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5,000 | Suppose that you have an abstract for a scientific paper: a solution is presented for the asymptotic growth rate of the awgn - pseudoweight distribution of regular low - density parity - check ( ldpc ) code ensembles for a selected graph cover degree @xmath0 .
the evaluation of the growth rate requires solution of a system of @xmath1 nonlinear equations in @xmath1 unknowns .
simulation results for the pseudoweight distribution of two regular ldpc code ensembles are presented for graph covers of low degree . .
And you have already written the first three sentences of the full article: in classical coding theory , the _ weight distribution _ of a code is a useful tool for measuring a linear code s performance under maximum likelihood ( ml ) decoding . for codes
decoded using modern high - performance suboptimal decoding algorithms such as sum - product ( sp ) or linear - programming ( lp ) decoding , the _ pseudoweight _ is the appropriate analog of the codeword weight .
there are different definitions of pseudoweight for different channels ; one of primary importance is the _ additive white gaussian noise _ ( awgn ) pseudoweight ..
Please generate the next two sentences of the article | the pseudoweight distribution considers all codewords in all codes derived from finite covers of the tanner graph , which compete with the codewords to be the best sp decoding solution .
the set of pseudocodewords has a succinct characterization in terms of the so - called _ fundamental polytope _ or equivalently , the _ fundamental cone _ |
5,001 | Suppose that you have an abstract for a scientific paper: it is a long - standing question in exoplanet research if hot jupiters can influence the magnetic activity of their host stars .
while cool stars usually spin down with age and become inactive , an input of angular momentum through tidal interaction , as seen for example in close binaries , can preserve high activity levels over time .
this may also be the case for cool stars hosting a hot jupiter .
however , selection effects from planet detection methods often dominate the activity levels seen in samples of exoplanet host stars , and planet - induced , systematically enhanced stellar activity has not been detected unambiguously so far .
we have developed an approach to identify planet - induced stellar spin - up avoiding the selection biases from planet detection , by using visual proper motion binaries in which only one of the stars possesses a hot jupiter .
this approach immediately rids one of the ambiguities of detection biases : with two co - eval stars , the second star acts as a negative control .
we present results from our ongoing observational campaign at x - ray wavelengths and in the optical , and present several outstanding systems which display significant age / activity discrepancies presumably caused by their hot jupiters . .
And you have already written the first three sentences of the full article: almost all planet - hosting stars known today are cool stars ( spectral types f - m ) .
all cool stars display stellar activity a summarizing term for the occurrance of magnetic phenomena including flares , spots , and coronal high - energy emission .
the magnetic activity of planet - hosting stars is an important factor to understand the evolution of exoplanets ..
Please generate the next two sentences of the article | high - energy irradiation of close - in planets can lead to atmospheric evaporation @xcite , and coronal mass ejections and the stellar wind can strip away parts of the planetary atmosphere @xcite .
the stability and chemistry of exoplanetary atmospheres are both influenced by these stellar activity phenomena . |
5,002 | Suppose that you have an abstract for a scientific paper: we review the properties of @xmath0 galaxies studied with _ hst _ and with the keck telescopes , and discuss the detectability of ly@xmath1 emission - line galaxies out to @xmath2 based on these data and ongoing narrowband imaging surveys .
the brightest sources may show @xmath3 color breaks , although the high sky background at @xmath4 ( @xmath5 ) , makes such observations challenging for typical faint sources .
keck lris observations of the @xmath6 sdss quasar and @xmath0 galaxies observed with _
hst _ in the hdf show that the strength of the lyman break is evolving more slowly than extrapolations from models at @xmath7 would predict . .
And you have already written the first three sentences of the full article: over the last year and a half , a number of very high redshift ( @xmath0 ) galaxies have been reported ( dey et al .
1998 , hu et al .
1998 , weymann et al ..
Please generate the next two sentences of the article | 1998 , spinrad et al .
1998 , chen et al . 1999 , |
5,003 | Suppose that you have an abstract for a scientific paper: we study the kinematics of deep inelastic scattering corresponding to the rotationally symmetric distribution of quark momenta in the nucleon rest frame .
it is shown that rotational symmetry together with lorentz invariance can in leading order impose constraints on the quark intrinsic momenta .
obtained constraints are discussed and compared with the available experimental data . .
And you have already written the first three sentences of the full article: the motion of quarks inside the nucleons plays an important role in some effects which are at present intensively investigated both experimentally and theoretically
. actual goal of this effort is to obtain a more consistent 3-d picture of the quark - gluon structure of nucleons .
for example the quark transversal momentum creates the asymmetries in particle production in polarized ( sidis ) or in unpolarized ( cahn effect ) experiments on deep inelastic scattering ( dis ) ..
Please generate the next two sentences of the article | relevant tool for the study of these effects is the set of the transverse momentum dependent distributions ( tmds ) .
apparently , a better understanding of the quark intrinsic motion is also a necessary condition to clarify the role of quark orbital angular momenta in generating nucleon spin . |
5,004 | Suppose that you have an abstract for a scientific paper: single - peakedness is one of the most important and well - known domain restrictions on preferences .
the computational study of single - peaked electorates has largely been restricted to elections with tie - free votes , and recent work that studies the computational complexity of manipulative attacks for single - peaked elections for votes with ties has been restricted to nonstandard models of single - peaked preferences for top orders .
we study the computational complexity of manipulation for votes with ties for the standard model of single - peaked preferences and for single - plateaued preferences .
we show that these models avoid the anomalous complexity behavior exhibited by the other models .
we also state a surprising result on the relation between the societal axis and the complexity of manipulation for single - peaked preferences . .
And you have already written the first three sentences of the full article: elections are a general and widely used framework for preference aggregation in human and artificial intelligence applications .
an important negative result from social choice theory , the gibbard - satterthwaite theorem @xcite , states that every reasonable election system is manipulable .
however , even though every election system is manipulable , it may be computationally infeasible to determine how to manipulate the outcome ..
Please generate the next two sentences of the article | bartholdi , tovey , and trick introduced the computational study of the manipulation problem and this began an exciting line of research that explores the computational complexity of different manipulative attacks on elections ( see , e.g. , @xcite ) .
the notion of single - peaked preferences introduced by black is the most important restriction on preferences from political science and economics and is naturally an important case to consider computationally . |
5,005 | Suppose that you have an abstract for a scientific paper: we derive self - reciprocity properties for a number of polyomino generating functions , including several families of column - convex polygons , three - choice polygons and staircase polygons with a staircase hole . in so doing ,
we establish a connection between the reciprocity results known to combinatorialists and the inversion relations used by physicists to solve models in statistical mechanics . for several classes of convex polygons ,
the inversion ( reciprocity ) relation , augmented by certain symmetry and analyticity properties , completely determines the anisotropic perimeter generating function .
keywords : inversion relations , combinatorial reciprocity theorems , polyominoes , self - avoiding polygons , convex polygons , statistical mechanics .
ams subject classification : 05a15 ( 05b50 , 82b20 , 82b23 ) .
* laboratoire bordelais de recherche en informatique + universit bordeaux i + * and + * department of mathematics and statistics + the university of melbourne + * june 1999 + * inversion relations , reciprocity and polyominoes + * m. bousquet - mlou@xmath0 , a.j .
guttmann@xmath1 , w.p . orrick@xmath1 and a. rechnitzer@xmath1 + @xmath0labri , cnrs + universit bordeaux
i + 351 cours de la libration + 33405 talence cedex + france + @xmath1department of mathematics and statistics + the university of melbourne + parkville , vic . 3052 + australia + .
And you have already written the first three sentences of the full article: symmetries are among the most important guiding principles in all of physics and mathematics .
it often happens that a problem may be solved by symmetry considerations alone , and even if not , understanding the symmetries of the solution can greatly reduce the amount of work needed to find it .
we study here a symmetry of functions which is known as `` self - reciprocity '' to combinatorialists and which is referred to as `` inversion relations '' in lattice statistical mechanics.
Please generate the next two sentences of the article | . our focus will be on polyomino enumeration problems which are of interest in both combinatorics and physics .
we shall demonstrate that one can find examples of functional symmetry in the resulting generating functions . |
5,006 | Suppose that you have an abstract for a scientific paper: in the nmssm , because of introducing a complex singlet superfield , the lightest cp - odd higgs boson , @xmath0 , can be a singlet - like state with a tiny doublet component in large regions of parameter space . in this paper
, we examine the discovery potential of @xmath0 produced in association with a bottom - antibottom pair at the lhc through @xmath1 and @xmath2 decay modes .
it is shown that an @xmath0 with mass @xmath3 can be extracted from the sm backgrounds by using the @xmath1 decay channel , a possibility precluded to the mssm .
in contrast , the @xmath2 decay mode is overwhelmed by backgrounds despite the fact that the branching ratio of this mode can reach unity when @xmath0 is a pure singlet .
preprint shep-10 - 37 + * low mass higgs signals at the lhc + in the next - to - minimal supersymmetric standard model * + + .
And you have already written the first three sentences of the full article: in the next - to - minimal supersymmetric standard model ( nmssm ) @xcite , the soft supersymmetry ( susy)-breaking higgs sector is described by the lagrangian contribution @xmath4 where @xmath5 and @xmath6 are the higgs doublet fields , @xmath7 the singlet one , @xmath8 and @xmath9 yukawa couplings while @xmath10 and @xmath11 are dimensionful parameters of order @xmath12 , the typical susy mass scale . as a result of the introduction of an extra complex singlet scalar field , which only couples to the two mssm - type higgs doublets ,
the higgs sector of the nmssm comprises of a total of seven mass eigenstates : a charged pair @xmath13 , three cp - even higgses @xmath14 ( @xmath15 ) and two cp - odd higgses @xmath16 ( @xmath17 ) .
consequently , higgs phenomenology in the nmssm may be plausibly different from that of the mssm and extremely rich of new signals ..
Please generate the next two sentences of the article | + for a start , the sum of the squares of the two lightest scalar higgs boson masses is given by @xcite : @xmath18 with @xmath19 .
the last expression can be translated into a modified upper bound of the @xmath20 mass as @xcite @xmath21 so that the upper bound on the nmssm lightest higgs boson mass is higher than the corresponding bound in the mssm . |
5,007 | Suppose that you have an abstract for a scientific paper: we compute population synthesis models for the variation of absorption indices ( and ) , as a function of age and metallicity in old stellar systems .
the models are based on the stelib spectral library of j .- f .
le borgne et al . , and defined at a resolution of 3 fwhm .
errors in the age and metallicity responses are derived by bootstrap resampling the input measurements on the stellar library .
the indices are found to be highly sensitive to age variation , with only moderate response to metallicity . for galaxies uncontaminated by nebular emission ,
our index is more powerful in breaking the age
metallicity degeneracy than or .
using a sample of red cluster galaxies from nelan et al .
, carefully selected to exclude objects with emission , we find a steep decline of with velocity dispersion ( slope @xmath0dex@xmath1 ) .
the slope can be translated to constraints on age and metallicity scaling relations , incorporating measurement errors and also the model errors determined from the bootstrap method .
if the @xmath2 slope is due only to age , we obtain age@xmath3 . because depends quite weakly on [ fe / h ] , a metallicity interpretation would require fe / h@xmath4 or steeper .
the @xmath2 slope is consistent with the combined age and metallicity scaling relations reported by nelan et al . from classical lick indices .
the relations obtained by thomas et al . significantly under - predict the observed slope . the discrepancy could arise from differences in the sample selection . in particular our sample probes a lower mass range ,
is not explicitly selected on morphological criteria and excludes objects significantly bluer than the red sequence .
we discuss in detail the effects of emission contamination on the results , and conclude that these are unlikely to yield the observed behaviour in the @xmath2 relations .
indeed , similar results are obtained using , despite its different sensitivity to and [ nii ] emission lines . the steep age
mass relation supports....
And you have already written the first three sentences of the full article: in the integrated spectra of old stellar systems , the strength of the balmer absorption lines reflects the luminosity - weighted effective temperature , which is dominated by the main sequence turn - off . in a simple ( i.e. single - age , single - metallicity ) system ,
the turn - off luminosity and temperature are sensitive primarily to the age of the population . on this basis ,
measurements of and line strengths have been widely used to constrain the ages of early - type galaxies both in clusters and in the field ( see thomas et al . 2004b , and many references therein ) . despite extensive work ,.
Please generate the next two sentences of the article | some fundamental questions remain unresolved , such as the influence of age variations in driving the `` red sequence '' of cluster ellipticals ( e.g. caldwell 2003 ; thomas et al .
2004b ; nelan et al . |
5,008 | Suppose that you have an abstract for a scientific paper: the smac project is a fundamental plane peculiar velocity survey of 56 clusters of galaxies to a depth of @xmath012000kms@xmath1 .
we present here some results from the analysis of the smac velocity field , focussing on three specific features : the best - fitting bulk - flow model for the smac data ; the agreement between the observed velocity field and predictions from the iras pscz redshift survey ; the role of the great attractor and shapley concentration in generating the local flows .
we argue that the local mass distribution , as probed by the pscz , can fully account for the observed cluster velocities . .
And you have already written the first three sentences of the full article: the ` streaming motions of abell clusters ' ( smac ) project is a fundamental plane ( fp ) survey of @xmath2700 early - type galaxies in 56 local rich clusters .
the cluster sample has approximately full - sky coverage , and a limiting depth of @xmath3kms@xmath1 . within each cluster
, distances are based upon data for 456 e / s0 galaxies ..
Please generate the next two sentences of the article | data for the smac project is drawn from a compilation of literature sources and an extensive body of new observations , carefully combined into a homogeneous database .
further details of the sample , the observations , and the data compilation procedures are reported by hudson et al . |
5,009 | Suppose that you have an abstract for a scientific paper: a new method of diagonalisation of the xy - hamiltonian of inhomogeneous open linear chains with periodic ( in space ) changing larmor frequencies and coupling constants is developed .
as an example of application , multiple quantum dynamics of an inhomogeneous chain consisting of 1001 spins is investigated .
intensities of multiple quantum coherences are calculated for arbitrary inhomogeneous chains in the approximation of the next nearest interactions . _
key words : _ linear spin chain , nearest neighbour approximation , three diagonal matrices , diagonalisation , fermions , multiple quantum nmr , multiple quantum coherence , intensities of multiple quantum coherences . _
pacs numbers : _ 05.30.-d ; 76.20.+q [ section ] [ section ] [ section ] [ section ] [ section ] [ section ] [ section ] .
And you have already written the first three sentences of the full article: one - dimensional exactly solvable models ( spin chains , rings ) @xcite have been actively employed for studying various problems of spin dynamics @xcite and quantum information theory @xcite .
substantial progress in our understanding of spin dynamics has been achieved on the basis of a homogeneous xy model for spin chains ( @xmath0 ) in transverse magnetic field @xcite .
recently , hamiltonians of the simplest inhomogeneous systems ( alternating systems ) have been diagonalised for the ring @xcite and the linear spin chain @xcite ..
Please generate the next two sentences of the article | development of methods for exact solution of inhomogeneous spin problems has become especially urgent in conjunction with recent progress in quantum computation and quantum information theories @xcite . in particular , these methods can be used for studying the quantum state transfer from one end of the chain to another one @xcite the qubit addressing problem can be attacked by variation of the larmor frequencies of different spins @xcite in classical one - dimensional models .
this immediately brings inhomogeneity into the xy model as diagonal elements of the corresponding hamiltonian are not equal . |
5,010 | Suppose that you have an abstract for a scientific paper: using geometrical approach exposed in refs .
@xcite , we explore the camassa holm equation ( both in its initial scalar form , and in the form of @xmath0-system ) .
we describe hamiltonian and symplectic structures , recursion operators and infinite series of symmetries and conservation laws ( local and nonlocal ) . .
And you have already written the first three sentences of the full article: the camassa
holm equation was introduced in @xcite in the form @xmath1 and was intensively explored afterwards ( see , for example , refs .
its superizations were also constructed , see @xcite . since is not an evolution equation , its integrability properties ( existence and even definition of hamiltonian structures , conservation laws , etc . ) are not standard to establish ..
Please generate the next two sentences of the article | one of the ways widely used to overcome this difficulty is to introduce a new unknown @xmath2 and transform eq . to the system @xmath3 which has _ almost _ evolutionary form .
we stress this `` almost '' , because the second equation in ( that can be considered as a constrain to the first one ) disrupts the picture and , at best , necessitates to invert the operator @xmath4 . at worst , dealing with eq . as with an evolution equation |
5,011 | Suppose that you have an abstract for a scientific paper: for a class @xmath0 of finite lattices , the question arises whether any lattice in @xmath0 can be embedded into some atomistic , _ biatomic _ lattice in @xmath0 .
we provide answers to the question above for @xmath0 being , respectively , * the class of all finite lattices ; * the class of all finite _ lower bounded _ lattices ( solved by the first author s earlier work ) . * the class of all finite _ join - semidistributive lattices _
( this problem was , until now , open ) .
we solve the latter problem by finding a quasi - identity valid in all finite , atomistic , biatomic , join - semidistributive lattices but not in all finite join - semidistributivelattices . .
And you have already written the first three sentences of the full article: a lattice @xmath1 is _ biatomic _ , if it is atomic ( i.e. , every element of @xmath2 lies above some atom of @xmath1 ) and whenever @xmath3 , @xmath4 , and @xmath5 are elements of @xmath1 such that @xmath3 is an atom , @xmath4 and @xmath5 are nonzero , and @xmath6 , there are atoms @xmath7 and @xmath8 such that @xmath9 , see definition [ d : atatbiat ] . in our first result of this paper , theorem [ t : allfinlatt ] , we prove that any finite lattice can be easily embedded atom - preservingly into a finite biatomic one .
biatomicity arises naturally in geometric lattices such as lattices of subspaces of a vector space or , more generally , projective geometries .
it was also noticed by m.k ..
Please generate the next two sentences of the article | bennett @xcite that in geometric lattices , biatomicity is equivalent to modularity .
biatomicity is probably even more common among _ |
5,012 | Suppose that you have an abstract for a scientific paper: domain specific languages are used to provide a tailored modelling notation for a specific application domain .
there are currently two main approaches to dsls : standard notations that are tailored by adding simple properties ; new notations that are designed from scratch .
there are problems with both of these approaches which can be addressed by providing access to a small meta - language based on packages and classes .
a meta - modelling approach based on _ meta - packages _ allows a wide range of dsls to be defined in a standard way .
the dsls can be processed using standard object - based extension at the meta - level and existing tooling can easily be defined to adapt to the new languages .
this paper introduces the concept of meta - packages and provides a simple example . .
And you have already written the first three sentences of the full article: the aim of any notation for software system design must be to faithfully capture the structure and behaviour of the proposed system .
the aim of any tooling that supports such a notation must be that it is reliable and provides useful functionality .
what kind of functionality ?.
Please generate the next two sentences of the article | certainly , the notation must be a good vehicle for communication - other people must be able to understand your ideas expressed in the notation .
however , communication is not sufficient ; the notation must support other useful tasks that contribute to the development of a system . |
5,013 | Suppose that you have an abstract for a scientific paper: we prove necessary and sufficient conditions for the informational completeness of an arbitrary set of gaussian observables on continuous variable systems with finite number of degrees of freedom .
in particular , we show that an informationally complete set either contains a single informationally complete observable , or includes infinitely many observables .
we show that for a single informationally complete observable , the minimal outcome space is the phase space , and the observable can always be obtained from the quantum optical @xmath0-function by linear postprocessing and gaussian convolution , in a suitable symplectic coordinatization of the phase space . in the case of projection valued gaussian observables ,
e.g. , generalized field quadratures , we show that an informationally complete set of observables is necessarily infinite .
finally , we generalize the treatment to the case where the measurement coupling is given by a general linear bosonic channel , and characterize informational completeness for an arbitrary set of the associated observables . .
And you have already written the first three sentences of the full article: the ability to determine an unknown quantum state produced by some source is central for many applications in quantum information science .
the procedure of reconstructing the quantum state , known as quantum state tomography , has therefore been under intense investigations and continues to attract a lot of attention @xcite . in the continuous variable regime , and in particular its quantum optical realizations , there are two commonly used approaches to quantum tomography . in optical homodyne tomography , the set of rotated quadratures is measured using balanced homodyne detection , thus allowing one to scan the phase space of the system @xcite .
the alternative method uses the husimi @xmath0-function which can be measured using a double homodyne detection scheme , and has the advantage that the reconstruction requires the measurement of only a single observable @xcite . both of the above instances fall under the class of gaussian measurements , i.e. , measurements which yield a gaussian measurement outcome distribution whenever the system is initially in a gaussian state @xcite ..
Please generate the next two sentences of the article | the purpose of this paper is to present a method for investigating whether or not a given set of such gaussian observables is informationally complete @xcite , i.e. , allows the reconstruction of an unknown quantum state of the system from the statistics .
we consider an @xmath1-mode electromagnetic field , whose phase space is therefore @xmath2-dimensional . we show that by measuring a gaussian observable one obtains the values of the weyl transform of the state on a linear subspace of the phase space . |
5,014 | Suppose that you have an abstract for a scientific paper: we present rotation curves of the galaxy based on the space - velocities of 197 ob stars and 144 classical cepheids , respectively , which range over a galactocentric distance interval of about 6 to 12kpc .
no significant differences between these rotation curves and rotation curves based solely on radial velocities assuming circular rotation are found .
we derive an angular velocity of the lsr of @xmath0mas / a ( ob stars ) and @xmath1mas / a ( cepheids ) , which is in agreement with the iau 1985 value of @xmath2mas / a .
if we correct for probable rotations of the fk5 system , the corresponding angular velocities are @xmath3mas / a ( ob stars ) and @xmath4mas / a ( cepheids ) .
these values agree better with the value of @xmath5mas / a derived from the vla measurement of the proper motion of sgra@xmath6 . .
And you have already written the first three sentences of the full article: the galactic rotation curve has been determined for the inner parts of the galactic disk , interior to the solar annulus , from hi - measurements using the tangential point method ( burton & gordon 1978 ) , whereas the outer rotation curve has been determined using radial velocities of objects with individually known distances , e.g. ob stars ( fich et al .
1989 ) , planetary nebulae ( schneider & terzian 1983 ) , young open clusters ( hron 1987 ) and carbon stars ( metzger & schechter 1994 ) . an alternative method is based on the vertical thickness of the galactic hi - layer ( merrifield 1992 ) .
recently brand & blitz ( 1993 ) have rederived the outer rotation curve from co radial velocities of ob stars associated with hii regions , and pont et al ..
Please generate the next two sentences of the article | ( 1994 ) have used new radial velocity measurements of classical cepheids for this purpose .
all these methods rely on the assumption of circular orbits around the galactic centre , so that radial velocities can be converted to circular velocities |
5,015 | Suppose that you have an abstract for a scientific paper: we present the faintest spectroscopically confirmed sample of @xmath0 lyman break galaxies to date .
the sample is based on slitless grism spectra of the hubble ultra deep field region from the grapes ( grism acs program for extragalactic science ) and pears ( probing evolution and reionization spectroscopically ) projects , using the g800l grism on the hst advanced camera for surveys .
we report here confirmations of 39 galaxies , pre - selected as candidate lyman break galaxies using photometric selection criteria .
we compare a `` traditional '' v - dropout selection to a more liberal one ( with @xmath1 ) , and find that the traditional criteria are about @xmath2 complete and @xmath3 reliable .
we also study the emission properties of our sample .
we find that emission is detected in @xmath4 of the sample , and that our broad - band color selected sample includes @xmath5 of previously published line - selected sources .
finally , we examine our stacked 2d spectra .
we demonstrate that strong , spatially extended ( @xmath6 ) emission is not a generic property of these lyman break galaxies , but that a modest extension of the photosphere ( compared to the starlight ) may be present in those galaxies with prominent emission . .
And you have already written the first three sentences of the full article: star forming galaxies in the early universe have been found in large numbers both by looking for strong lyman breaks , and by looking for line emission .
galaxies found by these two methods differ greatly in their typical properties .
this may indicate physically distinct galaxy populations , or selection effects inherent in the search methods , or a combination of the two . to help address these issues , we here examine the selection of lyman break galaxies in the hubble ultra deep field ( hudf ) ..
Please generate the next two sentences of the article | the depth of the hudf images means that emitting galaxies with fluxes typical of present surveys should all be detected ( down to flux @xmath7 ) , even if they have no continuum emission at all .
we combine these deep hudf images with the deepest slitless spectra ever obtained , from the grapes and pears projects ( see below ) . |
5,016 | Suppose that you have an abstract for a scientific paper: searching for a signal depending on unknown parameters in a noisy background with matched filtering techniques always requires an analysis of the data with several templates in parallel in order to ensure a proper match between the filter and the real waveform .
the key feature of such an implementation is the design of the filter bank which must be small to limit the computational cost while keeping the detection efficiency as high as possible .
this paper presents a geometrical method which allows one to cover the corresponding physical parameter space by a set of ellipses , each of them being associated to a given template . after the description of the main characteristics of the algorithm ,
the method is applied in the field of gravitational wave ( gw ) data analysis , for the search of damped sine signals .
such waveforms are expected to be produced during the de - excitation phase of black holes the so - called ringdown signals and
are also encountered in some numerically computed supernova signals .
first , the number of templates @xmath0 computed by the method is similar to its analytical estimation , despite the overlaps between neighbor templates and the border effects .
moreover , @xmath0 is small enough to test for the first time the performances of the set of templates for different choices of the minimal match @xmath1 , the parameter used to define the maximal allowed loss of signal - to - noise ratio ( snr ) due to the mismatch between real signals and templates .
the main result of this analysis is that the fraction of snr recovered is in average much higher than @xmath1 , which dramatically decreases the mean percentage of false dismissals .
indeed , it goes well below its estimated value of @xmath2 used as input of the algorithm .
thus , as this feature should be common to any tiling algorithm , it seems possible to reduce the constraint on the value of @xmath1 and indeed the number of templates and the computing power without loosing as much events as expected in....
And you have already written the first three sentences of the full article: in the next years , the first generation of large interferometric gravitational - wave detectors @xcite should reach a sensitivity good enough to expect the first direct detection of gw signals . in parallel of the experimental work consisting in operating the detectors at their working point with background noises as small as possible , the future data analysis methods are being prepared for the various expected sources of gw , each of them requesting specific tools . yet , the wiener filtering is used in most of these fields due to its optimal characteristics for signals whose time evolutions are known . indeed , it is not only the filter giving the highest signal - to - noise ratio ( snr ) among all the linear ones @xcite but it has also the property of having the lowest false dismissal rate for a given false alarm rate among all filters @xcite .
conversely , its main drawback is its poor robustness : as soon as the physical signal and the filter do not match exactly , the snr can be dramatically reduced . even if the searched waveform is analytically computed with high precision
, it always depends on a vector of parameters @xmath3 whose values are specific to a given source and thus unknown .
Please generate the next two sentences of the article | e.g. its mass , the main frequency of emission ... and whose accurate estimation is indeed a major aim of the data analysis .
the set of physically possible values for the vector @xmath3 is the continuous parameter space @xmath4 . |
5,017 | Suppose that you have an abstract for a scientific paper: observed unusual elemental abundances in globular cluster palomar 1 ( pal 1 ) could provide important information for us to study the relation between the globular cluster and our galaxy . in this work ,
we study the abundances of @xmath0 elements , fe - peak elements and neutron - capture elements in pal 1 .
we found that the abundances of the sne ia and main s - process components of pal 1 are larger than those of the disk stars and the abundances of the primary component of pal 1 are smaller than those of the disk stars with similar metallicity .
the fe abundances of pal 1 and the disk stars mainly originate from the sne ia and the primary component , respectively .
although the @xmath0 abundances dominantly produced by the primary process for the disk stars and pal 1 , the contributions of the primary component to pal 1 are smaller than the corresponding contributions to the disk stars .
the fe - peak elements v and co mainly originate from the primary and secondary components for the disk stars and pal 1 , but the contributions of the massive stars to pal 1 are lower than those of the massive stars to the disk stars .
the y abundances mainly originate from the weak r - component for the disk stars .
however the contributions of the main s- and main r - components to y are close to those of the weak r - component for pal 1 .
the ba abundances of pal 1 and the disk stars mainly originate from the main s - component and the main r - component , respectively .
our calculated results imply that the unusual abundances of pal could be explained by the top - light imf for pal 1 s progenitor - system . .
And you have already written the first three sentences of the full article: the heavy elements ( z@xmath130 ) are mainly produced by neutron - capture processes @xcite .
the slow neutron - capture process ( s - process ) contains two categories .
the weak s - process mainly produces the lighter neutron - capture elements and takes place in the massive stars @xcite ..
Please generate the next two sentences of the article | the main s - process occurs in the agb stars and is directly responsible for the heavier elements @xcite .
the rapid neutron - capture process ( r - process ) also contains two categories . |
5,018 | Suppose that you have an abstract for a scientific paper: weakly interacting massive particles ( wimps ) remain the strongest candidates for the dark matter in the universe . if wimps are the dark matter , they will form galactic halos according to the hierarchical clustering observed in n - body simulations .
cold dark matter ( cdm ) simulations show that large dark matter structures such as galactic and cluster halos are formed by the merging of many smaller clumps of dark matter .
each clump or halo is characterized by a centrally cusped density profile that can enhance the rate of wimp annihilation and make the annihilation products more easily detectable .
electrons and positrons generated as decay products of wimp annihilation emit synchrotron radiation in the galactic magnetic field .
we study the synchrotron signature from the clumps of dark matter in our galactic halo .
we find that the emission in the radio and microwave region of the electromagnetic spectrum can be above the cmb anisotropy level and should be detectable by cmb anisotropy experiments .
depending on the density profile of dark matter clumps , hundreds of clumps can have detectable fluxes and angular sizes . .
And you have already written the first three sentences of the full article: the density of dark matter in the present universe is observed via its gravitational effects on galaxies and clusters of galaxies to constitute at least about 30% of the critical density of the universe , but the nature of this dark matter is still unknown .
primordial nucleosynthesis constrains the density of baryonic matter to be less than about 5% of the critical density , thus most of the dark matter is non - baryonic .
the leading candidate for the dark matter is the lightest supersymmetric particle in supersymmetric extensions of the standard model that is stable by conservation of r - parity . in most scenarios this weakly interacting massive particle ( wimp ).
Please generate the next two sentences of the article | is the neutralino , @xmath0 ( for a review , see @xcite ) .
neutralinos may be detected directly as they traverse the earth or indirectly by the observation of their annihilation products . |
5,019 | Suppose that you have an abstract for a scientific paper: in this paper we study homogeneous gibbs measures on a cayley tree , subjected to an infinite - temperature glauber evolution , and consider their ( non-)gibbsian properties .
we show that the intermediate gibbs state ( which in zero field is the free - boundary - condition gibbs state ) behaves different from the plus and the minus state .
e.g. at large times , all configurations are bad for the intermediate state , whereas the plus configuration never is bad for the plus state .
moreover , we show that for each state there are two transitions . for the intermediate state
there is a transition from a gibbsian regime to a non - gibbsian regime where some , but not all configurations are bad , and a second one to a regime where all configurations are bad . for the plus and minus state ,
the two transitions are from a gibbsian regime to a non - gibbsian one and then back to a gibbsian regime again .
* ams 2000 subject classification : * .
_ keywords : _ non - gibbsianness , ising models , tree graphs , glauber dynamics . .
And you have already written the first three sentences of the full article: in this paper we consider the gibbsian properties of homogeneous low - temperature ising gibbs measures on trees , subjected to an infinite - temperature glauber evolution .
this problem has been considered before on regular lattices see e.g. @xcite , for ising spins , @xmath0-vector and unbounded spins , and for various finite- or infinite - temperature dynamics , of glauber , kawasaki , or diffusion type , and even for non - markovian evolutions . at high initial temperatures , or for suffiently short times , standard methods can be used to prove gibbsianness , also in our situation .
thus the interesting case is to find out what happens for low initial temperatures ..
Please generate the next two sentences of the article | as usual ( but see the mean - field analysis of @xcite ) low - temperature dynamics are beyond reach so far . for simplicity we will consider infinite - temperature dynamics , but high - temperature evolutions are expected to behave qualitatively similarly .
in contrast to what happens on regular lattices such as @xmath1 , the gibbsian properties of evolved gibbs measures for models on trees turn out to depend on which of the different gibbs measures ( plus or minus , versus intermediate ) one considers . in all cases there are two transition times : for the intermediate measure after the first transition time it becomes non - gibbsian in the familiar sense that some , but not all , configurations are `` bad '' ( that is , they are points of discontinuity ) , while it turns out that after a certain later time the evolved intermediate gibbs measure becomes `` totally bad '' ; thereafter it has the surprising property that _ all _ spin configurations are discontinuity points . |
5,020 | Suppose that you have an abstract for a scientific paper: it is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high - pressure environment in which numerous novel particles processes are likely to compete with each other .
these processes range from the generation of hyperons to quark deconfinement to the formation of kaon condensates and h - matter .
there are theoretical suggestions of even more exotic processes inside neutron stars , such as the formation of absolutely stable strange quark matter , a configuration of matter even more stable than the most stable atomic nucleus , iron . in the latter event ,
neutron stars would be largely composed of pure quark matter , eventually enveloped in a thin nuclear crust .
no matter which physical processes are actually realized inside neutron stars , each one leads to fingerprints , some more pronounced than others though , in the observable stellar quantities .
this feature combined with the unprecedented progress in observational astronomy , which allows us to see vistas with remarkable clarity that previously were only imagined , renders neutron stars to nearly ideal probes for a wide range of physical studies , including the role of strangeness in dense matter .
[ sctn ] fw - undap-08 - 00 + * strangeness in neutron stars * + fridolin weber + university of notre dame + department of physics + 225 nieuwland science hall + notre dame , in 46556 - 5670 , usa + http://nta0.lbl.gov/@xmath0fweber + + _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ presented at the 5th international conference + on + strangeness in quark matter ( strangeness 2000 ) + berkeley , california , usa + july 2025 , 2000 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ * strangeness in neutron stars * + fridolin weber + university of notre dame + department of physics + 225 nieuwland science hall + notre dame , in 46556 - 5670 , usa +....
And you have already written the first three sentences of the full article: neutron stars are spotted as pulsars by radio telescopes and x - ray satellites .
they are more massive ( i.e. @xmath1 ) than our sun but are typically only about @xmath2 kilometers across so that the matter in their centers is compressed to densities that are up to an order of magnitude higher than the density of atomic nuclei @xcite . at such densities
it is quite plausible that numerous subatomic particle processes will compete with each other and novel phases of matter like the quark - gluon plasma being sought at the most powerful terrestrial particle colliders could exist in the center of neutron stars ..
Please generate the next two sentences of the article | figure [ fig : cross ] summarizes the possible scenarios graphically , with the associated equations of state shown in figure [ fig : eos ] .
the strangeness - carrying @xmath3 quark is likely to play a vital role inside neutron stars , for several of the building blocks of matter may contain an @xmath3 quark as one of their constituents . |
5,021 | Suppose that you have an abstract for a scientific paper: assuming that the neutrino mass matrix is diagonalized by the tribimaximal mixing matrix , we explore the textures for the charged lepton mass matrix that render an @xmath0 lepton mixing matrix consistent with data .
in particular we are interested in finding the textures with the maximum number of zeros .
we explore the cases of real matrices with three and four zeros and find that only ten matrices with three zeros provide solutions in agreement with data .
we present the successful yukawa textures including the relative sizes of their non - zero entries as well as some new and interesting relations among the entries of these textures in terms of the charged lepton masses .
we also show that these relations can be obtained directly from a parametrization of the charged lepton mixing matrix @xmath1 . .
And you have already written the first three sentences of the full article: in the framework of discrete flavor symmetries one of the most used ansatz for the lepton mixing matrix @xmath0 is the tribimaximal mixing ( tbm ) matrix @xcite , which despite the non - zero value for @xmath2 recently confirmed by the t2k collaboration @xcite , double chooz @xcite , daya bay @xcite and reno @xcite experiments , can still be used as a good approximation .
contributions from the charged lepton sector and/or from renormalization effects , can generate a non - zero value for @xmath2 in agreement with the experimental data . for a classification of models predicting tbm mixing see @xcite and references therein , and for an overview of flavor symmetry models for neutrino mixing , based on non - abelian discrete symmetries that give the tbm pattern , see ref .
@xcite ..
Please generate the next two sentences of the article | other ansatzs for the neutrino mass matrix have been explored .
one such case consists on the so - called @xmath3-zero textures where , for example , taking the case of majorana neutrinos , it has been found that only two independent zero entries are allowed by current data @xcite . for dirac mass matrices |
5,022 | Suppose that you have an abstract for a scientific paper: universal extra dimensions ( ueds ) with compactification radius near the tev scale provide interesting phenomenology at future colliders .
the collider signals of the first kaluza - klein ( kk ) level are very similar to those of a supersymmetric model with a nearly degenerate superpartner spectrum .
the heavier first level kk states cascade decay to the lightest kk particles ( lkp ) , which is neutral and stable because of kk - parity .
the signatures involve missing energy and relatively soft jets and leptons which can be difficult for detection .
the kk electron signal in @xmath0 collisions is free from the problematic two photon background therefore provides a unique opportunity for a detailed studies of the kk electrons in the universal extra dimension scenario .
june 3 , 2002 efi-2002 - 86 + * universal extra dimensions + at the @xmath0 colliders * .5 in * hsin - chia cheng * .5 in _ enrico fermi institute , the university of chicago , chicago , il 60637 , usa _ .5 in .
And you have already written the first three sentences of the full article: large extra dimensions have recently attracted a lot of interest .
they provide many new theoretical ideas to explore questions in particle physics .
most excitingly , they also predict signals which will be tested at the upcoming collider experiments ..
Please generate the next two sentences of the article | in this talk we focus on the scenario of universal extra dimensions ( ueds ) @xcite . in ueds , all standard model ( sm ) fields propagates in extra dimensions of size @xmath1 .
there are many theoretical motivations for this scenario , such as electroweak symmetry breaking @xcite , proton decay @xcite , the number of generations @xcite , neutrino masses @xcite , etc . |
5,023 | Suppose that you have an abstract for a scientific paper: recently , from the _ hubble space telescope _ ( hst ) images of one of the large magellanic cloud ( lmc ) events taken 6.3 years after the original lensing measurement , alcock et al . were able to directly image the lens .
although the first resolved lens was identified for an lmc event , much more numerous lenses are expected to be resolved for galactic bulge events . in this paper
, we estimate the fraction of galactic bulge events whose lenses can be directly imaged under the assumption that all bulge events are caused by normal stars . for this determination ,
we compute the distribution of lens proper motions of the currently detected galactic bulge events based on standard models of the geometrical and kinematical distributions of lenses and their mass function .
we then apply realistic criteria for lens resolution , and the result is presented as a function of the time elapsed after an original lensing measurement , @xmath0 .
if followup observations are performed by using an instrument with a resolving power of @xmath1 , which corresponds to that of hst equipped with the new advanced camera for surveys , we estimate that lenses can be resolved for @xmath2 and @xmath3 of disk - bulge events and for @xmath4 and @xmath5 of bulge self - lensing events after @xmath6 and 20 years , respectively .
the fraction increases substantially with the increase of the resolving power . if the instrument has a resolution of @xmath7 , which can be achieved by the _ next generation space telescope _ , we estimate that lenses can be resolved for @xmath8 and @xmath9 of disk - bulge events and for @xmath10 and @xmath11 of bulge self - lensing events after @xmath6 and 20 years , respectively .
epsf # 1 [ firstpage ] gravitational lensing stars : fundamental parameters .
And you have already written the first three sentences of the full article: following the proposal of paczyski ( 1986 ) , experiments to search for lensing - induced light variations of stars ( microlensing events ) located in the galactic bulge and the magellanic clouds have been or are being conducted by several groups ( macho : alcock et al .
1993 ; eros : aubourg et al . 1993
; ogle : udalski et al . 1993 ; moa : bond et al . 2001 ; duo : alard & guibert 1997 ) ..
Please generate the next two sentences of the article | these experiments have successfully detected a large number of events ( @xmath12 ) , most of which are detected towards the galactic bulge . despite a large number of event detections , the nature of the lenses is still poorly known .
this is because the einstein ring radius crossing time @xmath13 ( einstein timescale ) , which is the only observable providing information about the physical parameters of the lens ( lens parameters ) , results from a combination of the lens parameters , i.e.@xmath14^{1/2},\ ] ] where @xmath15 is the einstein ring radius , @xmath16 is the lens mass , @xmath17 is the lens - source transverse speed , and @xmath18 and @xmath19 are the distances to the lens and the source from the observer , respectively . under this circumstance , the only approach one could pursue would be identifying the major lens population by statistically determining the lens mass function based on the observed timescale distribution . |
5,024 | Suppose that you have an abstract for a scientific paper: we evaluate the three - loop corrections to the matching coefficient of the vector current between quantum chromodynamics ( qcd ) and non - relativistic qcd .
the result is presented in the @xmath0 scheme where large perturbative corrections are observed .
the implications on the threshold production of top quark pairs are briefly discussed . .
And you have already written the first three sentences of the full article: in the recent years effective field theories constructed from quantum chromodynamics ( qcd ) have been enormously successful to describe phenomena where masses and momenta follow certain limits . among them
is non - relativistic qcd ( nrqcd ) @xcite which is applicable to a system of two heavy quarks moving with small relative velocity .
next to properties of the @xmath1 and @xmath2 families also the threshold production of top quark pairs is among the prominent examples ( see , e.g. , ref ..
Please generate the next two sentences of the article | @xcite for a review ) . the common method to construct an effective theory
is based on the so - called matching procedure : appropriately chosen green s functions are computed in the full and effective theory and equality is required up to power - suppressed terms . in this way the couplings of the effective operators ( i.e. the matching coefficients ) are determined which completely specifies the effective theory . |
5,025 | Suppose that you have an abstract for a scientific paper: we describe the implementation of quantum electrodynamic ( qed ) evolution at leading order ( lo ) along with quantum chromodynamic ( qcd ) evolution at next - to - leading order ( nlo ) in the cteq - tea global analysis package .
the inelastic contribution to the photon parton distribution function ( pdf ) is described by a two - parameter ansatz , coming from radiation off the valence quarks , and based on the ct14 nlo pdfs .
setting the two parameters to be equal allows us to completely specify the inelastic photon pdf in terms of the inelastic momentum fraction carried by the photon , @xmath0 , at the initial scale @xmath1 gev .
we obtain constraints on the photon pdf by comparing with zeus data @xcite on the production of isolated photons in deep inelastic scattering , @xmath2 . for this comparison we present a new perturbative calculation of the process that consistently combines the photon - initiated contribution with the quark - initiated contribution .
comparison with the data allows us to put a constraint at the 90% confidence level of @xmath3 for the inelastic photon pdf at the initial scale of @xmath1 gev in the one - parameter radiative ansatz .
the resulting inelastic ct14qed pdfs will be made available to the public .
in addition , we also provide ct14qedinc pdfs , in which the _ inclusive _ photon pdf at the scale @xmath4 is defined by the sum of the inelastic photon pdf and the elastic photon distribution obtained from the equivalent photon approximation . .
And you have already written the first three sentences of the full article: the high precision of current collider data requires comparable precision in the phenomenological predictions .
the state of the art in high - energy calculations is at next - to - next - to - leading order ( nnlo ) in quantum chromodynamics ( qcd ) .
consequently , major efforts have been undertaken to produce nnlo parton distribution functions ( pdfs ) from a global analysis of the available data ..
Please generate the next two sentences of the article | these include the ct14nnlo pdfs @xcite as well as others @xcite , all of which include lhc data in the determination of the pdfs .
in this paper we describe the introduction of qed evolution at leading order ( lo ) with the next - to - leading order ( nlo ) qcd evolution in the same cteq global analysis package that was used to produce the ct14 pdfs @xcite . |
5,026 | Suppose that you have an abstract for a scientific paper: we present the results of extensive calculations for charged and neutral current reactions of neutrinos and antineutrinos in the small @xmath0{gev^2}$ ] region .
the results include single @xmath1 and double @xmath2 differential cross sections at energies relevant for oscillation experiments .
we include nuclear corrections in the adler - nussinov - paschos model and point out that on isoscalar nuclear targets there are charge symmetry relations that hold in extended kinematic regions .
we discuss how the results can be used in long baseline experiments in order to study oscillation parameters and search for cp asymmetries . .
And you have already written the first three sentences of the full article: neutrino interactions have been studied in the resonance region in terms of form factors and have been compared with available data @xcite with considerable success . after the early experiments with larger errors , there is a new generation of experiments that provide more accurate data .
in addition , the oscillation phenomena and the finite mixing angle @xmath3 @xcite require more accurate theoretical predictions in order to decipher properties of oscillations including cp asymmetries .
all these require on the theoretical side estimates of amplitudes that are reliable . one property of production cross sections is the fact that for @xmath4 and @xmath5 the axial contribution is given by the partially conserved axialvector current ( pcac ) ..
Please generate the next two sentences of the article | we worked out this framework for resonance production @xcite and for coherent scattering on nuclei it has been reported by two groups @xcite . in this article we wish to present our results for many reactions , calculate explicitly the energy spectra of the produced pions and point out special properties .
for example , in the production of the delta resonance in the energy region @xmath6 to @xmath7{gev}$ ] the vector squared and the interference contributions are almost equal @xcite . |
5,027 | Suppose that you have an abstract for a scientific paper: radiative decays of the @xmath0 meson have been studied using a data sample of about 20 million @xmath0 decays collected by the cmd-2 detector at vepp-2 m collider in novosibirsk . from selected @xmath1 events
the @xmath2 decay has been observed for the first time . under the assumption that the intermediate @xmath3 state dominates in the @xmath4 decay , the corresponding branching ratio is @xmath5
. selected @xmath6 events were used to obtain @xmath7 for @xmath8 mev . using the same data sample , upper limits at 90% cl
have been obtained for the c - violating decay of the @xmath0 : @xmath9 ; and for the p- and cp - violating decay of the @xmath10 : @xmath11 . * first observation of the @xmath12 decay * r.r.akhmetshin , e.v.anashkin , m.arpagaus , v.m.aulchenko , v.s.banzarov , l.m.barkov , n.s.bashtovoy , a.e.bondar , d.v.bondarev , a.v.bragin , d.v.chernyak , a.s.dvoretsky , s.i.eidelman , g.v.fedotovich , n.i.gabyshev , a.a.grebeniuk , d.n.grigoriev , p.m.ivanov , s.v.karpov , v.f.kazanin , b.i.khazin , i.a.koop , p.p.krokovny , l.m.kurdadze , a.s.kuzmin , i.b.logashenko , p.a.lukin , a.p.lysenko , k.yu.mikhailov , i.n.nesterenko , v.s.okhapkin , e.a.perevedentsev , e.a.panich , a.s.popov , t.a.purlatz , n.i.root , a.a.ruban , n.m.ryskulov , a.g.shamov , yu.m.shatunov , b.a.shwartz , a.l.sibidanov , v.a.sidorov , a.n.skrinsky , v.p.smakhtin , i.g.snopkov , e.p.solodov , p.yu.stepanov , a.i.sukhanov , v.m.titov , yu.v.yudin , s.g.zverev + budker institute of nuclear physics , novosibirsk , 630090 , russia j.a.thompson + university of pittsburgh , pittsburgh , pa 15260 , usa .
And you have already written the first three sentences of the full article: the identification of scalar mesons and particularly the determination of the lightest scalar @xmath13 nonet is of extreme importance both for quark systematics and searches for non-@xmath13 objects like glueballs and multiquark states ( see the discussion of this problem in the minireview on scalar mesons by s.spanier and n.trnqvist , p.390 of ref .
it is generally accepted that the probabilities of the electric dipole radiative transitions of the @xmath0 meson are crucial for the clarification of the nature of @xmath14 and @xmath15 mesons @xcite .
a search for these decays has been earlier performed by the nd @xcite and cmd-2 @xcite groups ..
Please generate the next two sentences of the article | a number of new results has been recently published by snd @xcite and cmd-2 @xcite collaborations at the @xmath16 collider vepp-2 m @xcite where the radiative decays @xmath17 , @xmath18 and @xmath12 have been observed for the first time .
the mode with two charged pions has very large background because of the radiative processes @xmath19 where a photon comes from initial electrons or from final pions . |
5,028 | Suppose that you have an abstract for a scientific paper: the relativistic field theory model of the deuteron suggested in [ 1 ] is revised and applied to the calculation of the cross sections of the low energy radiative neutron
proton capture n + p @xmath0 d + @xmath1 and the low energy two proton fusion p + p @xmath0 d + @xmath2 + @xmath3 .
for the low energy radiative neutron
proton capture n + p @xmath0 d + @xmath1 our result agrees well with both the experimental data and the potential model prediction . in the case of the two proton fusion the cross section obtained
is 2.9 times as much as that given by the potential approach .
the obtained result is discussed in connection with the solar neutrino problem .
= 16truecm = 23.5truecm -1.5 cm -1.2 cm nuclear physics * a * ( in press ) .
And you have already written the first three sentences of the full article: 1.0truecm _ institut fr kernphysik , technische universitt wien , _ + + 1.0truecm 1.0truecm 1.0truecm pacs:11.10.ef , 13.75 .
cs , 14.20 .
+ keywords : relativistic field theory , deuteron , neutron , proton , radiative capture , weak interaction , w boson , fusion 1.0truecm.
Please generate the next two sentences of the article | in a recent publication [ 1 ] we have suggested a relativistic field theory model of the deuteron . this model , being some kind of a @xmath4model [ 2 ] , is based on the assumption that the physical deuteron state should be produced due to integration over low
energy proton |
5,029 | Suppose that you have an abstract for a scientific paper: we discuss the origin of physical properties of globular cluster systems ( gcss ) in galaxies in terms of galaxy formation and evolution processes .
based on numerical simulations of dynamical evolution of gcss in galaxies , we particularly discuss ( 1 ) the origin of radial density profiles of gcss , ( 2 ) kinematics of gcss in elliptical galaxies , ( 3 ) transformation from nucleated dwarf galaxies into gcs ( e.g. , omega centauri ) , and ( 4 ) the origin of gcss in the large magellanic cloud ( lmc ) . .
And you have already written the first three sentences of the full article: based on penetrative analysis of metal - poor halo stars and globular clusters ( gcs ) in the galaxy , two canonical galaxy formation scenarios the monolithic collapse scenario @xcite and the accretion / merging one @xcite were proposed , that have long been influential for later observational and theoretical studies of disk and elliptical galaxies . although observational studies of stellar halos in galaxies beyond the local group of galaxies have just recently started revealing structural and chemical properties of the halos @xcite@xcite , physical properties of globular cluster systems ( gcss ) in these galaxies have long been investigated in much more details @xcite .
wide - field imaging and spectroscopic studies with large ground - based telescopes ( e.g. , keck 10 m ) have recently revealed gcs structures and kinematics in galaxies with different hubble types @xcite .
furthermore a growing number of theoretical / numerical studies have recently been accumulated which have investigated dynamical and chemical properties of gcs and gcss based on admittedly realistic and self - consistent models of gc formation during galaxy formation and evolution @xcite@xcite . in this review paper.
Please generate the next two sentences of the article | , we therefore try to derive physical meanings from the selected four observed properties of gcs and gcss by comparing our numerical simulations of gc and gcs formation with latest observations . ) which an elliptical experienced during its formation ( bf06 ) . for clarity , the density distributions are normalized to their central values .
thin dotted lines represent power - law slopes ( @xmath0 ) of @xmath0 = @xmath1 , @xmath2 , @xmath3 , and @xmath4 . |
5,030 | Suppose that you have an abstract for a scientific paper: we study the properties of hypernuclei containing one @xmath0 hyperon in the framework of the correlated basis function theory with jastrow correlations .
fermi hypernetted chain integral equations are derived and used to evaluate energies and one body densities of @xmath0hypernuclei having a doubly closed shell nucleonic core in the @xmath1 coupling scheme , from carbon to lead .
we also study hypernuclei having the least bound neutron substituted by the @xmath0 particle . the semi - realistic afnan and tang nucleon - nucleon potential and bodmer and usmani @xmath0-nucleon potential are adopted .
the effect of many body forces are considered by means either of a three body @xmath0-nucleon - nucleon potential of the argonne type or of a density dependent modification of the @xmath0-nucleon interaction , fitted to reproduce the @xmath0 binding energy in nuclear matter .
while jastrow correlations underestimate the attractive contribution of the three body @xmath0 interaction , the density dependent potential provides a good description of the @xmath0 binding energies over all the nuclear masses range , in spite of the relative simplicity of the model .
16 cm 1.0 cm 1.cm .
And you have already written the first three sentences of the full article: the microscopic study of atomic nuclei has gained in the recent years a noticeable level of reliability , following the improved knowledge of the interaction between the nucleons and the development of new and more sophisticated many body theories .
it is now possible to exactly solve the schrdinger equation for nuclei containing up to @xmath2 nucleons@xcite , while the structure of medium and heavy nuclei can be to a large extent understood by means either of variational techniques@xcite or of highly refined perturbative expansions@xcite .
these relatively recent developments have clearly stressed several inadequacies of the independent particle model ( ipm ) , on which the time honoured shell model is based ..
Please generate the next two sentences of the article | for instance , the ipm completely fails in describing the large energy behaviour of the one nucleon momentum distribution and the quenching of the spectroscopic factors@xcite .
the scenario is not equally bright for hypernuclei , or bound systems of nucleons and one or more strange baryons , as the @xmath3 or @xmath4 hyperons . |
5,031 | Suppose that you have an abstract for a scientific paper: the average rate of emission of ionizing radiation per unit volume ( or emissivity ) in the universe can be calculated as the ratio of the intensity of the ionizing background to the mean free path of ionizing photons .
the intensity of the background is measured from the mean transmitted flux of the ly@xmath0 forest , and the mean free path is measured from the abundance of lyman limit systems , which has been observed so far up to @xmath1 .
this yields an emissivity that is not larger than 7 ionizing photons per hubble time for each atom in the universe at @xmath1 , which may reasonably arise from qsos and star - forming galaxies . in order for the reionization to end by @xmath2 , and assuming that the clumping factor of ionized gas during the reionization epoch is close to unity , this ionizing comoving emissivity can not decline from @xmath1 up to @xmath3 by more than a factor @xmath4 . if the clumping factor were much larger than unity , then the emissivity would need to rapidly increase with redshift .
unless the ionizing emissivity increases substantially from @xmath1 to @xmath5 , the thomson optical depth to the cmb must be in the range @xmath6 . .
And you have already written the first three sentences of the full article: the highest redshift quasar known at the present time , at @xmath7 , is the first one to show a complete gunn - peterson trough ( becker et al .
2001 ; djorgovski et al .
this suggests that the reionization of hydrogen was probably completed near the epoch @xmath2 ..
Please generate the next two sentences of the article | this conclusion is not yet completely certain because an ionized medium can produce a complete gunn - peterson trough if the neutral fraction is everywhere high enough ( owing to a low intensity of the ionizing background ) .
however , the abrupt change with redshift near @xmath2 of the fraction of transmitted flux in the ly@xmath0 region of the spectrum ( becker et al . |
5,032 | Suppose that you have an abstract for a scientific paper: we use the coadded spectra of 32 epochs of sloan digital sky survey ( sdss ) reverberation mapping project observations of 482 quasars with @xmath0 to highlight systematic biases in the sdss- and boss - pipeline redshifts due to the natural diversity of quasar properties .
we investigate the characteristics of this bias by comparing the boss - pipeline redshifts to an estimate from the centroid of heii@xmath11640 .
heii has a low equivalent width but is often well - defined in high - s / n spectra , does not suffer from self - absorption , and has a narrow component that , when present ( the case for about half of our sources ) , produces a redshift estimate that , on average , is consistent with that determined from [ oii ] to within 1@xmath2 of the quadrature sum of the heii and [ oii ] centroid measurement uncertainties .
the large redshift differences of @xmath31000 ^-1 km s@xmath4 , on average , between the boss - pipeline and heii - centroid redshifts suggest there are significant biases in a portion of boss quasar redshift measurements . adopting the heii - based redshifts
shows that iv civ does not exhibit a ubiquitous blueshift for all quasars , given the precision probed by our measurements .
instead , we find a distribution of iv civ centroid blueshifts across our sample , with a dynamic range that ( i ) is wider than that previously reported for this line , and ( ii ) spans iv civ centroids from those consistent with the systemic redshift to those with significant blueshifts of thousands of kilometers per second .
these results have significant implications for measurement and use of high - redshift quasar properties and redshifts and studies based thereon . .
And you have already written the first three sentences of the full article: mapping the location of stars and galaxies as a function of distance or redshift helps us understand not only the contents of the universe but also its structure and evolution and the physical principles shaping what we observe .
quasars , or active galactic nuclei ( agn ; used synonymously in this work ) , are arguably the most useful extra - galactic source for mapping the universe at high redshift .
these accreting super - massive black holes ( bhs ) can outshine their host galaxies by several orders of magnitude and are thus observable at much greater distances than their quiescent counterparts ..
Please generate the next two sentences of the article | moreover , quasar spectra are characterized by the presence of high equivalent width ( ew ) emission lines distributed across uv to nir wavelengths .
these emission lines can be identified and redshifts determined even with relatively low s / n , resource - economic , |
5,033 | Suppose that you have an abstract for a scientific paper: motivated by the recent neutron diffraction experiment on @xmath0 , we consider a microscopic model where each @xmath1 ion is occupied by two @xmath2 electrons of parallel spins with two fold degenerate orbital configurations .
the mean field classical solutions of the spin - orbital superexchange model predicts an antiferro - orbital ordering at a higher temperature followed by a c - type antiferromagnetic spin ordering at a lower temperature .
our results are qualitatively consistent with the observed orbital phase transition at @xmath3k and the spin phase transition at @xmath4k in @xmath0 . .
And you have already written the first three sentences of the full article: the transition metal perovskite oxides exhibit many interesting physical phenomena .
in some of these compounds , the orbital degrees of freedom play an important role in their magnetic properties due to the strong spin - orbital coupling @xcite .
examples include the mott - hubbard type insulators @xmath5 and @xmath6 , which show very unusual magnetic properties ..
Please generate the next two sentences of the article | although the early experiments on @xmath5 and @xmath6 were reported back in the mid 1970 s @xcite , there has been renewed interest in the past decade on these materials @xcite .
there are two magnetic phases in @xmath5 : c - type antiferromagnetic order ( ferromagnetic chains along the z - axis which stagger within the x - y plane ) at temperature @xmath7k @xmath8k , and g - type antiferromagnetic order ( staggered in all three directions ) at temperature @xmath9k @xcite . |
5,034 | Suppose that you have an abstract for a scientific paper: a new technique for performance regulation in event - driven systems , recently proposed by the authors , consists of an adaptive - gain integral control .
the gain is adjusted in the control loop by a real - time estimation of the derivative of the plant - function with respect to the control input .
this estimation is carried out by infinitesimal perturbation analysis ( ipa ) .
the main motivation comes from applications to throughput regulation in computer processors , where to - date , testing and assessment of the proposed control technique has been assessed by simulation .
the purpose of this paper is to report on its implementation on a machine , namely an intel haswell microprocessor , and compare its performance to that obtained from cycle - level , full system simulation environment .
the intrinsic contribution of the paper to the workshop on discrete event system is in describing the process of taking an ipa - based design and simulation to a concrete implementation , thereby providing a bridge between theory and applications . .
And you have already written the first three sentences of the full article: one of the objectives of systems control is _ performance regulation _ , namely the output tracking of a given setpoint reference despite modeling uncertainties , time - varying system s characteristics , noise , and other unpredictable factors having the effects of system - disturbances .
a commonly - practiced way to achieve tracking is by a feedback control law that includes an integrator .
an integral control alone may have destabilizing effects on the closed - loop system , and hence the controller often includes proportional and derivative elements as well thereby comprising the well - known pid control @xcite ..
Please generate the next two sentences of the article | recently there has been a growing interest in performance regulation of event - driven systems , including discrete event dynamic systems ( deds ) and hybrid systems ( hs ) , and a control technique has been proposed which leverages on the special structure of discrete - event dynamics @xcite .
the controller consists of a standalone integrator with an adaptive gain , adjusted in real time as part of the control law . |
5,035 | Suppose that you have an abstract for a scientific paper: the surface of a cr@xmath0o@xmath1 ( 0001 ) film epitaxially grown on cr undergoes an unusual reentrant sequence of structural phase transitions ( @xmath2 ) . in order to understand the underlying microscopic mechanisms , the structural and magnetic properties of the cr@xmath0o@xmath1 ( 0001 ) surface
are here studied using first - principles electronic structure calculations .
two competing surface cr sites are identified .
the energetics of the surface is described by a configurational hamiltonian with parameters determined using total energy calculations for several surface supercells .
effects of epitaxial strain and magnetic ordering on configurational interaction are also included .
the thermodynamics of the system is studied using monte carlo simulations . at zero strain
the surface undergoes a @xmath3 ordering phase transition at @xmath4 .
tensile epitaxial strain together with antiferromagnetic ordering drive the system toward strong configurational frustration , suggesting the mechanism for the disordering phase transition at lower temperatures . .
And you have already written the first three sentences of the full article: metal oxides demonstrate a variety of physical and chemical properties , sometimes in intriguing combinations .
apart from being ubiquitous in nature , metal - oxide surfaces and interfaces find diverse technological applications and are being explored for potential use in future electronic devices . in particular , surfaces of magnetoelectric antiferromagnets such as possess an equilibrium surface magnetization , @xcite making them suitable for use as active layers in electrically - switchable magnetic nanostructures .
@xcite the ( 0001 ) surface has been a subject of many experimental @xcite and theoretical @xcite studies , but its surface remains poorly understood ..
Please generate the next two sentences of the article | low - energy electron diffraction ( leed ) experiments for a thin ( 0001 ) film grown on a cr ( 110 ) single crystal revealed an unusual reentrant structural phase transition,@xcite in which the surface structure changes from @xmath5 to @xmath6 and back to @xmath5 under cooling from room temperature to 150 k and then further down to 100 k. the origin of these phase transitions is not understood .
while the high - temperature transition may , as suggested by the leed data , @xcite be a conventional order - disorder transition , the second one is unusual in that a more symmetric phase appears at lower temperatures . |
5,036 | Suppose that you have an abstract for a scientific paper: we have measured the profiles of the h and k chromospheric emission lines in 147 main sequence stars of spectral type m5-k7 ( masses 0.30 - 0.55 m@xmath0 ) using multiple high resolution spectra obtained during six years with the hires spectrometer on the keck 1 telescope . remarkably , the average fwhm , equivalent widths , and line luminosities of h and k _ increase _ by a factor of 3 with increasing stellar mass over this small range of stellar masses .
we fit the h and k lines with a double gaussian model to represent both the chromospheric emission and the non - lte central absorption .
most of the sample stars display a central absorption that is typically redshifted by @xmath10.1 relative to the emission .
this implies that the higher - level , lower density , chromospheric material has a smaller outward velocity ( or higher inward velocity ) by 0.1 than the lower - level material in the chromosphere , but the nature of this velocity gradient remains unknown .
the fwhm of the h and k emission lines increase with stellar luminosity , reminiscent of the wilson - bappu effect in fgk - type stars .
both the equivalent widths and fwhm exhibit modest temporal variability in individual stars . at a given value of @xmath2
, stars exhibit a spread in both the equivalent width and fwhm of h and k , due both to a spread in fundamental stellar parameters including rotation rate , age , and possibly metallicity , and to the spread in stellar mass at a given @xmath2 .
the k line is consistently wider than the h line , as expected , and its central absorption is more redshifted , indicating that the h and k lines form at slightly different heights in the chromosphere where the velocities are slightly different . the equivalent width of h@xmath3 correlates with h and k only for stars having equivalent widths above @xmath12 , suggesting the existence of a magnetic threshold above which the lower and upper chromosphere become thermally coupled . .
And you have already written the first three sentences of the full article: m dwarfs have received considerable attention regarding their internal stellar structure , their atmospheres , and their distribution in the galaxy ( see reviews by @xcite , @xcite and @xcite and references therein ) . however , their atmospheric structure , dynamics , and magnetic processes remain poorly understood .
m dwarfs show clear evidence of chromospheric heating , as revealed by emission lines in optical and uv wavelengths @xcite that constrain models of chromospheric structure @xcite .
they also contain hot coronae , as detected by their x - ray emission , with @xmath4 up to @xmath5 @xcite . @xcite and others have analyzed x - ray flaring in m dwarfs , and many observations of flaring activity have been made at other wavelengths @xcite . although hot outer atmospheres and flaring activity have been studied in stars of f , g , and k spectral types , m dwarfs deviate from chromospheric / coronal relations found in those stars , indicating a qualitative difference in atmospheric structure , velocity fields , and magnetic morphology @xcite ..
Please generate the next two sentences of the article | observations of chromospheres and coronae in m dwarfs have led to models that include significant amounts of nonradiative , magnetic heating in their outer atmospheres @xcite .
the observed scatter in x - ray luminosities and chromospheric emission line fluxes can be attributed to temporally changing surface inhomogeneities @xcite or differences in filling factor between stars @xcite . |
5,037 | Suppose that you have an abstract for a scientific paper: deep neural networks have greatly improved the performance of various applications including image processing , speech recognition , natural language processing , and bioinformatics .
however , it is still difficult to discover or interpret knowledge from the inference provided by a deep neural network , since its internal representation has many nonlinear and complex parameters embedded in hierarchical layers .
therefore , it becomes important to establish a new methodology by which deep neural networks can be understood . in this paper
, we propose a new method for extracting a global and simplified structure from a layered neural network . based on network analysis
, the proposed method detects communities or clusters of units with similar connection patterns .
we show its effectiveness by applying it to three use cases .
( 1 ) network decomposition : it can decompose a trained neural network into multiple small independent networks thus dividing the problem and reducing the computation time .
( 2 ) training assessment : the appropriateness of a trained result with a given hyperparameter or randomly chosen initial parameters can be evaluated by using a modularity index . and ( 3 ) data analysis : in practical data it reveals the community structure in the input , hidden , and output layers , which serves as a clue for discovering knowledge from a trained neural network .
+ _ keywords _ : layered neural networks , network analysis , community detection .
And you have already written the first three sentences of the full article: deep neural networks have recently been applied to various tasks @xcite , including image processing @xcite , speech recognition @xcite , natural language processing @xcite , and bioinformatics @xcite .
although they have simple layered structures of units and connections , they outperform other conventional models by their ability to learn complex nonlinear relationships between input and output data . in each layer ,
inputs are transformed into more abstract representations under a given set of the model parameters ..
Please generate the next two sentences of the article | these parameters are automatically optimized through training so that they extract the important features of the input data . in other words
, it does not require either careful feature engineering by hand , or expert knowledge of the data . |
5,038 | Suppose that you have an abstract for a scientific paper: using all the hst wfc / wfpc2 images of the field collected so far , we have performed an accurate relative astrometry analysis to re - assess the value of the vela pulsar proper motion .
although covering a much shorter time span , our measurement clearly confirms the previous result obtained by nasuti et al .
( 1997 ) using ground - based optical data and nails the proper motion value to @xmath0 mas @xmath1 . .
And you have already written the first three sentences of the full article: the vela pulsar is one of the isolated neutron stars with the widest observational database , spanning from radio waves to high - energy @xmath2-rays . nevertheless , the value of its distance is still in debate .
the canonical value of 500 parsec , derived by milne ( 1968 ) from the radio signals dispersion measure , has been recently questioned by several independent investigations .
studies of both the kinematics of the host supernova remnant ( cha et al ..
Please generate the next two sentences of the article | 1999 ; bocchino et al .
1999 ) and constraints on the neutron star radius imposed by the pulsar soft x - ray spectrum ( page et al . 1996 ) have suggested a significant downward revision of the distance . in both cases , a value of @xmath3 250 parsec appears more likely than the canonical one . |
5,039 | Suppose that you have an abstract for a scientific paper: what we are going to call in this paper diffractive phenomena " in billiards is far from being deeply understood .
these are sorts of singularities that , for example , some kind of corners introduce in the energy eigenfunctions . in this paper
we use the well - known scaling quantization procedure to study them .
we show how the scaling method can be applied to convex billiards with corners , taking into account the strong diffraction at them and the techniques needed to solve their helmholtz equation . as an example we study a classically pseudointegrable billiard , the truncated triangle .
then we focus our attention on the spectral behavior .
a numerical study of the statistical properties of high - lying energy levels is carried out .
it is found that all computed statistical quantities are roughly described by the so - called semi - poisson statistics , but it is not clear whether the semi - poisson statistics is the correct one in the semiclassical limit . .
And you have already written the first three sentences of the full article: in this work we calculate very high lying eigenvalues of a billiard system using the so - called scaling method @xcite .
this method has two main advantages , it is formulated on the boundary of the billiard ( allowing matrices of order @xmath0 , the wavenumber ) and it avoids zeroes searching algorithms .
we have solved the helmholtz equation with dirichlet boundary conditions on the billiard boundary ..
Please generate the next two sentences of the article | a point worth to mention is that any eigenfunction is @xmath1 at domain points . at straight segments of the boundary ,
eigenfunctions are reflected as odd functions , so that the result satisfies the dirichlet condition . |
5,040 | Suppose that you have an abstract for a scientific paper: ultra - luminous x - ray sources are usually believed to be black holes with mass about @xmath0 .
however , the recent discovery of nustar j095551 + 6940.8 in m82 by bachetti et al . shows that it holds the spin period @xmath1 and period derivative @xmath2 , which provides a strong evidence that some ultra - luminous x - ray sources could be neutron stars .
we obtain that the source may be an evolved magnetar according to our simulation by employing the model of accretion induced the polar magnetic field decay and standard spin - up torque of an accreting neutron star .
the results show that nustar j095551 + 6940.8 is still in the spin - up process , and the polar magnetic field decays to about @xmath3 after accreting @xmath4 , while the strong magnetic field exists in the out - polar region , which could be responsible for the observed low field magnetar .
the ultra luminosity of the source can be explained by the beaming effect and two kinds of accretion radial random accretion and disk accretion .
since the birth rate of magnetars is about ten percent of the normal neutron stars , we guess that several ultra - luminous x - ray sources should share the similar properties to that of nustar j095551 + 6940.8 .
[ firstpage ] accretion : accretion disks binaries : close x - rays : stars stars : magnetars .
And you have already written the first three sentences of the full article: ultra - luminous x - ray sources ( ulxs ) , also named super - eddington sources or super - luminous sources , were discovered by einstein observatory in 1980 s ( fabbiano 1989 ) .
they are usually thought as the point sources with luminosity about @xmath5 or above in the accreting systems .
assuming that the isotropic emission is with eddington limit , ulxs may be black holes whose mass go beyond those of the stellar black holes ( makeshima et al ..
Please generate the next two sentences of the article | 2000 ; feng and soria 2011 ; pasham et al .
2014 ; weng et al . |
5,041 | Suppose that you have an abstract for a scientific paper: associated to each ultrafilter @xmath0 on @xmath1 and each map @xmath2 is a dedekind cut in the ultrapower @xmath3 .
blass has characterized , under ch , the cuts obtainable when @xmath0 is taken to be either a p - point ultrafilter , a weakly - ramsey ultrafilter or a ramsey ultrafilter . dobrinen and todorcevic have introduced the topological ramsey space @xmath4 .
associated to the space @xmath4 is a notion of ramsey ultrafilter for @xmath4 generalizing the familiar notion of ramsey ultrafilter on @xmath1 .
we characterize , under ch , the cuts obtainable when @xmath0 is taken to be a ramsey for @xmath4 ultrafilter and @xmath5 is taken to be any map . in particular , we show that the only cut obtainable is the standard cut , whose lower half consists of the collection of equivalence classes of constants maps .
forcing with @xmath4 using almost - reduction adjoins an ultrafilter which is ramsey for @xmath4 . for such ultrafilters @xmath6 , dobrinen and todorcevic
have shown that the rudin - keisler types of the p - points within the tukey type of @xmath6 consists of a strictly increasing chain of rapid p - points of order type @xmath1 .
we show that for any rudin - keisler mapping between any two p - points within the tukey type of @xmath6 the only cut obtainable is the standard cut .
these results imply existence theorems for special kinds of ultrafilters . .
And you have already written the first three sentences of the full article: in this section , we define the notion of a rudin - keisler mapping and associate to each mapping a dedekind cut .
then we state some results of blass in @xcite characterizing , under ch , the types of cuts obtainable for rudin - keisler mappings from a p - point or a weakly - ramsey ultrafilter on @xmath1 . in last part of this section
, we provide an outline of the rest of the article and highlight its main results ..
Please generate the next two sentences of the article | we remind the reader of the rudin - keisler reducibility relation .
if @xmath0 is an ultrafilter on the base set @xmath7 and @xmath8 is an ultrafilter on the base set @xmath9 , then we say that @xmath8 is _ rudin - keisler reducible to _ @xmath0 and write @xmath10 if there there exists a function @xmath11 such that @xmath12 , where @xmath13 a _ rudin - keisler mapping from @xmath0 to @xmath8 _ is a function @xmath11 such that @xmath12 . |
5,042 | Suppose that you have an abstract for a scientific paper: abstract we investigate the dynamics of no - slip billiards , a model in which small rotating disks may exchange linear and angular momentum at collisions with the boundary .
we give new results on periodicity and boundedness of orbits which suggest that a class of billiards ( including all polygons ) is not ergodic .
computer generated phase portraits demonstrate non - ergodic features , suggesting chaotic no - slip billiards can not readily be constructed using the common techniques for generating chaos in standard billiards .
_ dedicated to the memory of kolya chernov _ .
And you have already written the first three sentences of the full article: no - slip ( or rough ) billiards are a type of billiard dynamical system based upon a model in which linear and angular momentum of a hard spherical particle , moving in an n - dimensional euclidean domain , may be exchanged on collisions at the boundary with total energy conserved , as indicated in the diagram of figure [ fig : intro ] .
gutkin and broomhead introduced no - slip collisions in two dimensions as a new model of a gas , in which `` the spheres interact with each other and with the container walls '' without slipping , in such a way that the impact `` conserves the total energy of the system , but mixes the tangential velocity components with the angular velocities of colliding spheres . ''
@xcite they demonstrate that in two dimensions energy may be conserved only by the specular collisions of the traditional gas model , well - known from standard billiards , or the unique conservative alternative of no - slip collisions . very little.
Please generate the next two sentences of the article | ( none to our knowledge ) seems to have been done regarding the dynamics of no - slip billiards since @xcite . in particular
, the broader implications of the main observation of that paper , concerning a striking boundedness property that they obtain in the very special case of an infinite strip billiard table , were not pursued . |
5,043 | Suppose that you have an abstract for a scientific paper: this paper is devoted to local sensing and communication for collective underwater systems used in networked and swarm modes .
it is demonstrated that a specific combination of modal and sub - modal communication , used simultaneously for robot - robot and robot - object detection , can create a dedicated cooperation between multiple auvs .
these technologies , platforms and experiments are shortly described , and allow us to make a conclusion about useful combinations of different signaling approaches for collective underwater systems . .
And you have already written the first three sentences of the full article: underwater exploration represents a very important economic , technologic and scientific challenge .
this is closely related to arctic and antarctic offshore resources , pollution monitoring , general oceanographic data collection and , recently , to underwater actuation @xcite .
due to very large underwater areas and high damping properties of water , application of multiple autonomous underwater vehicles ( auvs ) in cooperative missions seems very promising @xcite . for application of auvs in networked or swarm mode ,.
Please generate the next two sentences of the article | there is a number of crucial issues : underwater sensing and communication ( s&c ) , cooperation and mission control , design of auv platforms , autonomous behavior and several collective aspects of running multiple auvs . in this work we concentrate on minimalistic local s&c @xcite , and related coordination strategies , being motivated by the following reasons @xcite . in several past and running projects devoted to underwater swarms , such as aquajelly @xcite , angels @xcite , cocoro @xcite , a number of auv platforms and sensing technologies has been developed .
these works indicated two important issues : a successful auv platform needs a dedicated combination of different s&c technologies , moreover capabilities of underwater cooperation depends on the level of embodiment @xcite of on - board s&c systems . |
5,044 | Suppose that you have an abstract for a scientific paper: we present a theoretical study of the dynamical spin susceptibility for the intriguing fe - based superconductor fese , based on a tight - binding model developed to account for the temperature - dependent band structure in this system .
the model allows for orbital ordering in the @xmath0 channel below the structural transition and presents a strongly @xmath1 symmetry broken fermi surface at low temperatures which accounts for the nematic properties of this material .
the calculated spin excitations are peaked at wave vector @xmath2 in the 1-fe brillouin zone , with a broad maximum at energies of order a few mev . in this range ,
the occurrence of superconductivity sharpens this peak in energy , creating a @xmath2 `` neutron resonance '' as seen in recent experiments . with the exception of the quite low energy scale of these fluctuations , these results are roughly similar to standard behavior in fe pnictide systems . at higher energies , however , intensity increases and shifts to wave vectors along the @xmath2 - @xmath3 line .
we compare with existing inelastic neutron experiments and nmr data , and give predictions for further studies . .
And you have already written the first three sentences of the full article: the structurally simplest fe - based superconductor , fese , is one of the most mysterious at the present writing .
it exhibits a tetragonal to orthorhombic structural phase transition at @xmath4 , and displays very strong electronic nematic behavior below this temperature ( @xmath5 ) , but never orders magnetically as do the more familiar fe pnictide systems . while its critical temperature @xmath6 is relatively low for this class of materials , a very rapid increase of @xmath7 to about @xmath8
is observed under modest pressure@xcite ..
Please generate the next two sentences of the article | various intercalates of fese have @xmath7 of roughly this magnitude at ambient pressure as well , and the highest @xmath7 values of the entire class of fe - based superconductors , @xmath9 , are found in monolayer films of fese grown on srtio@xmath10 substrates.@xcite thus the bulk fese material , of which excellent single crystals are now available@xcite , gives the impression of being poised to become a high - temperature superconductor , such that efforts to understand its properties have accelerated in the past few years .
a starting point for these theoretical efforts is a reasonable band structure for fese . |
5,045 | Suppose that you have an abstract for a scientific paper: we describe an essential improvement of our recent algorithm for computing cohomology of lie ( super)algebra based on partition of the whole cochain complex into minimal subcomplexes .
we replace the arithmetic of rational numbers or integers by a much cheaper arithmetic of a modular field and use the inequality between the dimensions of cohomology @xmath0 over any modular field @xmath1 and over @xmath2 : @xmath3 . with this inequality we can , by computing over arbitrary @xmath4 quickly find the ( usually , rare ) subcomplexes for which @xmath5 and then carry out the full computation over @xmath2 within these subcomplexes .
we also present the results of application of the corresponding _ * c * _ program to the lie superalgebra of special vector fields preserving an `` odd - symplectic '' structure on the @xmath6-dimensional supermanifold .
for this algebra , we found some new basis elements of the cohomology in the trivial module . .
And you have already written the first three sentences of the full article: recently we proposed a new algorithm for computation of cohomology of a wide class of lie superalgebras .
this algorithm reduces the computation for the whole cochain complex to a number of smaller tasks within smaller subcomplexes .
one can demonstrate that if @xmath7 is the computation time for the whole complex , then partition of the complex into @xmath8 subcomplexes reduces the computation time roughly to the value @xmath9 ..
Please generate the next two sentences of the article | thus , the approach appeared to be efficient enough to cope with several difficult tasks in computing cohomology for particular lie ( super)algebras @xcite .
more detailed experiments with the _ * c * _ implementation of the algorithm , including profiling , reveal that arithmetic operations over @xmath2 take the main part of computation time ( usually more than 90% for large tasks ) . the same is true if @xmath2 is replaced by @xmath10 ( though computation becomes somewhat faster ) . |
5,046 | Suppose that you have an abstract for a scientific paper: we study the approximation properties of the class of nonstationary refinable ripplets introduced in @xcite .
these functions are solution of an infinite set of nonstationary refinable equations and are defined through sequences of scaling masks that have an explicit expression .
moreover , they are variation - diminishing and highly localized in the scale - time plane , properties that make them particularly attractive in applications . here
, we prove that they enjoy strang - fix conditions and convolution and differentiation rules and that they are bell - shaped .
then , we construct the corresponding minimally supported nonstationary prewavelets and give an iterative algorithm to evaluate the prewavelet masks . finally , we give a procedure to construct the associated nonstationary biorthogonal bases and filters to be used in efficient decomposition and reconstruction algorithms . as an example , we calculate the prewavelet masks and the nonstationary biorthogonal filter pairs corresponding to the @xmath0 nonstationary scaling functions in the class and construct the corresponding prewavelets and biorthogonal bases . a simple test showing their good performances in the analysis of a spike - like signal
is also presented . +
* keywords * : total positivity , variation - dimishing , refinable ripplet , bell - shaped function , nonstationary prewavelet , nonstationary biorthogonal basis + * msc * : 41a30 @xmath1 42c40 @xmath1 65t60 .
And you have already written the first three sentences of the full article: a _ ripplet _ is a function @xmath2 whose integer translate are _ totally positive _
@xcite , i.e. for any ordered real numbers @xmath3 , and any ordered integers @xmath4 , @xmath5 , it holds @xmath6 total positivity implies that the integer translates of @xmath2 are _ variation diminishing _ ,
i.e. for any finite sequence @xmath7 @xmath8 where @xmath9 denotes the strict sign changes of its argument ..
Please generate the next two sentences of the article | the disequality ( [ var.dim.1 ] ) in turn implies that the system @xmath10 has shape - preserving properties , which are known to play a crucial role in several applications , from approximation of data to cagd @xcite .
the concept of a ripplet was first introduced by goodman and micchelli in + @xcite , where the authors focused their interest on _ two - scale refinable ripplets _ , |
5,047 | Suppose that you have an abstract for a scientific paper: _ galex _
observations of comet 9p / tempel 1 using the near ultraviolet ( nuv ) objective grism were made before , during and after the deep impact event that occurred on 2005 july 4 at 05:52:03 ut when a 370 kg nasa spacecraft was maneuvered into the path of the comet .
the nuv channel provides usable spectral information in a bandpass covering 2000 3400 with a point source spectral resolving power of @xmath0 .
the primary spectral features in this range include solar continuum scattered from cometary dust and emissions from oh and cs molecular bands centered near 3085 and 2575 , respectively .
in particular , we report the only cometary cs emission detected during this event .
the observations allow the evolution of these spectral features to be tracked over the period of the encounter . in general ,
the nuv emissions observed from tempel 1 are much fainter than those that have been observed by _ galex _ from other comets .
however , it is possible to derive production rates for the parent molecules of the species detected by _ galex _ in tempel 1 and to determine the number of these molecules liberated by the impact .
the derived quiescent production rates are @xmath1 ( ) @xmath2 molecules s@xmath3 and @xmath1 ( ) @xmath4 molecules s@xmath3 , while the impact produced an additional @xmath5 molecules and @xmath6 molecules , a similar ratio as in quiescent outgassing . .
And you have already written the first three sentences of the full article: on 2005 july 4 at 05:52:03 ut ( as seen from earth ) a 370 kg nasa spacecraft was maneuvered into the path of comet 9p / tempel 1 @xcite .
the results of the impact were recorded by a host of ground and space based observatories with wavelength coverage spanning the sub - mm to the ultraviolet @xcite . here
we report on the results of low resolution slitless spectroscopy acquired with the _ galaxy evolution explorer _ ( _ galex _ ) in the near ultraviolet nuv channel 2 days before , immediately following , and 1 day after the impact event ..
Please generate the next two sentences of the article | the primary spectral features in this range include a solar continuum scattered from cometary dust and emissions from oh and cs molecular bands centered near 3085 and 2575 , respectively .
_ galex _ _ ( galaxy evolution explorer ) _ is a nasa small explorer whose primary mission is to map the history of star formation using two modes : two - band photometry ( fuv , 13501750 ; nuv , 17503100 ) and integrated field grism spectroscopy with 1020 spectral resolution . because of its large field - of - view , 12 , _ galex _ is also well suited to cometary coma studies as demonstrated by the 2005 march observations of c/2004 q2 machholz @xcite . |
5,048 | Suppose that you have an abstract for a scientific paper: the phase diagram of correlated , disordered electron systems is calculated within dynamical mean - field theory using the hlder mean local density of states . a critical disorder strength is determined in the anderson - falicov - kimball model and the arithmetically and the geometrically averages are found to be just particular means used respectively to detect or not the anderson localization .
correlated metal , mott insulator and anderson insulator phases , as well as coexistence and crossover regimes are analyzed in this new perspective . .
And you have already written the first three sentences of the full article: the properties of materials are strongly influenced by electronic interaction and randomness .
in particular , coulomb correlations and disorder are both driving forces behind metal - insulator transitions ( mit ) connected with the localization and delocalization of particles .
the mott - hubbard mit is caused by coulomb correlations ( electronic repulsion ) in the pure system @xcite ..
Please generate the next two sentences of the article | the anderson mit , also referred to as anderson localization , was established in @xcite and is the basis of the theory of localization of electrons in disordered systems .
it is due to coherent backscattering from randomly distributed impurities in a system without interaction @xcite . |
5,049 | Suppose that you have an abstract for a scientific paper: there have recently been several reports of apparently periodic variations in the light curves of quasars , e.g. pg 1302@xmath0102 by @xcite .
any quasar showing periodic oscillations in brightness would be a strong candidate to be a close binary supermassive black hole and , in turn , a candidate for gravitational wave studies . however , normal quasars powered by accretion onto a single , supermassive black hole
usually show stochastic variability over a wide range of timescales .
it is therefore important to carefully assess the methods for identifying periodic candidates from among a population dominated by stochastic variability . using a bayesian analysis of the light curve of pg 1302@xmath0102
, we find that a simple stochastic process is preferred over a sinusoidal variations .
we then discuss some of the problems one encounters when searching for rare , strictly periodic signals among a large number of irregularly sampled , stochastic time series , and use simulations of quasar light curves to illustrate these points . from a few thousand simulations of steep spectrum ( ` red noise ' ) stochastic processes
, we find many simulations that display few - cycle periodicity like that seen in pg 1302@xmath0102 .
we emphasise the importance of calibrating the false positive rate when the number of targets in a search is very large .
[ firstpage ] methods : data analysis methods : statistical surveys , quasars : general quasars : supermassive black holes .
And you have already written the first three sentences of the full article: detecting and characterising periodic variations in the brightness ( and other properties ) of astrophysical sources is a cornerstone of observational astronomy .
examples include the discovery of extrasolar planetary systems , using stellar pulsations to establish the cosmological distance scale , and the study of pulsars and interacting binary star systems .
nearly sinusoidal modulations are usually the result of orbital motion or rotation ..
Please generate the next two sentences of the article | however , many other astrophysical sources notably accreting sources such as interacting binary stars , young stellar objects , and active galactic nuclei ( agn ) show persistent , random ( aperiodic , stochastic , noise ) variations in their brightness driven by the complex and turbulent accretion process .
see @xcite for a brief review of random time series in astronomy . |
5,050 | Suppose that you have an abstract for a scientific paper: a perturbation spin - wave theory for the quantum heisenberg antiferromagnets on a square lattice is proposed to calculate the uniform static magnetic susceptibility at finite temperatures , where a divergence in the previous theories due to an artificial phase transition has been removed . to the zeroth order ,
the main features of the uniform static susceptibility are produced : a linear temperature dependence at low temperatures and a smooth crossover in the intermediate range and the curie law at high temperatures .
when the leading corrections from the spin - wave interactions are included , the resulting spin susceptibility in the full temperature range is in agreement with the numerical quantum monte carlo simulations and high - temperature series expansions . .
And you have already written the first three sentences of the full article: the quantum heisenberg antiferromagnet ( qhafm ) is a prototype model to describe the magnetic properties in the parent compounds of high temperature superconducting cuprates.@xcite non - linear sigma model is shown that its ground state has long - range order and its low energy excitations are in a renormalized classical state.chakravartyprl,chakravartyprb,chubukov these results are confirmed by the quantum monte carlo methods@xcite and are consistent with experimental data.@xcite moreover , the schwinger boson mean field theory@xcite and the variational spin - wave theorytakahashi have also been developed for the two - dimensional qhafm , leading to similar conclusions .
previous theoretical studies have concentrated in the low temperature region .
however , the low - energy interesting physics of the two - dimensional qhafm can persist up to the temperature region @xmath0 ..
Please generate the next two sentences of the article | moreover , the anomalous normal state in the charged doped qhafm in the cuprates@xcite relies on a theory for the magnetic fluctuations in the intermediate temperature range .
therefore , a theory is needed to be well defined in the full temperature range . |
5,051 | Suppose that you have an abstract for a scientific paper: we have used a combination of high resolution cosmological n - body simulations and semi - analytic modelling of galaxy formation to investigate the processes that determine the spatial distribution of galaxies in cold dark matter ( cdm ) models and its relation to the spatial distribution of dark matter .
the galaxy distribution depends sensitively on the efficiency with which galaxies form in halos of different mass . in small mass halos ,
galaxy formation is inhibited by the reheating of cooled gas by feedback processes , whereas in large mass halos , it is inhibited by the long cooling time of the gas . as a result
, the mass - to - light ratio of halos has a deep minimum at the halo mass , @xmath0 , associated with @xmath1 galaxies , where galaxy formation is most efficient .
this dependence of galaxy formation efficiency on halo mass leads to a scale - dependent bias in the distribution of galaxies relative to the distribution of mass . on large scales ,
the bias in the galaxy distribution is related in a simple way to the bias in the distribution of massive halos . on small scales ,
the correlation function is determined by the interplay between various effects including the spatial exclusion of dark matter halos , the distribution function of the number of galaxies occupying a single dark matter halo and , to a lesser extent , dynamical friction .
remarkably , these processes conspire to produce a correlation function in a flat , @xmath2 , cdm model that is close to a power - law over nearly four orders of magnitude in amplitude .
this model agrees well with the correlation function of galaxies measured in the apm survey . on small scales , the model galaxies are less strongly clustered than the dark matter , whereas on large scales they trace the occupied halos .
our clustering predictions are robust to changes in the parameters of the galaxy formation model , provided only those models that match the bright end of the galaxy luminosity function are considered .
galaxies :....
And you have already written the first three sentences of the full article: studies of the clustering of cosmological dark matter have progressed enormously in the past twenty years .
the dynamical evolution of the dark matter is driven by gravity and fully specified initial conditions are provided in current cosmological models . this problem can therefore be attacked quite cleanly using n - body simulations ( see jenkins et al .
1998 , gross et al . 1998 and references therein . ).
Please generate the next two sentences of the article | studies of the clustering properties of galaxies , on the other hand , are much more complicated because galaxy formation includes messy astrophysical processes such as gas cooling , star formation and feedback from supernovae .
these processes couple with the gravitational evolution of the dark matter to produce the clustering pattern of galaxies . |
5,052 | Suppose that you have an abstract for a scientific paper: using fully self - consistent n - body models for the dynamical evolution of the large magellanic cloud ( lmc ) in the galaxy , we show that if the lmc initially has an extended old stellar halo before its commencement of tidal interaction with the galaxy , physical properties of the stars stripped from the lmc stellar halo can have fossil information as to when and where the lmc was accreted onto the galaxy for the first time .
if the epoch of the first lmc accretion onto the galaxy from outside its viriral radius is more than @xmath0 gyr ago ( i.e. , at least two pericenter passages ) , the stars stripped from the stellar halo of the lmc can form an irregular polar ring or a thick disk with a size of @xmath1 kpc and rotational kinematics . on the other hand ,
if the lmc was first accreted onto the galaxy quite recently ( @xmath2 gyr ago ) , the stripped stars form shorter leading and trailing stellar stream at @xmath3 kpc .
also distributions of the stripped stars in phase space between the two cases can be significantly different . the derived differences in structure and kinematics of the stripped stars therefore suggest that if we compare the observed three - dimensional ( 3d ) distribution and kinematics of the outer galactic stellar halo along the polar - axis , then we can give strong constraints on the past orbit of the lmc .
we also discuss whether the orbital properties of the lmc in successful formation models for the magellanic stream ( ms ) can be consistent with orbital properties of the lmc - type systems in galaxy - type halos predicted from recent high - resolution cosmological simulations in a @xmath4cdm universe .
we find that the orbital properties of the lmc in the successful formation models are consistent with those predicted from the cosmological simulations .
we also find that the lmc can not merge with the galaxy within the last @xmath5 gyr in models consistent with predictions from the @xmath4cdm simulations .
given that the successful ms formation models predict at....
And you have already written the first three sentences of the full article: recent proper motion measurements of the lmc and the small magellanic cloud ( smc ) have suggested that the lmc is now moving around the galaxy with a velocity ( @xmath6 ) of @xmath7 km s@xmath8 with respect to the galaxy ( e.g. , kallivayalil et al .
2006 , k06 ; piatek et al .
the latest observational studies on the proper motions of the clouds ( vieira et al . 2010 , v10 ) have however derived significantly different @xmath6 ( @xmath9 km s@xmath8 ) , which is significantly smaller than @xmath6 derived by the above earlier studies ( see also costa et al . 2009 ,.
Please generate the next two sentences of the article | c09 , which derived @xmath10 km s@xmath8 ) . using n - body models of the lmc , bekki ( 2011 )
has recently shown that if the total number of the lmc fields used for the derivation of the center - of - mass proper motion of the lmc , then the derived center - of - mass proper motion of the lmc can significantly deviate from the true one . |
5,053 | Suppose that you have an abstract for a scientific paper: this paper is an update and extension of a result the authors first proved in 2003 .
the goal of this paper is to study factors which are known to be @xmath0-characteristic for certain nonconventional averages and prove that these factors are pointwise characteristic for the multiterm return times averages . in memory of dan rudolph . .
And you have already written the first three sentences of the full article: a major result in ergodic theory in the late 1980 s was the proof of the return times theorem by j. bourgain @xcite ( which was later simplified by j. bourgain , h. furstenberg , y. katznelson , d. ornstein in @xcite ) .
this theorem created a key strengthening of the birkhoff s pointwise ergodic theorem @xcite .
[ rtt1 ] let @xmath1 be an ergodic dynamical system of finite measure and @xmath2 ..
Please generate the next two sentences of the article | then there exists a set @xmath3 of full measure such that for any other ergodic dynamical system @xmath4 with @xmath5 and any @xmath6 : @xmath7 converges @xmath8-a.e . for all @xmath9 .
note that the set @xmath10 depends not only on the function @xmath11 chosen , but on the transformation @xmath12 in our dynamical system . in the bfko proof @xcite of the return times theorem , |
5,054 | Suppose that you have an abstract for a scientific paper: two - dimensional free - surface potential flows of an ideal fluid over a strongly inhomogeneous bottom are investigated with the help of conformal mappings .
weakly - nonlinear and exact nonlinear equations of motion are derived by the variational method for arbitrary seabed shape parameterized by an analytical function . as applications of this theory ,
band structure of linear waves over periodic bottoms is calculated and evolution of a strong solitary wave running from a deep region to a shallow region is numerically simulated . .
And you have already written the first three sentences of the full article: the classical problem of water waves over a variable seabed has attracted much attention ( see @xcite and references therein ) .
there are some significant differences in this interesting and practically important problem , as compared to the theory of waves on a deep water or in canals with a flat horizontal bottom . in situations where the fluid depth is less or of the same order as
a typical length of surface wave , inhomogeneity of the bottom is a reason for linear and nonlinear wave scattering and transformation , and it strongly affects wave propagation ..
Please generate the next two sentences of the article | these phenomena occur so widely that one can meet them almost everywhere , although with different scales .
examples of strongly nonlinear dynamics are ocean waves running on a beach , or motion of disturbed water in a puddle after a car . among linear effects due to bottom topography |
5,055 | Suppose that you have an abstract for a scientific paper: the solution of non - linear evolution equations for dense nuclear gluon density has been suggested as one of the relevant mechanisms of @xmath0 and @xmath1 collisions at collider energies .
here we study a simple parameterization for the unintegrated gluon distribution using the knowledge of asymptotic solutions of the balitsky - kovchegov equation , describing high - energy qcd in the presence of saturation effects .
a satisfactory description of nuclear shadowing at small-@xmath2 is obtained and it allows us to understand the qualitative behavior shown by data . .
And you have already written the first three sentences of the full article: the knowledge of the qcd dynamics at high energies is essential in understanding the hadronic interactions studied at current ( hera , tevatron ) and future ( lhc ) accelerators . in the physics of saturation
@xcite the relevant observable is the forward scattering amplitude of a quark - antiquark dipole off a target .
it enters several processes at high energy like deep inelastic scattering ( dis ) , photoproduction and hadron - hadron scattering ..
Please generate the next two sentences of the article | its quantum evolution has recently been the object of many studies @xcite .
the balitsky - kovchegov ( bk ) equation @xcite valid in the large @xmath3 limit and in the mean field approximation provides a tool to study the rapidity behavior of the gluon distribution in a large momentum range including the saturation region where the effects of gluon recombination , taken into account in the non - linear term , become important . |
5,056 | Suppose that you have an abstract for a scientific paper: we will present the results of a nicmos h - band imaging survey of a small sample of @xmath02 3 radio - quiet quasars .
we have resolved extension in at least 4 of 5 objects and find evidence for a wide range in the morphologies and magnitudes of these hosts .
the host galaxy luminosities range from sub - l@xmath1 to about 4 l@xmath1 , with most of the hosts having luminosities about l@xmath1 .
these host galaxies have magnitudes and sizes consistent with those of the ly break galaxies at similar redshifts and at similar rest wavelengths , but are about a magnitude fainter than the comparable 6c radio galaxies .
one residual host component is not centered on the quasar nucleus , and several have close companions ( within @xmath210 kpc ) , indications that these systems are possibly in some phase of a merger process . .
And you have already written the first three sentences of the full article: radio - quiet quasars ( rqq ) represent more than half the known agn at high redshift ( @xmath3 ) , yet information on the galaxies that host these active nuclei is currently extremely limited . at lower redshift ,
the luminous rqq are found primarily in giant ellipticals with luminosities of several times a @xmath4 galaxy at @xmath5 ( e.g. mclure et al . 1999 ) .
in addition , the luminosity of the host seems to correlate roughly with that of the nucleus ( mcleod & rieke 1995 ; mclure et al ..
Please generate the next two sentences of the article | 1999 , mcleod , rieke , & storrie - lombardi 1999 ) .
similarly , almost every nearby bulge - dominated galaxy contains a supermassive black hole candidate whose mass is roughly proportional to the mass of its bulge ( magorrian et al . |
5,057 | Suppose that you have an abstract for a scientific paper: suppose that wirelessly communicating sensors are placed in a regular fashion on the points of a lattice .
common communication protocols allow the sensors to broadcast messages at arbitrary times , which can lead to problems should two sensors broadcast at the same time .
it is shown that one can exploit a tiling of the lattice to derive a deterministic periodic schedule for the broadcast communication of sensors that is guaranteed to be collision - free .
the proposed schedule is shown to be optimal in the number of time slots .
* keywords : * distributed computing , scheduling sensors , lattice tiling , wireless communication . .
And you have already written the first three sentences of the full article: sensors are sometimes distributed in a regular fashion to monitor an area .
we assume that the sensors use wireless communication .
most wireless communication protocols allow the sensors to send at arbitrary times . however , this can cause the following _ collision problems _ : if two distinct sensors @xmath0 and @xmath1 send at the same time and @xmath1 is within the interference range of @xmath0 , then frequently hardware limitations prevent @xmath1 from receiving the message of @xmath0 correctly . in addition , if two distinct sensors @xmath0 and @xmath1 send at the same time and a sensor @xmath2 is within interference range of both @xmath0 and @xmath1 , then @xmath2 will not be able to correctly receive either message . in these cases , the sensors @xmath0 and.
Please generate the next two sentences of the article | @xmath1 need to resend their messages , which is evidently a waste of energy .
let us assume that the sensors have access to the current time , represented by an integer @xmath3 . |
5,058 | Suppose that you have an abstract for a scientific paper: we apply the causal interpretation of quantum mechanics to homogeneous and isotropic quantum cosmology where the sources of the gravitational field are either dust or radiation perfect fluids .
we find non - singular quantum trajectories which tends to the classical one when the scale factor becomes much larger then the planck length .
in this situation , the quantum potential becomes negligible .
there are no particle horizons . as
radiation is a good approximation for the matter content of the early universe , this result suggests that the universe can be eternal due to quantum effects .
pacs number(s ) : 98.80.h , 03.65.bz 6000 6000 40by -1 to epsf # 1 # 1#2#3 = # 1 in to # 1#2#3 # 3 .
And you have already written the first three sentences of the full article: the appearance of initial singularities in the classical cosmological models which better describe the universe we live in constitutes a big puzzle to all cosmologists . until now
, singularities are out of the scope of any physical theory .
if we assume that a physical theory can describe the whole universe at every instant , even at its possible moment of creation ( which is the best attitude because it is the only way to seek the limits of physical science ) , then these classical singular points must be avoided ..
Please generate the next two sentences of the article | indeed , no one expects that classical general relativity continues to be valid under extreme situations of very high energy density and curvature .
in particular , it is very plausible that quantum gravitational effects become important under these conditions , eliminating the singularities that appear classically . to see |
5,059 | Suppose that you have an abstract for a scientific paper: integral field spectroscopy ( ifs ) provides a spectrum simultaneously for each spatial sample of an extended , two - dimensional field .
it consists of an integral field unit ( ifu ) which slices and re - arranges the initial field along the entrance slit of a spectrograph .
this article presents an original design of ifu based on the advanced image slicer concept @xcite . to reduce optical aberrations ,
pupil and slit mirrors are disposed in a fan - shaped configuration that means that angles between incident and reflected beams on each elements are minimized .
the fan - shaped image slicer improves image quality in terms of wavefront error by a factor 2 comparing with classical image slicer and , furthermore it guaranties a negligible level of differential aberration in the field . as an exemple , we are presenting the design lam used for its proposal at the nirspec / ifu invitation of tender . .
And you have already written the first three sentences of the full article: integral field spectroscopy ( ifs ) provides a spectrum simultaneously for each spatial sample of an extended , two - dimensional field .
basically , an ifs is located in the focal plane of a telescope and is composed by an integral field unit ( ifu ) and a spectrograph . the ifu acts as a coupler between the telescope and the spectrograph by reformatting optically a rectangular field into a quasi - continuous pseudo - slit located at the entrance focal plane of the spectrograph .
therefore , the light from each pseudo - slit is dispersed to form spectra on the detector and a spectrum can be obtained simultaneously for each spatial sample within the ifu field ..
Please generate the next two sentences of the article | the ifu contains two main optical sub - systems : the fore - optics and the image slicer .
the fore - optics introduces an anamorphic magnification of the field with an aspect ratio of 1@xmath02 onto the set of slicer mirrors optical surfaces . in such way |
5,060 | Suppose that you have an abstract for a scientific paper: simultaneous space- and ground - based microlensing surveys , such as those planned with _ k2 _ s campaign 9 ( _ k2_c9 ) and , potentially , _ wfirst _ ,
facilitate measuring the masses and distances of free - floating planet ( ffp ) candidates .
ffps are initially identified as events arising from a single lensing mass with a short timescale , ranging from one day for a jupiter - mass planet to a few hours for an earth - mass planet .
measuring the mass of the lensing object requires measuring the angular einstein radius @xmath0 , typically by first determining the finite size of the source star @xmath1 , as well as the microlens parallax @xmath2 . a planet
that is gravitationally bound to , but widely separated from , a host star ( @xmath320 au ) can produce a light curve that is similar to that of an ffp .
this tension can be resolved with high - resolution imaging of the microlensing target to search for the lens flux @xmath4 from a possible host star . here
we investigate the accessible parameter space for each of these components @xmath2 , @xmath1 , and @xmath4 considering different satellite missions for a range of ffp masses , galactic distances , and source star properties .
we find that at the beginning of _
k2_c9 , when its projected separation from the earth ( as viewed from the center of its survey field ) is @xmath50.2 au , it will be able to measure @xmath2 for jupiter - mass ffp candidates at distances larger than @xmath62 kpc and to earth - mass lenses at @xmath68 kpc . at the end of its campaign ,
when @xmath7 au , it is sensitive to planetary - mass lenses for distances @xmath33.5 kpc , and even then only to those with mass @xmath3m@xmath8 . from lens flux constraints we find that it will be possible to exclude _ all _ stellar - mass host stars ( down to the deuterium - burning limit ) for events within @xmath62 kpc , and for events at any distance it will be possible to exclude main sequence host stars more massive than @xmath60.25 m@xmath9 .
together these indicate....
And you have already written the first three sentences of the full article: understanding the frequency and mass function of free - floating planets ( ffps ) is integral for a complete comprehension of the formation and evolution of planetary systems . using deep photometric imaging primarily in near - infrared bands and , in some cases ,
astrometric and/or spectroscopic follow - up data , jupiter - mass ffps and ffp candidates have been detected in the trapezium cluster @xcite , the @xmath10 orionis open cluster @xcite , the ab doradus moving group @xcite , the @xmath11 pictoris moving group @xcite , the upper scorpius association @xcite , and in the field @xcite .
yet detections from photometric surveys require and depend sensitively on an independent constraint for the object s age while the dynamical association of objects in moving groups is intrinsically more uncertain . in a broader statistical sense , @xcite examined two years of microlensing survey data from the microlensing observations in astrophysics ( moa ) collaboration ..
Please generate the next two sentences of the article | they found an excess of short - timescale events ( @xmath122 days ) above expectations based on an extrapolation of the stellar mass function down to low - mass brown dwarfs . from this
they inferred a population of ffp candidates that outnumber main sequence stars by a ratio of @xmath13 . |
5,061 | Suppose that you have an abstract for a scientific paper: the smoluchowski equation for a free particle with a time dependent sink is solved exactly for many special cases . in this method by knowing the probability distribution at the origin @xmath0 , one may derive the probability distribution at all positions _
i.e. , _ @xmath1 . .
And you have already written the first three sentences of the full article: the diffusion process of a particle in a potential with the presence of a sink studied through solution of the smoluchowski equation@xcite is of keen interest to many scientists in chemical dynamics as it serves a reference model for a wide variety of dynamical processes .
various attempts has been made to study the diffusion processes with a suitable position of the sink@xcite which can find application in diffusion controlled reactions@xcite .
such a model is used by wilemski and fixman@xcite to calculate the rate of diffusion controlled reactions as well as cyclization of polymer chain in solutions ..
Please generate the next two sentences of the article | ovchinnikova@xcite , zusman@xcite , marucs and nadler@xcite have used such a model for electron transfer reactions in polar solvents .
marcus@xcite recently used a diffusive equation with a sink term to develop a theory of uni - molecular reactions in clusters . |
5,062 | Suppose that you have an abstract for a scientific paper: a common goal in an experimental physics analysis is to extract information from a reaction with multi - dimensional kinematics .
the preferred method for such a task is typically the unbinned maximum likelihood method . in fits using this method , the likelihood is a goodness - of - fit quantity in that it effectively discriminates between available hypotheses ; however , it does not provide any information as to how well the best hypothesis describes the data . in this paper
, we present an _
ad - hoc _
procedure for obtaining @xmath0 values from unbinned maximum likelihood fits .
this method does not require binning the data , making it very applicable to multi - dimensional problems .
and 11.80.et,29.85.fj .
And you have already written the first three sentences of the full article: in many physics analyses , one seeks to extract information from a reaction with multi - dimensional kinematics
. fits to binned data are often limited by statistical uncertainties ; thus , use of the unbinned maximum likelihood method is generally preferred .
this method is well suited to obtaining estimators for unknown parameters in a hypothesis probability density function ( p.d.f . ) ..
Please generate the next two sentences of the article | it is also an excellent way of discriminating between hypotheses ; however , it does not provide a means of determining how well the best hypothesis describes the data . in this paper
, we describe an _ ad - hoc _ |
5,063 | Suppose that you have an abstract for a scientific paper: we performed a neutron - scattering experiment to investigate the effect of distortion of cuo@xmath0 planes on the low - energy spin correlation of la@xmath1sr@xmath2ce@xmath3cuo@xmath4 ( lscco ) . due to the carrier - compensation effect by co - doping of sr and
ce , lscco has a smaller orthorhombic lattice distortion compared to la@xmath5sr@xmath2cuo@xmath4 ( lsco ) with comparable hole concentration @xmath6 .
a clear gap with the edge - energy of 6@xmath77 mev was observed in the energy spectrum of local dynamical susceptibility @xmath8@xmath9(@xmath10 ) for both @xmath11=0.18 ( @[email protected] ) and @xmath11=0.24 ( @[email protected] ) samples as observed for optimally - doped lsco ( @[email protected] ) . for the @xmath11=0.14 ( @[email protected] ) sample ,
in addition to the gap - like structure in @xmath8@xmath9(@xmath10 ) we observed a low - energy component within the gap which develops below 2@xmath73mev with decreasing the energy .
the low - energy component possibly coincides with the static magnetic correlation observed in this sample .
these results are discussed from a view point of relationship between the stability of low - energy spin fluctuations and the distortion of cuo@xmath0 planes .
high-@xmath12 superconductivity , spin fluctuations , neutron - scattering .
And you have already written the first three sentences of the full article: extensive neutron - scattering experiments clarified a close relation between the spin correlations and the superconductivity in high-_t_@xmath13 superconductors@xcite . in the prototypical high-_t_@xmath13 superconductor la@xmath5sr@xmath2cuo@xmath4 ( lsco ) , in which the doping - dependence of physical properties can be easily investigated by changing sr concentration ,
following results were obtained : ( i ) the incommensurate ( ic ) spin correlations were observed in a whole superconducting ( sc ) phase with 0.055@xmath14@[email protected]@xcite .
( ii ) the direction of the ic wavevector in the sc phase differs by 45@xmath15 in angle from that observed one in the spin - glass phase for @[email protected]@xcite ..
Please generate the next two sentences of the article | ( iii ) the incommensurability ( @xmath17 ) is proportional to _ t_@xmath13 in underdoped region@xcite .
these experimental facts naturally suggest that the origin of ic spin correlations are important to be clarified for the understanding of role of magnetism in the mechanism of high-_t_@xmath13 superconductivity . on the other hand |
5,064 | Suppose that you have an abstract for a scientific paper: this is the second paper in a series on light scattering from optically anisotropic scatterers embedded in an isotropic medium .
the apparently complex t - matrix theory involving mixing of angular momentum components turns out to be an efficient approach to calculating scattering in these systems .
we present preliminary results of numerical calculations of the scattering by spherical droplets in some simple cases .
the droplets contain optically anisotropic material with local radial or uniform anisotropy .
we concentrate on cases in which the scattering is due only to the local optical anisotropy within the scatterer . for radial anisotropy
we find non - monotonic dependence of the scattering cross - section on the degree of anisotropy can occur in a regime for which both the rayleigh and semi - classical theories are inapplicable . for uniform anisotropy
the cross - section is strongly dependent on the angle between the incident light and the optical axis , and for larger droplets this dependence is non - monotonic . .
And you have already written the first three sentences of the full article: in the first paper in this series @xcite , we developed a _
t_-matrix theory of light scattering by spherical but optically anisotropic either radially or uniformly scatterers . whereas for radial anisotropic scatterers it is possible to derive closed form expressions for the elements of the t - matrix , in the uniformly anisotropic case this is no longer true . to further complicate matters , in this latter case the _
t_matrix elements can only be derived numerically by inverting a rather difficult set of matrix equations . because the spherical symmetry of a usual scattering problem is reduced in this case to cylindrical symmetry ,.
Please generate the next two sentences of the article | the scattering involves angular momentum mixing .
the consequence is that the set of equations to be inverted is in principle infinite in number . in this paper |
5,065 | Suppose that you have an abstract for a scientific paper: an isotropic three - dimentional perfect lens based on cubic meshes of interconnected transmission lines and bulk loads is proposed .
the lens is formed by a slab of a loaded mesh placed in between two similar unloaded meshes .
the dispersion equations and the characteristic impedances of the eigenwaves in the meshes are derived analytically , with an emphasis on generality .
this allows designing of transmission - line meshes with desired dispersion properties .
the required backward - wave mode of operation in the lens is realized with simple inductive and capacitive loads . an analytical expression for the transmission through the lens
is derived and the amplification of evanescent waves is demonstrated .
factors that influence enhancement of evanescent waves in the lens are studied and the corresponding design criteria are established .
a possible realization of the structure is outlined . .
And you have already written the first three sentences of the full article: in recent literature a lot of attention has been given to systems that are able to sense electromagnetic near fields ( evanescent waves ) and even to `` amplify '' them .
the superlens proposed by pendry@xcite is one of such systems .
his superlens is based on a veselago medium@xcite slab ..
Please generate the next two sentences of the article | the real parts of the permittivity and the permeability of the veselago slab are both negative at a certain wavelength .
thus , the eigenwaves in the slab are _ backward _ waves , i.e. the wave phase and group velocities are antiparallel . |
5,066 | Suppose that you have an abstract for a scientific paper: using a multistate smearing method , coulomb gauge wave functions of heavy - light mesons are studied in lattice qcd .
wave functions for the ground state , the first radially excited s - wave state , and the lowest p - wave states of a heavy - light meson are calculated in quenched approximation .
the results are found to be in remarkably good agreement with the predictions of a simple relativistic quark model . .
And you have already written the first three sentences of the full article: the evolution of lattice gauge theory techniques has greatly enhanced our understanding of quark - gluon dynamics in qcd .
heavy - light mesons provide an ideal laboratory for lattice qcd studies .
the static approximation ( @xmath0 ) in which the heavy quark propagator is replaced by a straight time - like wilson line provides a framework which allows a quantitative study of masses , decay constants , mixing amplitudes , and electroweak form factors.[1 ] since heavy - light mesons have only one dynamical light ( valence ) quark , these systems are also well suited to the study of constituent quark ideas [ 2 ] and the chiral quark model [ 3 ] . in view of the success of the nonrelativistic ( nr ) potential model for heavy @xmath1 mesons ,.
Please generate the next two sentences of the article | one interesting question for heavy - light systems is the nature and extent of the deviation from the nr potential picture as one of the quarks becomes light .
here we present results of a numerical lattice study of this question . |
5,067 | Suppose that you have an abstract for a scientific paper: the paper deals with asymptotic properties of the adaptive procedure proposed in the author paper , 2007 , for estimating a unknown nonparametric regression . we prove that this procedure is asymptotically efficient for a quadratic risk , i.e. the asymptotic quadratic risk for this procedure coincides with the pinsker constant which gives a sharp lower bound for the quadratic risk over all possible estimates . .
And you have already written the first three sentences of the full article: the paper deals with the estimation problem in the heteroscedastic nonparametic regression model @xmath0 where the design points @xmath1 , @xmath2 is an unknown function to be estimated , @xmath3 is a sequence of centered independent random variables with unit variance and @xmath4 are unknown scale functionals depending on the design points and the regression function @xmath5 . typically , the notion of asymptotic optimality is associated with the optimal convergence rate of the minimax risk ( see e.g. , ibragimov , hasminskii,1981 ; stone,1982 ) . an important question in optimality results is to study the exact asymptotic behavior of the minimax risk .
such results have been obtained only in a limited number of investigations .
as to the nonparametric estimation problem for heteroscedastic regression models we should mention the papers by efromovich , 2007 , efromovich , pinsker , 1996 , and galtchouk , pergamenshchikov , 2005 , concerning the exact asymptotic behavior of the @xmath6-risk and the paper by brua , 2007 , devoted to the efficient pointwise estimation for heteroscedastic regressions ..
Please generate the next two sentences of the article | heteroscedastic regression models are largely used in financial mathematics , in particular , in problem of calibrating ( see e.g. , belomestny , reiss , 2006 ) .
an example of heteroscedastic regression models is given by econometrics ( see , for example , goldfeld , quandt , 1972 , p. 83 ) , where for consumer budget problems one uses some parametric version of model with the scale coefficients defined as @xmath7 where @xmath8 , @xmath9 and @xmath10 are some unknown positive constants . |
5,068 | Suppose that you have an abstract for a scientific paper: following talagrand s concentration results for permutations picked uniformly at random from a symmetric group @xcite , luczak and mcdiarmid have generalized it to more general groups @xmath0 of permutations which act suitably ` locally ' .
here we extend their results by setting transport - entropy inequalities on these permutations groups .
talagrand and luczak - mc - diarmid concentration properties are consequences of these transport - entropy inequalities .
we also consider transport - entropy inequalities on @xmath0 for a larger class of measures . by projection
, we derive transport - entropy inequalities for the uniform law on the slice of the discrete hypercube and more generally for the multinomial law .
the transport - entropy inequalities settled in this paper are new examples , in discrete setting , of weak transport - entropy inequalities introduced in @xcite . .
And you have already written the first three sentences of the full article: let @xmath1 denote the symmetric group of permutations acting on a set @xmath2 of cardinality @xmath3 , and @xmath4 denote the uniform law on @xmath1 , @xmath5 a seminal concentration result on @xmath1 obtained by maurey is the following .
@xcite[permmau ] let @xmath6 be the hamming distance on the symmetric group , for all @xmath7 , @xmath8 then for any subset @xmath9 such that @xmath10 , and for all @xmath11 , one has @xmath12 where @xmath13 . milman and schechtman @xcite generalized this result to some groups whose distance is invariant by translation .
for example , in the above result we may replace ( up to constants ) the hamming distance by the _ transposition distance _ @xmath14 that corresponds to the minimal number of transpositions @xmath15 such that @xmath16 ..
Please generate the next two sentences of the article | the distances @xmath17 and @xmath6 are comparable , @xmath18 ( we refer to @xcite for comments about these comparison inequalities ) . a few years later , a stronger concentration property in terms of dependence in the parameter @xmath3 , has been settled by talagrand using the so - called `` convex - hull '' method @xcite ( see also @xcite ) .
this property implies maurey s result with a slitly worse constant . |
5,069 | Suppose that you have an abstract for a scientific paper: observations indicate that the magnetotail convection is turbulent and bi - modal , consisting of fast bursty bulk flows ( bbf ) and a nearly stagnant background .
we demonstrate that this observed phenomenon may be understood in terms of the intermittent interactions , dynamic mergings and preferential accelerations of coherent magnetic structures under the influence of a background magnetic field geometry that is consistent with the development of an x - point mean - field structure . .
And you have already written the first three sentences of the full article: recent satellite observations indicate that the earth s magnetotail is generally in a state of intermittent turbulence constantly intermixed with localized fast bursty bulk flows ( bbf ) [ _ angelopoulos et al .
_ , 1996 ; _ lui _ , 1998 ] . a model of sporadic and localized merging of coherent magnetic structures has been proposed by _
chang _ [ 1999 ; and references contained therein ] to describe the dynamics of the magnetotail ..
Please generate the next two sentences of the article | when conditions are favorable , the coherent structures may merge , interact , convect and evolve into forced and/or self- organized critical ( fsoc ) states [ _ chang _ , 1992 ] , a condition satisfied by the observational statistics of the burst duration characteristics of the bbf [ _ angelopoulos _ , 1999 ] .
when considered with the realistic magnetotail geometry , the coarse - grained dissipation of turbulent fluctuations produced by the interacting multi - scale coherent structures may trigger `` fluctuation - induced nonlinear instabilities '' and possibly initiate substorms . |
5,070 | Suppose that you have an abstract for a scientific paper: the expected performance of gaia satellite on eclipsing binaries is reviewed on the basis of ( @xmath0 ) combined hipparcos and ground - based observations mimicking gaia data harvest , and ( @xmath1 ) accurate simulations using the latest instrument model .
it is found that for a large majority of the 16000 sb2 eclipsing binaries that gaia will discover at magnitudes @xmath213 , the orbital solutions and physical parameters will be derived with formal accuracies better than 2% . for the same stars the gaia parallax errors will be @xmath35 _ micro_-arcsec , i.e. an error of 0.5% at 1 kpc , which will allow iterative refine of the parameters and physics used in orbital modeling .
the detectability of sb2 binaries by the already up and running spectral survey rave is discussed .
it is found that all f - to - m sb2 binaries showing a velocity separation @xmath435 km sec@xmath5 and a luminosity ratio @xmath40.5 will be recognized as such .
# 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: gaia is the ambitious flagship mission approved by esa for a launch not later than 2012 , and possibly already by q2 of 2010 .
the mission is designed to obtain extremely precise astrometry ( in the _ micro-_arcsec regime ) , multi - band photometry and medium / high resolution spectroscopy for a large sample of stars .
the goals call for astrometry and photometry ( 5 broad and 11 medium bands covering the optical range ) to be complete over the whole sky to @xmath6 , and spectroscopy complete to @xmath7 . the spectroscopy is primarily meant to provide the radial velocities and thus the 6@xmath8 component in the phase - space to complement the other five provided by astrometry ..
Please generate the next two sentences of the article | each star will be visited around a hundred times during the five year mission life - time , in a fashion similar to the highly successful _ hipparcos _ scanning mode .
the spectra , photometry and astrometry acquired at each transit _ epoch _ will be individually accessible . |
5,071 | Suppose that you have an abstract for a scientific paper: expectations about the correlation of cue phrases , the duration of unfilled pauses and the structuring of spoken discourse are framed in light of grosz and sidner s theory of discourse and are tested for a directions - giving dialogue .
the results suggest that cue phrase and discourse structuring tasks may align , and show a correlation for pause length and some of the modifications that speakers can make to discourse structure . .
And you have already written the first three sentences of the full article: because an utterance is best understood in the context in which it is delivered , its interpreters must be able to identify the relevant context and recognize when it is altered , supplanted or revived .
the transient nature of speech makes this task difficult .
however , the difficulty is alleviated by the abundance of lexical and prosodic cues available to a speaker for communicating the location and type of contextual change ..
Please generate the next two sentences of the article | the investigation of the interaction between these cues presupposes a theory of contextual change in discourse .
the theory relating attention , intentions and discourse structure@xcite is particularly useful because it provides a computational account of the current context and the mechanisms of contextual change . |
5,072 | Suppose that you have an abstract for a scientific paper: light - cone qcd sum rules to leading order in qcd are used to investigate the tensor form factors of the @xmath0 , @xmath1 and @xmath2 transitions in the range @xmath3 @xmath4 .
the das of @xmath5 , @xmath6 and @xmath7 baryon have been calculated without higher - order terms .
then , studies including higher - order corrections have been done for the @xmath5 and @xmath7 baryon .
the resulting form factors are obtained using these two das .
we make a comparison with the predictions of the chiral quark soliton model . _
keywords _ tensor form factors , octet - octet hyperon transitions , light cone qcd sum rules .
And you have already written the first three sentences of the full article: how the hadrons are built from quarks and gluons , the fundamental degrees of freedom of qcd , is one of the main open questions in the theory of strong interactions . an efficient way to probe
the hadron structure is to study the hadron form factors as these quantities include direct information about the hadron structure .
therefore , the form factors have recently received considerable attention both in theory and experiment . like other form factors ,.
Please generate the next two sentences of the article | the tensor form factors encode the important information about the quark - gluon structure of baryons .
the quark distributions in the leading twist are given by the unpolarized distribution @xmath8 , helicty distribution @xmath9 and transversity distribution @xmath10 function of the quark . |
5,073 | Suppose that you have an abstract for a scientific paper: in this article we compare the mean - square stability properties of the @xmath0-maruyama and @xmath0-milstein method that are used to solve stochastic differential equations . for the linear stability analysis , we propose an extension of the standard geometric brownian motion as a test equation and consider a scalar linear test equation with several multiplicative noise terms .
this test equation allows to begin investigating the influence of multi - dimensional noise on the stability behaviour of the methods while the analysis is still tractable .
our findings include : ( i ) the stability condition for the @xmath0-milstein method and thus , for some choices of @xmath0 , the conditions on the step - size , are much more restrictive than those for the @xmath0-maruyama method ; ( ii ) the precise stability region of the @xmath0-milstein method explicitly depends on the noise terms .
further , we investigate the effect of introducing partially implicitness in the diffusion approximation terms of milstein - type methods , thus obtaining the possibility to control the stability properties of these methods with a further method parameter @xmath1 .
numerical examples illustrate the results and provide a comparison of the stability behaviour of the different methods . _
keywords : _ stochastic differential equations , asymptotic mean - square stability , @xmath0-maruyama method , @xmath0-milstein method , linear stability analysis .
_ ams subject classification : _
60h10 , 65c20 , 65u05 , 65l20 .
And you have already written the first three sentences of the full article: in recent years the area of numerical analysis of stochastic differential equations ( sdes ) has expanded at a fast pace .
this interest has been driven by different application areas , such as computational finance , neuroscience or electrical circuit engineering .
a large part of research in stochastic numerics has been aimed towards the development and strong and weak convergence analysis of several classes of numerical methods . a further important issue for the investigation of numerical methods consists of examining methods for their ability to preserve qualitative features of the continuous system they are developed to approximate ..
Please generate the next two sentences of the article | a linear stability analysis is usually the first step of an analysis in this direction . for this
the method of interest is applied to a scalar linear test equation and stability conditions on method parameters and step - size are derived and compared with the stability condition for the test equation . in deterministic numerical analysis the underlying idea for a linear stability analysis is based on the following line of reasoning : one linearises and centres a nonlinear ordinary differential equation @xmath2 around an equilibrium , the resulting linear system @xmath3 ( @xmath4 the jacobian of @xmath5 evaluated at equilibrium ) is then diagonalised and the system thus decoupled , justifying the use of the scalar test equation @xmath6 , for the analysis . |
5,074 | Suppose that you have an abstract for a scientific paper: we describe deva , a multistep ap3m - like - sph code particularly designed to study galaxy formation and evolution in connection with the global cosmological model .
this code uses a formulation of sph equations which ensures both energy and entropy conservation by including the so - called @xmath0 terms .
particular attention has also been paid to angular momentum conservation and to the accuracy of our code .
we find that , in order to avoid unphysical solutions , our code requires that cooling processes must be implemented in a non - multistep way .
we detail various cosmological simulations which have been performed to test our code and also to study the influence of the @xmath0 terms .
our results indicate that such correction terms have a non - negligible effect on some cosmological simulations , especially on high density regions associated either to shock fronts or central cores of collapsed objects .
moreover , they suggest that codes paying a particular attention to the implementation of conservation laws of physics at the scales of interest , can attain good accuracy levels in conservation laws with limited computational resources . .
And you have already written the first three sentences of the full article: in the last few years most cosmological parameters have been determined up to a few percent .
the values of @xmath1 , @xmath2 , @xmath3 and @xmath4 can now be constrained with an unprecedent degree of accuracy ( see , for example , * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* ; * ? ? ? |
5,075 | Suppose that you have an abstract for a scientific paper: + * * www.ncbi.nlm.nih.gov/cbbresearch/yu/downloads/ppitrim.html .
And you have already written the first three sentences of the full article: the current decade has witnessed a significant amount of effort towards discovering the networks of protein - protein interactions ( interactomes ) in a number of model organisms .
these efforts resulted in hundreds of thousands of individual interactions between pairs of proteins being reported @xcite .
repositories such as the biogrid @xcite , intact @xcite , mint @xcite , dip @xcite , bind @xcite and hprd @xcite have been established to store and distribute sets of interactions collected from high - throughput scans as well as from curation of individual publications ..
Please generate the next two sentences of the article | depending on its goals , each interaction database , maintained by a different team of curators located around the world includes and annotates interactions differently .
consequently , while many interactions of specific interactomes are shared among databases @xcite , no one contains the complete known interactome for any model organism . constructing a full - coverage protein - protein interaction network |
5,076 | Suppose that you have an abstract for a scientific paper: this paper investigates the stability of switched linear systems whose switching signal is modeled as a stochastic process called a regenerative process .
we show that the mean stability of such a switched system is characterized by the spectral radius of a matrix .
the matrix is obtained by taking the expectation of the transition matrix of the system on one cycle of the underlying regenerative process .
the characterization generalizes floquet s theorem for the stability analysis of linear time - periodic systems .
we illustrate the result with the stability analysis of a linear system with a failure - prone controller under periodic maintenance
. switched linear system , regenerative process , mean stability , periodic maintenance .
And you have already written the first three sentences of the full article: the stability analysis of stochastic switched linear systems has attracted a significant amount of attention in the last two decades . in particular , their mean stability , which requires that the power of the norm of the state variable converges to zero in expectation .
some early results on the mean stability of switched linear systems with an independent and identically distributed ( i.i.d . )
switching signal can be found in @xcite ..
Please generate the next two sentences of the article | the stability characterizations of switched linear systems driven by an extension of homogeneous markov processes called semi - markov processes @xcite are available in @xcite .
it is known that homogeneous markov processes having certain irreducibility and recurrence properties and discrete - time i.i.d . |
5,077 | Suppose that you have an abstract for a scientific paper: we examine embedding diagrams of hypersurfaces in the reissner - nordstrm black hole spacetime .
these embedding diagrams serve as useful tools to visualize the geometry of the hypersurfaces and of the whole spacetime in general . .
And you have already written the first three sentences of the full article: the reissner - nordstrm ( rn ) spacetime describes a vacuum where matter and electric charge exist in a singularity at the center @xmath0 .
when the mass is large enough compared to the electric charge , @xmath1 , which is the case we explore here , a black hole engulfs the singularity .
this black hole is far more complex than the simple schwarzschild black hole ..
Please generate the next two sentences of the article | the rn spacetime has been extensively investigated in the past ( see e.g. @xcite ) .
our aim here is to describe the embedding diagrams of typical hypersurfaces of this spacetime . |
5,078 | Suppose that you have an abstract for a scientific paper: results of granat / art - p observations of three x - ray pulsars in non - pulsing states are presented : 1 ) a statistically significant non - pulsing flux with a simple power - law spectrum was detected during the `` off''- state of her x-1 ; 2 ) a significant ( 13 @xmath0 ) non - pulsing flux with a strong iron emission line at energies 6.7 - 6.9 kev was detected during the eclipse ingress of cen x-3 ; 3 ) a weak non - pulsing flux was detected during the x - ray eclipse of vela x-1 , which probably resulted from scattering of the pulsar emission in the stellar wind of an optical star .
# 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in @xmath1 .
And you have already written the first three sentences of the full article: the `` off '' state of the x - ray pulsar her x-1 was observed with the telescope art - p on board granat three times in 1990 - 1991 .
the source persistent flux in this state was detected at the level of few mcrabs ( several percents of its high - state flux ) and was characterized by the absence of x - ray pulsations the @xmath2 upper limit on the pulse fraction in the 3 - 20 kev band varied between 2.9% and 18% in different observations .
the source s `` off '' state spectra are well described by a simple power law without evidence of a cutoff in the hard energy band or of emission lines ..
Please generate the next two sentences of the article | the spectral slopes differ by a factor of @xmath3 , with the photon flux in the energy band 3 - 20 kev being virtually the same .
her x-1 is observed in its `` off '' state if the compact source is hidden behind the outer edge of a warped ( or tilted to the orbital plane ) accretion disk and , as it is believed , the source emission can greatly scattered in a hot corona ( it s height is @xmath4 cm ) above the outer parts of the disk |
5,079 | Suppose that you have an abstract for a scientific paper: * purpose * we present a new morphometric measure of trabecular bone micro - architecture , called _
mean node strength _ ( ndstr ) , which is part of a newly - developed approach called _
long range node - strut analysis_. our general aim is to describe and quantify the apparent `` lattice - like '' micro - architecture of the trabecular bone network . * methods * similar in some ways to the topological node - strut analysis introduced by garrahan et al .
, our method is distinguished by an emphasis on long - range trabecular connectivity .
thus , while the topological classification of a pixel ( after skeletonisation ) as a node , strut , or terminus , can be determined from the @xmath0 neighbourhood of that pixel , our method , which does not involve skeletonisation , takes into account a much larger neighbourhood .
in addition , rather than giving a discrete classification of each pixel as a node , strut , or terminus , our method produces a continuous variable , _ node strength_. the node strength is averaged over a region of interest to produce the _ mean node strength _ ( ndstr ) of the region .
* results * we have applied our long range node - strut analysis to a set of 26 high - resolution peripheral quantitative computed tomography ( pqct ) axial images of human proximal tibiae acquired 17 mm below the tibial plateau .
we found that ndstr has a strong positive correlation with volumetric trabecular bone mineral density ( bmd ) .
after an exponential transformation , we obtain a pearson s correlation coefficient of @xmath1 .
qualitative comparison of images with similar bmd but with very different ndstr values suggests that the latter measure has successfully quantified the prevalence of the `` lattice - like '' micro - architecture apparent in the image .
moreover , we found a strong correlation ( @xmath2 ) , between ndstr and the conventional node - terminus ratio ( nd / tm ) of garrahan et al .
the nd / tm ratios were computed using traditional histomorphometry....
And you have already written the first three sentences of the full article: several studies have shown that measures of trabecular bone micro - architecture and bone strength are correlated . @xcite together with loss of bone mass , changes in the trabecular bone micro - architecture occur during ageing , during development of osteopenia and osteoporosis as well as in connection with immobilisation or space flight , and can lead to an increased risk of bone fracture . the vertebral bodies and the epiphyses and metaphyses of the long bones consist mainly of trabecular bone surrounded by a thin cortical shell .
@xcite a dramatic change in the state of the trabecular bone leads to an increased fracture risk .
@xcite bone mineral density ( bmd ) is the most commonly used predictor of bone strength and fracture risk , and also the most commonly used general descriptor of the state of the bone ..
Please generate the next two sentences of the article | non - linear relationships have been established between volumetric bmd and compressive bone strength and elastic modulus .
@xcite however , for trabecular bone , it has been established that a part of the variation in the strength of the bone can not be explained by bmd alone , but is instead due to the micro - architecture of the trabecular network . |
5,080 | Suppose that you have an abstract for a scientific paper: we propose in this article an unambiguous definition of the local density of electromagnetic states ( ldos ) in a vacuum near an interface in an equilibrium situation at temperature @xmath0 .
we show that the ldos depends only on the electric field green function of the system but does not reduce in general to the trace of its imaginary part as often used in the literature .
we illustrate this result by a study of the ldos variations with the distance to an interface and point out deviations from the standard definition .
we show nevertheless that this definition remains correct at frequencies close to the material resonances such as surface polaritons .
we also study the feasability of detecting such a ldos with apetureless snom techniques .
we first show that a thermal near - field emission spectrum above a sample should be detectable and that this measurement could give access to the electromagnetic ldos .
it is further shown that the apertureless snom is the optical analog of the scanning tunneling microscope which is known to detect the electronic ldos .
we also discuss some recent snom experiments aimed at detecting the electromagnetic ldos . .
And you have already written the first three sentences of the full article: the density of states ( dos ) is a fundamental quantity from which many macroscopic quantities can be derived . indeed , once the dos is known , the partition function can be computed yielding the free energy of the system .
it follows that the heat capacity , forces , etc can be derived .
a well - known example of a macroscopic quantity that follows immediately from the knowledge of the electromagnetic dos is the casimir force@xcite ..
Please generate the next two sentences of the article | other examples are shear forces @xcite and heat transfer @xcite between two semi - infinite dielectrics .
recently , it has been shown that unexpected coherence properties of thermal emission at short distances from an interface separating vacuum from a polar material are due to the contribution to the density of states of resonant surface waves @xcite . |
5,081 | Suppose that you have an abstract for a scientific paper: this paper summarizes the main results of our recent study of the non - blazhko rr lyrae stars observed with the _ kepler _ space telescope .
these stars offer the opportunity for studying the stability of the pulsations of rr lyrae stars and for providing a reference against which the blazhko rr lyrae stars can be compared .
of particular interest is the stationarity of the low - dispersion ( @xmath0mmag ) light curves constructed from @xmath118000 long - cadence ( 30-min ) and ( for fn lyr and aw dra ) the @xmath1150000 short - cadence ( 1-min ) photometric data points .
fourier - based [ fe / h ] values and other physical characteristics are also derived . when the observed periods are compared with periods computed with the warsaw non - linear convective pulsation code better agreement
is achieved assuming _ pulsational _ @xmath2 and @xmath3 values rather than the ( higher ) _ evolutionary _ @xmath2 and @xmath3 values .
[ 1996/06/01 ] 2@xmath4 2c ii 4c iv 2fe ii 3fe iii 1 mg i 2 mg ii 2si ii 4si iv 2al ii 3al iii 1o
i 1n i 1h i = .
And you have already written the first three sentences of the full article: in the 105 deg@xmath5 field of the _ kepler _ space telescope there are @xmath140 rr lyr stars brighter than 17th magnitude being observed at both long and short cadence ( _ i.e. _ , integrated exposure times of @xmath130-min and 1-min , respectively ) . with the notable exception of rr lyrae itself ( kolenberg _ et al .
_ 2010 , 2011 ) little was known about the stars prior to the launch of telescope .
several of the rr lyrae stars are c - type stars pulsating in the first overtone mode ( moskalik _ et al ..
Please generate the next two sentences of the article | _ 2011 , in preparation ) .
the remainder are ab - type stars pulsating in the fundamental mode , approximately half of which exhibit the blazhko effect ( see benk _ et al . _ 2010 ) and show phase and amplitude variations of the light curves occurring on time scales of @xmath110 to hundreds of days . the other half of the rrab stars appear to oscillate in a remarkably constant manner and are the subject of our recent paper `` fourier analysis of non - blazhko ab - type rr lyrae stars observed with the _ kepler _ space telescope '' ( nemec _ et al . |
5,082 | Suppose that you have an abstract for a scientific paper: we study the flavor changing @xmath0 decay in the framework of the general two higgs doublet model , so called model iii . here , we take the yukawa couplings complex and switch on the cp violating effects .
we predict the branching ratio six orders larger compared to the one calculated in the sm , namely @xmath1 , and observe a measurable cp asymmetry , at the order of @xmath2 . .
And you have already written the first three sentences of the full article: the top quark reaches great interest since it breaks the @xmath3 symmetry maximally and it has rich decay products due to its large mass .
the rare decays of the top quark have been studied in the literature , in the framework of the standard model ( sm ) and beyond @xcite-@xcite ; the one - loop flavor changing transitions @xmath4 in @xcite and @xmath0 in @xcite . in the sm ,
these decays are suppressed as a result of glashow - iliopoulos- miaiani ( gim ) mechanism @xcite ..
Please generate the next two sentences of the article | the branching ratios ( @xmath5 ) of the decays @xmath4 have been predicted in the sm as @xmath6 in @xcite .
@xmath0 , which can give strong clues about the nature of electroweak symmetry breaking , has been calculated at the order of the magnitude of @xmath7 in the sm , in @xcite . |
5,083 | Suppose that you have an abstract for a scientific paper: we studied a constraint on the primordial helium abundance @xmath0 from current and future observations of cmb . using the currently available data from wmap , acbar , cbi and boomerang
, we obtained the constraint as @xmath1 at 68% c.l .
we also provide a forecast for the planck experiment using the markov chain monte carlo approach .
in addition to forecasting the constraint on @xmath0 , we investigate how assumptions for @xmath0 affect constraints on the other cosmological parameters .
may 2008 + .5 in * primordial helium abundance from cmb : + a constraint from recent observations and a forecast * .45 in kazuhide ichikawa@xmath2 , toyokazu sekiguchi@xmath3 , and tomo takahashi@xmath4 .45 in _
@xmath3 institute for cosmic ray research , university of tokyo , kashiwa 277 - 8582 , japan + @xmath5 department of physics and astronomy , university college london , gower street , london , wc1e 6bt , u.k .
+ @xmath4 department of physics , saga university , saga 840 - 8502 , japan _
.4 in .
And you have already written the first three sentences of the full article: current cosmological observations are very precise to give us a lot of information on the evolution and present state of the universe .
we usually extract the information by constraining cosmological parameters such as energy densities of baryon , dark matter and dark energy , the hubble constant , reionization optical depth , spectral index of primordial fluctuation and so on . among them , in this paper , we focus on the primordial helium abundance @xmath0 , which has been of great interest in cosmology .
one of the reasons why the primordial helium abundance has been considered to be interesting and important is that , in the context of the standard big bang nucleosynthesis ( sbbn ) , we can know the baryon density once @xmath0 is determined from observations ..
Please generate the next two sentences of the article | however , it has been discussed that a significant systematic error dominates when one infers the value of @xmath0 from measurements in low - metallicity extragalactic hii region @xcite .
furthermore , there have been some discussions that there may be a large uncertainty in the neutron lifetime @xcite , which results in uncertainties in the predictions for the abundances of light elements . in this respect |
5,084 | Suppose that you have an abstract for a scientific paper: we calculate supernova electron capture and @xmath0 decay rates for various @xmath1-shell nuclei using large - scale shell model techniques .
we show that the centroid of the gamow - teller strength distribution has been systematically misplaced in previous rate estimates .
our total electron capture rates are significantly smaller than currently adopted in core collapse calculations , while the total @xmath0 decay rates change less .
our calculation shows that for electron - to - baryon ratios @xmath2 - 0.46 @xmath0 decay rates are larger than the competing electron capture rates . 2 .
And you have already written the first three sentences of the full article: weak interaction processes play a decisive role in the early stage of the core collapse of a massive star @xcite .
first , electron capture on nuclei in the iron mass region , starting after the core mass exceeds the appropriate chandrasekhar mass limit , reduces the electron pressure , thus accelerating the collapse , and lowers the electron - to - baryon ratio , @xmath3 , thus shifting the distribution of nuclei present in the core to more neutron - rich material .
second , many of the nuclei present can also @xmath0 decay . while this process is quite unimportant compared to electron.
Please generate the next two sentences of the article | capture for initial @xmath3 values around 0.5 , it becomes increasingly competative for neutron - rich nuclei due to an increase in phase space related to larger @xmath4 values .
however , @xmath0 decay on nuclei with masses @xmath5 have not yet been considered in core collapse studies @xcite . |
5,085 | Suppose that you have an abstract for a scientific paper: we studied , for the first time , the near infrared , stellar and baryonic tully - fisher relations for a sample of field galaxies taken from an homogeneous fabry - perot sample of galaxies ( the ghasp survey ) .
the main advantage of ghasp over other samples is that maximum rotational velocities were estimated from 2d velocity fields , avoiding assumptions about the inclination and position angle of the galaxies .
by combining these data with 2mass photometry , optical colors , hi masses and different mass - to - light ratio estimators , we found a slope of [email protected] and [email protected] for the stellar and baryonic tully - fisher relation , respectively .
we found that these values do not change significantly when different mass - to - light ratios recipes were used .
we also point out , for the first time , that rising rotation curves as well as asymmetric rotation curves show a larger dispersion in the tully - fisher relation than flat ones or than symmetric ones . using the baryonic mass and the optical radius of galaxies
, we found that the surface baryonic mass density is almost constant for all the galaxies of this sample . in this study
we also emphasize the presence of a break in the nir tully - fisher relation at m@xmath120 and we confirm that late - type galaxies present higher total - to - baryonic mass ratios than early - type spirals , suggesting that supernova feedback is actually an important issue in late - type spirals . due to the well defined sample selection criteria and the homogeneity of the data analysis , the tully - fisher relation for ghasp galaxies can be used as a reference for the study of this relation in other environments and at higher redshifts .
[ firstpage ] galaxies : evolution galaxies : kinematics and dynamics .
And you have already written the first three sentences of the full article: the tully - fisher relation ( tully & fisher , 1977 ) is a direct indication of a close relationship between the detected baryons and the total mass in spiral galaxies .
the detected baryons consist of the stellar and gaseous content , i.e. the visible mass , and this sets the luminosity profile of the galaxy while the total gravitational mass , which includes the dark matter content ( and possibly a component of baryonic dark matter ) , sets its rotation velocity .
numerous studies have been carried out to investigate this relation , crucial in determining extragalactic distances ( e. g. pierce & tully 1988 , tully & pierce 2000 ) , in the study of evolution of galaxies ( e.g. puech et al ..
Please generate the next two sentences of the article | 2008 ) and also in giving constraints on cosmological galaxy formation models ( e. g. portinari & sommer - larsen 2007 ) .
the tully - fisher relation is undoubtedly a crucial test for galaxy evolution models and although it has been the focus of a number of studies , its origin is still being debated . a few authors argue a cosmological origin ( e. g. avila - reese , firmani & hernndez 1998 ) while others suggest that this relation is regulated by star forming processes ( e. g. silk 1997 ) . on the other hand , |
5,086 | Suppose that you have an abstract for a scientific paper: we examined properties of a josephson - junction system composed of two coupled cooper - pair boxes ( charge qubits ) as a candidate for observation of quantum holonomies .
we construct a universal set of transformations in a twofold degenerate ground state , and discuss the effects of noise in the system . .
And you have already written the first three sentences of the full article: appearance of the geometric phases in physical systems has been , since their first systematic treatment by @xcite , among the most fascinating physical phenomena .
generalized to systems with degenerate spectrum,@xcite they give the possibility to devise systems in which the dynamical contribution is only the overall phase factor , and the actual transformations are of purely geometric origin . + quantum geometric transformations ( below referred to as _ holonomies _ ) have attracted even more attention after @xcite proved their potential use in quantum computing . as compared to the ordinary , dynamical computation , quantum gates are here realized by cyclic evolution of parameters , and the result depends only on the geometry of the traversed path .
construction of holonomies has been discussed for various physical realizations , among them are also superconducting nanocircuits ..
Please generate the next two sentences of the article | @xcite in these realizations the necessary number of independent tunable parameters results in high complexity of the considered systems . here , motivated also by the recent experiment with josephson - junction system composed of two coupled charge qubits , @xcite we consider a similar design as a potential candidate for observation of quantum holonomies . as compared to the proposals in refs .
@xcite , where the simplest two - dimensional holonomies are constructed using four coupled charge qubits , we achieve substantial simplification using only two qubits . also , we realize the transformations within a twofold degenerate ground state , rather than excited state ( as in @xcite ) . in this way |
5,087 | Suppose that you have an abstract for a scientific paper: agreement between the experimental value @xmath0 and the number predicted via a one - loop chiral perturbation theory calculation has been cited as a success for the latter . on the other hand the one - loop prediction for the closely related process
@xmath1 has been found to be a factor three below the experimental value . using the inputs of unitarity and dispersion relations
, we demonstrate the importance of higher order loop effects to both of these processes . .
And you have already written the first three sentences of the full article: during the past decade , we have learned ( at last ) how to make rigorous contact between experimental low energy hadronic physics and qcd which is presumed to underlie such processes .
this contact is provided by chiral perturbation theory ( chpt ) @xcite , which exploits the ( broken ) chiral invariance of the light quark component of the qcd lagrangian and provides a representation for interaction amplitudes as an expansion in energy - momentum divided by the chiral scale parameter @xmath2 gev @xcite .
a review of chpt techniques will not be attempted here , but has been presented in a number of sources , wherein it is shown that , at least in the goldstone boson sector , such a chiral approach provides a remarkably successful and predictive representation of a wide variety of experimental processes @xcite ..
Please generate the next two sentences of the article | the chiral technology begins by writing down an effective chiral lagrangian , the simplest ( two - derivative ) form of which is , in the goldstone sector , @xcite @xmath3 where @xmath4 is a nonlinear function of the pseudoscalar fields , @xmath5 is the quark mass matrix , @xmath6 is a phenomenological constant , @xmath7 is the covariant derivative , and @xmath8 is the pion decay constant in the limit of chiral symmetry .
although these are only two of an infinite number of terms , already at this level there exists predictive power |
5,088 | Suppose that you have an abstract for a scientific paper: the fidelity and entropy in an easy - axis antiferromagnetic heisenberg spin-1 chain are studied numerically . by using the method of density - matrix renormalization - group , the effects of anisotropy on fidelity and entanglement
entropy are investigated .
their relations with quantum phase transition are analyzed .
it is found that the quantum phase transition from haldane spin liquid to nel spin solid can be well characterized by the fidelity .
the phase transition can be hardly detected by the entropy .
but it can be successfully detected by the first deviation of the entropy . .
And you have already written the first three sentences of the full article: in condense matter physics , quantum phase transitions imply fluctuations , which happened at the zero temperature @xcite .
when a controlling parameter changes across critical point , some properties of the many - body system will change dramatically .
many results show that entanglement existed naturally in the spin chain when the temperature is at zero ..
Please generate the next two sentences of the article | the quantum entanglement of a many - body system has been paid much attention since the entanglement is considered as the heart in quantum information and computation @xcite . as the bipartite entanglement measurement in a pure state , the von neumann entropy @xcite in the antiferromagnetic anisotropic spin chain @xcite and isotropic spin chain @xcite
are investigated respectively . by using the cross fields of quantum many - body theory and quantum - information theory , |
5,089 | Suppose that you have an abstract for a scientific paper: we present the results of magnetization and magneto - transport measurements in the superconducting state of an as - cast nb@xmath0zr@xmath1 alloy .
we also report the careful investigation of the microstructure of our sample at various length scales by using optical , scanning electron and transmission electron microscopies .
the information of microstructure is used to understand the flux pinning properties in the superconducting state within the framework of collective pinning .
the magneto - transport measurements show a non - arrhenius behaviour of the temperature and field dependent resistivity in the flux flow region .
this non - arrhenius behaviour is understood in terms of a model , which was originally proposed for viscous flow of disordered solids and is popularly known in the literature as the ` shoving ' model .
the activation energy for flux flow is obtained from magneto - transport measurements and is assumed to be mainly the elastic energy stored in the flux - line lattice .
the critical current density estimated from magnetization measurements is moderately high of the order of 10@xmath2 am@xmath3 at a temperature of 2k .
the scaling of pinning force density with respect to reduced field indicates the presence of two pinning mechanisms of different origins .
the elastic constants of the flux - line lattice are estimated from magnetization measurements and are used to estimate the length scale of vortex lattice movement , or the volume displaced by the flux - line lattice , during flux flow .
it appears that the vortex lattice displacement estimated from elastic energy considerations is of the same order of magnitude as that of the flux - bundle hopping length when a finite resistance appears during flux flow .
our results could provide possible directions for establishing a framework where vortex matter and glass forming liquids or amorphous solids can be treated in a similar manner for understanding the phenomenon of viscous flow in disordered solids or more generally....
And you have already written the first three sentences of the full article: the phenomena of flux creep@xcite and thermally activated flux flow@xcite were initially discovered in conventional hard type - ii superconductors .
the irreversibility line " in the @xmath4 plane , which separates the reversible ( or flux flow ) and irreversible magnetization ( or flux pinned ) regions , was thought to be exclusive to the high - temperature superconductors and was thus interpreted as a quasi de almeida - thouless line " in analogy to the irreversibility observed between the zero - field - cooled ( zfc ) and field - cooled ( fc ) magnetization in spin glasses and the possibility of a superconducting glass phase was conjectured.@xcite the vortex - glass phase was suggested to be a new thermodynamic phase within the mixed state of a type - ii superconductor.@xcite the term vortex glass was used to the signify the destruction of long range translational order in the abrikosov lattice due to flux pinning by the underlying disorder in the superconducting material .
the irreversibility line was shown to be a sharp boundary across a thermodynamic phase transition between the disordered vortex solid ( or glass ) and the vortex liquid where thermally activated flux flow is possible.@xcite an alternate interpretation of the irreversibility line , without invoking the glass phase in the mixed state , was later offered in terms of the more conventional phenomenon like the flux creep.@xcite these paradigms of high-@xmath5 superconductors were applied to conventional type - ii materials like niobium thin films where it was found that the irreversibility line represents the vortex - melting transition.@xcite the model of the giant flux creep"@xcite was extended to explain the _ width _ and _ shape _ of the resistive transition as a function of applied magnetic field.@xcite the key ingredient to the flux creep picture is the estimate of the activation energy @xmath6 which must be surmounted for the flux movement to occur.@xcite the elemental volume of the flux line lattice which moves during the creep is....
Please generate the next two sentences of the article | we try to address one of the fundamental questions arising in the studies of vortex matter , which is , how much distance does the fluxon ( or the elemental volume of flux - line lattice ) move for a finite resistance to appear across the resistive transition in a hard type - ii superconductor ? " while this question can be of technological importance for tuning the nature of quenched disorder to achieve desirable critical current densities , it can also lead to fundamental understanding of elastic systems influenced by disorder and driven by external force .
we have chosen the nb@xmath0zr@xmath1 alloy for this study . |
5,090 | Suppose that you have an abstract for a scientific paper: the present study seeks to investigate mathematical structures of a multi - frequency subspace migration weighted by the natural logarithmic function for imaging of thin electromagnetic inhomogeneities from measured far - field pattern . to this end
, we designed the algorithm and calculated the indefinite integration of square of bessel function of order zero of the first kind multiplied by the natural logarithmic function .
this is needed for mathematical analysis of improved algorithm to demonstrate the reason why proposed multi - frequency subspace migration contributes to yielding better imaging performance , compared to previously suggested subspace migration algorithm .
this analysis is based on the fact that the singular vectors of the collected multi - static response ( msr ) matrix whose elements are the measured far - field pattern can be represented as an asymptotic expansion formula in the presence of such inhomogeneities . to support the main research results , several numerical experiments with noisy data
are illustrated .
multi - frequency subspace migration , weighted by natural logarithmic function , thin electromagnetic inhomogeneities , multi - static response ( msr ) matrix , numerical experiments . .
And you have already written the first three sentences of the full article: the inverse scattering problem , non - destructive evaluation , is one of the intriguing research topics since it is closely related to human life . it is because it applies not only to physics , engineering , or image medical science but also to identifying the cracks of the structures such as concrete walls , machines , or buildings
therefore , it has been considerably investigated by many researchers to suggest the algorithm regarding this problem or to experiment and analyze previously suggested algorithms .
related works can be found in @xcite and references therein . however , the inverse scattering problem is such a difficult problem that not many methods have been studied other than the reconstruction method based on the iterative method such as newton - type method , refer to @xcite ..
Please generate the next two sentences of the article | regarding the algorithms of using a newton - type method , in case the initial shape is quite different from the unknown target , the reconstruction of material leads to failure with the non - convergence or yielding faulty shapes . even though the reconstruction ends up with a successful result
, it could take a great deal of time . |
5,091 | Suppose that you have an abstract for a scientific paper: ly@xmath0 absorption spectra of qsos at redshifts @xmath1 show complete gunn - peterson absorption troughs ( dark gaps ) separated by tiny leaks .
the dark gaps are from the intergalactic medium ( igm ) where the density of neutral hydrogen are high enough to produce almost saturated absorptions , however , where the transmitted leaks come from is still unclear so far .
we demonstrate that leaking can originate from the lowest density voids in the igm as well as the ionized patches around ionizing sources using semi - analytical simulations .
if leaks were produced in lowest density voids , the igm might already be highly ionized , and the ionizing background should be almost uniform ; in contrast , if leaks come from ionized patches , the neutral fraction of igm would be still high , and the ionizing background is significantly inhomogeneous .
therefore , the origin of leaking is crucial to determining the epoch of inhomogeneous - to - uniform transition of the the ionizing photon background .
we show that the origin could be studied with the statistical features of leaks .
actually , ly@xmath0 leaks can be well defined and described by the equivalent width @xmath2 and the full width of half area @xmath3 , both of which are less contaminated by instrumental resolution and noise .
it is found that the distribution of @xmath2 and @xmath3 of ly@xmath0 leaks are sensitive to the modeling of the ionizing background .
we consider four representative models : uniform ionizing background ( model 0 ) , the photoionization rate of neutral hydrogen @xmath4 and the density of igm are either linearly correlated ( model i ) , or anti - correlated ( model ii ) , and @xmath4 is correlated with high density peaks containing ionizing sources ( model iii ) . although all of these models can match to the mean and variance of the observed effective optical depth of the igm at @xmath5 , their distribution of @xmath2 and @xmath3 are very different from each other .
consequently , the leak statistics provides an....
And you have already written the first three sentences of the full article: in the last decade , the ly@xmath0 forests of qso s absorption spectra at redshifts @xmath8 have played an important role in understanding the diffuse cosmic baryon gas and the uv ionizing photon background , and constraining cosmological models and parameters ( e.g. rauch et al .
1997 ; croft et al . 2002 ; bolton et al . 2005 ; seljak et al .
2005 ; jena et al ..
Please generate the next two sentences of the article | 2005 ; viel et al .
2006 ) . recently , |
5,092 | Suppose that you have an abstract for a scientific paper: muon colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines .
they should be regarded as complementary .
parameters are given of 4 tev high luminosity collider , and of a 0.5 tev lower luminosity demonstration machine .
we discuss the various systems in such muon colliders .
@xmath0 ) = = 10000 .
And you have already written the first three sentences of the full article: the possibility of muon colliders was introduced by skrinsky et al.@xcite , neuffer@xcite , and others .
more recently , several workshops and collaboration meetings have greatly increased the level of discussion@xcite,@xcite .
a detailed feasibility study@xcite was presented at snowmass 96 ..
Please generate the next two sentences of the article | hadron collider energies are limited by their size , and technical constraints on bending magnetic fields .
lepton ( or ) colliders , because they undergo simple , single - particle interactions , can reach higher energy final states than an equivalent hadron machine . |
5,093 | Suppose that you have an abstract for a scientific paper: in this note we give the highest of reasonable estimates for the value of cross section of the double pomeron higgs meson production and suggest a new mechanism for heavy quark diffractive production which will dominate at the tevatron energies .
# 1eq .
( [ # 1 ] ) bnl - nt-99/9 + taup-2615 - 99 + .
And you have already written the first three sentences of the full article: in this note we consider three reactions @xmath0 + h + [ lrg ] + p \,\ , ; \label{r1}\\ p + p & \longrightarrow & x_1 + [ lrg ] + h + [ lrg ] + x_2 \,\ , ; \label{r2}\\ p + p & \longrightarrow & b + \bar b + x + [ lrg ] + p \,\,;\label{r3}\end{aligned}\ ] ] where lrg denotes the large rapidity gap between produced particles and @xmath1 corresponds to a system of hadrons with masses much smaller than the total energy .
the first two reactions are so called double pomeron production of higgs meson while the third is the single diffraction production of bottom - antibottom pair . the goals of this note are the following : 1 . to give the highest from reasonable estimates for the cross sections of reactions and ; 2 . to summarize all uncertainties which we see in doing these estimates ; 3 . to show that there is a new mechanism of diffractive heavy quark production ( ) which is suppressed in dis and dominates in hadron - hadron collision at the tevatron ; 4 . to estimate the value of the cross section of reaction due to this new mechanism and to show that all attempts to compare the diffraction dissociation in hadron - hadron collisions and dis@xcite look unreliable without a detail experimental study of this process at fermilab .
inclusive higgs production has been studied in many details @xcite for the tevatron energies ..
Please generate the next two sentences of the article | the main source for higgs is gluon - gluon fusion which gives @xmath2 for higgs with mass @xmath3 @xcite .
the reference point for our estimates is the cross section of higgs production due to w and z fusion which is equal to @xmath4 @xcite . in this process |
5,094 | Suppose that you have an abstract for a scientific paper: we introduce a family of discrete determinantal point processes related to orthogonal polynomials on the real line , with correlation kernels defined via spectral projections for the associated jacobi matrices . for classical weights ,
we show how such ensembles arise as limits of various hypergeometric orthogonal polynomials ensembles .
we then prove that the q - laplace transform of the height function of the asep with step initial condition is equal to the expectation of a simple multiplicative functional on a discrete laguerre ensemble a member of the new family .
this allows us to obtain the large time asymptotics of the asep in three limit regimes : ( a ) for finitely many rightmost particles ; ( b ) gue tracy - widom asymptotics of the height function ; ( c ) kpz asymptotics of the height function for the asep with weak asymmetry .
we also give similar results for two instances of the stochastic six vertex model in a quadrant .
the proofs are based on limit transitions for the corresponding determinantal point processes . .
And you have already written the first three sentences of the full article: since the early 1960 s , determinantal ( and closely related pfaffian ) random point processes have served as a key tool in asymptotic analysis of exactly solvable probabilistic systems in mathematics and physics . in the late 1990 s , the domain of their applicability
was extended to random growth models and interacting particle systems in ( 1 + 1 ) dimensions , see , e.g. , the surveys of johansson @xcite , ferrari - spohn @xcite , borodin - gorin @xcite , and references therein .
about ten years ago , the work of tracy - widom @xcite on asymptotics of the partially asymmetric simple exclusion process ( asep , for short ) started a new wave of developments ..
Please generate the next two sentences of the article | the asep is one of the most basic interacting particle systems whose large time asymptotics did not seem to be susceptible to standard determinantal or pfaffian methods .
tracy - widom employed a different approach ( coordinate bethe ansatz ) , and a flurry of activity followed , see , e.g. , a survey of corwin @xcite and references therein . |
5,095 | Suppose that you have an abstract for a scientific paper: geometric approaches to network analysis combine simply defined models with great descriptive power . in this work
we provide a method for embedding directed acyclic graphs into minkowski spacetime using multidimensional scaling ( mds).first we generalise the classical mds algorithm , defined only for metrics with a euclidean signature , to manifolds of any metric signature .
we then use this general method to develop an algorithm to be used on networks which have causal structure allowing them to be embedded in lorentzian manifolds .
the method is demonstrated by calculating embeddings for both causal sets and citation networks in minkowski spacetime .
we finally suggest a number of applications in citation analysis such as paper recommendation , identifying missing citations and fitting citation models to data using this geometric approach . .
And you have already written the first three sentences of the full article: one success of network science has been to identify that some complex systems can be simplified by considering just the topology of the pairwise interactions between their parts . abstracting a complex system as a graph can bring physical insights and predictive power .
yet these graphs can still be very complicated .
network geometry is an approach which further abstracts the system by modelling the nodes of the network as points in a geometric space ..
Please generate the next two sentences of the article | most existing approaches use riemannian spaces , the simplest example of which is euclidean space . random geometric graphs ( rgg ) are graphs embedded in euclidean space @xcite .
recently there has been much interest in geometric approaches to the study of networks in non - euclidean spaces @xcite . |
5,096 | Suppose that you have an abstract for a scientific paper: we have performed self - consistent calculations of the dynamical response of the ( 111 ) surface of the noble metals cu , ag , and au .
our results indicate that the partially occupied surface - state band in these materials yields the existence of acoustic surface plasmons with linear dispersion at small wave vectors . here
we demonstrate that the sound velocity of these low - energy collective excitations , which had already been predicted to exist in the case of be(0001 ) , is dictated not only by the fermi velocity of the two - dimensional surface - state band but also by the nature of the decay and penetration of the surface - state orbitals into the solid .
our linewidth calculations indicate that acoustic surface plasmons should be well defined in the energy range from zero to @xmath0 mev . .
And you have already written the first three sentences of the full article: during the last decades a variety of metal surfaces , such as be(0001 ) and the ( 111 ) surfaces of the noble metals cu , ag , and au , have become a testing ground for many experimental and theoretical investigations.@xcite these surfaces are known to support a partially occupied band of shockley surface states with energies near the fermi level .
since these states are strongly localized near the surface and disperse with momentum parallel to the surface , they can be considered to form a quasi two - dimensional ( 2d ) surface - state band with a 2d fermi energy @xmath1 equal to the surface - state binding energy at the @xmath2 point . in the absence of the three - dimensional ( 3d ) substrate , partially occupied shockley surface states would support a 2d collective oscillation , the energy of this plasmon being given by ( unless stated otherwise , atomic units are used , i.e. , @xmath3)@xcite @xmath4 where @xmath5 represents the density of occupied surface states : @xmath6 , @xmath7 represents the magnitude of a 2d wave vector , and @xmath8 is a 2d effective mass .
( [ one ] ) shows that at very long wavelengths plasmons in a 2d electron gas have low energies ; however , they do not affect electron - hole ( e - h ) and phonon dynamics near the fermi level , due to their square - root dependence on the wave vector ..
Please generate the next two sentences of the article | much more effective than ordinary 2d plasmons in mediating , e.g. , superconductivity would be the so - called acoustic plasmons with sound - like long - wavelength dispersion.@xcite recently , it has been demonstrated that in the presence of the 3d substrate the dynamical screening at the surface provides a mechanism for the existence of a _ new _ acoustic collective mode , whose energy exhibits a linear dependence on the 2d wave vector.@xcite we refer to this mode as _ acoustic surface plasmon _ ( asp ) , to distinguish it from the conventional surface plasmon predicted by ritchie.@xcite the energy of this latter plasmon is known to be @xmath9 , where @xmath10 is the plasmon energy of a homogeneous electron gas of density @xmath11 : @xmath12 . .
all other states of the semi - infinite metal are assumed to comprise a plane - bounded 3d electron gas at @xmath13 . |
5,097 | Suppose that you have an abstract for a scientific paper: recently , multiple time scale characteristics of heart dynamics have received much attention for distinguishing healthy and pathologic cardiac systems . despite structural peculiarities of the fetal cardiovascular system , the fetal heart rate(fhr )
displays multiple time scale characteristics similar to the adult heart rate due to the autorhythmicity of its different oscillatory tissues and its interaction with other neural controllers . in this paper , we investigate the event and time scale characteristics of the normal and two pathologic fetal heart rate groups with the help of the new measure , called the unit time block entropy(utbe ) , which approximates the entropy at each event and time scale based on symbolic dynamics .
this method enables us to match the measurement time and the number of words between fetal heart rate data sets simultaneously .
we find that in the small event scale and the large time scale , the normal fetus and the two pathologic fetus are completely distinguished .
we also find that in the large event scale and the small time scale , the presumed distress fetus and the acidotic distress fetus are significantly distinguished .
event scale , time scale , symbolization , fetal heart rate , dynamics , complexity 87.19.hh , 87.10.+e , 89.75.-k .
And you have already written the first three sentences of the full article: fetal distress is generally used to describe the lack of the oxygen of the fetus , which may result in damage or death if not reversed or the fetus is delivered immediately .
thus the emergent action by discriminating the fetal distress is an important issue in the obstetrics . in particular
, it is important to discriminate the normal fetal heart rate(fhr ) and two types of fetal distress groups(the presumed distress and the acidotic distress ) and reduce the wrong diagnosis rate in which about 65% of the presumed distress fetus(not serious but in need of careful monitoring ) are diagnosed as the acidotic distress fetus(serious , needing an emergent action ) , experiencing a useless surgical operation . in this paper.
Please generate the next two sentences of the article | , we try to discriminate the normal and pathologic fetal heart rate group with a robust and reliable method .
+ the cardiovascular system of the fetus is a complex system . |
5,098 | Suppose that you have an abstract for a scientific paper: we construct the classification scheme for all possible evolution scenarios and find the corresponding global geometries for dynamics of a thin spherical vacuum shell in the schwarzschild - desitter metric .
this configuration is suitable for the modelling of vacuum bubbles arising during cosmological phase transitions in the early universe .
the distinctive final types of evolution from the local point of view of a rather distant observer are either the unlimited expansion of the shell or its contraction with a formation of black hole ( with a central singularity ) or wormhole ( with a baby universe in interior ) . .
And you have already written the first three sentences of the full article: one of the promising mechanisms of primordial black holes and wormholes formation is a collapse of vacuum bubbles during phase transitions in the early universe @xcite .
the supermassive black holes in the centers of galaxies may be also originated by this mechanism .
we will describe the possible types of dynamical evolution of vacuum bubbles in the schwarzschild - desitter metric by using the thin shell approximation for the boundary between the true and false vacuum ..
Please generate the next two sentences of the article | the formalism of thin shells in general relativity was first developed by w. israel @xcite . later this formalism was elaborated and adjusted for the case of cosmological vacuum phase transitions @xcite .
the boundary of vacuum bubble divides the schwarzschild - desitter space - time into internal and external regions . in the following these regions |
5,099 | Suppose that you have an abstract for a scientific paper: several key problems of qcd sum rules in the spin-0 glueball channels are resolved by implementing nonperturbative short - distance physics from direct instantons and topological charge screening .
a lattice - based instanton size distribution and the ir renormalization of the nonperturbative wilson coefficients are also introduced .
results of a comprehensive quantitative sum rule analysis are reviewed and their implications discussed . .
And you have already written the first three sentences of the full article: the gluonium states of qcd have remained intriguing for almost four decades@xcite .
their `` exotic '' nature reflects itself not least in several long - standing problems which the qcd sum rule approach faces in the spin-0 glueball channels@xcite . in the scalar ( @xmath0 ) glueball correlator ,
in particular , the departure from asymptotic freedom sets in at unusually small distances@xcite and the perturbative wilson coefficients of the standard operator product expansion ( ope ) proved inadequate to establish consistency both among the @xmath0 glueball sum rules and with an underlying low - energy theorem@xcite ..
Please generate the next two sentences of the article | although nonperturbative contributions due to direct ( i.e. small ) instantons@xcite were early candidates for the missing short - distance physics@xcite , insufficient knowledge of the instanton size distribution@xcite prevented their quantitative implementation at the time .
only recently , the derivation of the exact instanton contributions ( to leading order in @xmath1 ) , their duality continua and the corresponding borel sum - rule analysis@xcite showed that direct instantons indeed solve the mentioned key problems in the scalar glueball channel . below |
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