article

nucleon ( @xmath5 ) scattering . almost all modern @xmath5 potentials have been constructed considering the electromagnetic ( em ) interaction used in the nijmegen partial - wave analysis which includes the mm interaction between the two spin-@xmath6 particles as well as corrections to the @xmath7 coulomb potential as two - photon exchange , darwin - foldy and vacuum polarization terms .

Suppose that you have an abstract for a scientific paper: the relativistic time dilatation effect and einstein s second postulate of special relativity are used to analyse train / embankment thought expriments , both einstein s original one , and an extension where observers on two trains moving at different speeds , as well as on the embankment , are considered . whereas the relativistic analysis of einstein s experiment shows , in contradiction to einstein s interpretation , no ` relativity of simultaneity ' effect , the latter is apparent for certain events in the two - train experiment . the importance of relativistic kinematics embodied for photons in einstein s second postulate for the correct interpretation of the experiments is pointed out and demonstrated by detailed calculation of a related example . 24.5 cm -5pt -5pt -50pt addtoresetequationsection * j.h.field * dpartement de physique nuclaire et corpusculaire universit de genve . 24 , quai ernest - ansermet ch-1211 genve 4 . e - mail : john.field@cern.ch . And you have already written the first three sentences of the full article: einstein s train - embankment thought experiment ( tete ) , introduced in his popular book ` relativity , the special and general theory ' @xcite , first published in 1920 , has been used in many introductory textbooks and articles in the pedagogical literature @xcite , to introduce the concept of ` relativity of simultaneity ' of special relativity ( sr ) before considering the space - time lorentz transformation ( lt ) . since the complete relativistic interpretation of the tete depends both on direct physical consequences of the space - time lt the time dilatation effect and an understanding of the relativistic kinematics of photons as embodied in einstein s second postulate of sr , the possibility of introducing ` relativity of simultaneity ' in this simple way is illusory . this will become clear later in the present paper . however , as will be shown , a somewhat more sophisticated tete involving observers on the embankment and in two trains , with suitably chosen speeds , does indeed demonstrate the existence of a genuine relativity of simultaneity effect for certain events .. Please generate the next two sentences of the article

in contrast , the correct relativistic analysis of einstein s original tete shows that the ` lightning strokes ' will be judged to be simultaneous by both the train and the embankment observers , in contradiction to einstein s conclusion . the fallacy in einstein s reasoning is simple to understand .

Suppose that you have an abstract for a scientific paper: we analyze the possibility of encountering resonant transitions of high energy majorana neutrinos produced in active galactic nuclei ( agn ) . we consider gravitational , electromagnetic and matter effects and show that the latter are ignorable . resonant oscillations due to the gravitational interactions are shown to occur at energies in the pev range for magnetic moments in the @xmath0 range . coherent precession will dominate for larger magnetic moments . the alllowed regions for gravitational resonant transitions are obtained . # 1*@xmath1 # 1 @xmath1 * l c u ps . p . And you have already written the first three sentences of the full article: majorana particles are natural representations of massive neutrinos since the most general mass term for a four component fermion field describes two majorana particles with different masses . majorana neutrinos also appear in many extensions of the minimal standard model ; this is the case , for example , in so(10 ) grand unified theories @xcite . neutrinos in general , and in particular majorana neutrinos , can be used to probe the core of some of the most interesting cosmological objects . due to their small cross sections. Please generate the next two sentences of the article

these particles can stream out unaffected from even the most violent environments such as those present in active galactic nuclei ( agn ) . the presence of several neutrino flavors and spin states modifies this picture : in their trek from their source to the detector the neutrinos can undergo flavor and/or spin transitions which can obscure some of the features of the source . because of this , and due to the recent interest in neutrino astronomy ( e.g. amanda , nestor , baikal , etc .

Suppose that you have an abstract for a scientific paper: future observations with alma will be able to detect star - forming primordial galaxies , and perhaps even their dwarf spheroidal satellites , in co emission lines at redshifts approaching 10 . these observations will compliment other tools designed to study the dawn of galaxy formation , such as ngst and first . -0.5 in # 1/#1 # 1 [ firstpage ] cosmology : theory galaxies : evolution galaxies : starburst ism : molecules . And you have already written the first three sentences of the full article: modern cosmology continues to push the boundaries of the known universe to higher and higher redshifts . we are designing telescopes capable of detecting the very first objects that formed in the universe . the real breakthrough will occur in the next decade : the new generation space telescope ( ngst ) , the the far ir and submillimiter space telescope ( first ) , and the atacama large millimeter array ( alma ) will allow us to reach cosmological redshifts in excess of 10 .. Please generate the next two sentences of the article

alma is especially important , because it can observe co emission from primordial galaxies redshifted into the millimeter band . because the cosmic microwave background ( cmb ) temperature increases toward the past , higher rotational levels of the co molecule are populated at high redshifts @xcite , resulting in a large negative k - correction .

Suppose that you have an abstract for a scientific paper: a phase transformation in a metastable phase can be affected when it is subjected to a high intensity ultrasound wave . in this study we determined the effect of oscillation in pressure and temperature on a phase transformation using the gibbs droplet model in a generic format . the developed model is valid for both equilibrium and non - equilibrium clusters formed through a stationary or non - stationary process . we validated the underlying model by comparing the predicted kinetics of water droplet formation from the gas phase against experimental data in the absence of ultrasound . our results demonstrated better agreement with experimental data in comparison with classical nucleation theory . then , we determined the thermodynamics and kinetics of nucleation and the early stage of growth of clusters in an isothermal sonocrystallisation process . this new contribution shows that the effect of pressure on the kinetics of nucleation is cluster size - dependent in contrast to classical nucleation theory . . And you have already written the first three sentences of the full article: a phase transformation in a liquid phase can be affected when it is subject to high intensity acoustic waves . the rarefaction pressure swing of the wave can nucleate bubbles or induce a liquid - gas transition , @xcite called acoustic cavitation . several theoretical and experimental studies have shown that wave propagation in melts and supercooled liquids causes periodic phase transformation resulting in enhanced crystallisation .. Please generate the next two sentences of the article

@xcite for instance , liquid helium exposed to a high intensity focused ultrasound field undergoes liquid - solid transformation . @xcite nucleation of solid helium was observed to happen over the compression cycle followed by a decay and finally melting during the rarefaction cycle .

Suppose that you have an abstract for a scientific paper: we develop a practical forward fitting method based on the _ simplex algorithm with shaking _ , which allows the derivation of the magnetic field and other parameters along a solar flaring loop using microwave imaging spectroscopy of gyrosynchrotron emission . we illustrate the method using a model loop with spatially varying magnetic field , filled with uniform ambient density and an evenly distributed fast electron population with an isotropic , power - law energy distribution . . And you have already written the first three sentences of the full article: the coronal magnetic field is a key parameter controlling most solar flaring activity , particle acceleration and transport . however , unlike photospheric ( e.g. , * ? ? ? * ) and chromospheric @xcite magnetography data , there is currently a clear lack of quantitative information on the coronal magnetic field in the dynamically flaring region , which complicates the detailed modeling of fundamental physical processes occurring in the corona . it has been recognized that the use of radio imaging spectroscopy data can provide valuable information on the steady - state magnetic fields in active regions from the analysis of the gyroresonant and free - free radiation @xcite . one more way to deduce the coronal magnetic field value integrated along the line of sight is the use of imaging spectropolarimetry utilizing some optically thin infrared forbidden lines ( e.g. , * ? ? ?. Please generate the next two sentences of the article

however , the release of free magnetic energy in solar flares implies that the coronal magnetic field changes on relatively short time scales . from the optical measurements we know that magnetic field changes are seen _ after _ flares @xcite , but changes _ during _ flares can not be observed with available tools and methods . clearly the direct detection of these changes is of critical importance to understanding the energy release process .

Suppose that you have an abstract for a scientific paper: in this preceedings paper we report on a calculation of graphene s landau levels in a magnetic field . our calculations are based on a self - consistent hartree - fock approximation for graphene s massless - dirac continuum model . we find that because of graphene s chiral band structure interactions not only shift landau - level energies , as in a non - relativistic electron gas , but also alter landau level wavefunctions . we comment on the subtle continuum model regularization procedure necessary to correctly maintain the lattice - model s particle hole symmetry properties . . And you have already written the first three sentences of the full article: graphene , a one - atom - thick two - dimensional crystal of carbon atoms arranged in a honeycomb lattice , is a gapless semiconductor with an unusual massless dirac - fermion band structure that has long attracted theoretical interest @xcite . the low - energy properties of graphene are characterized by quasiparticle dispersion @xcite linear in momentum and by vanishing density - of - states at the neutral system fermi energy . the band eigenstates can be considiered as sublattice - pseudospin spinors and have a chiral property which qualitatively alters the way in which electron - electron interactions influence electronic properties . in particular electron - electron interactions. Please generate the next two sentences of the article

lead to a logarithimic enhancement of the fermi velocity in doped and undoped graphene related to a lack of screening at the dirac point @xcite . + in the presence of a magnetic field , graphene s electronic structure also changes in a nontrivial way when compared to the non - relativistic two dimensional electron gas ( 2deg ) case , leading to the so - called half - quantized hall effect @xcite in which the plateau values of the hall conductivity are given by @xmath0 .

Suppose that you have an abstract for a scientific paper: results on multi - lepton events at high transverse momenta , isolated lepton events with large missing transverse energy and single w production reported to this conference are based for the first time on the full data samples taken by two colliding experiments , h1 and zeus , at hera . the data correspond to an integrated luminosity of about @xmath0 from both experiments . . And you have already written the first three sentences of the full article: the data taking at hera , where electrons or positrons of @xmath1 collided with protons of up to @xmath2 , ended in june 2007 . each of the h1 and zeus experiments collected around @xmath3 data from the whole running period 1992 - 2007 . the largest samples are from the second data taking period 2003 - 2007 ( hera-2 ) . in comparison with hera-1 ,. Please generate the next two sentences of the article

the integrated luminosity of the @xmath4 and @xmath5 samples has a 2- and 10-fold increase , respectively . in addition , the @xmath6 and @xmath7 beams at hera-2 were longitudinally polarised .

Suppose that you have an abstract for a scientific paper: on the basis of the deformed series in quantum calculus , we generalize the partition function and the mass exponent of a multifractal , as well as the average of a random variable distributed over self - similar set . for the partition function , such expansion is shown to be determined by binomial - type combinations of the tsallis entropies related to manifold deformations , while the mass exponent expansion generalizes the known relation @xmath0 . we find equation for set of averages related to ordinary , escort , and generalized probabilities in terms of the deformed expansion as well . multifractals related to the cantor binomial set , exchange currency series , and porous surface condensates are considered as examples . + keywords : multifractal set ; deformation ; power series . + pacs 02.20.uw , 05.45.df + _ @xmath1institute of applied physics , nat . acad . sci . of ukraine , 58 , + petropavlovskaya st . , 40030 sumy , ukraine + _ _ @xmath2sumy state university , 2 , rimskii - korsakov st . , 40007 sumy , ukraine _ . And you have already written the first three sentences of the full article: fractal conception @xcite has become a widespread idea in contemporary science ( see refs . @xcite for review ) . characteristic feature of fractal sets is known to be the self - similarity : if one takes a part of the whole set , it looks like the original set after appropriate scaling .. Please generate the next two sentences of the article

formal basis of the self - similarity is the power - law function @xmath3 with the hurst exponent @xmath4 ( for time series , value @xmath5 is reduced to the fluctuation amplitude and @xmath6 is the interval size within which this amplitude is determined ) . while the simple case of monofractal is characterized by a single exponent @xmath4 , a multifractal system is described by a continuous spectrum of exponents , singularity spectrum @xmath7 with argument @xmath8 being the exponent deforming measures of elementary boxes that cover the fractal set @xcite . on the other hand ,

Suppose that you have an abstract for a scientific paper: entanglement of dipole - dipole interacting spins 1/2 is usually investigated when the energy of interaction with an external magnetic field ( the zeeman energy ) is greater than the energy of dipole interactions by three orders . under this condition only a non - equilibrium state of the spin system , realized by pulse radiofrequence irradiations , results in entanglement . the present paper deals with the opposite case : the dipolar interaction energy is the order of magnitude or even larger than the zeeman one . it was shown that entanglement appears under the thermodynamic equilibrium conditions and the concurrence reaches the maximum when the external field is directed perpendicular to the vector connecting the nuclei . for this direction of the field and a system of two spins with the hamiltonian accounting the realistic dipole - dipole interactions in low external magnetic field , the exact analytical expression for concurrence was also obtained . the condition of the entanglement appearance and the dependence of concurrence on the external magnetic field , temperature , and dipolar coupling constant were studied . . And you have already written the first three sentences of the full article: appreciation of the role of quantum entanglement @xcite as a resource in quantum teleportation @xcite , quantum communication @xcite , quantum computation @xcite , and quantum metrology @xcite has stimulated intensive qualitative and quantitative research . entanglement , as the quantum correlation , can bring up richer possibilities in the various fields of modern technology . therefore , in the past few years great efforts have been done to understand and create entanglement .. Please generate the next two sentences of the article

entanglement between two quantum systems can be generated due to their interaction only @xcite . it has recently been shown that , in a chain of nuclear spins @xmath0 = 1/2 , which is described by the idealized xy model for a spin system under the thermodynamic equilibrium conditions , entanglement appears at very low temperatures @xmath1 @xmath2k @xcite . in most real quantum systems , such as dipolar coupling spin system ,

Suppose that you have an abstract for a scientific paper: we examine the existence and stability of frozen waves in diblock copolymers with local conservation of the order parameter , which are described by the modified cahn hilliard model . it is shown that a range of stable waves exists and each can emerge from a ` general ' initial condition ( not only the one with the lowest density of free energy ) . we discuss the implications of these results for the use of block copolymers in templating nanostructures . . And you have already written the first three sentences of the full article: the cahn hilliard equation @xcite is often used to model microstructures arising from spinodal decomposition in , say , polymer mixtures . one of the simplest systems exhibiting this behavior would be a mixture of two polymers made from monomers , a and b , with distinct chemical properties e.g. , if a is hydrophilic whereas b is hydrophobic . in such cases ,. Please generate the next two sentences of the article

a monomer unit is attracted to units of the same type , while being repelled by the other type , implying that the most energetically favorable state is the one where a and b units are fully segregated . such a tendency is indeed confirmed by numerical modelling of the cahn hilliard equation @xcite and is also in agreement with stability analysis of similar models @xcite . one feature of the cahn

Suppose that you have an abstract for a scientific paper: the inclusion of fermionic loops contribution in numerical stochastic perturbation theory ( nspt ) has a nice feature : it does not cost so much ( provided only that an fft can be implemented in a fairly efficient way ) . focusing on lattice @xmath0 , we report on the performance of the current implementation of the algorithm and the status of first computations undertaken . . And you have already written the first three sentences of the full article: at lattice 2000 we discussed how to include fermionic loops contributions in numerical stochastic perturbation theory for lattice @xmath0 , an algorithm which we will refer to as unspt ( unquenched nspt ) . our main message here is that unquenching nspt results in not such a heavy computational overhead , provided only that an @xmath1 can be implemented in a fairly efficient way . @xmath1 is the main ingredient in constructing the fermion propagator by inverting the dirac kernel order by order . for a discussion of the foundations of unspt we refer the reader to @xcite . [. Please generate the next two sentences of the article

cols="<,<,<,<,<",options="header " , ] + the need for an efficient @xmath1 is what forced us to wait for apemille : our @xmath1 implementation mimic @xcite , which is based on a @xmath2 plus transpositions , an operation which asks for local addressing on a parallel architecture .