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5,800 | Suppose that you have an abstract for a scientific paper: we consider the singularly perturbed limit of periodically excited two - dimensional fitzhugh - nagumo systems .
we show that the dynamics of such systems are essentially governed by an one - dimensional map and present a numerical scheme to accurately compute it together with its lyapunov exponent .
we then investigate the occurrence of chaos by varying the parameters of the system , with especial emphasis on the simplest possible chaotic oscillations .
our results corroborate and complement some recent works on bifurcations and routes to chaos in certain particular cases corresponding to piecewise linear fitzhugh - nagumo - like systems .
chaos , excitable systems , fitzhugh - nagumo systems , neuron model .
And you have already written the first three sentences of the full article: the fitzhugh - nagumo system is a simplified model for nerve conduction which has become a paradigm for dynamical and neuronal investigations since , despite of being considerably simple , it is still able to reproduce qualitatively the main dynamical behaviors of realistic neural models .
the literature on this subject is quite vast and , in many times , rather confusing with respect to definitions and names .
we adopt here the nomenclature and the main conventions of @xcite . the fitzhugh - nagumo model for a single externally excited neuron.
Please generate the next two sentences of the article | is given by the following two dimensional non - autonomous system of first order differential equations [ fhn ] \
{ l v = f(v ) - w + ( t ) + w = v - w . where @xmath0 and @xmath1 are non - negative parameters and @xmath2 stands for the external excitation . |
5,801 | Suppose that you have an abstract for a scientific paper: we show vector boson transverse momentum distributions at the tevatron , obtained by running the herwig monte carlo event generator with matrix - element corrections .
we compare our results with some recent d and cdf data .
ur1589 + er/40685/939 + hep - ph/9911536 + november 1999 vector boson production at hadron colliders is a fundamental process to test quantum chromodynamics and the standard model of the electroweak interactions .
the lowest order processes @xmath0 and @xmath1 are not sufficient to perform reliable phenomenological predictions , but the initial - state radiation has to be taken into account . a possible way to deal with such multiple emissions consists in running a monte carlo event generator .
standard monte carlo algorithms @xcite describe parton cascades in the soft / collinear approximation , with ` dead zones ' in the phase space which can be filled by the using of the exact first - order matrix element .
in @xcite we implemented matrix - element corrections to the herwig simulation of drell yan interactions : we filled the missing phase space using the exact @xmath2 matrix element ( hard corrections ) and corrected the shower in the already - populated region using the exact amplitude for every hardest - so - far emission ( soft corrections ) . for @xmath3 production at the tevatron , about 4% of the events
are generated in the dead zone , about half of which are @xmath4 events .
similar results hold for @xmath5 production as well . an interesting observable
to study is the vector boson transverse momentum @xmath6 , which is the object of many theoretical and experimental analyses .
while in the parton shower approximation it has to be @xmath7 , after matrix - element corrections a fraction of events with larger values of @xmath6 is to be expected . in fig .
[ wqt ] ( a ) , we plot the @xmath3 @xmath6 spectrum at the tevatron according to herwig 5.9 , the latest public version , and to herwig 6.1 , the new version including matrix - element....
And you have already written the first three sentences of the full article: 99 g. marchesini et al . ,
_ comput . phys
. commun . _ * 67 * ( 1992 ) 465 ..
Please generate the next two sentences of the article | g. corcella and m.h .
seymour , hep - ph/9908335 . |
5,802 | Suppose that you have an abstract for a scientific paper: a weyl solution describing two schwarzschild black holes is considered .
we focus on the @xmath0 invariant solution , with adm mass @xmath1 , where @xmath2 is the komar mass of each black hole . for this solution
the set of fixed points of the discrete symmetry is a totally geodesic sub - manifold .
the existence and radii of circular photon orbits in this sub - manifold are studied , as functions of the distance @xmath3 between the two black holes . for @xmath4
there are two such orbits , corresponding to @xmath5 and @xmath6 in schwarzschild coordinates . as the distance increases
, it is shown that the two photon orbits approach one another and merge when @xmath7 , where @xmath8 is the golden ratio . beyond this distance
there exist no circular photon orbits .
the two null orbits delimit a forbidden band for time - like circular orbits , which is interpreted in terms of optical geometry . for large @xmath9 ,
time - like circular orbits are allowed everywhere , as in the analogous newtonian problem .
the analysis is generalised by considering a @xmath0 invariant weyl solution with an array of @xmath10 black holes and also by charging the black holes , which connects the weyl solution to a majumdar - papapetrou spacetime . .
And you have already written the first three sentences of the full article: euler s 3-body problem is a soluble special case of the general 3-body problem , in which a test particle moves in the gravitational field of two gravitational sources - point masses - which are fixed in space .
it is liouville integrable since , besides the energy and one component of the angular momentum , there is a third constant of the motion ( see e.g. @xcite ; see @xcite for a hyperbolic space version of the problem which is still integrable ) .
a natural relativistic generalisation of this problem is to consider the motion of test particles in a weyl solution describing two schwarzschild black holes , which are kept in equilibrium due to a strut in between them . for this problem.
Please generate the next two sentences of the article | there is no known analogue to euler s constant ( see @xcite for a discussion about this point ) ; equivalently , there is no known separability for the geodesic equations .
generic geodesics have , therefore , to be studied numerically . for |
5,803 | Suppose that you have an abstract for a scientific paper: starting from a field theory containing classical vortex solutions , we obtain an effective string theory of these vortices as a path integral over the two transverse degrees of freedom of the string .
we carry out a semiclassical expansion of this effective theory , and use it to obtain corrections to regge trajectories due to string fluctuations . .
And you have already written the first three sentences of the full article: the goal of this paper is to derive an effective string theory of vortices beginning with a field theory containing classical vortex solutions .
the abelian higgs model is an example of such a theory .
nielsen and olesen @xcite showed that this model has classical magnetic vortex solutions ..
Please generate the next two sentences of the article | these vortices are tubes of magnetic flux with constant energy per unit length .
the motivation for this work came from the dual superconductor picture of confinement @xcite . in this picture , |
5,804 | Suppose that you have an abstract for a scientific paper: new and previously published measurements on the deep inelastic @xmath0 scattering cross section by the h1 and zeus collaborations are presented .
the uncertainties can be significantly reduced by a model independent combination procedure , which treats the systematic error correlations in a coherent way .
the combined h1 and zeus measurements of the inclusive neutral and charged current cross sections are used to perform a common nlo qcd fit , called herapdf @xmath1 .
the resulting set of parton density functions ( pdfs ) have a much improved experimental uncertainty compared to previous extractions using the uncombined h1 or zeus data . .
And you have already written the first three sentences of the full article: the hera collider facility in hamburg , germany , was a unique machine for lepton - proton scattering at highest energies .
for the two experiments h1 and zeus protons with an energy of up to @xmath2 gev and electrons or positrons with an energy of @xmath3 gev were collided .
this is equivalent to a maximal centre of mass energy of @xmath4 gev . at the end of june 2007.
Please generate the next two sentences of the article | the data taking finished . in deep inelastic scattering ( dis ) of leptons off nucleons the substructure of the nucleons
was discovered . |
5,805 | Suppose that you have an abstract for a scientific paper: we present a concept of surface decomposition extended from double fourier series to nonnegative sinusoidal wave surfaces , on the basis of which linear ion sources apply to the ultra - precision fabrication of complex surfaces and diffractive optics .
it is the first time that we have a surface descriptor for building a relationship between the fabrication process of optical surfaces and the surface characterization based on psd analysis , which akin to zernike polynomials used for mapping the relationship between surface errors and seidel aberrations . also , we demonstrate that the one - dimensional scanning of linear ion source is applicable to the removal of surface errors caused by small - tool polishing in raster scan mode as well as the fabrication of beam sampling grating of high diffractive uniformity without a post - processing procedure .
the simulation results show that , in theory , optical fabrication with linear ion source is feasible and even of higher output efficiency compared with the conventional approach . 99 g. forbes , `` shape specification for axially symmetric optical surfaces , '' * 15*(8 ) , 52185226 ( 2007 ) .
p. jester , c. menke , and k. urban , `` b - spline representation of optical surfaces and its accuracy in a ray trace algorithm , '' * 50*(6 ) , 822828 ( 2011 ) .
p. jester , c. menke , and k. urban , `` wavelet methods for the representation , analysis and simulation of optical surfaces , '' i m a j. appl . math . * 77*(4 ) , 495515 ( 2012 ) . g. forbes , `` fitting freeform shapes with orthogonal bases , '' * 21*(16 ) , 1906119081 ( 2013 ) .
c. ferreira , j. l. lpez , r. navarro , and e. p. sinusa , `` orthogonal basis with a conicoid first mode for shape specification of optical surfaces , '' * 24*(5 ) , 54485462 ( 2016 ) .
g. forbes , `` manufacturability estimates for optical aspheres , '' * 19*(10 ) , 99239942 ( 2011 ) .
r. k. tyson , `` conversion of zernike aberration coefficients to seidel and higher - order....
And you have already written the first three sentences of the full article: the optics community has taken a lot of effort into the development of surface modeling methods for optical design @xcite . unfortunately
, none of those methods are developed to improve manufacturability @xcite or to reduce the difficulty of fabrication of optical surfaces .
for example , zernike polynomials are widely applied to describe surface errors and express wavefront data in the field of optical fabrication and testing . because there is a theoretical relationship between zernike coefficients and seidel aberrations often observed in optical tests @xcite . however , basically , the standard 36-term zernike polynomial set does not aim to or help to optimize the process of optical fabrication or polishing ..
Please generate the next two sentences of the article | when it comes to ultra - precision fabrication of optical surfaces , ion beam technologies play a key role in improving surface precision to extreme .
as one of the most precise methods , ion beam figuring ( ibf ) @xcite is employed for finishing lithography optics and telescope mirrors . |
5,806 | Suppose that you have an abstract for a scientific paper: this report reviews the conceptual and theoretical links between granger causality and directed information theory .
we begin with a short historical tour of granger causality , concentrating on its closeness to information theory .
the definitions of granger causality based on prediction are recalled , and the importance of the observation set is discussed .
we present the definitions based on conditional independence . the notion of instantaneous coupling
is included in the definitions .
the concept of granger causality graphs is discussed .
we present directed information theory from the perspective of studies of causal influences between stochastic processes .
causal conditioning appears to be the cornerstone for the relation between information theory and granger causality . in the bivariate case ,
the fundamental measure is the directed information , which decomposes as the sum of the transfer entropies and a term quantifying instantaneous coupling .
we show the decomposition of the mutual information into the sums of the transfer entropies and the instantaneous coupling measure , a relation known for the linear gaussian case .
we study the multivariate case , showing that the useful decomposition is blurred by instantaneous coupling .
the links are further developed by studying how measures based on directed information theory naturally emerge from granger causality inference frameworks as hypothesis testing . *
keyword : * granger causality , transfer entropy , information theory , causal conditioning , conditional independence .
And you have already written the first three sentences of the full article: this review deals with the analysis of influences that one system , be it physical , economical , biological or social , for example , can exert over another .
in several scientific fields , the finding of the influence network between different systems is crucial . as examples
, we can think of gene influence networks @xcite , relations between economical variables @xcite , communication between neurons or the flow of information between different brain regions @xcite , or the human influence on the earth climate @xcite , and many others ..
Please generate the next two sentences of the article | the context studied in this report is illustrated in figure [ network : fig ] .
for a given system , we have at disposal a number of different measurements . in neuroscience |
5,807 | Suppose that you have an abstract for a scientific paper: we study lower bounds on information dissemination in adversarial dynamic networks .
initially , @xmath0 pieces of information ( henceforth called tokens ) are distributed among @xmath1 nodes .
the tokens need to be broadcast to all nodes through a synchronous network in which the topology can change arbitrarily from round to round provided that some connectivity requirements are satisfied .
if the network is guaranteed to be connected in every round and each node can broadcast a single token per round to its neighbors , there is a simple token dissemination algorithm that manages to deliver all @xmath0 tokens to all the nodes in @xmath2 rounds .
interestingly , in a recent paper , dutta et al . proved an almost matching @xmath3 lower bound for deterministic token - forwarding algorithms that are not allowed to combine , split , or change tokens in any way . in the present paper , we extend this bound in different ways . if nodes are allowed to forward @xmath4 tokens instead of only one token in every round , a straight - forward extension of the @xmath2 algorithm disseminates all @xmath0 tokens in time @xmath5 .
we show that for any randomized token - forwarding algorithm , @xmath6 rounds are necessary . if nodes can only send a single token per round , but we are guaranteed that the network graph is @xmath7-vertex connected in every round , we show a lower bound of @xmath8 , which almost matches the currently best @xmath9 upper bound .
further , if the network is @xmath10-interval connected , a notion that captures connection stability over time , we prove that @xmath11 rounds are needed .
the best known upper bound in this case manages to solve the problem in @xmath12 rounds .
finally , we show that even if each node only needs to obtain a @xmath13-fraction of all the tokens for some @xmath14 $ ] , @xmath15 are still required . .
And you have already written the first three sentences of the full article: the growing abundance of ( mobile ) computation and communication devices creates a rich potential for novel distributed systems and applications . unlike classical networks ,
often the resulting networks and applications are characterized by a high level of churn and , especially in the case of mobile devices , a potentially constantly changing topology .
traditionally , changes in a network have been studied as faults or as exceptional events that have to be tolerated and possibly repaired ..
Please generate the next two sentences of the article | however , particularly in mobile applications , dynamic networks are a typical case and distributed algorithms have to properly work even under the assumption that the topology is constantly changing .
consequently , in the last few years , there has been an increasing interest in distributed algorithms that run in dynamic systems . |
5,808 | Suppose that you have an abstract for a scientific paper: the nature of carbon burning flames in type ia supernovae is explored as they interact with kolmogorov turbulence .
one - dimensional calculations using the linear eddy model of @xcite elucidate three regimes of turbulent burning . in the simplest case , large scale turbulence folds and deforms thin laminar flamelets to produce a flame brush with a total burning rate given approximately by the speed of turbulent fluctuations on the integral scale , @xmath0 .
this is the regime where the supernova explosion begins and where most of its pre - detonation burning occurs . as the density declines , turbulence starts to tear the individual flamelets , making broader structures that move faster . for a brief time , these turbulent flamelets are still narrow compared to their spacing and the concept of a flame brush moving with an overall speed of @xmath0 remains valid .
however , the typical width of the individual flamelets , which is given by the condition that their turnover time equals their burning time , continues to increase as the density declines . eventually , mixed regions almost as large as the integral scale itself are transiently formed . at that point
, a transition to detonation can occur .
the conditions for such a transition are explored numerically and it is estimated that the transition will occur for densities near @xmath1 g @xmath2 , provided the turbulent speed on the integral scale exceeds about 15% sonic . an example calculation shows the details of a detonation actually developing . .
And you have already written the first three sentences of the full article: [ sec : intro ] @xcite first discussed multiple regimes of turbulent chemical combustion and gave scaling relations for each . in modern terms , the two regimes can be distinguished by their karlovitz number , ka , ( e.g. , * ? ? ?
* ) , @xmath3 or equivalently , @xmath4 here @xmath0 is the _ rms _ velocity of turbulent fluctuations on an integral scale , @xmath5 ; @xmath6 is the laminar conductive speed ; @xmath7 is the width of the laminar flame ; and @xmath8 is the gibson length . for isotropic kolmogorov turbulence ( assumed throughout this paper ) ,
the turbulent speed on the scale of the flame thickness is @xmath9 and the gibson scale , the size of the eddy that turns over in a ( laminar ) flame crossing time , is @xmath10 for ka @xmath11 , individual laminar flames are moved around by the largest turbulent eddies while smaller eddies have little effect ..
Please generate the next two sentences of the article | the overall burning progresses at a speed determined by turbulence properties and is independent of the burning rate on small scales .
this regime has been extensively explored in the astrophysical context @xcite and its properties are reflected in the munich group s subgrid model for flame propagation @xcite . |
5,809 | Suppose that you have an abstract for a scientific paper: in this paper , we address which sources contributed most of the reionizing photons .
our argument assumes that the reionization ended around @xmath0 and that it was a relatively quick process , i.e. , that there was a non - negligible fraction of neutral hydrogen in the universe at somewhat earlier epochs . starting from our earlier estimate of the luminosity function ( lf ) of galaxies at @xmath0
, we quantitatively show that the major sources of reionization are most likely galaxies with @xmath1 .
our approach allows us to put stronger constraints to the lf of galaxies at @xmath0 . to have the universe completely ionized at this redshift
, the faint - end slope of the lf should be steeper than @xmath2 , which is the value measured at lower redshifts ( @xmath3 ) , unless either the normalization ( @xmath4 ) of the lf or the clumping factor of the ionized hydrogen has been significantly underestimated . if @xmath4 is actually lower than what we assumed by a factor of two , a steep slope close to @xmath5 is required .
our lf predicts a total of 50 80 @xmath0 galaxies in the hst ultra deep field ( udf ) to a depth of @xmath6 mag , which can be used to constraint both @xmath4 and @xmath7 .
we conclude that the @xmath8 luminous galaxies existing at this redshift should reach as low as some critical luminosity in order to accumulate the entire reionizing photon budget . on the other hand ,
the existence of significant amounts of neutral hydrogen at slightly earlier epochs , e.g. @xmath9 , requires that the @xmath8 luminous galaxies should not be fainter than another critical value ( i.e. , the lf should cut - off at this point ) . .
And you have already written the first three sentences of the full article: high resolution uv spectra of @xmath10 quasars found in the sloan digital sky survey ( sdss ) provide solid evidence that the intergalactic hydrogen was in a _ completely ionized _ state up to an early epoch of @xmath0 ( e.g. , fan etal .
2001 ) . at slightly higher redshifts ,
however , a small fraction of neutral hydrogen is being seen , as indicated by the complete gunn - peterson trough found in several sdss quasars at @xmath11 6.43 ( becker etal ..
Please generate the next two sentences of the article | 2001 ; fan etal .
2003 ) . this has been used to argue that @xmath0 marks the end of the reionization era , and that the redshift at which the reionization began may not be much higher than @xmath0 ( becker etal . |
5,810 | Suppose that you have an abstract for a scientific paper: we analyse the cluster structure of the final multihadron states resulting from heavy ion collisions using the concept of jaynes - shannon entropy .
further evidence for an interesting differentiation of events is provided . 23.0 cm 16.0 cm -2.0 cm -1.0 cm -1.0 cm k. fiakowski , r. wit _ m. smoluchowski institute of physics + jagellonian university + 30 - 059 krakw , ul.reymonta 4 , poland _ pacs : 25.70.-z + _ keywords : _ heavy ion collisions , cluster analysis , monte carlo + 4 october , 1999 + .
And you have already written the first three sentences of the full article: the analysis of the klm collaboration data @xcite for pb(158 gev / nucleon)-ag / br collisions indicated the existence of events with `` strong dynamical fluctuations '' . the use of factorial moments as a tool for preliminary selection of events was suggested . in our previous paper @xcite we analyzed the cluster structure of events resulting from the heavy ion collision data and from the monte carlo ( mc ) generators .
we investigated the dependence of the cluster distributions on the parameter defining a cluster size .
the quantity we worked with was the second scaled factorial moment as a function of averaged multiplicity @xmath0 with `` two subtracted '' ( i.e. @xmath0 - 2 ) : @xmath1 we gave also a motivation for the choice of such a discrimination tool . in full agreement with the suggestions following from ref ..
Please generate the next two sentences of the article | @xcite we have found two different patterns in the first four published experimental events . in this note
we would like to present some further analysis concerning the same subject . |
5,811 | Suppose that you have an abstract for a scientific paper: there is no known fundamental reason to demand as a cosmological initial condition that the bulk possess an @xmath0 isometry . on the contrary ,
one expects bulk curvature terms that violate the @xmath0 isometry at early epochs , leading to a violation of lorentz invariance on our brane . demanding that the lorentz noninvariant terms are small leads to a new `` flatness '' problem , not solved by the usual formulation of inflation .
furthermore , unlike in four dimensions , the lorentz violations induced from the bulk curvature can not always be removed as the infrared cutoff is taken arbitrarily large .
this means that the equivalence principle in higher dimensions does not guarantee the equivalence principle in dimensionally reduced theories .
near - future experiments are expected to severely constrain these lorentz - violating `` signatures '' of extra dimensions . 0.0 in .
And you have already written the first three sentences of the full article: theories with extra dimensions have long played a role in attempts to unify other forces with gravity @xcite .
traditional ideas about hiding extra dimensions involved making them compact and small @xcite ( generally assumed to be of the order of the planck length @xcite ) , so that propagation of standard model matter in the extra dimensions requires energy of the inverse of the size of the extra dimensions .
thus , if the extra dimensions are small enough , they effectively decouple from the low - energy theory ..
Please generate the next two sentences of the article | the mechanism of confining standard - model fields on @xmath1-dimensional subspaces ( 3-branes , or just branes ) @xcite of a higher - dimensional manifold leads to the possibility of scenarios with large extra dimensions . in models where the spacetime geometry is of a simple factorizable form
, the space of extra dimensions ( the bulk ) may be compact and perhaps as large as a millimeter @xcite . |
5,812 | Suppose that you have an abstract for a scientific paper: these proceedings summarize the latest measurements on top production , top properties and searches using the atlas detector at the lhc .
the measurements are performed on @xmath0 collision data with a center of mass energy @xmath1 and @xmath2 tev . .
And you have already written the first three sentences of the full article: the top quark is the heaviest known elementary particle of the standard model ( sm ) .
it has a life - time shorter than the hadronization time and offers a window to search for new physics . with large numbers of top events produced at lhc in run-1
, it is possible to study its properties in detail ..
Please generate the next two sentences of the article | these proceedings present measurements of top production , top properties and searches at the center of mass energy of 7 , 8 and 13 tev by the atlas experiment @xcite .
the atlas experiment has performed measurements of the inclusive top - antitop production cross section of @xmath3 production at center of mass energy of 7 , 8 and 13 tev in the dilepton channel @xcite . |
5,813 | Suppose that you have an abstract for a scientific paper: the paper considers a bidirectional power flow model of the electric vehicles ( evs ) in a charging station .
the evs can inject energies by discharging via a vehicle - to - grid ( v2 g ) service which can enhance the profits of the charging station .
however , frequent charging and discharging degrade battery life .
a proper compensation needs to be paid to the users to participate in the v2 g service .
we propose a menu - based pricing scheme , where the charging station selects a price for each arriving user for the amount of battery utilization , the total energy , and the time ( deadline ) that the ev will stay .
the user can accept one of the contracts or rejects all depending on their utilities .
the charging station can serve users using a combination of the renewable energy and the conventional energy bought from the grid . we show that though there exists a profit maximizing price which maximizes the social welfare , it provides no surplus to the users if the charging station is aware of the utilities of the users .
if the charging station is not aware of the exact utilities , the social welfare maximizing price may not maximize the expected profit .
in fact , it can give a zero profit .
we propose a pricing strategy which provides a guaranteed fixed profit to the charging station and it also maximizes the expected profit for a wide range of utility functions .
our analysis shows that when the harvested renewable energy is small the users have higher incentives for the v2 g service .
we , numerically , show that the charging station s profit and the user s surplus both increase as v2 g service is efficiently utilized by the pricing mechanism . .
And you have already written the first three sentences of the full article: electric vehicles ( evs ) have several advantages over the traditional gasoline powered vehicles . for example , evs are more environment friendly and more energy efficient . realizing the above
, regulators ( e.g. federal energy regulator commission ( ferc ) ) are providing incentives to the consumers to switch to electric vehicles .
manufacturers ( e.g. tesla , nissan ) are increasingly developing evs equipped with superior technologies . as a result , electric vehicles.
Please generate the next two sentences of the article | are increasingly become popular .
however , a wide deployment of evs requires an extensive network of charging stations which can be capable of charging large number of vehicles . |
5,814 | Suppose that you have an abstract for a scientific paper: the @xmath0polynomial of a manifold whose boundary consists of a single torus is generalised to an _
eigenvalue variety _ of a manifold whose boundary consists of a finite number of tori , and the set of strongly detected boundary curves is determined by bergman s _ logarithmic limit set _ , which describes the exponential behaviour of the eigenvalue variety at infinity .
this enables one to read off the detected boundary curves of a multi
cusped manifold in a similar way to the 1cusped case , where the slopes are encoded in the newton polygon of the @xmath0polynomial . .
And you have already written the first three sentences of the full article: let @xmath1 be an algebraic variety in @xmath2 .
the first section discusses the _ logarithmic limit set _ @xmath3 of @xmath1 , which we use to define the set of ideal points of @xmath1 .
we show that each point with rational coordinate ratios in @xmath3 is an ideal point of a curve in @xmath1 ..
Please generate the next two sentences of the article | thus , the logarithmic limit set lends itself to applications of culler shalen theory , where essential surfaces are associated to ideal points of curves in the character variety of a 3manifold . given a compact , orientable , irreducible 3manifold with boundary consisting of a single torus ,
one calls boundary slopes of essential surfaces associated to ideal points of the character variety _ strongly detected_. it is shown in @xcite that the slope of each side of the newton polygon of the @xmath0polynomial is a strongly detected boundary slope . in the second section , |
5,815 | Suppose that you have an abstract for a scientific paper: the effect of solvent quality on dilute and semi - dilute regimes of polymers in solution is studied by means of monte carlo simulations . the equation of state , adsorptions near a hard wall , wall - polymer surface tension and effective depletion potentials are all calculated as a function of concentration and solvent quality .
we find important differences between polymers in good and theta solvents . in the dilute regime
, the physical properties for polymers in a theta solvent closely resemble those of ideal polymers . in the semi - dilute regime , however , significant differences are found . .
And you have already written the first three sentences of the full article: the properties of polymers in solution are determined by the balance between effective monomer - monomer attractions and excluded volume repulsions . upon increasing the relative strength of the attractions , for example by cooling ,
several regimes are encountered . as long as the thermal energy @xmath0 far exceeds the absolute value @xmath1 of the effective monomer - monomer attraction ,
good solvent conditions prevail , and individual polymer coils are swollen due to the dominance of excluded volume effects . the polymer radius of gyration @xmath2 scales like @xmath3 , where @xmath4 is the number of monomers or ( kuhn ) segments , and @xmath5 is the flory exponent@xcite ..
Please generate the next two sentences of the article | when the temperature is lowered , the coils shrink due to the action of effective ( solvent - induced ) monomer - monomer attraction , until the theta regime is reached ; at the theta - temperature @xmath6 , monomer - monomer repulsion and attraction cancel , at least at the two - body level , and individual coils behave essentially like ideal ( random walk ) polymers , such that their radius of gyration scales like @xmath7 .
below @xmath6 individual coils collapse into dense globules with @xmath8 . moving away from the infinite dilution limit , |
5,816 | Suppose that you have an abstract for a scientific paper: we investigate the dependence of physical properties of galaxies brighter than @xmath0 in the sloan digital sky survey ( sdss ) on environment , as measured by local density using an adaptive smoothing kernel .
we find that variations of galaxy properties with environment are almost entirely due to the dependence of morphology and luminosity on environment . because galaxy properties depend not only on luminosity but also on morphology , it is clear that galaxy properties can not be determined solely by dark halo mass .
when morphology and luminosity are fixed , other physical properties , such as color , color - gradient , concentration , size , velocity dispersion , and star formation rate , are nearly independent of local density , without any break or feature .
the only feature is the sharp decrease of the late type fraction above the critical luminosity of about @xmath1 in the morphology versus luminosity relation .
weak residual dependences on environment include that of the color of late types ( bluer at lower density ) and of the @xmath2-@xmath3 relation of early types ( larger dispersion at higher density for bright galaxies ) .
the fraction of galaxies with early morphological type is a monotonically increasing function of local density and luminosity .
the morphology - density - luminosity relation , as measured in this work , should be a key constraint on galaxy formation models .
we demonstrate that the dependence on environment of the morphology of galaxies originates from variations in density on effective gaussian smoothing scales much smaller than @xmath4mpc .
we find that galaxy morphology varies both with density measured on an effective gaussian smoothing scale of @xmath5mpc and with distance to the nearest bright galaxy , particularly when the distance is about 0.2 @xmath6 mpc .
we propose as a mechanism that the morphology of galaxies in galaxy systems is transformed by the tidal force . .
And you have already written the first three sentences of the full article: the origin of the morphology of galaxies is one of the mysteries of galaxy formation .
recently , there has been a great deal of effort to understand the origin of morphology by inspecting dependences of galaxy properties on environment .
this line of study dates back to the 1930 s ( e.g. hubble & humason 1931 ) when it was realized that clusters were dominated by ellipticals and lenticulars and that environmental factors played an important role in determining the morphology of galaxies ..
Please generate the next two sentences of the article | oemler ( 1974 ) found the morphology - radius relation ; the late type galaxy fraction decreases with radius within a cluster .
this relation was confirmed by dressler ( 1980 ) who argued that the fraction of morphological types is a function of local galaxy density . |
5,817 | Suppose that you have an abstract for a scientific paper: we show that the auger air shower array has the potential to detect neutrinos of energies in the @xmath0ev range through horizontal air showers . assuming some simple conservative trigger requirements we obtain the acceptance for horizontal air showers as induced by high energy neutrinos by two alternative methods and we then give the expected event rates for a variety of neutrino fluxes as predicted in different models which are used for reference .
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And you have already written the first three sentences of the full article: high energy neutrino detection is one of the experimental challenges in particle astrophysics for the forthcoming years because it opens a new window to the regions of the universe that are otherwise shielded from us by large amounts of matter .
it is widely believed that one of the most appropriate techniques for neutrino detection consists of detecting the erenkov light from muons or showers produced by the neutrino interactions in underground water or ice .
this allows the instrumentation of large enough volumes to compensate for both the low neutrino cross section and the low fluxes expected ..
Please generate the next two sentences of the article | there are several projects under way to build sufficiently large detectors to measure the expected signals from a variety of sources@xcite .
on the other hand many years ago it was suggested that deeply penetrating high energy particles , such as muons and neutrinos , initiate large horizontal air showers that can be detected at ground level @xcite . at large |
5,818 | Suppose that you have an abstract for a scientific paper: experiments performed on a wide range of glassy materials display many interesting phenomena , such as aging behavior . in recent years , a large body of experiments probed this nonequilibrium glassy dynamics through elaborate protocols , in which external parameters are shifted , or cycled in the course of the experiment .
we review here these protocols , as well as experimental and numerical results .
then , we critically discuss various theoretical approaches put forward in this context .
emphasis is put more on the generality of the phenomena than on a specific system .
experiments are also suggested . .
And you have already written the first three sentences of the full article: in this summer school , we were given many examples of glassy systems , glassy dynamics , and glass transitions , even though a proper definition of the word ` glassy ' was not really provided .
however , all glassy materials share the property that their relaxation times are extremely large compared to the time scale of a typical experiment , at least in a part of their phase diagram . for practical purposes , they are thus out of equilibrium , meaning that in principle the whole sample history is relevant to a description of their physical properties .
this paper is dedicated to the study of some specific histories applied to various glassy materials . as physicists , we want to study the simplest histories that allow for an understanding of all the relevant mechanisms at work ..
Please generate the next two sentences of the article | hopefully , an understanding of simple protocols will also allow for prediction or calculation of the behavior resulting from increasingly elaborate procedures . over the last decades
, the experiment most often performed has been the _ simple aging _ experiment , see fig . |
5,819 | Suppose that you have an abstract for a scientific paper: we address the problem of clustering words ( or constructing a thesaurus ) based on co - occurrence data , and using the acquired word classes to improve the accuracy of syntactic disambiguation .
we view this problem as that of estimating a joint probability distribution specifying the joint probabilities of word pairs , such as noun verb pairs .
we propose an efficient algorithm based on the minimum description length ( mdl ) principle for estimating such a probability distribution .
our method is a natural extension of those proposed in @xcite and @xcite , and overcomes their drawbacks while retaining their advantages .
we then combined this clustering method with the disambiguation method of @xcite to derive a disambiguation method that makes use of both automatically constructed thesauruses and a hand - made thesaurus .
the overall disambiguation accuracy achieved by our method is @xmath0 , which compares favorably against the accuracy ( @xmath1 ) obtained by the state - of - the - art disambiguation method of @xcite . .
And you have already written the first three sentences of the full article: we address the problem of clustering words , or that of constructing a thesaurus , based on co - occurrence data .
we view this problem as that of estimating a joint probability distribution over word pairs , specifying the joint probabilities of word pairs , such as noun verb pairs . in this paper
, we assume that the joint distribution can be expressed in the following manner , which is stated for noun verb pairs for the sake of readability : the joint probability of a noun and a verb is expressed as the product of the joint probability of the noun class and the verb class which the noun and the verb respectively belong to , and the conditional probabilities of the noun and the verb given their respective classes . as a method for estimating such a probability distribution.
Please generate the next two sentences of the article | , we propose an algorithm based on the minimum description length ( mdl ) principle .
our clustering algorithm iteratively merges noun classes and verb classes in turn , in a bottom up fashion . for each merge it performs |
5,820 | Suppose that you have an abstract for a scientific paper: we have computed the time evolution of bolometric , far - infrared , h@xmath0 line , ultraviolet ( both intrinsic and escaping the star forming region ) and the nonthermal radio continuum luminosities for continuous and constant star formation terminating at 95 myr .
the luminosity rises to a plateau value and declines after the termination of starburst , but only gradually .
the time evolution profiles are broad and different for different star formation indicators .
the broad profiles lead to uncertainties in the star formation rate derived depending on the initial mass function , duration of starburst , its distribution and the observational epoch . .
And you have already written the first three sentences of the full article: in recent years there have been several studies of the cosmological history of star formation rate ( sfr ) in galaxies .
usually the sfr is derived from the luminosity density in a selected wavelength band which is an indicator of star formation .
some of the sf indicators that have been used are : h@xmath0 line , far - infrared ( fir ) , submm , ultraviolet ( uv ) and nonthermal radio continuum emissions ..
Please generate the next two sentences of the article | each indicator is sensitive to a certain range of stellar masses and the total sfr is obtained by assuming an initial mass function ( imf ) of stars at birth , usually a power - law form .
further , the observed luminosity depends on the star formation history and the epoch of observation . even for a constant rate of star formation |
5,821 | Suppose that you have an abstract for a scientific paper: we study exotic mesons with double charm and bottom flavor ( @xmath0 ) , whose quark configuration is @xmath1 .
this quark configuration has no annihilation process of quark and antiquark , and hence is a genuinely exotic states .
we take a hadronic picture by considering the molecular states composed of a pair of heavy mesons , such as @xmath2 , @xmath3 and @xmath4 for charm flavor , and @xmath5 , @xmath6 and @xmath7 for bottom flavor .
the interactions between heavy mesons are derived from the heavy quark effective theory .
all molecular states are classified by @xmath8 quantum numbers , and are systematically studied up to the total angular momentum @xmath9 . by solving the coupled channel schrdinger equations , due to the strong tensor force of one pion exchanging ,
we find bound and/or resonant states of various quantum numbers . .
And you have already written the first three sentences of the full article: exotic hadrons which include multiquark configurations provide us with important information in hadron physics .
there is a key to understand one of the most important problems in hadron physics ; what are the constituent particles of hadrons , and what are the interactions among the constituent particles at relevant low energies .
those questions are related to the fundamental questions of the qcd , such as to color confinement , chiral symmetry breaking and so on . nowadays.
Please generate the next two sentences of the article | the exotic hadrons are studied , not only in light flavor sectors , but also in heavy flavor sectors with charm and bottom quarks @xcite .
recent experimental observations of heavy exotic hadrons , @xmath10 , @xmath11 , @xmath12 , @xmath13 in charm sector , and @xmath14 , @xmath15 in bottom sector have motivated intensive discussions about possible new dynamics in the heavy hadrons . many of those hadrons have unusual mass , decay width and branching ratios , which may not be explained as normal hadrons , such as @xmath16 and @xmath17 . as candidates of flavor exotics for future experiments , |
5,822 | Suppose that you have an abstract for a scientific paper: an ensemble of multilevel atoms is a good candidate for a quantum information storage device .
the information is encrypted in the collective ground state atomic coherence , which , in the absence of external excitation , is decoupled from the vacuum and therefore decoherence free .
however , in the process of manipulation of atoms with light pulses ( writing , reading ) , one inadvertently introduces a coupling to the environment , i.e. a source of decoherence .
the dissipation process is often treated as an independent process for each atom in the ensemble , an approach which fails at large atomic optical depths where cooperative effects must be taken into account . in this paper , the cooperative behavior of spin decoherence and population transfer for a system of two , driven multilevel - atoms is studied . not surprisingly , an enhancement in the decoherence rate is found , when the atoms are separated by a distance that is small compared to an optical wavelength ; however , it is found that this rate increases even further for somewhat larger separations for atoms aligned along the direction of the driving field s propagation vector .
a treatment of the cooperative modification of optical pumping rates and an effect of polarization swapping between atoms is also discussed , lending additional insight into the origin of the collective decay . .
And you have already written the first three sentences of the full article: a system of atoms interacting with a common reservoir ( the electromagnetic vacuum ) is often treated using an assumption of independent dissipation rates for the atoms .
this is a valid assumption for the case when the interatomic distances are large ( compared to an optical wavelength ) ; however , when the distances between atoms become smaller or comparable to an optical wavelength , the mode structure around one atom is changed due to the presence of other atoms located in its immediate vicinity , and the decay rates are modified .
equivalently , the radiation emitted by one atom can be scattered off the second atom , thus changing the radiative properties of the system . as a consequence.
Please generate the next two sentences of the article | , the radiative decay of the ensemble must be viewed as a cooperative effect .
a quantitative analysis of cooperative effects was given by dicke @xcite for an ensemble of two - level systems confined to a spherical volume whose radius is much smaller than an optical wavelength . |
5,823 | Suppose that you have an abstract for a scientific paper: in this article we classify indecomposable objects of the derived categories of finitely - generated modules over certain infinite - dimensional algebras .
the considered class of algebras ( which we call nodal algebras ) contains such well - known algebras as the complete ring of a double nodal point @xmath0/(xy)$ ] and the completed path algebra of the gelfand quiver . as a corollary
we obtain a description of the derived category of harish - chandra modules over @xmath1 .
we also give an algorithm , which allows to construct projective resolutions of indecomposable complexes . in the appendix
we prove the krull - schmidt theorem for homotopy categories .
_ key words : _ derived categories ; tame matrix problems ; harish - chandra modules ; krull - schmidt theorem . [ section ] [ theorem]corollary [ theorem]remark [ theorem]example [ theorem]lemma [ theorem]proposition [ theorem]statement [ theorem]definition [ theorem]conjecture [ theorem]problem [ theorem]question # 1\{#1 } # 1#2\{#1|#2 } # 1#1mod # 1#1pro # 1#1 = derived categories of nodal algebras igor burban and yuriy drozd universitt kaiserslautern , fachbereich mathematik , + postfach 3049 , 67653 , kaiserslautern , germany + and + department of mechanics and mathematics , + kyiv taras shevchenko university , 01033 kyiv , ukraine + e - mails : [email protected] , [email protected] .
And you have already written the first three sentences of the full article: let @xmath2 be a _ pure noetherian complete algebra _ ,
i.e. an associative @xmath3-algebra such that : 1 .
its center @xmath4 is a complete local noetherian @xmath3-algebra ..
Please generate the next two sentences of the article | @xmath2 is finitely generated @xmath4-module without minimal submodules .
denote by @xmath5 the radical of @xmath2 . |
5,824 | Suppose that you have an abstract for a scientific paper: as gravity is a long - range force , one might _ a priori _ expect the universe s global matter distribution to select a preferred rest frame for local gravitational physics . at the post - newtonian approximation , two parameters suffice to describe the phenomenology of preferred - frame effects .
one of them has already been very tightly constrained ( @xmath0 , 90% c.l . ) , but the present bound on the other one is much weaker ( @xmath1 , 90% c.l . ) .
it is pointed out that the observation of particular orbits of artificial earth satellites has the potential of improving the @xmath2 limits by a couple of orders of magnitude , thanks to the appearance of small divisors which enhance the corresponding preferred - frame effects .
there is a discrete set of inclinations which lead to arbitrarily small divisors , while , among zero - inclination ( equatorial ) orbits , geostationary ones are near optimal .
the main @xmath2-induced effects are : ( i ) a complex secular evolution of the eccentricity vector of the orbit , describable as the vectorial sum of several independent rotations ; and ( ii ) a yearly oscillation in the longitude of the satellite . .
And you have already written the first three sentences of the full article: the absence of preferred frames in local experiments ( or local boost invariance ) is verified everyday in high - energy experiments but is much more difficult to test for the gravitational interaction .
metrically coupled tensor
scalar theories of gravity ( la jordan fierz brans dicke ) , including general relativity , do not predict any violation of this invariance ( see _ e.g. _ @xcite and references therein ) . on the other hand ,.
Please generate the next two sentences of the article | one expects the universe s global matter distribution to select a preferred rest frame for the gravitational interaction if it is mediated in part by a long - range vector field ( or a second tensor field besides the unique one postulated by einstein ) @xcite .
tests of the boost - invariance of gravity in localized systems are therefore of special interest to determine the _ field content _ of the gravitational interaction , _ |
5,825 | Suppose that you have an abstract for a scientific paper: a strongly coupled spin chain can mediate long - distance effective couplings or entanglement between remote qubits , and can be used as a quantum data bus .
we study how the fidelity of a spin-1/2 heisenberg chain as a spin bus is affected by static random exchange couplings and magnetic fields .
we find that , while non - uniform exchange couplings preserve the isotropy of the qubit effective couplings , they cause the energy levels , the eigenstates , and the magnitude of the couplings to vary locally . on the other hand , random local magnetic fields lead to an avoided level crossing for the bus ground state manifold , and cause the effective qubit couplings to be anisotropic .
interestingly , the total magnetic moment of the ground state of an odd - size bus may not be parallel to the average magnetic field .
its alignment depends on both the direction of the average field and the field distribution , in contrast with the ground state of a single spin which always aligns with the applied magnetic field to minimize the zeeman energy .
lastly , we calculate sensitivities of the spin bus to such local variations , which are potentially useful for evaluating decoherence when dynamical fluctuations in the exchange coupling or magnetic field are considered . .
And you have already written the first three sentences of the full article: a qubit is the elementary unit of quantum information , and can be realized with a variety of two - level systems , such as confined electron spins in a semiconductor nanostructure . for electron spin based qubits , universal quantum gates
can be realized using zeeman coupling and spin - spin exchange interaction .
@xcite the direct heisenberg exchange coupling between two electron spins is determined by the overlap of electron orbitals , and is thus a short - range nearest neighbor interaction . in order to implement quantum algorithms efficiently ,.
Please generate the next two sentences of the article | quantum gate operations on remote qubits , i.e. , controllable long - range couplings , are needed .
various quantum data buses have been introduced to bridge this gap . |
5,826 | Suppose that you have an abstract for a scientific paper: was discovered while following up an unusually bright x - ray transient ( xt ) in the nearby spiral galaxy ngc2770 .
we present early optical spectra ( obtained 1.75 days after the xt ) which allowed the first identification of the object as a supernova ( sn ) at redshift @xmath0 .
these spectra were acquired during the initial declining phase of the light curve , likely produced in the stellar envelope cooling after shock breakout , and rarely observed .
they exhibit a rather flat spectral energy distribution with broad undulations , and a strong , w - shaped feature with minima at 3980 and 4190 ( rest frame ) .
we also present extensive spectroscopy and photometry of the sn during the subsequent photospheric phase . unlike sne associated with gamma - ray bursts , displayed prominent he features and is therefore of type ib . .
And you have already written the first three sentences of the full article: on 2008 january 9.56 ut , while observing the supernova ( sn ) 2007uy in the nearby spiral galaxy ngc2770 ( @xmath0 ) , the x - ray telescope onboard _ swift _ detected a bright x - ray transient ( xt ) , with a peak luminosity of @xmath1 erg s@xmath2 and a duration of about 10 minutes @xcite .
its power - law spectrum and light curve shape were reminiscent of gamma - ray bursts ( grbs ) and x - ray flashes , but the energy release was at least 2 orders of magnitude lower than for typical and even subluminous grbs , also allowing for beaming ( e.g. , @xcite ) .
the discovery of the xt prompted the search for , and discovery of , an optical counterpart @xcite ..
Please generate the next two sentences of the article | we performed spectroscopy of the source as soon as possible , starting 1.75 days after the xt , using the fors2 spectrograph on the eso very large telescope ( vlt ) .
subsequent spectroscopic monitoring of the object was carried out at the nordic optical telescope ( not ) and the william herschel telescope ( wht ) . |
5,827 | Suppose that you have an abstract for a scientific paper: we performed a large - scale crawl of the world wide web , covering @xmath0 million domains , including all high - traffic sites of the internet .
we present a study of the correlations found between quantities measuring the structural relevance of each node in the network ( the in- and out - degree , the local clustering coefficient , the first - neighbor in - degree and the alexa rank ) .
we find that some of these properties show strong correlation effects and that the dependencies occurring out of these correlations follow power laws not only for the averages , but also for the boundaries of the respective density distributions .
in addition , these scale - free limits do not follow the same exponents as the corresponding averages . in our study
we retain the directionality of the hyperlinks and develop a statistical estimate for the clustering coefficient of directed graphs .
we include in our study the correlations between the in - degree and the alexa traffic rank , a popular index for the traffic volume , finding non - trivial power - law correlations .
we find that sites with more / less than about @xmath1 links from different domains have remarkably different statistical properties , for all correlation functions studied , indicating towards an underlying hierarchical structure of the world wide web . .
And you have already written the first three sentences of the full article: the emergence of the world wide web ( www ) belongs arguably to the most relevant events of the present time .
the interest in this system and in networks in general permeated through all the society , including physics .
this led , at the turn of the century , to a large amount of studies of what with the time came to be known as `` network science '' ..
Please generate the next two sentences of the article | most studies of the www were performed , however , in the early 2000s @xcite and large - scale studies of the www are rather hard to find nowadays , despite the immense growth of the internet in the last 10 years .
a remarkable finding of the first generation studies of the www is the emergence of scale - free degree distributions , which can be explained potentially from the view of preferential attachment , although the exponents obtained are not universal @xcite . |
5,828 | Suppose that you have an abstract for a scientific paper: processive molecular motors which drive the traffic of organelles in cells move in a directed way along cytoskeletal filaments . on large time scales , they perform motor walks , i.e. , peculiar random walks which arise from the repeated unbinding from and rebinding to filaments .
unbound motors perform brownian motion in the surrounding fluid .
in addition , the traffic of molecular motors exhibits many cooperative phenomena .
in particular , it faces similar problems as the traffic on streets such as the occurrence of traffic jams and the coordination of ( two - way ) traffic .
these issues are studied here theoretically using lattice models . , and molecular motors , active movement , random walks , lattice models , traffic jams 87.16.nn , 05.40.-a , 05.60.-k .
And you have already written the first three sentences of the full article: the idea of constructing nanometer - sized devices and machines has created a lot of excitement during the last years . despite the progress made ,
the functionality of artificial nano - devices is , however , still rather limited . at the same time , more and more biomolecular nano - machines have been identified in the cells of living beings where they accomplish a huge variety of tasks .
many of these molecular motors are now rather well studied and were found to work with an amazing degree of precision and efficiency as a result of billions of years of evolution , @xcite . in the following , we will focus on one class of molecular motors which has been studied quite extensively during the last decade , namely processive cytoskeletal motors which drive the traffic of vesicles and organelles within cells ..
Please generate the next two sentences of the article | these motors hydrolyze adenosinetriphosphate ( atp ) and convert the free energy from this chemical reaction into directed movements along filaments of the cytoskeleton .
this class of motors contains kinesins and dyneins , which move along microtubules , and certain myosins , which move along actin filaments . |
5,829 | Suppose that you have an abstract for a scientific paper: agn feedback is an important ingredient in galaxy evolution , however its treatment in numerical simulations is necessarily approximate , requiring subgrid prescriptions due to the dynamical range involved in the calculations .
we present a suite of sph simulations designed to showcase the importance of the choice of a particular subgrid prescription for agn feedback .
we concentrate on two approaches to treating wide - angle agn outflows : thermal feedback , where thermal and kinetic energy is injected into the gas surrounding the smbh particle , and virtual particle feedback , where energy is carried by tracer particles radially away from the agn .
we show that the latter model produces a far more complex structure around the smbh , which we argue is a more physically correct outcome .
we suggest a simple improvement to the thermal feedback model - injecting the energy into a cone , rather than spherically symmetrically - and show that this markedly improves the agreement between the two prescriptions , without requiring any noticeable increase in the computational cost of the simulation .
quasars : general accretion , accretion discs ism : evolution methods : numerical .
And you have already written the first three sentences of the full article: feedback from active galactic nuclei ( agn ) is a key ingredient in modern galaxy evolution models .
it is required in order to explain the sharp drop - off in the galaxy mass function above @xmath0 , prevent the cooling catastrophe in galaxy clusters and produce the hot gas atmospheres seen around many galaxies . observations of massive kpc - scale outflows and pc - scale relativistic winds provide further evidence that agn affect their host galaxies in a significant way .
one outstanding issue in understanding the precise effects of feedback is the range of spatial scales over which it operates ..
Please generate the next two sentences of the article | the agn jets and winds are launched from the accretion disc on scales @xmath1 pc , while the observed effects on host galaxies span @xmath2 pc or more .
this means that in order to model the agn feedback precisely , a simulation should span at least 5 orders of magnitude in linear scale , resulting in @xmath3 resolution elements for a 3d model , a resolution which is not likely to be reached any time soon . |
5,830 | Suppose that you have an abstract for a scientific paper: we present a global hybrid meta - generalized gradient approximation ( meta - gga ) with three empirical parameters , as well as its underlying semilocal meta - gga and a meta - gga with only one empirical parameter .
all of them are based on the new meta - gga resulting from the understanding of kinetic - energy - density dependence [ j. chem .
phys . * 137 * , 051101 ( 2012 ) ] .
the obtained functionals show robust performances on the considered molecular systems for the properties of heats of formation , barrier heights , and noncovalent interactions .
the pair - wise additive dispersion corrections to the functionals are also presented . .
And you have already written the first three sentences of the full article: the kohn - sham ( ks ) density functional theory ( dft ) @xcite is one of the most widely used electronic structure theories for atoms , molecules and solids in various areas of physics , chemistry and molecular biology due to its computational efficiency and useful accuracy .
it simplifies a many - electron wave - function problem to an auxiliary one - electron problem , with only its exchange - correlation part carrying the many - electron effects to be approximated in practice . among numerous exchange - correlation approximations , the local spin density approximation ( lsda ) @xcite ,
the standard perdew - burke - ernzerhof ( pbe ) generalized gradient approximation ( gga ) @xcite , and the becke-3-lee - yang - parr ( b3lyp ) @xcite hybrid gga dominate the user market of dft @xcite ..
Please generate the next two sentences of the article | the former two are efficient semilocal functionals widely used for extended systems , while the latter is a computationally more expensive nonlocal functional that hybridizes a gga with the exact exchange energy and is popular for finite systems . at the semilocal level , however , meta - gga ( mgga ) is the highest rung of the so - called jacob s ladder in dft @xcite and potentially the most accurate one @xcite , which can also serve as a better base for hybridizing with the exact exchange energy .
semilocal approximations ( e.g. , refs . |
5,831 | Suppose that you have an abstract for a scientific paper: extending the sensitivity to new physics beyond the anticipated reach of the lhc is a prime aim of future colliders .
this paper summarises the potential of an @xmath0 linear collider , at and beyond 1 tev , using a realistic simulation of the detector response and the accelerator induced background .
the possible lc energy - luminosity trade - offs offered in probing multi - tev scales for new phenomena with electro - weak observables are also discussed . .
And you have already written the first three sentences of the full article: the lhc is expected to directly probe possible new physics beyond the standard model ( sm ) up to a scale of a few tev . while its data should provide answers to several of the major open questions in the present picture of elementary particle physics
, it is important to start examining how this sensitivity can be further extended at a next generation of colliders .
today we have a number of indications that new physics could be of supersymmetric nature ..
Please generate the next two sentences of the article | if this is the case , the lhc will have a variety of signals to discover these new particles and the linear collider ( lc ) will be required to complement the probe of the susy spectrum with detailed measurements .
however , beyond supersymmetry there is a wide range of other scenarios invoking new phenomena at , and beyond , the tev scale . |
5,832 | Suppose that you have an abstract for a scientific paper: transmission electron microscopy has been a promising candidate for mapping atomic orbitals for a long time . here , we explore its capabilities by a first principles approach .
for the example of defected graphene , exhibiting either an isolated vacancy or a substitutional nitrogen atom , we show that three different kinds of images are to be expected , depending on the orbital character . to judge the feasibility of visualizing orbitals in a real microscope , the effect of the optics aberrations is simulated .
we demonstrate that , by making use of energy - filtering , it should indeed be possible to map atomic orbitals in a state - of - the - art transmission electron microscope .
the possibility to _ see _ atomic orbitals has always attracted great scientific interest . at the same time , however , the real meaning of `` measuring orbitals '' has been a subject that scientists have long and much dwelt upon ( see , e.g. , @xcite and references therein ) . in the past , significant efforts have been devoted to the development of experimental approaches and theoretical models that allow for orbital reconstruction from experimental data @xcite .
based on the generation of higher harmonics by femtoseconds laser pulses , a tomographic reconstruction of the highest occupied molecular orbital ( homo ) for simple diatomic molecules in the gas phase was proposed @xcite .
direct imaging of the homo and the lowest - occupied molecular orbital ( lumo ) of pentacene on a metallic substrate was theoretically predicted and experimentally verified with scanning - tunnelling microscopy ( stm ) @xcite .
more recently , real - space reconstruction of molecular orbitals from angle - resolved photoemission data has been demonstrated @xcite .
this method has been subsequently further developed to retrieve both the spatial distribution @xcite and the phase of electron wavefunctions of pentacene and perylene-3,4,9,10-tetracarboxylic dianhydride ( ptcda ) adsorbed on silver @xcite .
the reconstruction of....
And you have already written the first three sentences of the full article: financial support by the austrian science fund ( projects i543-n20 and j3732-n27 ) and the german research foundation within the dach framework is acknowledged .
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Please generate the next two sentences of the article | |
5,833 | Suppose that you have an abstract for a scientific paper: we present a novel technique for encoding and decoding constant weight binary codes that uses a geometric interpretation of the codebook .
our technique is based on embedding the codebook in a euclidean space of dimension equal to the weight of the code .
the encoder and decoder mappings are then interpreted as a bijection between a certain hyper - rectangle and a polytope in this euclidean space .
an inductive dissection algorithm is developed for constructing such a bijection .
we prove that the algorithm is correct and then analyze its complexity .
the complexity depends on the weight of the code , rather than on the block length as in other algorithms .
this approach is advantageous when the weight is smaller than the square root of the block length .
constant weight codes , encoding algorithms , dissections , polyhedral dissections , bijections , mappings , dehn invariant . .
And you have already written the first three sentences of the full article: we consider the problem of encoding and decoding binary codes of constant hamming weight @xmath0 and block length @xmath1 .
such codes are useful in a variety of applications : a few examples are fault - tolerant circuit design and computing @xcite , pattern generation for circuit testing @xcite , identification coding @xcite and optical overlay networks @xcite .
the problem of interest is that of designing the encoder and decoder , i.e. , the problem of mapping all binary ( information ) vectors of a given length onto a subset of length-@xmath1 vectors of constant hamming weight @xmath0 in a one - to - one manner . in this work ,.
Please generate the next two sentences of the article | we propose a novel geometric method in which information and code vectors are represented by vectors in @xmath0-dimensional euclidean space , covering polytopes for the two sets are identified , and a one - to - one mapping is established by dissecting the covering polytopes in a specific manner .
this approach results in an invertible integer - to - integer mapping , thereby ensuring unique decodability . |
5,834 | Suppose that you have an abstract for a scientific paper: we present the calculation of the virtual- and bremsstrahlung corrections of @xmath0 to the matrix elements @xmath1 .
this is the missing piece in the full next - to - next - to - leading logarithmic ( nnll ) results for various observables associated with the process @xmath2 , like the branching ratio , the cp - rate asymmetry and the forward - backward asymmetry .
this paper is an extension of analogous calculations done by some of us for the process @xmath3 .
as the contributions of the diagrams induced by the four - quark operators @xmath4 and @xmath5 with a @xmath6-quark running in the quark loop are strongly ckm suppressed , they were omitted in the analysis of @xmath3 .
this is no longer possible for @xmath7 , as the corresponding contributions are not suppressed .
the main new work therefore consists of calculating the @xmath8 corrections to @xmath9 . in this paper we restrict ourselves to the range @xmath10 ( @xmath11 is the invariant mass of the lepton pair ) , which lies above the @xmath12- and @xmath13-resonances and below the @xmath14-resonance .
we present the analytic results for the mentioned observables related to the process @xmath15 as expansions in the small parameters @xmath16 , @xmath17 and @xmath18 . in the phenomenological analysis at the end of the paper
we discuss the impact of the nnll corrections on the observables mentioned above . .
And you have already written the first three sentences of the full article: it is well - known that various observables associated with inclusive rare @xmath19-decays like @xmath20 and @xmath21 sensitively depend on potential new physics contributions .
but even in the absence of new physics these observables are important , because they provide checks on the one - loop structure of the standard model ( sm ) theory and can be used to gain information on the cabibbo - kobayashi - maskawa ( ckm ) matrix elements @xmath22 and @xmath23 , which are difficult to measure directly . at present , a lot of data already exists on @xmath24 @xcite and on @xmath25 @xcite and it is expected that in the future also data on the ckm suppressed counterparts , i.e. on @xmath26 and on @xmath27 will become available .
the same holds for experimental information on additional observables , like cp - rate asymmetries or forward - backward asymmetries in the decays @xmath21 . in order to fully exploit and interpret the experimental data , it is obvious that precise calculations in the sm ( or certain extensions thereof ) are needed . the main problem in the theoretical description of the decay @xmath28 is due to the long - distance contributions induced by @xmath29 resonant states and in principle also by @xmath30 resonant states.
Please generate the next two sentences of the article | the latter are , however , strongly ckm suppressed .
this suppression is not present in the case of @xmath7 , as the ckm factors involved in the contributions from @xmath29 and @xmath30 resonant states are of the same order . when the invariant mass @xmath31 of the lepton pair is close to the mass of a resonance , only model dependent predictions for such long distance contributions are available at present . |
5,835 | Suppose that you have an abstract for a scientific paper: we show that for a large class of contact @xmath0-manifolds the groups of vassiliev invariants of legendrian and of framed knots are canonically isomorphic . as a corollary
, we obtain that the group of finite order arnold s @xmath1-type invariants of wave fronts on a surface @xmath2 is isomorphic to the group of vassiliev invariants of framed knots in the spherical cotangent bundle @xmath3 of @xmath2 . on the other hand
we construct the first examples of contact manifolds for which vassiliev invariants of legendrian knots can distinguish legendrian knots that realize isotopic framed knots and are homotopic as legendrian immersions . .
And you have already written the first three sentences of the full article: in this section we describe the main results of the paper .
( in case any of the terminology appears to be new to the reader , the corresponding definitions are given in the next section . )
if a contact structure on a @xmath0-manifold is cooriented , then every legendrian knot ( i.e. a knot that is everywhere tangent to the contact distribution ) has a natural framing ( a continuous normal vector field ) . hence when studying legendrian knots in such contact manifolds the main question is to distinguish those of them that realize isotopic framed knots ..
Please generate the next two sentences of the article | similarly if the contact structure is parallelized , then every transverse knot ( i.e. a knot that is everywhere transverse to the contact distribution ) also has a natural framing , and when studying transverse knots in such contact manifolds again the main question is to distinguish those of them that realize isotopic framed knots .
vassiliev invariants proved to be an extremely useful tool in the study of framed knots , and the conjecture is that they are sufficient to distinguish all the isotopy classes of framed knots . |
5,836 | Suppose that you have an abstract for a scientific paper: in this paper we study the surface tension and the curvature energy of three - flavor quark matter in equilibrium under weak interactions within the nambu - jona - lasinio model .
we include the effect of color superconductivity and describe finite size effects within the multiple reflection expansion ( mre ) framework .
our calculations result in large values of the surface tension which disfavor the formation of mixed phases at the hadron - quark inter - phase inside a hybrid star . .
And you have already written the first three sentences of the full article: the study of the surface tension of deconfined quark matter has attracted much attention recently @xcite because a detailed knowledge of it may contribute to a better comprehension of the physics of compact star interiors .
in fact , surface tension plays a crucial role in quark matter nucleation during the formation of compact stellar objects , because it determines the nucleation rate and the associated critical size of the nucleated drops @xcite .
it is also determinant in the formation of mixed phases at the core of hybrid stars which may arise only if the surface tension is smaller than a critical value of the order of tens of mev / @xmath0 @xcite ..
Please generate the next two sentences of the article | also , surface tension affects decisively the properties of the most external layers of a strange star which may fragment into a charge - separated mixture , involving positively - charged strangelets immersed in a negatively charged sea of electrons , presumably forming a crystalline solid crust @xcite . this would happen below a critical surface tension which is typically of the order of a few mev/@xmath0 @xcite .
however , in spite of its key role for compact star physics , the surface tension is still poorly known for quark matter . |
5,837 | Suppose that you have an abstract for a scientific paper: inspired by a recent experiment , we study the influence of thermal fluctuations on the @xmath0-@xmath1 characteristics of a josephson junction , coupled to a strongly resistive environment .
we obtain analytical results in the limit where the josephson energy is larger than the charging energy and quasiparticles are absent . .
And you have already written the first three sentences of the full article: as it is well - known , the dynamics of a small josephson tunnel junction is characterized by two energies : the josephson coupling energy @xmath2 and the charging energy @xmath3 @xcite .
the behavior of the junction is determined by the competition between these two energy scales . if the josephson coupling energy dominates , a superconducting state with a well - defined phase difference @xmath4 across the junction is possible .
the junction will carry a cooper pair current @xmath5 in the absence of an external voltage @xmath1 . here.
Please generate the next two sentences of the article | @xmath6 is the josephson critical current ( @xmath7 is the electron charge ) .
if on the other hand the charging energy dominates , an insulating state with a well - defined charge @xmath8 on the junction is possible . |
5,838 | Suppose that you have an abstract for a scientific paper: iris recognition has drawn a lot of attention since the mid - twentieth century . among all biometric features , iris is known to possess a rich set of features .
different features have been used to perform iris recognition in the past . in this paper , two powerful sets of features
are introduced to be used for iris recognition : scattering transform - based features and textural features .
pca is also applied on the extracted features to reduce the dimensionality of the feature vector while preserving most of the information of its initial value .
minimum distance classifier is used to perform template matching for each new test sample .
the proposed scheme is tested on a well - known iris database , and showed promising results with the best accuracy rate of 99.2% . .
And you have already written the first three sentences of the full article: to personalize an experience or make an application more secure and less accessible to undesired people , we need to be able to distinguish a person from everyone else .
it is done using marks from the users to identify them and block unauthorized access , or personalize it based on the trusted identity .
to do so , many alternatives are on the table , such as keys , passwords and cards ..
Please generate the next two sentences of the article | the most secure options so far , however , are biometric features which can not be imitated by any other than the desired person himself .
they are divided into behavioral features that the person can uniquely create or express , such as signatures , walking rhythm , and physiological characteristics that the person possesses , such as fingerprints and iris pattern . |
5,839 | Suppose that you have an abstract for a scientific paper: in the framework of the nonrelativistic qcd and a quark - diquark model of baryons we have obtained the fragmentation functions for heavy quark to split into spin-1/2 and spin-3/2 double heavy baryons . it was predicted the production rates as well as the shape of the energy spectra for the @xmath0 and @xmath1baryons in the region of @xmath2 peak at lep collider .
-2.0 cm -3.0 cm * heavy quark fragmentation into baryons + in a quark - diquark model * + a.p.martynenko , v.a.saleev + samara state university , samara , russia .
And you have already written the first three sentences of the full article: in the last decade the great success was obtained in the study of the heavy quarkonium production and decay ( see , for example , refs.@xcite ) .
the investigation of the processes with the heavy quarks is based on the factorization hypothesis @xcite .
the mass of heavy quark @xmath3 is much larger than the scale of strong interactions @xmath4 ..
Please generate the next two sentences of the article | so the presence of the small parameter @xmath5 has allowed one to separate the effects of small and long distances .
the heavy hadron production amplitude may be presented as the product of the partonic part , which can be calculated using the perturbative qcd , and the nonperturbative factor , which describes the free quarks to final hadron transition . in the framework of the nonrelativistic quark model |
5,840 | Suppose that you have an abstract for a scientific paper: high - resolution , 2-d hydrodynamical simulations with a large dynamic range are performed to study the turbulent nature of the interstellar medium ( ism ) in galactic disks .
the simulations are global , where the self - gravity of the ism , realistic radiative cooling , and galactic rotation are taken into account . in the analysis undertaken here , feedback processes from stellar energy source are omitted .
we find that the velocity field of the disk in a non - linear phase shows a steady power - law energy spectrum over three - orders of magnitude in wave number .
this implies that the random velocity field can be modeled as fully - developed , stationary turbulence .
gravitational and thermal instabilities under the influence of galactic rotation contribute to form the turbulent velocity field .
the toomre effective @xmath0 value , in the non - linear phase , ranges over a wide range , and gravitationally stable and unstable regions are distributed patchily in the disk .
these results suggest that large - scale galactic rotation coupled with the self - gravity of the gas can be the ultimate energy sources that maintain the turbulence in the local ism .
we find that our models of turbulent rotating disks are consistent with the velocity dispersion of an extended hi disk in the dwarf galaxy , ngc 2915 , where there is no prominent active star formation .
numerical simulations show that the stellar bar in ngc 2915 enhances the velocity dispersion , and it also drives spiral arms as observed in the hi disk . .
And you have already written the first three sentences of the full article: observational and theoretical studies have suggested that there are supersonic hydrodynamical or magneto - hydrodynamical turbulent motions in molecular clouds and also in various phases of the ism @xcite .
a number of numerical studies showed , however , that the turbulence in the clouds decays as @xmath1 , with @xmath2 @xcite .
the dissipation time of the turbulence is of the order of the flow crossing time or smaller , even in the presence of strong magnetic fields @xcite ..
Please generate the next two sentences of the article | these numerical experiments suggest that energy input is necessary to maintain the turbulent motion in the molecular clouds .
some energy sources originating in stellar activity have been proposed : stellar winds from young stars @xcite , photoionization @xcite , and supernova explosions @xcite |
5,841 | Suppose that you have an abstract for a scientific paper: we study the mount wilson indices we obtained indirectly from iue high and low resolution spectra of the rs cvn - type systems ii peg ( k2iv ) , ux ari ( k0iv+g5v ) and v711 tau ( k1iv+g5v ) , extensively observed by iue from 1978 to 1996 .
we analyze the activity signatures , which correspond to the primary star , with the lomb - scargle periodogram . from the analysis of v711 tau data
, we found a possible chromospheric cycle with a period of 18 years and a shorter @xmath03 year cycle , which could be associated to a chromospheric flip - flop cycle .
the data of ii peg also suggest a chromospheric cycle of @xmath021 years and a flip - flop cycle of @xmath09 years .
finally , we obtained a possible chromospheric cycle of @xmath06 years for ux ari .
address = instituto de astronoma y fsica del espacio , conicet - uba , buenos aires , argentina . .
And you have already written the first three sentences of the full article: rs cvn - type stars are binary systems where the most massive primary component is a g - k giant or subgiant and the secondary is a subgiant or dwarf of spectral classes g to m. these systems are well known due to their strong chromospheric plages , coronal x - ray emission , and strong flares in the optical , uv , radio , and x - ray .
most long - term stellar activity studies of rs cvn stars are derived from the easily detected optical photometric variations produced by their long - lived large spots . in most cases ,
the mean magnitude reflects a stellar activity cycle similar to the 11-year solar one . on the other hand.
Please generate the next two sentences of the article | , the peak - to - peak magnitude shows a shorter cycle , called flip - flop cycle , which reflects the non axisymmetrical redistribution of the spotted area on the stellar surface .
the iue database provides a large number of uv high and low resolution spectra of these type of stars . furthermore , the iue satellite monitored these stars continuously during several seasons . in the present work |
5,842 | Suppose that you have an abstract for a scientific paper: we report on the development of two dual worm constructions that lead to cluster algorithms for efficient and ergodic monte carlo simulations of frustrated ising models with arbitrary two - spin interactions that extend up to third - neighbours on the triangular lattice .
one of these algorithms generalizes readily to other frustrated systems , such as ising antiferromagnets on the kagome lattice with further neighbour couplings .
we characterize the performance of both these algorithms in a challenging regime with power - law correlations at finite wavevector . .
And you have already written the first three sentences of the full article: ising models of ferromagnetism , with `` spins '' @xmath0 that take on two values @xmath1 , provide simple examples of systems which undergo a continuous phase transition from a high temperature disordered state to a low temperature state which spontaneously breaks the global symmetry @xmath2 .
the vicinity of this continuous transition poses a challenge to monte carlo methods that rely on local updates . in this critical regime ,
the spin correlation length becomes very large , and local updates are unable to significantly change the state of the system . in such ferromagnetic ising models , this `` critical slowing - down '' of local updates.
Please generate the next two sentences of the article | can be combated using the well - known wolff or swendsen - wang cluster algorithms.@xcite when the interactions between the spins are antiferromagnetic and the underlying lattice non - bipartite , the geometry of the lattice causes these antiferromagnetic interactions to compete with each other .
this `` geometric frustration '' is often associated with a macroscopic degeneracy of minimum exchange - energy configurations . |
5,843 | Suppose that you have an abstract for a scientific paper: galaxies are faint enough when one observes just their light distributions , but in studying their full dynamical structure the stars are spread over the six dimensions of phase space rather than just the three spatial dimensions , making their densities very low indeed .
this low signal is unfortunate , as stellar dynamics hold important clues to these systems life histories , and the issue is compounded by the fact that the most interesting information comes from the faintest outer parts of galaxies , where dynamical timescales ( and hence memories of past history ) are longest . to extract this information ,
we have constructed a special - purpose instrument , the planetary nebula spectrograph , which observes planetary nebulae as kinematic tracers of the stellar population , and allows one to study the stellar dynamics of galaxies down to extremely low surface brightnesses .
here , we present results from this instrument that illustrate how it can uncover the nature of low surface - brightness features such as thick disks by studying their kinematics , and trace faint kinematic populations that are photometrically undetectable .
address = school of physics & astronomy , university of nottingham , uk , [email protected] address = http://www.astro.rug.nl/~pns/ .
And you have already written the first three sentences of the full article: because stars are well - spaced , even the inner parts of galaxies can appear faint , comparable in surface brightness to the darkest of night skies . not surprisingly , then , when we start exploring the full six - dimensional phase space of velocities and positions that stars occupy in galaxies , the signal per phase space element becomes almost vanishingly small . in the case of the milky way ,
for example , the fascinating stellar streams in the halo @xcite have widths of only @xmath0 , and velocity dispersions of maybe @xmath1 .
if we were to divide the galaxy , with a linear dimension of @xmath2 and velocities spanning @xmath3 , into resolution elements this small , we would end up with @xmath4 of them , many more than there are stars in the milky way , so the average occupation number per element would be very small indeed ..
Please generate the next two sentences of the article | thus , if we are to study the detailed kinematics of galaxies , we need to do two things .
first , we must be able to detect stellar populations at extremely low phase densities , which essentially means detecting individual stars . |
5,844 | Suppose that you have an abstract for a scientific paper: the one - loop radiative corrections to the higgs boson potential in the mssm , originating from the top quark and squark loops , are summed in the leading log approximation using the renormalization group .
the rg improved effective potential is minimized and the corrections to the cp - odd and cp - even higgs boson masses are calculated .
the resulting masses exhibit smoother top mass dependence than those calculated without rg summation . we have also found that for preferable values of the top mass the light higgs mass does not exceed 100 gev . 6.3 in .2 in .2 in jinr - e2 - 94 - 400
+ october 1994 * renormalization group improved radiative corrections + to the supersymmetric higgs boson masses * .
And you have already written the first three sentences of the full article: it has been recently pointed out @xcite that the radiative corrections to the masses of the higgs bosons in the framework of the mssm @xcite , @xcite , @xcite can be relatively large .
the leading correction to the effective potential comes from the top quark and squark loops , being proportional to the top yukawa coupling , which is considered to be big due to the heaviness of the top quark .
the other corrections happen to be smaller , though in some cases their effect is not negligible as well ..
Please generate the next two sentences of the article | the net effect of the radiative corrections is to increase the masses of the higgs bosons .
this increase may be very significant for the future searches , since it can achieve several dozen gev , implying that the higgs mass could exceed the @xmath0 boson mass . |
5,845 | Suppose that you have an abstract for a scientific paper: we describe a superconducting device capable of producing laser light in the visible range at half of the josephson generation frequency with the optical phase of the light locked to the superconducting phase difference .
it consists of two single - level quantum dots embedded in a _
p - n _ semiconducting heterostructure and surrounded by a cavity supporting a resonant optical mode .
we study decoherence and spontaneous switching in the device .
lasers and superconductors are both systems with macroscopic quantum coherence . in lasers ,
photons form a coherent state induced by stimulated emission of a driven system into a cavity mode .
the resulting visible coherent light is characterized by an optical phase @xcite . in superconductors ,
the ground state arising from spontaneous symmetry breaking is also characterized by a phase @xcite .
traditionally , lasers and superconductors are studied separately .
recently @xcite , it has been realized that the superconducting ( sc ) phase difference and the optical phase may interact in a single device that combines two superconductors and a semiconducting _ p - n _ junction .
the latter is a common system for light generation as the electron - hole recombination produces photons of visible frequency @xcite . combining semi- and superconductors within a nanostructure
has been a difficult technological problem that attracted attention for a long time @xcite .
it has been solved using semiconductor nanowires @xcite or quantum wells @xcite , opening up the possibility to make combined devices .
the device in question has been termed a josephson led [ fig .
[ fig : setup](a ) ] .
it employs a double quantum dot ( qd ) in a _
p - n _ semiconductor nanowire connected to sc leads @xcite .
the device , biased with a voltage @xmath0 , exhibits two types of photon emission : `` blue '' photons at the josephson frequency @xmath1 due to the recombination of a cooper pair from each side of the junction , and `` red '' photons at about....
And you have already written the first three sentences of the full article: this material consists of three parts . in the first part
we show explicitly how to find stationary values @xmath79 of the ssrs from eq . using a simple toy two - level model of the qd . in the second part
, we provide a detailed example of the averaged quantities , lasing intensity and current , in dependence on voltage as promised in the main text ..
Please generate the next two sentences of the article | finally , we briefly consider a device made by placing many josephson leds into the same optical cavity .
a presentational problem with the setup described in the main text , is a relatively large number of qd states even when using all conservation laws ( @xmath132 states for the odd parity or @xmath133 states for the even parity ) . to circumvent this problem and |
5,846 | Suppose that you have an abstract for a scientific paper: a long - term variation is detected in the north - south differences of the solar activity , the phase difference of hemispheric cycles alternates by four schwabe cycles .
this variability is demonstrated by two different methods .
it can be the related to the gleissberg cycle .
the variation of the sunspot group tilts is similar to the hemispheric phase lags on a shorter timescale .
some possible relations are mentioned . .
And you have already written the first three sentences of the full article: asymmetry is an important feature of astrophysical dynamos and its properties may be important in understanding the specific processes . in the case of solar dynamo several asymmetric properties are well discussed , they may have important roles to maintain the dynamo process in spite of the cowling theorem .
the mirror asymmetry of the rotating vortices due to the coriolis force in the northern and southern hemispheres ( murakzy and ludmny , 2008 ) are important ingredients of the alpha effect .
deviations from the axial symmetry manifest themselves in a multipole structure by producing active longitudes ( berdyugina et al . , 2003 ) ..
Please generate the next two sentences of the article | these are also important in the active stars ( olh et al . , 2009 ) .
the present work focuses on the solar north - south asymmetry with special emphasis on its variations . |
5,847 | Suppose that you have an abstract for a scientific paper: arp 104 is a pair of luminous interacting galaxies consisting of ngc 5216 , an elliptical , and ngc 5218 , a disturbed disk galaxy and joined by a stellar bridge .
we obtained optical imaging to support photometric and color studies of the system .
ngc 5216 lies on the red sequence , while the unusual distribution of stellar population properties in combination with intense central star formation in a dusty region result in ngc 5218 being a nearby example of an intermediate color ( green valley ) system .
the stellar bridge has remarkably uniform optical surface brightness , with colors consistent with its stars coming from the outskirts of ngc 5218 , but is relatively gas - poor while the northern tidal tail is rich in hi . while both galaxies contain shells , the shell structures in ngc 5218 are pronounced , and some appear to be associated with counter - rotating gas .
this combination of features suggests that arp 104 could be the product of distinct multiple interactions in a small galaxy group , possibly resulting from a hierarchical merging process , and likely leading to the birth of a relatively massive and isolated early - type galaxy .
_ astrophysical journal , in press , august 2010 _ .
And you have already written the first three sentences of the full article: interactions play a major role in the evolution of galaxies , from the hierarchical growth of small systems at high redshifts to a range of mergers in the current universe ( e.g. , schweizer 2000 ) . even though models have been describing the nature of gravitational interactions between galaxies for more than 50 years
( e.g. , holmberg 1941 , toomre & toomre 1972 ) , much remains to be learned .
for example , debate continues over the nature of the interactions even in such well studied systems as m51 , where models have been proposed involving either single or multiple close passages of the companion ( toomre 1978 , salo & laurakainen 2000 , wahde & donner 2001 , dobbs et al ..
Please generate the next two sentences of the article | 2009 ) .
observational studies of interacting galaxies therefore continue to add value in providing empirical descriptions of how perturbed galaxies behave , in the process yielding better insights into their structures . |
5,848 | Suppose that you have an abstract for a scientific paper: we present new x - ray observations of the high mass x - ray binary ( hmxrb ) pulsar oao 1657 - 415 , obtained during one orbital period ( 10.44 days ) with the rossi x - ray timing explorer ( rxte ) . using the binary orbital parameters , obtained from burst and transient source experiment ( batse ) observations , we resolve the fluctuations in the pulse frequency at time scales on the order of one day for the first time .
recent batse results showed that oao 1657 - 415 has spin - up / down trends in its pulse frequency time series , without any correlation with the x - luminosity at energies @xmath020 kev ( baykal 1997 ) . in the present rxte observations
the source is found to be in an extended phase of spin - down .
we also find a gradual increase in the x - ray luminosity which is correlated with a marginal spin - up episode .
the marginal correlation between the gradual spin - up ( or decrease in spin - down rate ) and increase in x - ray luminosity suggests that the oao 1657 - 415 is observed during a stable accretion episode where the prograde accretion disk is formed . .
And you have already written the first three sentences of the full article: the high mass x - ray binary source hmxrb source oao 1657 - 415 ( oao 1653 - 40 ) was first detected by the copernicus satellite ( polidan et al .
1978 ) in the 4 - 9 kev range .
the heao-1 observations also showed 38.22 sec pulsations in the 1 - 40 kev and 40 - 80 kev bands ( white @xmath1 pravdo 1979 , byrne et al ..
Please generate the next two sentences of the article | observations with ginga and granat ( kamata et al .
1990 , gilfanov et al . |
5,849 | Suppose that you have an abstract for a scientific paper: we investigate the decoherence of a qubit coupled to either a quantum two - level system ( tls ) again coupled to an environment , or a classical fluctuator modeled by random telegraph noise . in order to do this
we construct a model for the quantum tls where we can adjust the temperature of its environment , and the decoherence rate independently .
the model has a well - defined classical limit at any temperature and this corresponds to the appropriate random telegraph process , which is symmetric at high temperatures and becomes asymmetric at low temperatures .
we find that the difference in the qubit decoherence rates predicted by the two models depends on the ratio between the qubit - tls coupling and the decoherence rate in the pointer basis of the tls .
this is then the relevant parameter which determines whether the tls has to be treated quantum mechanically or can be replaced by a classical telegraph process .
we also compare the mutual information between the qubit and the tls in the classical and quantum cases . .
And you have already written the first three sentences of the full article: the interaction between a quantum system and its environments leads to loss of quantum coherence , or decoherence , in the system .
understanding decoherence is crucial for grasping the boundary between quantum and classical physics .
@xcite it is also essential for testing theories describing quantum measurements ..
Please generate the next two sentences of the article | @xcite from an engineering point of view , the decay of coherence in quantum bit devices ( qubits ) is the most important obstacle for constructing a working quantum computer .
solid state qubits are leading candidates in the projects of designing quantum circuits , where the coherence times of the qubits are required to be sufficiently long to allow for manipulations and transfer of information by logical gates . |
5,850 | Suppose that you have an abstract for a scientific paper: quasi - crystals formed by charged mesoscopic dust grains ( dust lattices ) , observed since hardly a decade ago , are an exciting paradigm of a nonlinear chain . in laboratory discharge experiments ,
these quasi - lattices are formed spontaneously in the sheath region near a negative electrode , usually at a levitated horizontal equilibrium configuration where gravity is balanced by an electric field .
it is long known ( and experimentally confirmed ) that dust - lattices support linear oscillations , in the longitudinal ( acoustic mode ) as well as in the transverse , in plane ( acoustic- ) or off - plane ( optic - like mode ) directions . either due to the ( typically yukawa type ) electrostatic inter - grain interaction forces or to the ( intrinsically nonlinear ) sheath environment
, nonlinearity is expected to play an important role in the dynamics of these lattices .
furthermore , the coupling between the different modes may induce coupled nonlinear modes . despite this evidence ,
the elucidation of the nonlinear mechanisms governing dust crystals is in a rather preliminary stage . in this study
, we derive a set of ( coupled ) discrete equations of motion for longitudinal and transverse ( out - of - plane ) motion in a one dimensional model chain of charged dust grains . in a continuum approximation , i.e. assuming a variation scale which is larger than the lattice constant , one obtains a set of coupled modified boussinesq - like equations .
different nonlinear solutions of the coupled system are discussed , based on localized travelling wave anstze and on coupled equations for the envelopes of co - propagating quasi - linear waves . .
And you have already written the first three sentences of the full article: recent studies of various collective processes in dust contaminated plasmas ( dp ) @xcite have been of significant interest in relation with linear and nonlinear waves which are observed in laboratory and space plasmas .
an issue of particular importance is the formation of strongly coupled dp crystals by highly charged dust grains , for instance in the sheath region above a horizontal negatively biased electrode in experiments @xcite .
low - frequency oscillations may occur in these mesoscopic dust grain quasi - lattices , in both longitudinal ( acoustic mode ) @xcite and transverse ( in - plane shear acoustic mode , off - plane optic - like mode ) directions , as theoretically predicted and experimentally observed ( see in ref ..
Please generate the next two sentences of the article | @xcite for a review ) . in this paper
, we focus on the nonlinear description of dust grain displacements in a one - dimensional dust crystal , which is suspended in a levitated horizontal equilibrium position where gravity and electric ( or , possibly magnetic @xcite ) forces balance each other . considering the coupling between the horizontal ( @xmath0 ) and vertical ( off - plane , @xmath1 ) degrees of freedom , and an arbitrary inter - grain interaction potential form @xmath2 ( e.g. debye or else ) and sheath potential @xmath3 ( not necessary parabolic ) |
5,851 | Suppose that you have an abstract for a scientific paper: the use of resistive technologies to mpgd detectors is taking advantage for many new applications , including high rate and energetic particle flux scenarios .
the recent use of these technologies in large area detectors makes necessary to understand and characterize the response of this type of detectors in order to optimize or constrain the parameters used in its production , material resistivity , strip width , or layer thickness .
the values to be chosen will depend on the environmental conditions in which the detector will be placed , and the requirements in time resolution and gain , improving the detector performance for each given application .
we present two different methods to calculate the propagation of charge diffusion through different resistive topologies ; one is based on a fem of solving the telegraph equation in our particular strip detector scheme , the other is based on a semi - analytical approach of charge diffusion and is used to determine the charge evolution in a resistive layer .
micromegas , charge diffusion .
And you have already written the first three sentences of the full article: one of the most prominent problems associated with gas - filled proportional chambers is the sparking induced by heavily ionizing particles producing large deposits .
amplified by the avalanche process they could reach a critical charge density , related to the raether s
limit @xcite , and could evolve into a discharge . as a result.
Please generate the next two sentences of the article | , a large fraction of the stored charge defining the amplification field is lost .
the presence of discharges _ limits the high rate operation _ of the detector due to the required power supply recovery time , _ reduces the mean life _ of the detector and _ risks the damage of the readout electronics _ due to the high currents reached by these spark processes . to avoid any damage of the electronics , most of the detectors are using an additional protecting circuit , which interfaces the readout strips or pads with the front - end electronics . |
5,852 | Suppose that you have an abstract for a scientific paper: it has been recently proved that a slab of negative refractive index material acts as a perfect lens in that it makes accessible the sub - wavelength image information contained in the evanescent modes of a source . here
we elaborate on perfect lens solutions to spherical shells of negative refractive material where magnification of the near - field images becomes possible .
the negative refractive materials then need to be spatially dispersive with @xmath0 and @xmath1 .
we concentrate on lens - like solutions for the extreme near - field limit .
then the conditions for the tm and te polarized modes become independent of @xmath2 and @xmath3 respectively . .
And you have already written the first three sentences of the full article: the possibility of a perfect lens @xcite whose resolution is not limited by the classical diffraction limit has been subject to intense debate by the scientific community during the past two years .
this perfect lens could be realised by using a slab of material with @xmath4 where @xmath3 is the dielectric constant and the @xmath2 is the magnetic permeability .
veselago had observed@xcite that such a material would have a negative refractive index of @xmath5 ( the negative sign of the square root needs to be chosen by requirements of causality ) , and a slab of such a material would act as a lens in that it would refocus incident rays from a point source on one side into a point on the other side of the slab ( see fig ..
Please generate the next two sentences of the article | 1 ) . due to the unavailability of materials with simultaneously negative @xmath3 and @xmath2
, negative refractive index remained an academic curiosity until recently when it became possible to fabricate structured meta - materials that have negative @xmath6 and @xmath2 @xcite . |
5,853 | Suppose that you have an abstract for a scientific paper: ewald summation and physically equivalent methods such as particle - mesh ewald , kubic - harmonic expansions , or lekner sums are commonly used to calculate long - range electrostatic interactions in computer simulations of polar and charged substances .
the calculation of pressures in such systems is investigated .
we find that the virial and thermodynamic pressures differ because of the explicit volume dependence of the effective , resummed ewald potential .
the thermodynamic pressure , obtained from the volume derivative of the helmholtz free energy , can be expressed easily for both ionic and rigid molecular systems . for a system of rigid molecules , the electrostatic energy and the forces at the atom positions
are required , both of which are readily available in molecular dynamics codes .
we then calculate the virial and thermodynamic pressures for the extended simple point charge ( spc / e ) water model at standard conditions .
we find that the thermodynamic pressure exhibits considerably less system size dependence than the virial pressure . from an analysis of the cross correlation between the virial and thermodynamic pressure ,
we conclude that the thermodynamic pressure should be used to drive volume fluctuations in constant - pressure simulations . .
And you have already written the first three sentences of the full article: pressure is one of the fundamental thermodynamic variables . the calculation of pressures in fluid systems using computer simulations is generally considered to be a routine task .
however , difficulties arise in the presence of long - range interactions . here
, we investigate the calculation of pressures in computer simulations of charged and polar systems , where the long - range coulomb interactions are commonly treated with ewald lattice summation@xcite or physically equivalent methods like particle - mesh ewald,@xcite kubic - harmonic expansions,@xcite or lekner sums.@xcite a mechanistic definition of the pressure leads to the standard virial expression ..
Please generate the next two sentences of the article | a thermodynamic definition of the pressure is based on the volume dependence of the helmholtz free energy .
when the coulomb interactions are resummed by using , e.g. , the ewald method , the resulting effective pair interactions depend explicitly on the volume . |
5,854 | Suppose that you have an abstract for a scientific paper: * using the helium abundance measured by galileo in the atmosphere of jupiter and interior models reproducing the observed external gravitational field , we derive new constraints on the composition and structure of the planet . we conclude that , except for helium which must be more abundant in the metallic interior than in the molecular envelope , jupiter could be homogeneous ( no core ) or could have a central dense core up to 12@xmath0 .
the mass fraction of heavy elements is less than 7.5 times the solar value in the metallic envelope and between 1 and 7.2 times solar in the molecular envelope . the total amount of elements other than hydrogen and helium in the planet is between 11 and 45@xmath0 .
* : _ icarus _ number of manuscript pages : 15 + number of tables : 0 + number of figures : 2 + keywords : jupiter , + interiors , planets + chemical abundances running head : composition of the interior of jupiter as shown by wildt ( 1938 ) , jupiter is mainly composed with hydrogen and helium .
however , the question of the abundance and partitioning of the other species ( `` heavy elements '' ) throughout the planet is still unsolved .
answering this question would yield much better constraints on models of formation of the giant planets .
it would also give insight into the behavior of chemical species at high pressures and generally into physical processes in the planet s interior .
a precise determination of the seismic properties of the planet would certainly be the best way to determine accurately its internal composition .
global oscillations of jupiter seem to have been detected ( mosser et al .
1993 ) , but the accuracy of the measurements have yet to be improved and the vibration modes more clearly identified . to date , constraints on the interior structure of the planet can be provided solely by interior models matching the observed gravitational field ( i.e. the radius , mass and gravitational moments @xmath1 , @xmath2 and @xmath3 ) and surface conditions (....
And you have already written the first three sentences of the full article: we thank d. saumon for helpful discussions , and making available unpublished calculations , and d.j .
stevenson for constructive referee comments . this work was supported by the european community through a training and mobility of researchers grant to t.g .
\1989 . abundances of the elements : meteoritic and solar . _ geochim ..
Please generate the next two sentences of the article | cosmochim . acta _ * 53 * , 197 - 214 . 1995 . solar models with helium and heavy elements diffusion .
modern physics _ * 67 * , 781808 . 1992 . |
5,855 | Suppose that you have an abstract for a scientific paper: progress in the effective field theory of two and three nucleon systems is sketched , concentrating on the low energy version in which pions are integrated out as explicit degrees of freedom .
examples given are calculations of deuteron compton scattering , three body forces and the triton , and @xmath0 partial waves . fewfeyn .
And you have already written the first three sentences of the full article: this presentation is a cartoon of the effective field theory ( eft ) of two and three nucleon systems as it emerged in the last three years , using a lot of words and figures , and a few cheats . for details ,
i refer to the bibliographies in @xcite as well as a recent review @xcite , and papers with j .- w .
chen , r.p ..
Please generate the next two sentences of the article | springer and m.j .
savage @xcite , p.f . |
5,856 | Suppose that you have an abstract for a scientific paper: we report the first observation of exclusive @xmath0 production in ultra - peripheral collisions at rhic .
the @xmath0 are produced electromagnetically at large impact parameters where no hadronic interactions occur .
the produced @xmath0 have a small perpendicular momentum , consistent with production that is coherent on both the photon emitting and scattering nuclei .
we observe both exclusive @xmath0 production , and @xmath0 production accompanied by electromagnetic dissociation of both nuclei .
we discuss models of vector meson production and the correlation with nuclear breakup .
we also observe @xmath1 pair production in these ultra - peripheral collisions .
address=70 - 319 lbnl , berkeley , ca , 94720 usa , [email protected] , thanks = this work was commissioned by the aip presented at inpc 2001 , july 30-aug . 3 , 2001 , berkeley , ca . .
And you have already written the first three sentences of the full article: vector mesons can be produced by photonuclear interactions in ultra - peripheral heavy ion collisions ( upc ) .
the electromagnetic interactions occur at impact parameters @xmath2 larger than twice the nuclear radius @xmath3 , where no hadronic interactions can occur@xcite . in these upcs , the electromagnetic field of one nucleus acts as almost - real photon field , following the weizscker - williams approach
. these photons can fluctuate into a quark - antiquark pair , which can scatter elastically from the other nucleus , emerging as a real vector meson ..
Please generate the next two sentences of the article | the photons can also fluctuate into virtual @xmath4 pairs , with one of the pions scattering from the other nucleus and emerging as a real pion pair .
purely electromagnetic interactions also occur . at energy scales above @xmath5 , for most purposes , |
5,857 | Suppose that you have an abstract for a scientific paper: with assumptions that the violation of the distance - duality relation entirely arises from non - conservation of the photon number and the absorption is frequency independent in the observed frequency range , we perform cosmological - model - independent tests for the cosmic opacity .
the observational data include the largest union2.1 type ia supernova sample , which is taken for observed @xmath0 , and galaxy cluster samples compiled by de filippis _ et al . _ and bonamente _ et al .
_ , which are responsible for providing observed @xmath1 .
two parameterizations , @xmath2 and @xmath3 are adopted for the optical depth associated to the cosmic absorption .
we find that , an almost transparent universe is favored by filippis _
et al .
_ sample but it is only marginally accommodated by bonomente _
et al . _
samples at 95.4% confidence level ( c. l. ) ( even at 99.7% c. l. when the @xmath4-cut spherical @xmath5 model is considered ) . taking the possible cosmic absorption ( in 68.3% c. l. range ) constrained from the model - independent tests into consideration , we correct the distance modulus of sne ia and then use them to study their cosmological implications . the constraints on the @xmath6cdm show that a decelerating expanding universe with @xmath7 is only allowed at 99.7% c. l. by observations when the bonamente _
et al . _
sample is considered .
therefore , our analysis suggests that an accelerated cosmic expansion is still needed to account for the dimming of sne and the standard cosmological scenario remains being supported by current observations . .
And you have already written the first three sentences of the full article: the type ia supernovae ( sne ia ) are observed to be fainter than expected from the luminosity - redshift relationship in a decelerating universe .
this unanticipated dimming was first attributed to an accelerating expansion of the universe @xcite .
although the existence of cosmic acceleration has been verified by several other observations , initially , there had been some debates on the interpretation of underlying physical mechanism for the observed sne ia dimming ..
Please generate the next two sentences of the article | for example , dust in the milk way and oscillation of photons propagating in extragalactic magnetic fields into very light axions had been proposed to account for the dimming @xcite .
any kind of photon number violation , such as absorption , scattering or axion - photon mixing , sensibly imprints its influence on the tolman test @xcite , which can be rewritten as a relationship among cosmological distance measurements known as the famous distance - duality ( dd ) relation @xcite , @xmath8 where @xmath9 is the redshift , @xmath0 and @xmath1 are the luminosity distance and the angular diameter distance ( add ) respectively . |
5,858 | Suppose that you have an abstract for a scientific paper: the inverse ac josephson effect involves rf - induced ( shapiro ) steps that cross over the zero - current axis ; the phenomenon is of interest in voltage standard applications .
the standard analysis of the step height in current , which yields the well - known bessel - function dependence on an effective ac drive amplitude , is valid only when the drive frequency is large compared with the junction plasma frequency or the drive amplitude is large compared with the zero - voltage josephson current . using a first - order krylov - bogoliubov power - balance approach we derive an expression for the threshold value of the drive amplitude for zero - crossing steps that is not limited to the large frequency or large amplitude region .
comparison with numerical solutions of the rsj differential equation shows excellent agreement for both fundamental and subharmonic steps .
the power - balance value for the threshold converges to the bessel - function value in the high - frequency limit .
the term ` inverse ac josephson effect ' was coined by levinsen _
et al .
_ @xcite to describe shapiro steps @xcite in the current - voltage characteristic of a small josephson junction that cross over the zero - current axis .
the phenomenon was recognized as being potentially important for voltage - standard applications inasmuch as the elimination of the dc bias current would eliminate one possible pathway for the entry of noise into the system .
it was studied extensively experimentally , analytically , and computationally by a number of authors ( see , _
e.g. _ , kautz @xcite plus references therein ) .
the ` standard ' analysis that emerged from these studies expressed the height in current of phase - locked shapiro steps in terms of bessel functions of an effective drive amplitude ; this analysis was shown to be appropriate when the frequency of the ac drive is large compared with the junction plasma frequency or when the amplitude of the ac drive is large compared with the zero - voltage josephson....
And you have already written the first three sentences of the full article: 1 . comparison of power - balance prediction ( solid curve ) and bessel - function prediction ( dashed curve ) with numerical integration result ( diamonds ) , at fundamental frequency ( @xmath42 ) .
parameters : ( a ) @xmath44 ; ( b ) @xmath45 ..
Please generate the next two sentences of the article | |
5,859 | Suppose that you have an abstract for a scientific paper: we use computer simulations to study the thermodynamic properties of a glass former in which a fraction @xmath0 of the particles has been permanently frozen . by thermodynamic integration , we determine the kauzmann , or ideal glass transition , temperature @xmath1 at which the configurational entropy vanishes .
this is done without resorting to any kind of extrapolation , _
i.e. _ , @xmath1 is indeed an equilibrium property of the system .
we also measure the distribution function of the overlap , _
i.e. _ , the order parameter that signals the glass state . we find that the transition line obtained from the overlap coincides with that obtained from the thermodynamic integration , thus showing that the two approaches give the same transition line .
finally we determine the geometrical properties of the potential energy landscape , notably the @xmath2and @xmath3dependence of the saddle index and use these properties to obtain the dynamic transition temperature @xmath4 .
the two temperatures @xmath1 and @xmath4 cross at a finite value of @xmath0 and indicate the point at which the glass transition line ends .
these findings are qualitatively consistent with the scenario proposed by the random first order transition theory . upon cooling ,
glass - forming liquids show a dramatic increase of their viscosities and relaxation times before they eventually fall out of equilibrium at low temperatures @xcite .
this laboratory glass transition is a purely kinetic effect since it occurs at the temperature at which the relaxation time of the system crosses the time scale imposed by the experiment , _
e.g. _ , via the cooling rate . despite the intensive theoretical , numerical , and experimental studies of the last five decades , the mechanism responsible for the slowing down and thus for the ( kinetic ) glass transition is still under debate and hence a topic of intense research . from a fundamental point of view
the ultimate goal of these studies is to find an answer to the big question in....
And you have already written the first three sentences of the full article: recently a novel idea to bypass this difficulty has been proposed @xcite . by freezing , or pinning , a fraction of the degrees of freedom of the system
, the ideal glass transition temperature has been predicted to rise to a point at which experiments and simulations _ in equilibrium _ are feasible thus allowing to probe the nature of this transition . in ref .
@xcite the authors have studied the effect of pinning for the case of a mean - field spin glass model which is known to exhibit a dynamical mct - transition at a temperature @xmath7 and a thermodynamic transition at a lower temperature @xmath5 ..
Please generate the next two sentences of the article | it was demonstrated that , by pinning a fraction @xmath0 of the degree of freedoms of the spins ( selected at random ) in the equilibrated system , both @xmath1 and @xmath4 increase with @xmath0 .
thus by equilibrating the non - pinned system at an intermediate temperature and subsequently increasing @xmath0 , one can access and probe the ideal glass state in _ thermal equilibrium _ |
5,860 | Suppose that you have an abstract for a scientific paper: let @xmath0 be the operation of re - ordering a sequence by one pass of bubble sort .
we completely answer the question of when the inverse image of a principal pattern class under @xmath0 is a pattern class . .
And you have already written the first three sentences of the full article: bubble sort is an elementary ( and inefficient ) sorting algorithm that proceeds in a number of passes . in each
pass the sequence to be sorted is scanned from left to right . in any pass every item found to be greater than the item immediately to its right is exchanged with this item .
as the algorithm proceeds items move to the right ( bubble up the sequence ) until blocked by some larger item . in general , many passes are required before the sorting is complete . in this paper.
Please generate the next two sentences of the article | we are interested in the permutational effect of a single pass of bubble sort .
we shall see that this effect has some unexpected connections with the theory of permutation patterns . |
5,861 | Suppose that you have an abstract for a scientific paper: we provide a general product formula for the solution of nonautonomous abstract delay equations .
after having shown the convergence we obtain estimates on the order of convergence for differentiable history functions .
finally , the theoretical results are demonstrated by some typical numerical examples . .
And you have already written the first three sentences of the full article: operator splitting is a widely used time discretization method for the numerical solution of complicated equations .
the importance and main applications of these procedures is described , for example , in the monographs by farag and havasi @xcite , holden et al .
@xcite and lubich @xcite ..
Please generate the next two sentences of the article | the present paper investigates a special operator splitting for a class of nonautonomous delay differential equations .
this method , which can be applied to equations with distributed delays very effectively , was first investigated in csoms and nickel @xcite and in btkai , csoms and nickel @xcite in the autonomous case . |
5,862 | Suppose that you have an abstract for a scientific paper: the objective of this work enclosed with the study of spatially homogeneous anisotropic bianchi type - i universe in @xmath0 gravity ( where @xmath1 is the ricci scalar and @xmath2 is the trace of stress energy momentum tensor ) in two different cases viz . @xmath3 and @xmath4 with bulk viscosity matter content . in this study , we consider a time varying deceleration parameter , which generates an accelerating universe to obtain the exact solution of the field equations .
the physical and kinematical properties of both the models are discussed in detail for the future evolution of the universe .
we have explored the nature of wec , dec , sec and energy density for both the cases .
we have found that both the models , with bulk viscosity matter component , show an acceleration of the universe .
we have also shown that the cosmic jerk parameter is compatible with the three kinematical data sets . .
And you have already written the first three sentences of the full article: the revolution in the understanding of the present universe has become possible due to the research in observational cosmology in the past two decade .
recent observational data from plank collaboration @xcite , baryon oscillation spectroscopic survey ( boss ) @xcite and atacama cosmology telescope polarimeter ( actpol ) collaboration @xcite provides relevant experimental evidence about the acceleration of our universe . in the last century
, modern cosmology reached a new vision to establish considerable advancements in the account of the current accelerated expanding universe ..
Please generate the next two sentences of the article | the two crucial observational groups including supernovae cosmology project and the high - redshift supernovae search team have provided the main evidence for the cosmic acceleration of the universe @xcite .
the other cosmic observations like cosmic microwave background ( cmb ) fluctuations @xcite , large - scale structure ( lss ) @xcite , cosmic microwave radiation ( cmbr ) @xcite indicate that the present universe is undergoing an accelerated expansion . |
5,863 | Suppose that you have an abstract for a scientific paper: the luminosity of young giant planets can inform about their formation and accretion history .
the directly imaged planets detected so far are consistent with the hot - start " scenario of high entropy and luminosity .
if nebular gas passes through a shock front before being accreted into a protoplanet , the entropy can be substantially altered . to investigate this , we present high resolution , 3d radiative hydrodynamic simulations of accreting giant planets .
the accreted gas is found to fall with supersonic speed in the gap from the circumstellar disk s upper layers onto the surface of the circumplanetary disk and polar region of the protoplanet .
there it shocks , creating an extended hot supercritical shock surface .
this shock front is optically thick , therefore , it can conceal the planet s intrinsic luminosity beneath .
the gas in the vertical influx has high entropy which when passing through the shock front decreases significantly while the gas becomes part of the disk and protoplanet .
this shows that circumplanetary disks play a key role in regulating a planet s thermodynamic state .
our simulations furthermore indicate that around the shock surface extended regions of atomic sometimes ionized hydrogen develop .
therefore circumplanetary disk shock surfaces could influence significantly the observational appearance of forming gas - giants .
[ firstpage ] accretion , accretion discs hydrodynamics methods : numerical planets and satellites : formation planet - disc interactions .
And you have already written the first three sentences of the full article: giant planets are thought to form either via core - accretion @xcite or gravitational instability scenario @xcite . to get a handle on which formation scenario led to an observed gas giant
, the post - formation entropy of the planet was initially thought to distinguish between the two cases @xcite .
traditionally , planets formed by core accretion were thought to have a low luminosity and entropy ( @xmath09.5 @xmath1/baryon ) corresponding to the so called cold - start " scenario whereas gravitational instability was thought to lead to giant planets having a high luminosity and entropy the hot - start " scenario ( @xmath29.5 @xmath1/baryon , @xcite ) ..
Please generate the next two sentences of the article | recent studies , however , pointed out that the situation is more complex .
the entropy of the planets is affected by whether the accretion of gas onto the planet happens through a supercritical shock front , as indicated by one - dimensional spherically symmetric models @xcite . |
5,864 | Suppose that you have an abstract for a scientific paper: the assembly of banana - shaped rodlike proteins on membranes , and the associated membrane shape transformations , are investigated by analytical theory and coarse - grained simulations .
the membrane - mediated interactions between two banana - shaped inclusions are derived theoretically using a point - like formalism , both for zero surface tension and for finite surface tension . on a larger scale ,
the interactions between assemblies of such rodlike inclusions are determined analytically .
meshless membrane simulations are performed in the presence of a large number of inclusions of two types , corresponding to rods of opposite curvatures , both for flat membranes and vesicles .
rods of the same type aggregate into linear assemblies perpendicular to the rod axis , leading to membrane tubulation .
however , rods of the other type , those of opposite curvature , are attracted to the lateral sides of these assemblies , and stabilize a straight bump structure that prevents tubulation .
when the two types of rods have almost opposite curvatures , the bumps attract one another , forming a stripe structure .
positive surface tension is found to stabilize the stripe formation .
the simulation results agree well with the theoretical predictions . .
And you have already written the first three sentences of the full article: in living cells , membrane shape transformation plays a key role in biological functions such as endo / exocytosis and vesicle transports .
cell organelles have specific shapes depending on their functions .
various types of proteins participate in the regulation of these dynamic and static membrane shapes @xcite ..
Please generate the next two sentences of the article | these proteins mainly control local membrane shapes in two ways : hydrophobic insertions ( wedging ) and scaffolding . in the former mechanism ,
a part of the protein , such as an amphipathic @xmath0-helix , is inserted into the lipid bilayer membrane . in the latter mechanism , |
5,865 | Suppose that you have an abstract for a scientific paper: electronic structure of a novel superconducting noncentrosymmetric compound mg@xmath0ir@xmath1b@xmath2 was calculated using the korringa - kohn - rostoker method .
electronic part of the electron - phonon coupling constant , mcmillan - hopfield parameters , were calculated using the rigid - muffin - tin approximation ( rmta ) .
the magnitude of the electron - phonon coupling constant @xmath3 , analysing atomic contributions , is discussed .
our results show , that superconductivity in mg@xmath0ir@xmath1b@xmath2 is presumably mediated by electron - phonon interaction . .
And you have already written the first three sentences of the full article: the interest in noncentrosymmetric structures , exhibiting superconductivity , has grown up in the past years .
there are only a few examples of this type , which belong to various classes of materials , e.g. an antiferromagnetic heavy fermion system cept@xmath4si @xcite , ferromagnetic uranium compound uir , superconducting under pressure @xcite , or non - magnetic ternary borides li@xmath5pd@xmath4b @xcite and li@xmath5pt@xmath4b @xcite .
the main reason , why these systems are especially attracting , is related to the role of inversion symmetry in electron pairing ..
Please generate the next two sentences of the article | the absence of inversion symmetry may suppress the triplet pairing or mix singlet and triplet symmetry @xcite .
very recently , klimczuk and co - workers @xcite synthesised a new type of intermetallic light - element based compound mg@xmath0ir@xmath1b@xmath2 , exhibiting superconductivity near 5 k. this novel material also belongs to the rare noncentrosymmetric structures , and crystallises in a large and rather complex @xmath6 cell ( space group i-43@xmath7 ) @xcite . |
5,866 | Suppose that you have an abstract for a scientific paper: we showed that if the non - thermal emission from the galactic center in the range @xmath0 kev is due to inverse bremsstrahlung emission of subrelativistic protons , their interactions with hot and cold fractions of the interstellar medium are equally important .
our estimation show that about 30% of the total non - thermal flux from the gc in the range @xmath0 kev is generated in regions of cold gas while the rest is produced by proton interaction with hot plasma . from the spatial distribution of 6.7 kev iron line we concluded the spatial distribution of hot plasma is strongly non - uniform that should be taken into account in analysis of protons propagation in the gc . from the suzaku data we got independent estimates for the diffusion coefficient of subrelativistic protons in the gc , which was in the range
@xmath1 @xmath2s@xmath3 .
And you have already written the first three sentences of the full article: this is a final paper of the series ( @xcite ; dogiel et al .
2009abc ) on energetic processes in the galactic center ( gc ) .
in these papers we presented our interpretation of x - ray and gamma - ray emission from the galactic center ..
Please generate the next two sentences of the article | we supposed that all these phenomena had common origin and were initiated by accretion processes onto the central supermassive black hole .
we showed that the the observed x - ray continuum and line emission from the gc might be produced by a flux of subrelativistic protons which resulted from an unbounded part of stars accreted onto the central black hole . |
5,867 | Suppose that you have an abstract for a scientific paper: a group of four compact hii regions associated with the well - known 50 molecular cloud is the closest site of on - going star formation to the dynamical center of the galaxy , at a projected distance of @xmath06 pc .
we present a study of ionized gas based on the [ neii ] ( 12.8@xmath1 m ) line , as well as multi - frequency radio continuum , hst pa@xmath2 and spitzer irac observations of the most compact member of the hii group , sgr a east hii d. the radio continuum image at 6 cm shows that this source breaks up into two equally bright ionized features , d1 and d2 .
the sed of the d source is consistent with it being due to a 25@xmath3 star with a luminosity of @xmath4 .
the inferred mass , effective temperature of the uv source and the ionization rate are compatible with a young o9-b0 star .
the ionized features d1 and d2 are considered to be ionized by uv radiation collimated by an accretion disk .
we consider that the central massive star photoevaporates its circumstellar disk on a timescale of 3@xmath5 years giving a mass flux @xmath6myr@xmath7 and producing the ionized material in d1 and d2 expanding in an inhomogeneous medium .
the ionized gas kinematics , as traced by the [ ne ii ] emission , is difficult to interpret , but it could be explained by the interaction of a bipolar jet with surrounding gas along with what appears to to be a conical wall of lower velocity gas .
the other hii regions , sgr a east a - c , have morphologies and kinematics that more closely resemble cometary flows seen in other compact hii regions , where gas moves along a paraboloidal surface formed by the interaction of a stellar wind with a molecular cloud .
km s@xmath7 # 1 10^#1 # 1 # 2 ^#2 u#1
i v .
And you have already written the first three sentences of the full article: the galactic center region is known to have a high concentration of massive , warm , dense and turbulent molecular clouds . due to strong tidal forces exerted by the gravitational potential of the nuclear cluster and the massive black hole , sgr a * ,
only dense molecular gas is expected to survive in this region ( see * ? ? ?
this has the ramification that the formation of massive stellar clusters must be pervasive in this region as evidenced by the arches and quintuple clusters as well as the nuclear massive cluster centered on sgr a * ( * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* and the references therein ) . |
5,868 | Suppose that you have an abstract for a scientific paper: the modeling of cascade processes in multi - agent systems in the form of complex networks has in recent years become an important topic of study due to its many applications : the adoption of commercial products , spread of disease , the diffusion of an idea , etc . in this paper , we begin by identifying a desiderata of seven properties that a framework for modeling such processes should satisfy : the ability to represent attributes of both nodes and edges , an explicit representation of time , the ability to represent non - markovian temporal relationships , representation of uncertain information , the ability to represent competing cascades , allowance of non - monotonic diffusion , and computational tractability .
we then present the @xmath0 language , a formalism based on logic programming that satisfies all these desiderata , and focus on algorithms for finding minimal models ( from which the outcome of cascades can be obtained ) as well as how this formalism can be applied in real world scenarios .
we are not aware of any other formalism in the literature that meets all of the above requirements .
[ representation languages ] .
And you have already written the first three sentences of the full article: an epidemic working through a population , cascading electrical power failures , product adoption , and the spread of a mutant gene are all examples of diffusion processes that can happen in multi - agent systems structured as complex networks .
these network processes have been studied in a variety of disciplines , including computer science @xcite , biology @xcite , sociology @xcite , economics @xcite , and physics @xcite .
much existing work in this area is based on pre - existing models in sociology and economics in particular the work of @xcite ..
Please generate the next two sentences of the article | however , recent examinations of social networks both analysis of large data sets and experimental have indicated that there may be additional factors to consider that are not taken into account by these models .
these include the attributes of nodes and edges , competing diffusion processes , and time . in this paper , |
5,869 | Suppose that you have an abstract for a scientific paper: we show that the turbulent particle spectra found in numerical simulations of the behavior of matter fields during reheating admit a simple interpretation in terms of hydrodynamic models of the reheating period .
we predict a particle number spectrum @xmath0 with @xmath1 for @xmath2 principal pacs no 98.80.cq ; additional pacs nos : 04.62.+v , 11.10.wx , 47.27 .
And you have already written the first three sentences of the full article: the reheating period in the early universe stands out as a challenge to theorists due to the close interrelationship of nonlinear and gravitational phenomena in its unfolding ( see @xcite , henceforth
papers 1 - 5 ) .
the observation that , due to the high occupation numbers produced during preheating , most of the physics of reheating may be understood in terms of the behavior of nonlinear classical waves@xcite has been the key to sustantial progress ..
Please generate the next two sentences of the article | the authors of papers 1 - 5 have undertaken systematic numerical simulations of the behavior of matter fields during reheating , finding that the reheating period is actually composed of three consecutive phases : an early one or preheating , where the dominant effect is the parametric amplification of matter fields out of the dynamical inflaton and gravitational backgrounds @xcite , an intermediate stage where the dominant phenomenon is the redistribution of energy among matter field modes through rescattering ( in the terminology of papers 1 - 5 ) , and a final stage where thermal equilibrium sets in . during the intermediate stage ,
spectra of occupation numbers for the matter fields reduce to simple power laws both in the infrared and ultraviolet limits . |
5,870 | Suppose that you have an abstract for a scientific paper: we present results for the corrections of order @xmath0 to the lamb shift .
we compute all the contributing feynman diagrams in dimensional regularization and a general covariant gauge using a mixture of analytical and numerical methods .
we confirm results obtained by other groups and improve their precision .
values of the 32 `` master integrals '' for this and similar problems are provided . .
And you have already written the first three sentences of the full article: recent developments in spectroscopy have led to very precise experimental values for the @xmath1 lamb shift and the rydberg constant @xcite , so that now the lamb shift provides the best test of quantum electrodynamics for an atom .
these achievements have spurred great theoretical efforts aimed at matching the current experimental accuracy ( for a review of the present status and recent developments in the theory of light hydrogenic atoms , see @xcite ) .
the theoretical prediction is expressed in terms of three small parameters : @xmath2 describing effects due to the binding of an electron to a nucleus of atomic number @xmath3 ; @xmath4 ( frequently accompanied by @xmath5 ) from electron selfinteractions ; and the ratio of electron to nucleus masses ..
Please generate the next two sentences of the article | the lamb shift is of the order @xmath6 ; all corrections through the second order in the small parameters are known , as well as some of the third order @xcite .
another source of corrections is the spatial distribution of the nuclear charge . even for hydrogen , the experimental uncertainty in the measurement of the proton root mean |
5,871 | Suppose that you have an abstract for a scientific paper: one may consider cross - correlation routines applied to stellar spectra as a way to determine not only the radial velocities but also to assess the properties of stellar atmospheres .
we show that this is not the case . high value of the cross - correlation coefficient between the observed and a template spectrum does not mean that the template corresponds to correct values of stellar temperature , gravity or metallicity .
cross - correlation operates in normalized space , so it is not sensitive to scaling or shifting of stellar flux .
it is argued that cross - correlation is useful to efficiently determine the velocity shift between the observed and the template spectrum . but minimal distance methods need to be used to determine which template gives the best match to the observed spectrum , and so derive values of physical parameters . to illustrate the point we use data from the rave project which are being obtained at very similar spectral resolution and wavelength domain as will be the case for gaia s rvs .
[ 2004/06/22 1.2 ( kof ) ; 2001/04/25 1.1 ( pwd ) ] .
And you have already written the first three sentences of the full article: in the attempt to extract values of physical parameters from stellar spectra one first tries to determine the value of radial velocity .
if the spectra have a wide wavelength coverage , like in the case of elodie spectra , it can be assumed that a fixed spectral mask gives radial velocities with sufficient accuracy ( katz et al .
analysis of gaia radial velocity spectrometer ( rvs ) data will profit from quite accurate knowledge of stellar parameters obtained from on - board photometric observations ..
Please generate the next two sentences of the article | so all simulations of gaia radial velocity determination assumed that the choice of a proper template is given by complimentary photometric data ( katz et al .
2004 , munari et al . |
5,872 | Suppose that you have an abstract for a scientific paper: igrj18483 - 0311 was discovered with in 2003 and later classified as a supergiant fast x - ray transient .
it was observed in outburst many times , but its quiescent state is still poorly known . here
we present the results of , , and observations of 18483 .
these data improved the x - ray position of the source , and provided new information on the timing and spectral properties of 18483 in quiescence .
we report the detection of pulsations in the quiescent x - ray emission of this source , and give for the first time a measurement of the spin - period derivative of this source . in 18483 the measured spin - period derivative of -([email protected])@xmath110@xmath2 s s@xmath3 likely results from light travel time effects in the binary .
we compare the most recent observational results of 18483 and 18 , the two supergiant fast x - ray transients for which a similar orbital period has been measured .
x - rays : binaries - stars : individual ( 18483 , 18 ) -stars : neutron - x - rays : stars .
And you have already written the first three sentences of the full article: 18483 was discovered in 2003 during deep observations of the galactic center @xcite .
the mean source x - ray flux was @xmath410 mcrab in the 15 - 40 kev , and @xmath45 mcrab in the 40 - 100 kev band @xcite .
the 18.5 days orbital period of the system was discovered by @xcite using _ rxte _ archival data , and was later confirmed with @xcite ..
Please generate the next two sentences of the article | data also showed that 18483 usually undergoes relatively long outbursts ( @xmath43 days ) that comprise several fast flares with typical timescales of a few hours . during these bright events , the broad band
( 3 - 50 kev ) spectrum is best fit by an absorbed cutoff power law model ( photon index @xmath5=1.4 , cut - off energy @xmath6=22 kev , and absorption column density @xmath7=9@xmath110@xmath8 @xmath9 ) . @xcite |
5,873 | Suppose that you have an abstract for a scientific paper: multiple quantum ( mq ) nmr methods @xcite are applied to the analysis of various problems of quantum information processing .
it is shown that the two - spin / two - quantum hamiltonian @xcite describing mq nmr dynamics is related to the flip - flop hamiltonian of a one - dimensional spin system in the approximation of the nearest neighbor interactions . as a result , it is possible to organize quantum state transfer along a linear chain .
mq nmr experiments are performed on quasi - one - dimensional chains of nuclei in calcium fluorapatite .
relaxation of the mq nmr coherences is considered as the simplest model of decoherence processes .
a theory of the dipolar relaxation of the mq nmr coherences in one - dimensional systems is developed .
a good agreement of the theoretical predictions and the experimental data is obtained . .
And you have already written the first three sentences of the full article: the development of experimental and theoretical methods of quantum information processing ( qip ) is an important direction of quantum informatics .
nmr methods are the simplest ones among different experimental approaches @xcite .
it is well known that the liquid state nmr methods @xcite are widely used for experimental realizations of quantum gates and algorithms on the basis of the pseudo - pure states @xcite.
Please generate the next two sentences of the article | . however , the possibilities of qip based on the liquid state nmr are limited because the number of correlated qubits is very small ( about 10 ) @xcite and quantum correlations in such systems are not strong .
in particular , entanglement is almost absent @xcite . at the same time , the potential of the solid state nmr methods @xcite is not exhausted yet . |
5,874 | Suppose that you have an abstract for a scientific paper: we discuss whether modern machine learning methods can be used to characterize the physical nature of the large number of objects sampled by the modern multi - band digital surveys .
in particular , we applied the mlpqna ( multi layer perceptron with quasi newton algorithm ) method to the optical data of the sloan digital sky survey - data release 10 , investigating whether photometric data alone suffice to disentangle different classes of objects as they are defined in the sdss spectroscopic classification .
we discuss three groups of classification problems : _
( i ) _ the simultaneous classification of galaxies , quasars and stars ; _ ( ii ) _ the separation of stars from quasars ; _ ( iii ) _ the separation of galaxies with normal spectral energy distribution from those with peculiar spectra , such as starburst or starforming galaxies and agn . while confirming the difficulty of disentangling agn from normal galaxies on a photometric basis only , mlpqna proved to be quite effective in the three - class separation . in disentangling quasars from stars and galaxies , our method achieved an overall efficiency of @xmath0 and a qso class purity of @xmath1 .
the resulting catalogue of candidate quasars / agns consists of @xmath2 million objects , of which about half a million are also flagged as robust candidates , and will be made available on cds vizier facility .
[ firstpage ] methods : data analysis - techniques : photometric - catalogues - galaxies : active - quasars : general .
And you have already written the first three sentences of the full article: broad band photometry from wide - field imagers mounted on dedicated telescopes and instruments has been and will continue to be our main source of information for a large fraction of the extragalactic universe .
spectroscopy provides a more detailed and deeper understanding of the physical properties of individual objects than photometry .
however , spectroscopy will never be able to fully sample the populations of galactic or extragalactic objects in either number or depth ..
Please generate the next two sentences of the article | it is therefore of great interest to determine whether it is possible to extract estimates of physical parameters , such as distance , metallicity , star formation rate , morphology and the presence or absence of an active nucleus , from the coarse information provided by photometry . for a given object , photometric quantities , such as magnitudes in different bands , momenta of the light distribution and morphological indexes , define its position in a high dimensional parameter space which we shall call the observed parameter space ( or ops , cf .
@xcite ) . the de - projection of the ops into the physical parameter space ( pps , i.e. the parameter space defined by the physical quantities ) , is however a complex operation , made in some cases almost impossible by the degeneracy existing in both the data and the physical parameters themselves . |
5,875 | Suppose that you have an abstract for a scientific paper: we study the finite temperature crossovers in the vicinity of a zero temperature quantum phase transition .
the universal crossover functions are observables of a continuum quantum field theory .
particular attention is focussed on the high temperature limit of the continuum field theory , the so - called `` quantum - critical '' region .
basic features of crossovers are illustrated by a simple solvable model of dilute spinless fermions , and a partially solvable model of dilute bosons .
the low frequency relaxational behavior of the quantum - critical region is displayed in the solution of the transverse - field ising model .
the insights from these simple models lead to a fairly complete understanding of the system of primary interest : the two - dimensional quantum rotor model , whose phase transition is expected to be in the same universality class as those in antiferromagnetic heisenberg spin models .
recent work on the experimental implications of these results for the cuprate compounds is briefly reviewed .
proceedings of the + 19th iupap international conference on statistical physics + xiamen , china , july 31 - august 4 1995 + world scientific , to be published , edited by b .-
l .
hao . .
And you have already written the first three sentences of the full article: consider a quantum system on an infinite lattice described by the hamiltonian @xmath0 , with @xmath1 a dimensionless coupling constant .
for any reasonable @xmath1 , all observable properties of the _ ground state _ of @xmath2 will vary smoothly as @xmath1 is varied
. however , there may be special points , like @xmath3 , where there is a non - analyticity in some property of the ground state : we identify @xmath4 as the position of a quantum phase transition . in finite lattices ,.
Please generate the next two sentences of the article | non - analyticities can only occur at level crossings ; the possibilities in infinite systems are richer as avoided level crossings can become sharp in the thermodynamic limit . in this paper , i will restrict my discussion to second order quantum transitions , or transitions in which the correlation length and correlation time diverge as @xmath1 approaches @xmath4 .
as i will review below , any such quantum transition can be used to define a continuum quantum field theory ( cqft ) : the cqft has no intrinsic short - distance ( or ultraviolet ) cutoff . |
5,876 | Suppose that you have an abstract for a scientific paper: in today s world , we follow news which is distributed globally .
significant events are reported by different sources and in different languages . in this work ,
we address the problem of tracking of events in a large multilingual stream . within a recently developed system event registry @xcite
we examine two aspects of this problem : how to compare articles in different languages and how to link collections of articles in different languages which refer to the same event . taking a multilingual stream and clusters of articles from each language
, we compare different cross - lingual document similarity measures based on wikipedia .
this allows us to compute the similarity of any two articles regardless of language .
building on previous work , we show there are methods which scale well and can compute a meaningful similarity between articles from languages with little or no direct overlap in the training data . using this capability
, we then propose an approach to link clusters of articles across languages which represent the same event .
we provide an extensive evaluation of the system as a whole , as well as an evaluation of the quality and robustness of the similarity measure and the linking algorithm . .
And you have already written the first three sentences of the full article: content on the internet is becoming increasingly multilingual .
a prime example is wikipedia . in 2001 , the majority of pages were written in english , while in 2015 , the percentage of english articles has dropped to 14% . at the same time , online news has begun to dominate reporting of current events .
however , machine translation remains relatively rudimentary ..
Please generate the next two sentences of the article | it allows people to understand simple phrases on web pages , but remains inadequate for more advanced understanding of text . in this paper
we consider the intersection of these developments : how to track events which are reported about in multiple languages . |
5,877 | Suppose that you have an abstract for a scientific paper: we define a two - variable polynomial invariant of finite quandles . in many cases
this invariant completely determines the algebraic structure of the quandle up to isomorphism .
we use this polynomial to define a family of link invariants which generalize the quandle counting invariant .
keywords : finite quandles , link invariants 2000 msc : 57m27 , 176d99 .
And you have already written the first three sentences of the full article: a _ quandle _ is an algebraic structure whose axioms are transcriptions of the three reidemeister moves , making quandles a natural source of invariants of knots and links . in @xcite , joyce associated a finitely generated quandle to each tame knot or link @xmath0 and proved that this knot quandle determines the knot type up to orientation - reversing homeomorphism of pairs @xmath1 .
since then , much work has been done in the study of knot invariants defined in terms of the knot quandle , such as @xcite , @xcite , etc .
in particular , for any finite quandle @xmath2 there are invariants of knots and links defined in terms of the set @xmath3 of quandle homomorphisms from the knot quandle @xmath4 into a finite target quandle @xmath2 ..
Please generate the next two sentences of the article | since isomorphic target quandles @xmath2 and @xmath5 define the same invariants , we would like to have a convenient way of distinguishing finite quandles .
moreover , understanding the structure of these finite quandles can lead to a better understanding of their link invariants . in this paper |
5,878 | Suppose that you have an abstract for a scientific paper: in this paper , we are concerned with jacobi polynomials @xmath0 on the bernstein ellipse with motivation mainly coming from recent studies of convergence rate of spectral interpolation .
an explicit representation of @xmath0 is derived in the variable of parametrization .
this formula further allows us to show that the maximum value of @xmath1 over the bernstein ellipse is attained at one of the endpoints of the major axis if @xmath2 . for the minimum value ,
we are able to show that for a large class of gegenbauer polynomials ( i.e. , @xmath3 ) , it is attained at two endpoints of the minor axis .
these results particularly extend those previously known only for some special cases .
moreover , we obtain a more refined asymptotic estimate for jacobi polynomials on the bernstein ellipse .
* keywords : * spectral method , jacobi polynomials , bernstein ellipse , extrema , asymptotic estimate * ams classifications : * 65n35 , 65d05 , 41a05 , 41a25 . .
And you have already written the first three sentences of the full article: spectral collocation method is a classical and powerful tool to solve integral and differential equations .
suppose that the equation is defined on a finite interval @xmath4 $ ] , the basic idea of this approach is to approximate the solution of the equation by its polynomial interpolant of the form @xmath5 where @xmath6 is a set of distinct nodes and @xmath7 are the lagrange fundamental polynomials .
the values @xmath8 are determined by requiring that the interpolant @xmath9 satisfies the equation exactly at the nodes @xmath10 . to ensure rapid convergence of the spectral collocation method , the interpolation nodes @xmath11 with the distribution of density @xmath12 are preferable , and the ideal candidates are the zeros or extrema of classical orthogonal polynomials such as gegenbauer polynomials , or more generally , the jacobi polynomials ; cf ..
Please generate the next two sentences of the article | @xcite . the interpolation procedure described above
is also known as spectral interpolation . |
5,879 | Suppose that you have an abstract for a scientific paper: the inversion of gravitational lens systems is hindered by the fact that multiple mass distributions are often equally compatible with the observed properties of the images . besides using clear examples to illustrate the effect of the so - called monopole and mass sheet degeneracies
, this article introduces the most general form of said mass sheet degeneracy .
while the well known version of this degeneracy rescales a single source plane , this generalization allows any number of sources to be rescaled .
furthermore , it shows how it is possible to rescale each of those sources with a different scale factor . apart from illustrating that the mass sheet degeneracy is not broken by the presence of multiple sources at different redshifts
, it will become apparent that the newly constructed mass distribution necessarily alters the existing mass density precisely at the locations of the images in the lens system , and that this change in mass density is linked to the factors with which the sources were rescaled . combined with the fact that the monopole degeneracy introduces a large amount of uncertainty about the density in between the images ,
this means that both degeneracies are in fact closely related to substructure in the mass distribution .
an example simulated lensing situation based on an elliptical version of a navarro - frenk - white profile explicitly shows that such degeneracies are not easily broken by observational constraints , even when multiple sources are present .
instead , the fact that each lens inversion method makes certain assumptions , implicit or explicit , about the smoothness of the mass distribution means that in practice the degeneracies are broken in an artificial manner rather than by observed properties of the lens system .
[ firstpage ] gravitational lensing dark matter .
And you have already written the first three sentences of the full article: not only can strong gravitational lensing yield impressive images , from multiply imaged quasars over deformed galaxies to partial or full einstein rings , it is also an invaluable tool to estimate the mass of the deflector .
moreover , since the precise positions and deformations of the images of a source depend on the exact distribution of the mass , gravitational lensing even holds the promise of constraining the shape of said mass distribution . in principle
, this strong lens inversion sounds fairly straightforward : use a particular model and optimize its parameters so that it reproduces the observations as well as possible . in practice however , one is hindered by gravitational lensing degeneracies which allow a wide range of mass distributions to produce the exact same image configuration ..
Please generate the next two sentences of the article | on the level of parametric lens inversion results , this can manifest itself as parameter degeneracies ( e.g. @xcite ) , but at their core the degeneracies are or course present at the level of the mass distribution . there , the mass sheet degeneracy ( e.g. @xcite or @xcite ) will rescale the projected mass distribution while adding a constant density mass sheet ( or disc ) , only affecting the time delays between the images .
recently it was shown that a similar procedure is still possible when multiple sources at different redshifts are observed @xcite . |
5,880 | Suppose that you have an abstract for a scientific paper: during the past decade @xmath0 car has brightened markedly , possibly indicating a change of state . here
we summarize photometry gathered by the hubble space telescope as part of the hst treasury project on this object .
our data include stis / ccd acquisition images , acs / hrc images in four filters , and synthetic photometry in flux - calibrated stis spectra .
the hst s spatial resolution allows us to examine the central star separate from the bright circumstellar ejecta . _
its apparent brightness continued to increase briskly during 200206 , especially after the mid-2003 spectroscopic event . _
if this trend continues , the central star will soon become brighter than its ejecta , quite different from the state that existed only a few years ago .
one precedent may be the rapid change observed in 19381953 .
we conjecture that the star s mass - loss rate has been decreasing throughout the past century . .
And you have already written the first three sentences of the full article: eta carinae s photometric record is unparalleled among well - studied objects , especially since it has been near or exceeded the classical eddington limit during the past two or three centuries . from 1700 to 1800
it gradually brightened from 4th to 2nd magnitude , and then experienced its famous great eruption or `` supernova impostor event '' beginning about 1837 . for twenty years it was one of the brightest stars in the sky , rapidly fluctuating between magnitudes 1.5 and 0.0 , briefly attaining @xmath1 .
after 1858 it faded below 7th magnitude , presumably enshrouded in the nascent homunculus nebula ..
Please generate the next two sentences of the article | subsequent behavior , however , has been more complex than one might have expected .
a mysterious secondary eruption occurred in 18871900 ; then the apparent brightness leveled off around @xmath2 for about 40 years , followed by a rapid increase in 193853 ; after that it brightened at a fairly constant rate for another 40-year interval , and most recently the rate accelerated in the 1990 s . |
5,881 | Suppose that you have an abstract for a scientific paper: we investigate the convergence properties of an algorithm which has been recently proposed to measure the competitiveness of countries and the quality of their exported products .
these quantities are called respectively fitness @xmath0 and complexity @xmath1 .
the algorithm was originally based on the adjacency matrix @xmath2 of the bipartite network connecting countries with the products they export , but can be applied to any bipartite network .
the structure of the adjacency matrix turns to be essential to determine which countries and products converge to non zero values of @xmath0 and @xmath1 .
also the speed of convergence to zero depends on the matrix structure .
a major role is played by the shape of the ordered matrix and , in particular , only those matrices whose diagonal does not cross the empty part are guaranteed to have non zero values as outputs when the algorithm reaches the fixed point .
we prove this result analytically for simplified structures of the matrix , and numerically for real cases .
finally , we propose some practical indications to take into account our results when the algorithm is applied . .
And you have already written the first three sentences of the full article: among the many theories which try to explain the features of the economic development of countries ( see for example @xcite ) , a recent , data driven and innovative approach is the one known as _ economic complexity_.
this approach is based on the country - product matrix @xmath2 , whose binary elements indicates if the given country exports a certain products or not ( in particular , if the country shows a revealed comparative advantage @xcite in that market ) . in contrast with the ricardian specialization paradigm @xcite , the @xmath2 matrix is , when suitably ordered , not block diagonal but triangular : this means that ubiquitous products are produced by all countries , while rare products are produced only by diversified countries . in a first attempt to use this information to evaluate the goodness of countries and products , hidalgo and
hausmann @xcite proposed an algorithm on the matrix @xmath2 ..
Please generate the next two sentences of the article | tacchella and al .
@xcite deeply revisited the algorithm and proposed a new metrics to estimate the country s potential of growth , called the _ fitness f _ , in terms of the quality , or _ |
5,882 | Suppose that you have an abstract for a scientific paper: we determine the structural relaxations around paramagnetic impurities ( ti , cr , fe ) in corundum ( @xmath0-al@xmath1o@xmath2 ) , by combining x - ray absorption near edge structure ( xanes ) experiments and _ ab initio _ calculations .
the structural relaxations are found to be very local .
we then show that xanes is sensitive to small variations in interatomic distances within the coordination shell of the absorbing atom .
the experiments were carried out on single crystals of ruby and sapphires .
linear dichroic signals are essential to characterize the geometry of the impurity site .
the calculations were performed within a self - consistent `` non muffin - tin '' framework , that uses pseudopotentials , plane - wave basis set , and the continued fraction for the absorption cross section . .
And you have already written the first three sentences of the full article: the presence of impurities in a crystal can influence its mechanical , magnetic , semiconducting , superconducting , dielectric , spectroscopic and transport properties . to cite just a few specific examples
, impurities can improve the voltage holdoff capability of insulating materials@xcite , they are critical for the optical properties of most laser materials and gemstones , and they turned out to be the secret of ancient damascus steel blades.@xcite still , the physics of impurity systems is not well developed .
the local crystallographic structure around impurities is unknown in most cases , although it is an essential piece of information to undestand their influence on the physical properties of the host and to carry out _ ab initio _ simulations of these materials ..
Please generate the next two sentences of the article | this situation is due to the experimental and theoretical difficulties that are met to obtain microscopic information on impurity systems . from the theoretical point of view , quantum calculations of impurity systems require the use of large supercells that have long not been computationally manageable . from the experimental point of view , impurity systems can only be measured with methods which can selectively probe certain atomic species . among such methods ,
many of them , such as electronic paramagnetic resonance , give only indirect information on the position and nature of the atoms surrounding the impurity . |
5,883 | Suppose that you have an abstract for a scientific paper: we derive the spectrum of the dirac operator for the linear @xmath0model with quarks in the large @xmath1 approximation using renormalization group flow equations . for small eigenvalues ,
the banks casher relation and the vanishing linear term are recovered .
we calculate the coefficient of the next to leading term and investigate the spectrum beyond the low energy regime . /#10=
0=0 1= 1=1 0>1 # 1 / .
And you have already written the first three sentences of the full article: the qcd dirac operator contains all information about the quark dynamics in qcd
. therefore its spectrum is of high interest . in the literature
one considers the euclidean dirac operator which reads @xmath2 ..
Please generate the next two sentences of the article | we will use euclidean space time throughout this work .
since the dirac operator is antihermitean , its eigenvalues are purely imaginary . with the eigenvalue equation @xmath3 one defines the spectral density @xmath4 where the averaging is over the gluon background . |
5,884 | Suppose that you have an abstract for a scientific paper: we study a new baryogenesis scenario in a class of braneworld models with low fundamental scale , which typically have difficulty with baryogenesis .
the scenario is characterized by its minimal nature : the field content is that of the standard model and all interactions consistent with the gauge symmetry are admitted .
baryon number is violated via a dimension-6 proton decay operator , suppressed today by the mechanism of quark - lepton separation in extra dimensions ; we assume that this operator was unsuppressed in the early universe due to a time - dependent quark - lepton separation .
the source of @xmath0 violation is the ckm matrix , in combination with the dimension-6 operators .
we find that almost independently of cosmology , sufficient baryogenesis is nearly impossible in such a scenario if the fundamental scale is above 100 tev , as required by an unsuppressed neutron - antineutron oscillation operator .
the only exception producing sufficient baryon asymmetry is a scenario involving out - of - equilibrium @xmath1 quarks interacting with equilibrium @xmath2 quarks . .
And you have already written the first three sentences of the full article: the experimental lower limit on the lifetime of the proton is a severe problem for models in which the fundamental scale of quantum gravity is low compared to the supersymmetric gut scale @xmath3gev @xcite .
a baryon number u@xmath4 symmetry can not be gauged in field theory ; like other accidental symmetries it is expected to be violated by effects at the string scale or by quantum wormholes and virtual black holes @xcite . such @xmath5 violation would appear at low energies as nonrenormalizable operators , for example of the form @xmath6 where @xmath7 is the fundamental scale and @xmath8 is expected to be @xmath9 in the absence of suppression mechanisms . then for @xmath7 in the @xmath10tev range , for which collider signals of the fundamental degrees of freedom or of large extra dimensions may be observable , @xmath11 comes out to be under a second , to be compared with the ( mode - dependent ) experimental bounds of order @xmath12 _ years _ @xcite .
various solutions have been proposed @xcite all of which have implications for the production of an excess of baryons over antibaryons in the early universe , for which @xmath5 violation is a precondition ..
Please generate the next two sentences of the article | the production of gravitational kaluza - klein modes in the early universe in such models , in which some compactified extra dimensions are orders of magnitude larger than the fundamental length , gives a severe upper bound on the maximum temperature attained consistent with cosmological observations .
even for the maximum number ( usually considered as 6 ) of large extra dimensions and the relatively large value @xmath13tev , a maximum temperature of a few gev is the upper bound if overclosure of the universe , disruption of the successful predictions of nucleosynthesis , and an observationally unacceptable level of background gamma - rays from k - k mode decay are to be avoided @xcite . the energy density in k - k modes would also affect the evolution of density fluctuations by altering the time of matter - radiation equality @xcite . |
5,885 | Suppose that you have an abstract for a scientific paper: the iron chalcogenides fese and fes are superconductors composed of two - dimensional sheets held together by van der waals interactions , which makes them prime candidates for the intercalation of various guest species .
we review the intercalation chemistry of fese and fes superconductors and discuss their synthesis , structure , and physical properties .
before we review the latest work in this area , we provide a brief background on the intercalation chemistry of other inorganic materials that exhibit enhanced superconducting properties upon intercalation , which include the transition metal dichalcogenides , fullerenes , and layered cobalt oxides . from past studies of these intercalated superconductors ,
we discuss the role of the intercalates in terms of charge doping , structural distortions , and fermi surface reconstruction .
we also briefly review the physical and chemical properties of the host materials mackinawite - type fes and @xmath0-fese .
the three types of intercalates for the iron chalcogenides can be placed in three categories : 1 . )
alkali and alkaline earth cations intercalated through the liquid ammonia technique ; 2 . )
cations intercalated with organic amines such as ethylenediamine ; and 3 . )
layered hydroxides intercalated during hydrothermal conditions .
a recurring theme in these studies is the role of the intercalated guest in electron doping the chalcogenide host and in enhancing the two - dimensionality of the electronic structure by spacing the fese layers apart .
we end this review discussing possible new avenues in the intercalation chemistry of transition metal monochalcogenides , and the promise of these materials as a unique set of new inorganic two - dimensional systems .
iron chalcogenides , superconductors , magnetic structure .
And you have already written the first three sentences of the full article: we review the recent work on the intercalation chemistry of iron chalcogenide superconductors . given that they exhibit zero resistance for electrical currents below a critical temperature ( @xmath1 ) ,
superconductors hold great promise in our future energy needs.@xcite furthermore , superconductors have been proposed for devices that stabilize the electrical power grid by storing energy mechanically in flywheels or electromagnetically in toroidal magnets.@xcite much as previously known superconducting materials , the iron - based compounds have a role to play in our future energy needs.@xcite the iron chalcogenide superconductors remain topical due to their versatile solid state chemistry that allows new materials to be discovered and their ability to be isolated as single layers .
furthermore , the highest @xmath1 so far observed in any iron - based system has been in single layered fese where reports vary from 65 k to 100 k.@xcite just like the high-@xmath1 cuprates , the iron - based systems appear to be unconventional in their superconducting mechanism@xcite and this raises more hope that solid state chemists will continue to make significant discoveries in this field ..
Please generate the next two sentences of the article | although similar in many respects to the iron - based pnictides , the chalcogenides do show considerable differences in their physical and chemical properties . while the arsenide phases are held together by ionic forces between the cationic layers , @xmath2 ( lao)@xmath3 and ba@xmath4 , and the anionic ( feas)@xmath5 layers , the chalcogenides can be held by van der waals interactions alone .
these comparatively weaker interactions make the fe@xmath6 layers , where @xmath7s@xmath8 and se@xmath8 , ideal hosts for intercalation chemistry such as alkali metal insertion along with various other types of guest species such as ammonia . |
5,886 | Suppose that you have an abstract for a scientific paper: charge and heat transport through a single molecule tunnel - coupled to external normal electrodes have been studied .
the molecule with sufficiently strong interaction between electrons and vibrational internal degrees of freedom can be characterized by the negative effective charging energy u@xmath0 . such a molecule has been considered and modeled by the anderson hamiltonian .
the electrical conductance , thermopower and thermal conductance of the system have been calculated as a function of gate voltage in the weak coupling limit within the rate equation approach . in the linear regime
the analytic formulae for the transport coefficients in the pair dominated tunneling are presented .
the effects found in the nonlinear transport include _ inter alia _ the rectification of the heat current .
the sense of forward ( reverse ) direction , however , depends on the tuning parameter and can be controlled by the gate voltage .
we also discuss the quantitation of the thermal conductance and the departures from the wiedemann - franz law . .
And you have already written the first three sentences of the full article: the appearance of the effective attractive interactions between electrons in metals @xcite is responsible for the instability of the fermi surface and the resulting phenomenon of superconductivity ; one of the most spectacular quantum effects on a macroscopic scale .
the strong local electron
phonon interaction may induce formation of polaron or bipolaron quasiparticles which are at the heart of bipolaronic theory of superconductivity @xcite ..
Please generate the next two sentences of the article | the so - called negative u centers @xcite are not only a source of superconducting instability but also play an important role in physics and chemistry of materials @xcite ( see , however @xcite ) . the tendency towards bipolaron formation
is enhanced @xcite in the confined structures like quantum dots@xcite . |
5,887 | Suppose that you have an abstract for a scientific paper: we study the scattering in a quantum star graph with a flp
tsutsui coupling in its vertex and with external potentials on the lines .
we find certain special couplings for which the probability of the transmission between two given lines of the graph is strongly influenced by the potential applied on another line . on the basis of this phenomenon
we design a tunable quantum band - pass spectral filter .
the transmission from the input to the output line is governed by a potential added on the controlling line .
the strength of the potential directly determines the passband position , which allows to control the filter in a macroscopic manner .
generalization of this concept to quantum devices with multiple controlling lines proves possible .
it enables the construction of spectral filters with more controllable parameters or with more operation modes .
in particular , we design a band - pass filter with independently adjustable multiple passbands .
we also address the problem of the physical realization of flp tsutsui couplings and demonstrate that the couplings needed for the construction of the proposed quantum devices can be approximated by simple graphs carrying only @xmath0 potentials .
quantum graphs , threshold resonance , singular vertex coupling , quantum control 03.65.-w , 03.65.nk , 73.63.nm .
And you have already written the first three sentences of the full article: quantum mechanics on graphs is recently attracting more and more attention due to its current and prospective use in nanosciences , especially nanoelectronics @xcite .
in particular , since quantum graphs serve as effective models of graph - like structures of submicron sizes , they allow to study single electron devices based on interconnected nanoscale wires .
one of the first such applications emerged in the spectral filtering ..
Please generate the next two sentences of the article | it is known that a line carrying the @xmath0-interaction is usable as a high - pass filter , and similarly , a line carrying the @xmath1-interaction works as a low - pass filter .
more complex spectral filters have been developed as well , for instance a trident filter @xcite , or a y - shaped branching filter , functionning as a high - pass / low - pass junction @xcite . if a quantum device is easily controllable , its usefulness is markedly enhanced . in principle , |
5,888 | Suppose that you have an abstract for a scientific paper: i present a simple two - party quantum communication complexity protocol with higher success rate than the best possible classical protocol for the same task .
the quantum protocol is shown to be equivalent to a quantum non - locality test , except that it is not necessary to close the locality loophole .
i derive bounds for the detector efficiency and background count rates necessary for an experimental implementation and show that they are close to what can be currently achieved using ion trap technology .
i also analyze the requirements for a three - party protocol and show that they are less demanding than those for the two - party protocol .
the results can be interpreted as sufficient experimental conditions for quantum non - locality tests using two or three entangled qubits . .
And you have already written the first three sentences of the full article: in the last few years there has been a growing interest in quantum information theory , in particular in uses of entanglement like teleportation @xcite , quantum cryptographic key distribution @xcite and dense coding @xcite .
in addition to extensive theoretical work , some tasks involving manipulation of entanglement have been successfully demonstrated in practice , including teleportation @xcite and quantum key distribution @xcite . in this paper
i discuss the feasibility of experimentally implementing another application of quantum entanglement : quantum communication complexity protocols ..
Please generate the next two sentences of the article | the scenario of communication complexity ( cc ) was introduced by yao @xcite , who investigated the following problem involving two separated parties ( alice and bob ) .
alice receives a @xmath0-bit string @xmath1 and bob another @xmath0-bit string @xmath2 , and the goal is for one of them ( say bob ) to compute a certain function @xmath3 with the least amount of communication between them . |
5,889 | Suppose that you have an abstract for a scientific paper: _ gaia _ s radial velocity spectrometer ( rvs ) has been operating in routine phase for over one year since initial commissioning
. rvs continues to work well but the higher than expected levels of straylight reduce the limiting magnitude .
the end - of - mission radial - velocity ( rv ) performance requirement for g2v stars was 15 km s@xmath0 at @xmath1 mag .
instead , 15 km s@xmath0 precision is achieved at @xmath2 mag , consistent with simulations that predict a loss of 1.4 mag
. simulations also suggest that changes to _ gaia _ s onboard software could recover @xmath30.14 mag of this loss . consequently _ gaia _ s onboard software was upgraded in april 2015 .
the status of this new commissioning period is presented , as well as the latest scientific performance of the on - ground processing of rvs spectra .
we illustrate the implications of the rvs limiting magnitude on _ gaia _ s view of the milky way s halo in 6d using the _ gaia _ universe model snapshot ( gums ) . .
And you have already written the first three sentences of the full article: _ gaia _ s radial velocity spectrometer @xcite data are processed on - ground by the data processing and analysis consortium ( dpac ) co - ordination unit ( cu ) 6 spectroscopic processing pipeline @xcite .
the pipeline formally runs at the cu6 data processing centre .
we present offline tests of the cu6 pipeline running at the mullard space science laboratory . as already presented in @xcite , fig ..
Please generate the next two sentences of the article | [ fig1 ] ( left ) presents tentative evidence that the cu6 pipeline is able to achieve the end - of - mission rv precision predicted by simulations that include the straylight . the majority of the stars in fig .
[ fig1 ] ( left ) are g dwarfs so the measured @xmath4 km s@xmath0 at @xmath2 mag is consistent with simulations that predict a loss of 1.4 mag . |
5,890 | Suppose that you have an abstract for a scientific paper: the structure of the reported excitation spectra of the light unflavored baryons is described in terms of multi - spin valued lorentz group representations of the so called rarita - schwinger ( rs ) type @xmath0 $ ] with @xmath1 , and @xmath2 .
we first motivate legitimacy of such pattern as fundamental fields as they emerge in the decomposition of triple fermion constructs into lorentz representations .
we then study the baryon realization of rs fields as composite systems by means of the quark version of the @xmath3 symmetric diatomic rovibron model . in using the @xmath4 reduction chain , we are able to reproduce quantum numbers and mass splittings of the above resonance assemblies .
we present the essentials of the four dimensional angular momentum algebra and construct electromagnetic tensor operators .
the predictive power of the model is illustrated by ratios of reduced probabilities concerning electric de - excitations of various resonances to the nucleon . .
And you have already written the first three sentences of the full article: one of the basic quality tests for any model of composite baryons is the level of reached in describing the nucleon and @xmath6 excitation spectra . in that respect ,
the knowledge on the degeneracy group of baryon spectra appears as a key tool in constructing the underlying hamiltonian of the strong - interaction dynamics as a function of the casimir operators of the symmetry group . to uncover the latter
, one can analyze isospin by isospin how the masses of the resonances from the full baryon listing in ref ..
Please generate the next two sentences of the article | @xcite spread with spin and parity .
such an analysis has been performed in prior work @xcite where it was found that breit - wigner masses reveal on the mass / spin ( @xmath7 ) plane a well pronounced spin- and parity clustering . |
5,891 | Suppose that you have an abstract for a scientific paper: we present calculations of the @xmath0 cross section in nuclear matter within the one - pion exchange model taking into account pion collectivity , vertex renormalization by the contact nuclear interactions and dirac effective masses of the baryons due to coupling with the scalar @xmath1 field . introducing the dirac effective masses leads to an in - medium reduction of the cross section .
the experimental data on pion multiplicities from the collisions of ca+ca , ru+ru and au+au at @xmath2 a gev are well described by buu calculations with the in - medium cross section . .
And you have already written the first three sentences of the full article: while transport calculations have , in general , been very successful in describing particle production in heavy - ion collisions @xcite , one of the remaining open problems in the transport - theoretical description of heavy - ion collisions at sis energies ( @xmath3 a gev ) is an overprediction of the pion multiplicity @xcite . at the beam energies of a few a gev the dominating mechanism of the pion production is the excitation of the @xmath4 resonance in a nucleon - nucleon ( nn ) collision followed by its decay : @xmath0 , @xmath5 .
the pion multiplicity , therefore , depends crucially on the value of the in - medium @xmath0 cross section which by detailed balance also determines the pion reabsorption . in ref .
@xcite a phenomenological density - dependent modification factor of the vacuum @xmath0 cross section has been proposed ..
Please generate the next two sentences of the article | the buu calculations with the density dependent @xmath6 cross sections are in a reasonable agreement with the experimental data on pion production @xcite . the purpose of the present work is to get rid of the ad - hoc description of ref .
@xcite and to calculate the in - medium @xmath6 cross sections on the basis of the one - pion exchange model ( opem ) with medium modifications . |
5,892 | Suppose that you have an abstract for a scientific paper: we present the newly developed broadband transient monitor using the _ swift _ burst alert telescope ( bat ) and the _ maxi _ gas slit camera ( gsc ) data .
our broadband transient monitor monitors high energy transient sources from 2 kev to 200 kev in seven energy bands by combining the bat ( 15 - 200 kev ) and the gsc ( 2 - 20 kev ) data . currently , the daily and the 90-minute ( one orbit ) averaged light curves are available for 106 high energy transient sources .
our broadband transient monitor is available to the public through our web server , http://yoshidalab.mydns.jp/bat_gsc_trans_mon/ , for a wider use by the community .
we discuss the daily sensitivity of our monitor and possible future improvements to our pipeline . .
And you have already written the first three sentences of the full article: high energy astrophysical sources show a temporal variability in a broad spectral range . the x - ray ( 1 - 10 kev ) and hard x - ray ranges ( 10 - 100 kev ) are especially important observing windows to understand the temporal characteristics of high energy sources which involve spectral changes .
for instance , a black hole candidate shows state changes in its flux and spectrum ; in the quiescent state the x - ray emission is dominated by the hard emission , whereas in outburst the soft emission from the accretion disk becomes dominate .
some low mass x - ray binaries produces bright bursts in x - rays , so called x - ray bursts , which are caused by thermonuclear flashes of accreting material on the surface of the neutron star ..
Please generate the next two sentences of the article | an accreting x - ray binary pulsar sometimes shows intense outbursts in x - rays when the neutron star passes the disk or dense stellar wind of its companion .
cyclotron resonance lines , one of the direct observational approaches to measure the magnetic field of a neutron star , are most easily observable in the hard x - ray range from binary pulsar during outburst . |
5,893 | Suppose that you have an abstract for a scientific paper: noncommutative generalizations of yang - mills theories using seiberg - witten map are in general not unique .
we study these ambiguities and see that @xmath0 gut , at first order in the noncommutativity parameter @xmath1 , is unique and therefore is a truly unified theory , while @xmath2 is not .
we then present the noncommutative standard model compatible with @xmath0 gut .
we next study the reality , hermiticity and @xmath3 properties of the seiberg - witten map and of these noncommutative actions at all orders in @xmath4 .
this allows to compare the standard model discussed in @xcite with the present gut inspired one . .
And you have already written the first three sentences of the full article: there are different examples of noncommutative theories , we here concentrate on the case where noncommutativity is described by a constant parameter @xmath5 .
the commutation relations among the coordinates read @xmath6\equiv x^\mu\*x^\nu - x^\nu\ * x^\mu = i\th^{\mu\nu}$ ] , where the star product between functions @xmath7 is given by @xmath8 .
we do not claim that spacetime has exactly this noncommutativity , rather we are interested in investigating a mathematically sound gauge theory based on this easiest noncommutative structure ..
Please generate the next two sentences of the article | general aspects of this noncommutative theory will then probably be in common with more refined choices of @xmath1 .
in particular the choice @xmath9 constant breakes the lorentz group in a spontaneous way ; in a bigger theory we would like to consider @xmath10 ( or the related @xmath11 field ) dynamical and not frozen to a constant value , thus recovering lorentz covariance . |
5,894 | Suppose that you have an abstract for a scientific paper: we reexamine a very classical problem , the spinning behavior of the tippe top on a horizontal table .
the analysis is made for an eccentric sphere version of the tippe top , assuming a modified coulomb law for the sliding friction , which is a continuous function of the slip velocity @xmath0 at the point of contact and vanishes at @xmath1 .
we study the relevance of the gyroscopic balance condition ( gbc ) , which was discovered to hold for a rapidly spinning hard - boiled egg by moffatt and shimomura , to the inversion phenomenon of the tippe top .
we introduce a variable @xmath2 so that @xmath3 corresponds to the gbc and analyze the behavior of @xmath2 .
contrary to the case of the spinning egg , the gbc for the tippe top is not fulfilled initially .
but we find from simulation that for those tippe tops which will turn over , the gbc will soon be satisfied approximately .
it is shown that the gbc and the geometry lead to the classification of tippe tops into three groups : the tippe tops of group i never flip over however large a spin they are given .
those of group ii show a complete inversion and the tippe tops of group iii tend to turn over up to a certain inclination angle @xmath4 such that @xmath5 , when they are spun sufficiently rapidly .
there exist three steady states for the spinning motion of the tippe top . giving a new criterion for stability
, we examine the stability of these states in terms of the initial spin velocity @xmath6 . and we obtain a critical value @xmath7 of the initial spin which is required for the tippe top of group ii to flip over up to the completely inverted position .
( 5,2)(-270,-520 ) ( 2.3,35)ynu - hepth-05 - 102 ( 2.3,20)july 2005 .
And you have already written the first three sentences of the full article: spinning objects have historically been interesting subjects to study .
the spin reversal of the rattleback @xcite ( also called a celt or wobblestone ) and the behavior of the tippe top are typical examples . in the latter case ,
when a truncated sphere with a cylindrical stem , a so - called ` tippe top ' , is spun sufficiently rapidly on a table with its stem up , it will flip over and rotate on its stem ..
Please generate the next two sentences of the article | this inversion phenomenon has fascinated physicists and has been studied for over a century @xcite . in the present paper
we revisit and study this very classical problem from a different perspective . |
5,895 | Suppose that you have an abstract for a scientific paper: we consider the possibility that a large fraction of the ultrahigh energy cosmic rays are decay products of z bosons which were produced in the scattering of ultrahigh energy cosmic neutrinos on cosmological relic neutrinos .
we compare the observed ultrahigh energy cosmic ray spectrum with the one predicted in the above z - burst scenario and determine the required mass of the heaviest relic neutrino as well as the necessary ultrahigh energy cosmic neutrino flux via a maximum likelihood analysis .
we show that the value of the neutrino mass obtained in this way is fairly robust against variations in presently unknown quantities , like the amount of neutrino clustering , the universal radio background , and the extragalactic magnetic field , within their anticipated uncertainties .
much stronger systematics arises from different possible assumptions about the diffuse background of ordinary cosmic rays from unresolved astrophysical sources . in the most plausible case that these ordinary cosmic rays are protons of extragalactic origin ,
one is lead to a required neutrino mass in the range @xmath0 ev @xmath1 ev at the 68% confidence level .
this range narrows down considerably if a particular universal radio background is assumed , e.g. to @xmath0 ev @xmath2 ev for a large one .
the required flux of ultrahigh energy cosmic neutrinos near the resonant energy should be detected in the near future by amanda , rice , and the pierre auger observatory , otherwise the z - burst scenario will be ruled out . .
And you have already written the first three sentences of the full article: big bang cosmology predicts the existence of a background gas of free photons and neutrinos . the measured cosmic microwave background ( cmb ) radiation supports the applicability of standard cosmology back to photon decoupling which occured approximately one hundred thousand years after the big bang .
the relic neutrinos , on the other hand , have decoupled when the universe had a temperature of one mev and an age of just one second .
thus , a measurement of the relic neutrinos , with a predicted average number density of @xmath3 per light ( @xmath4 mev ) neutrino species @xmath5 , would provide a new window to the early universe ..
Please generate the next two sentences of the article | their predicted number density is comparable to the one of the microwave photons .
however , since neutrinos interact only weakly , the relic neutrinos have not yet been detected directly in laboratory experiments @xcite . |
5,896 | Suppose that you have an abstract for a scientific paper: it is shown that the fiducial distribution in a group model , or more generally a quasigroup model , determines the optimal equivariant frequentist inference procedures .
the proof does not rely on existence of invariant measures , and generalizes results corresponding to the choice of the right haar measure as a bayesian prior .
classical and more recent examples show that fiducial arguments can be used to give good candidates for exact or approximate confidence distributions .
it is here suggested that the fiducial algorithm can be considered as an alternative to the bayesian algorithm for the construction of good frequentist inference procedures more generally . .
And you have already written the first three sentences of the full article: fiducial theory was introduced by @xcite to avoid the problems related to the choice of a prior distribution .
fiducial inference has not gained much popularity as such , but the related theory has been historically influential [ @xcite ] , and is still important in the current flow of statistical developments [ @xcite ] .
fisher s own view on fiducial inference evolved over the years as can be inferred from a reading of his initial [ fisher ( @xcite ) ] and more final formulation of the theory [ @xcite ] ..
Please generate the next two sentences of the article | he was in particular very positive to the developments by fraser ( @xcite ) , and we most certainly share this point of view .
fraser ( @xcite ) develops the theory and uses the label _ |
5,897 | Suppose that you have an abstract for a scientific paper: we derive the explicit analytic expression for the stokes drift in one dimension in the presence of a dichotomic markov forcing . for small amplitudes of the forcing ,
the drift is enhanced , but the enhancement is reduced with increasing frequency of the forcing . on the other hand ,
a reduction of the drift or even a flux reversal can be induced at larger amplitudes , while the flux is now found to be an increasing function of the perturbation frequency .
pacs numbers : 02.50.-r , 05.40.+j , 05.60.+w .
And you have already written the first three sentences of the full article: a longitudinal wave travelling through a fluid imparts a net drift motion to the suspended particles - an effect known as _
drift_. the _ classical _ stokes drift @xcite refers only to the deterministic behavior , i.e. it does not account for the stochastic fluctuations or perturbations in the system .
it has been extensively studied in various practical contexts like , for instance , the motion of tracers in meteorology and oceanography @xcite and that of the ( doping ) impurities in crystal growth @xcite ..
Please generate the next two sentences of the article | a simple intuitive explanation of classical stokes drift is that the suspended particles spend a longer time in the regions of the wave - train where the force due to the wave acts in the direction of wave s propagation than the time spent in those regions where the force acts in the opposite direction ; therefore particles are driven in the sense of wave s propagation .
when several linearly superposed waves are present , the resulting drift velocity is simply the sum of the contributions from each wave @xcite . recently , there has been some interest in _ stochastic _ |
5,898 | Suppose that you have an abstract for a scientific paper: the paper deals with a theoretical investigation of the peristaltic transport of a physiological fluid in a porous asymmetric channel under the action of a magnetic field . the stream function , pressure gradient and axial velocity are studied by using appropriate analytical and numerical techniques .
effects of different physical parameters such as permeability , phase difference , wave amplitude and magnetic parameter on the velocity , pumping characteristics , streamline pattern and trapping are investigated with particular emphasis .
the computational results are presented in graphical form .
the results are found to be in perfect agreement with those of a previous study carried out for a non - porous channel in the absence of a magnetic field .
+ _ keywords : peristaltic transport , asymmetric channel , flow reversal , trapping . _ 0.8 cm -.1 in -.1 in 0.0 cm 22.5 cm [ section ] [ theorem]definition [ theorem]observation [ theorem ] [ theorem]proposition [ theorem]rule 22.5 cm = currsize .
And you have already written the first three sentences of the full article: peristaltic transport is a natural mechanism of pumping most physiological fluids induced by a progressive wave of area contraction or expansion along the length of the boundary of a fluid - filled distensible tube .
different physiological phenomena , such as the flow of urine from kidney to the bladder through ureters as well as the transport of food material through the digestive tract , semen in the vas differences , fluids in lymphatic vessels , bile from gall bladder into the duodenum , movement of spermatozoa in the ductus efferentes of the male reproductive tract and cervical canal and the transport of ovum in the fallopian tube , the movement of cilia , circulation of blood in small blood vessels , take place by the peristalsis mechanism .
this phenomenon is also observed in the propulsion of some industrial fluids ..
Please generate the next two sentences of the article | [ cols= " < , < " , ] this mechanism finds applications in roller and finger pumps , heart - lung machine , blood pump machine , dialysis machine and also noxious fluid transport in nuclear industries .
some of the recent important theoretical studies on peristaltic transport include those by usha and rao @xcite , misra and pandey @xcite , mishra and rao @xcite , mekheimer @xcite , afifi @xcite , eytan et al . |
5,899 | Suppose that you have an abstract for a scientific paper: the properties of neutrinos and especially their rest mass play an important role at the intersections of cosmology , particle physics and astroparticle physics . at present
there are two complementary approaches to address this topic in laboratory experiments .
the search for neutrinoless double beta decay probes whether neutrinos are majorana particles and determines an effective neutrino mass value . on the other hand experiments such as mare , katrin and
the recently proposed project 8 will investigate the spectral shape of @xmath0-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model - independent method . here ,
because of neutrino flavour mixing , the neutrino mass appears as an average of all neutrino mass eigenstates contributing to the electron neutrino . the karlsruhe tritium neutrino experiment ( katrin )
is currently the experiment in the most advanced status of commissioning .
it combines an ultra - luminous molecular windowless gaseous tritium source with an integrating high - resolution spectrometer of mac - e filter type . it will investigate the neutrino rest mass with @xmath1 ( 90% c.l . )
sensitivity and allow @xmath0 spectroscopy close to the @xmath2 endpoint at 18.6 kev with unprecedented precision .
direct neutrino mass , beta decay spectroscopy , mare , katrin , project 8 .
And you have already written the first three sentences of the full article: ever since pauli postulated the neutrino , its influence and significance for particle physics as well as for astrophysics has steadily been growing .
the observation of flavour oscillations of atmospheric and solar neutrinos , as well as of reactor and accelerator neutrinos at long baseline , is a compelling evidence that neutrinos are massive .
due to this fact and owing to their large abundance in the universe , neutrinos are considered as the primary candidate for hot dark matter in cosmology ..
Please generate the next two sentences of the article | thus , they could play an important role for the evolution of large scale structures ( lss ) in the universe . on the other hand ,
the on - going investigations of neutrino properties , their mass hierarchy and especially their rest mass will open a door to the understanding of the origin of mass . here , a precision measurement of the neutrino rest mass can discriminate between different @xmath3-mass models , in particular whether they are of hierarchical type @xmath4 or of quasi - degenerate type @xmath5 . although experiments on neutrino flavour oscillation provide compelling evidence that neutrinos are massive , they can not provide an absolute mass value . |
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