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3,600 | Suppose that you have an abstract for a scientific paper: one- and two - parameter families of flows in @xmath0 near an andronov - hopf bifurcation ( ahb ) are investigated in this work .
we identify conditions on the global vector field , which yield a rich family of multimodal orbits passing close to a weakly unstable saddle - focus and perform a detailed asymptotic analysis of the trajectories in the vicinity of the saddle - focus .
our analysis covers both cases of sub- and supercritical ahb . for the supercritical case , we find that the periodic orbits born from the ahb are bimodal when viewed in the frame of coordinates generated by the linearization about the bifurcating equilibrium .
if the ahb is subcritical , it is accompanied by the appearance of multimodal orbits , which consist of long series of nearly harmonic oscillations separated by large amplitude spikes .
we analyze the dependence of the interspike intervals ( which can be extremely long ) on the control parameters .
in particular , we show that the interspike intervals grow logarithmically as the boundary between regions of sub- and supercritical ahb is approached in the parameter space .
we also identify a window of complex and possibly chaotic oscillations near the boundary between the regions of sub- and supercritical ahb and explain the mechanism generating these oscillations .
this work is motivated by the numerical results for a finite - dimensional approximation of a free boundary problem modeling solid fuel combustion . .
And you have already written the first three sentences of the full article: systems of differential equations in both finite- and infinite - dimensional settings close to an ahb have been subject to intense research due to their dynamical complexity and importance in applications .
the latter range from models in fluid dynamics @xcite to those in the life sciences , in particular , in computational neuroscience @xcite .
when the proximity to the ahb coincides with certain global properties of the vector field , it may result in a very complex dynamics @xcite ..
Please generate the next two sentences of the article | the formation of the smale horseshoes in systems with a homoclinic orbit to a saddle - focus equilibrium provides one of the most representative examples of this type @xcite .
canard explosion in relaxation systems affords another example @xcite . |
3,601 | Suppose that you have an abstract for a scientific paper: the classical hodgkin huxley ( hh ) model neglects the time dependence of ion concentrations in spiking dynamics .
the dynamics is therefore limited to a time scale of milliseconds , which is determined by the membrane capacitance multiplied by the resistance of the ion channels , and by the gating time constants .
we study slow dynamics in an extended hh framework that includes time
dependent ion concentrations , pumps , and buffers .
fluxes across the neuronal membrane change intra and extracellular ion concentrations , whereby the latter can also change through contact to reservoirs in the surroundings .
ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies .
our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models .
also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations .
the dynamics on three distinct slow times scales is determined by the cell volume to surface area ratio and the membrane permeability ( seconds ) , the buffer time constants ( tens of seconds ) , and the slower backward buffering ( minutes to hours ) .
the modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity , and spreading depression in migraine aura and stroke , respectively . .
And you have already written the first three sentences of the full article: the classical theory by hodgkin and huxley ( hh ) describes nerve impulses ( spikes ) that manifest communication between nerve cells .
the underlying mechanism of a single spike is excitability , i.e. , a small disturbance triggers a large excursion that reverts without further input to the original state .
a spike lasts a 1/1000 second and even though during this period ions are exchanged across the nerve cell membrane , the change in the corresponding ion concentrations can become significant only in series of such spikes . under certain pathological conditions.
Please generate the next two sentences of the article | changes in ion concentrations become massive and last minutes to hours before they recover .
this establishes a new type of excitability underlying communication failure between nerve cells during migraine and stroke . to clarify this mechanism and to recognize the relevant factors that determine the slow time scales of ion changes |
3,602 | Suppose that you have an abstract for a scientific paper: we present results of transport properties measurement on a single crystal of v@xmath0si showing distinct signature of peak - effect in its vortex state .
the field variation of the electrical resistance in the flux - line lattice prepared by different experimental path , namely zero field cooling ( zfc ) and field cooling ( fc ) , shows a distinct path dependence in the vicinity of the peak - effect regime . in the field
cooled state , small cycling of magnetic field modifies the resistance drastically around the peak - effect regime , highlighting the metastable nature of that state in the concerned regime . .
And you have already written the first three sentences of the full article: the a15 superconductor v@xmath0si has been quite well known over the years both for its interesting normal state @xcite and superconducting properties @xcite and the correlation between the two states @xcite .
there is some renewed interest in v@xmath0si in recent years , first due to the observation of de haas - van alphen ( dhva ) effect @xcite , and lately due to the suggestion of the magnetic field induced phase transition in the flux - lattice structure @xcite .
the observation of dhva effect in a superconductor is quite puzzling to start with , since the superconducting energy gap is likely to eliminate quantum oscillations ..
Please generate the next two sentences of the article | recent works on v@xmath0si @xcite and various other superconductors like nbse@xmath1 @xcite , nb@xmath0sn @xcite , ceru@xmath1 @xcite , uru@xmath1si@xmath1 @xcite have provided more interesting results , but both the experimental and theoretical situations are yet to be understood completely @xcite . in a very recent neutron measurement
it has been observed that in certain field direction , the hexagonal flux - line lattice ( fll ) of v@xmath0si distorts with the increase in magnetic field and abruptly becomes of square symmetry @xcite . |
3,603 | Suppose that you have an abstract for a scientific paper: we present gpu implementations of two fast force calculation methods , based on series expansions of the poisson equation .
one is the self - consistent field ( scf ) method , which is a fourier - like expansion of the density field in some basis set ; the other is the multipole expansion ( mex ) method , which is a taylor - like expansion of the green s function .
mex , which has been advocated in the past , has not gained as much popularity as scf .
both are particle - field method and optimized for collisionless galactic dynamics , but while scf is a `` pure '' expansion , mex is an expansion in just the angular part ; it is thus capable of capturing radial structure easily , where scf needs a large number of radial terms . we show that despite the expansion bias , these methods are more accurate than direct techniques for the same number of particles . the performance of our gpu code , which we call _ etics _ , is profiled and compared to a cpu implementation . on the tested gpu hardware , a full force calculation for one million particles took @xmath0 seconds ( depending on expansion cutoff ) , making simulations with as many as @xmath1 particles fast on a comparatively small number of nodes . .
And you have already written the first three sentences of the full article: a galaxy is a self - gravitating system where stellar dynamics is governed by newton s law .
it could be naively described as a set of @xmath2 coupled , second - order , non - linear ordinary differential equations , where @xmath3 is the number of stars , which ranges between @xmath4 and @xmath5 @xcite .
solving such an equation set numerically is practically only possible at the very low end of the @xmath3-range , and even so very challenging with current computer hardware ..
Please generate the next two sentences of the article | thus , various techniques are used to simplify the mathematical description of the system ; these are often designed to fit a particular problem in stellar dynamics and yield unphysical results when applied to another problem .
direct @xmath6-body simulation is one of the main techniques used to study gravitational systems in general and galaxies in particular . in this technique , |
3,604 | Suppose that you have an abstract for a scientific paper: while strictly black and white images have been the basis for visual cryptography , there has been a lack of an easily implemented format for colour images .
this paper establishes a simple , yet secure way of implementing visual cryptography with colour , assuming a binary data representation . .
And you have already written the first three sentences of the full article: traditional methods for visual cryptography have been established , are consistent and easily understood .
unfortunately , these methods exist for black and white pictures only , leaving the encryption of colour images wanting . while there are a handful of attempts at bringing colour to visual cryptography
, it is still an open field with implementations of varying efficiency . in this paper.
Please generate the next two sentences of the article | , we will establish some basic standards for encrypting colour pictures , as well as a simple , yet efficient method for encryption based upon those rules . while black and white pictures are fairly easy to work with due to their simple nature , colour pictures contain much more information and possibly details that may not be lost in the process .
this leads to a need for the static that normally appears in the decryption of black and white pictures to have to be absent[1 ] . |
3,605 | Suppose that you have an abstract for a scientific paper: let @xmath0 be a finite set of circles in the plane .
we point out that the usual convex closure restricted to @xmath0 yields a convex geometry , that is , a combinatorial structure introduced by p.h .
edelman in 1980 under the name `` anti - exchange closure system '' .
we prove that if the circles are collinear and they are arranged in a `` concave way '' , then they determine a convex geometry of convex dimension at most 2 , and each finite convex geometry of convex dimension at most 2 can be represented this way .
the proof uses some recent results from lattice theory , and some of the auxiliary statements on lattices or convex geometries could be of separate interest .
the paper is concluded with some open problems . .
And you have already written the first three sentences of the full article: the concept of convex geometries was introduced by edelman @xcite and @xcite , see also edelman and jamison @xcite , adaricheva , gorbunov , and tumanov @xcite , and armstrong @xcite .
_ convex geometries _ are combinatorial structures : finite sets with anti - exchange closures such that the emptyset is closed .
they are equivalent to antimatroids , which are particular greedoids , and also to meet - distributive lattices . actually , the concept of convex geometries has many equivalent variants ..
Please generate the next two sentences of the article | the first of these variants is due to dilworth @xcite , and the early ones were surveyed in monjardet @xcite .
since it would wander to far if we overviewed the rest , more than a dozen approaches , we only mention adaricheva @xcite , abels @xcite , caspard and monjardet @xcite , avann @xcite , jamison - waldner @xcite , and ward @xcite for additional sources , and stern @xcite , adaricheva and czdli @xcite , and czdli @xcite for some recent overviews . however , we need only a small part of the theory of convex geometries , and the present paper is intended to be self - contained for those who know the rudiments of lattice theory up to , say , the concept of semimodularity . from combinatorial point of view |
3,606 | Suppose that you have an abstract for a scientific paper: matching cross - view images is challenging because the appearance and viewpoints are significantly different .
while low - level features based on gradient orientations or filter responses can drastically vary with such changes in viewpoint , semantic information of images however shows an invariant characteristic in this respect .
consequently , semantically labeled regions can be used for performing cross - view matching . in this paper
, we therefore explore this idea and propose an automatic method for detecting and representing the semantic information of an rgb image with the goal of performing cross - view matching with a ( non - rgb ) geographic information system ( gis ) . a segmented image forms the input to our system with segments assigned to semantic concepts such as traffic signs , lakes , roads , foliage , etc .
we design a descriptor to robustly capture both , the presence of semantic concepts and the spatial layout of those segments .
pairwise distances between the descriptors extracted from the gis map and the query image are then used to generate a shortlist of the most promising locations with similar semantic concepts in a consistent spatial layout . an experimental evaluation with challenging query images and
a large urban area shows promising results . .
And you have already written the first three sentences of the full article: in this paper , we consider the cross - view and cross - modality matching problem between street - level rgb images and a geographic information system ( gis ) . specifically , given an image taken from street - level , the goal is to query a database assembled from a gis in order to return likely locations of the street - level query image which contain similar semantic concepts in a consistent layout . relying only on visual data is important in gps - denied environments , for images where
such tags have been removed on purpose ( e.g. for applications in intelligence or forensic sciences ) , for historical images , or images from the web which are lacking any gps tags . traditionally , such matching problems are solved by establishing pairwise correspondences between interest points using local descriptors such as sift @xcite with a subsequent geometric verification stage .
unfortunately , even if top - down satellite imagery is available , such an approach based on local appearance features is not applicable to the wide - baseline cross - view matching considered in our setting , mainly because of the following two reasons ..
Please generate the next two sentences of the article | firstly , the extremely wide baseline between top - view gis imagery and the street - level image leads to a strong perspective distortion , and secondly , there can be drastic changes in appearance , e.g. due to different weather conditions , time of day , camera response function , etc . in this paper , we present a system to handle those two challenges .
we propose to phrase the cross - view matching problem in a semantic way . |
3,607 | Suppose that you have an abstract for a scientific paper: x - ray emission following charge exchange has been studied on the university of california lawrence livermore national laboratory electron beam ion traps ebit - i and ebit - ii using a high - resolution microcalorimeter .
the measured spectra include the k - shell emission from hydrogenlike and heliumlike c , n , o , and ne needed for simulations of cometary x - ray emission .
a comparison of the spectra produced in the interaction of o@xmath0 with n@xmath1 and ch@xmath2 is presented that illustrates the dependence of the observed spectrum on the interaction gas .
charge exchange , x - ray lines , comets , microcalorimeter 34.70.+e , 32.30.rj , 96.50.gn .
And you have already written the first three sentences of the full article: x - ray production by charge exchange has received attention when a plausible link was established between cometary x - ray emission and solar wind heavy ions . fully stripped and
hydroglenlike carbon , nitrogen , oxygen , and neon , which are part of the solar wind , were thought to interact with gases in the cometary coma , producing k - shell x rays via the charge exchange mechanism @xcite .
recently , high - resolution techniques became available to study the x - ray emission of highly charged ions following charge exchange @xcite ..
Please generate the next two sentences of the article | these measurements were able to resolve most x - ray lines , even those from levels with high principal quantum number @xmath3 . because the measurements were performed on an electron beam ion trap
, these measurements also included the emission from the @xmath4 level , which could not be detected in fast - ion experiments @xcite because of the slow radiative rate associated with this transition . |
3,608 | Suppose that you have an abstract for a scientific paper: we prove the affine pieri rule for the cohomology of the affine flag variety conjectured by lam , lapointe , morse and shimozono .
we study the cap operator on the affine nilhecke ring that is motivated by kostant and kumar s work on the equivariant cohomology of the affine flag variety .
we show that the cap operators for pieri elements are the same as pieri operators defined by berg , saliola and serrano .
this establishes the affine pieri rule . .
And you have already written the first three sentences of the full article: affine schubert calculus is a subject that ties combinatorics , algebraic geometry and representation theory together .
its modern development is motivated by the relation between @xmath0-schur functions and the ( co)homology of the affine grassmannian of @xmath1 .
@xmath0-schur functions were introduced by lapointe , lascoux , morse @xcite in the study of macdonald polynomial positivity , a mostly combinatorial branch of symmetric function theory . + peterson @xcite identified the equivariant homology of the affine grassmannian with a subalgebra of the affine nilhecke algebra @xmath2 , now called the peterson algebra ..
Please generate the next two sentences of the article | lam @xcite proved that @xmath0-schur functions can be identified with the schubert classes of the homology of the affine grassmannian of @xmath1 .
the nilhecke ring acts as divided difference operators on the equivariant cohomology of kac - moody partial flag varieties . by using the correspondence |
3,609 | Suppose that you have an abstract for a scientific paper: we apply the concept of dynamic propensity to a simple kinetically constrained model of glass formers , the two - vacancy assisted triangular lattice gas , or ( 2)-tlg .
we find that the propensity field , defined in our case as the local root - mean square displacement averaged over the ensemble of trajectories with identical initial configurations , is a good measure of dynamical heterogeneity .
this suggests a configurational origin for spatial fluctuations of the dynamics , but just as in the case of atomistic systems , we find that propensity is not correlated to any simple structural property .
we show instead that certain extended clusters of particles connected to vacancies correlate well with propensity , indicating that these are the fundamental excitations of the ( 2)-tlg .
we also discuss time - correlations and the correlation between configurations within the propensity ensemble . .
And you have already written the first three sentences of the full article: on approach to their glass transition @xcite glass forming systems display increasingly heterogeneous dynamics @xcite .
this dynamic heterogeneity is not correlated in any obvious way to structural features . in order to uncover a possible configurational origin for dynamic heterogeneity harrowell and
coworkers recently proposed the concept of dynamic propensity @xcite : a particle s propensity is defined as some measure of its mobility over a period of time , such as its mean square displacement , averaged over all dynamic trajectories which start from the same initial configuration ..
Please generate the next two sentences of the article | this ensemble of trajectories is sometimes referred to as the iso - configurational ensemble .
dynamic propensity was found to be a good indicator of dynamic heterogeneity in simulations of atomistic models @xcite for times at least as long as the structural relaxation time . |
3,610 | Suppose that you have an abstract for a scientific paper: we present an efficient entanglement concentration protocol ( ecp ) for mobile electrons with charge detection .
this protocol is quite different from other ecps for one can obtain a maximally entangled pair from a pair of less - entangled state and a single mobile electron with a certain probability . with the help of charge detection , it can be repeated to reach a higher success probability .
it also does not need to know the coefficient of the original less - entangled states .
all these advantages may make this protocol useful in current distributed quantum information processing .
entanglement plays an important role in the current quantum communication @xcite and distributed quantum information processing field @xcite . for most of the practical quantum communication and computation protocols ,
people need to share a maximally entangled state with each other .
however , the entanglement resource is fragile , for the maximally entangled state may be degraded into a mixed state or become a less - entangled state when it interacts with the noisy environment .
people usually resort to the entanglement purification @xcite to increase the fidelity of the mixed state and the entanglement concentration @xcite which will be detailed here to recover the less - entangled state to a maximally entangled state .
currently , most of the protocols for purification and concentration are focused on optical systems @xcite , for during the transmission , the photons have weak interaction with the environment . on the other hand
, there is another candidate for the flying qubit , that is the mobile electron .
a strong interaction between different electrons makes them feasible to interact flying electron spins with other solid electron spins , since the coulomb interaction between each electrons is strongly screened . in the recent years
, the investigation about the flying electron qubits becomes an active study area @xcite . in 2004 , beenakker _
et al .
_ broke through the obstacle....
And you have already written the first three sentences of the full article: this work was supported by the national natural science foundation of china under grant no . 11104159 , scientific research foundation of nanjing university of posts and telecommunications under grant no .
ny211008 , university natural science research foundation of jiangsu province under grant no .
11kja510002 , the open research fund of key lab of broadband wireless communication and sensor network technology ( nanjing university of posts and telecommunications ) , ministry of education , china , and a project funded by the priority academic program development of jiangsu higher education institutions ..
Please generate the next two sentences of the article | f. g. deng , x. h. li , c. y. li , p. zhou , and h. y. zhou , phys .
a * 72 * , 044301 ( 2005 ) ; f. g. deng , x. h. li , c. y. li , p. zhou , and h. y. zhou , europ . |
3,611 | Suppose that you have an abstract for a scientific paper: we study noise spectra of currents through a tunnel junction in weak tunneling limit .
we introduce effective capacitance to take into account the interaction effect and explicitly incorporate the electromagnetic environment of the junction into the formulation .
we study the effect of charging energy and macroscopic environment on noise spectra .
we calculate current fluctuations at tunneling barrier and fluctuations measured at leads .
it is shown that two fluctuations have different noise spectra and the relation between them is nontrivial .
we provide an explanation for the origin of the difference .
experimental implications are discussed . .
And you have already written the first three sentences of the full article: even though `` noise '' usually represents unwanted fluctuations which blur information , noise is on the fundamental level closely connected with the dynamics of a system and it contains variety of information . in this context , there have been many recent studies on a noise spectrum of current in small devices . in ballistic systems ,
the noise power can be suppressed to zero due to pauli exclusion principle@xcite . in diffusive systems ,
the noise power is suppressed to @xmath0 of the classical value@xcite ..
Please generate the next two sentences of the article | there have been attempts to study the effect of electron - electron interaction on the noise .
for example , noise spectrum in 1d systems was calculated from luttinger liquid approximation@xcite . in this paper , we study current fluctuations of ultra - small tunnel junctions made of two pieces of metal separated by a thin insulating barrier . |
3,612 | Suppose that you have an abstract for a scientific paper: we have obtained new near - infrared images of both ggtau and uyaur circumbinary disks with the polarimetric modes of nicmos aboard the hubble space telescope .
the 1 intensity map of ggtau reveals a more complete elliptical shape than in previous ground - based images .
its eastern and western sides are definitely asymmetric .
our image strongly supports the ring geometry proposed by guilloteau , dutrey & simon ( 1999 ) on the basis of their millimetre interferometry images : a geometrically thick and sharply edged ring surrounding an empty gap around the binary . around uyaur
, we identify structures that are in excellent agreement with the optical images of mnard et al .
( 1999 ) , which confirms that the inclination of the system to the line - of - sight is about 60 degrees .
we also find tentative new structures closer to the stars .
# 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: the presence of circumstellar disks around ttauri stars has been suspected for a long time , but it is only very recently that these disks were directly detected , using high - angular millimetre imaging .
these images revealed extended gas structures which appeared to be in keplerian rotation around the central object . among the rare detections so far , two disks were found around binary ttauri stars : ggtau ( dutrey , guilloteau & simon 1994 ) and uyaur ( duvert et al . 1998 ) .
the separations of the binaries are 025 and 089 respectively , which correspond to projected physical separations of 35 and 125au at the distance of the taurus star - forming region ( 140pc ) ..
Please generate the next two sentences of the article | in both cases , light scattered off the surface of the disks has been detected afterwards with adaptive optics imaging at near - infrared wavelengthes .
roddier et al . |
3,613 | Suppose that you have an abstract for a scientific paper: we present results on hard diffraction obtained by the cdf collaboration in run ii proton - antiproton collisions at the fermilab tevatron .
run i cdf results on hard diffraction are also reviewed . .
And you have already written the first three sentences of the full article: diffractive events in @xmath0 collisions are characterized by the presence of a leading proton or antiproton which remains intact , and/or a rapidity gap , defined as a pseudorapidity of a particle is defined as @xmath1 , where @xmath2 is the polar angle of the particle with respect to the proton beam direction . ]
region devoid of particles .
diffractive events involving hard processes ( `` hard diffraction '' ) , such as production of high @xmath3 jets ( see fig . [.
Please generate the next two sentences of the article | fig : diff_diagram ] ) , have been studied extensively to understand the nature of the exchanged object , the pomeron , which in qcd is a color singlet entity with vacuum quantum numbers .
one of the most interesting questions in hard diffractive processes is whether or not they obey qcd factorization , in other words , whether the pomeron has a universal , process independent , parton distribution function ( pdf ) . |
3,614 | Suppose that you have an abstract for a scientific paper: we have found the possible region of parameters of the minimal supersymmetric standard model ( mssm ) within the bounds from the experimental results of the higgs mass , the rare decay mode of @xmath0-quark , the muon @xmath1 , the dark matter abundance , and the direct searches for the lighter stop ( i.e. , one of the supersymmetric partners of top quark ) at the lhc .
we present numerical results of calculations for the one loop effects of supersymmetric particles in the processes of @xmath2 , @xmath3 , @xmath4 , and @xmath5 production at the ilc by using benchmark points within the possible region of the mssm parameters . .
And you have already written the first three sentences of the full article: the standard model ( sm ) of particle physics is considered to be an effective theory despite the fact that it has succeeded in describing known experimental data available up to now .
supersymmetry ( susy ) between bosons and fermions at the unification - energy scale is believed to be one of the most promising extension of the sm . among the supersymmetric theories ,
the minimal supersymmetric extension of the sm ( mssm ) is a well studied framework of susy because of its compactness . in the mssm , however , there are many unfixed parameters . for limiting the possible region of the mssm parameters ,.
Please generate the next two sentences of the article | a promising approach is so - called natural susy " . in the framework of the natural susy ,
a light stop with a large a - term and light higgsinos give a solution of fine - tunings in the mssm@xcite . |
3,615 | Suppose that you have an abstract for a scientific paper: magnetic skyrmions can be considered as topologically protected quasiparticles . due to their stability , their small size , and the possibility to move them by low electric currents they are promising candidates for spintronic devices . leaving the topological protection untouched ,
it is possible to create skyrmion - antiskyrmion pairs , as long as the total skyrmion number remains unchanged .
we derive a skyrmion equation of motion which reveals how spin - polarized charge currents create skyrmion - antiskyrmion pairs .
it allows to identify general prerequisites for the pair creation process .
we corroborate these general principles by numerical simulations . on a lattice , where topological protection becomes imperfect ,
the antiskyrmion partner of the pairs is annihilated and only the skyrmion survives .
this eventually changes the total skyrmion number and yields a new way of creating and controlling skyrmions .
magnetic skyrmions ( sks ) are vortex - like localized magnetization configurations @xcite which have been predicted @xcite before they were discovered experimentally @xcite in magnetic layers with a strong spin - orbit interaction @xcite . despite their size being much smaller @xcite than , for example ,
that of topologically trivial magnetic bubbles , their thermodynamic stability is amazing @xcite .
this is a consequence of the particular magnetic configuration which can be characterized by a topological sk number @xmath0 .
it can take integer values only and therefore can not be changed continuously @xcite .
this feature protects magnetic sks against typical drawbacks of solid state systems such as disorder or imperfect fabrication @xcite .
together with the property of easy repositioning by rather tiny in - plane electrical currents @xcite , this makes diluted sks attractive candidates for future racetrack memory devices @xcite .
creation of sks has been reported in the vicinity of notches @xcite or by sweeping the back ground magnetic field @xcite .....
And you have already written the first three sentences of the full article: in the main body of the paper , we focus on the dynamics of the skyrmion density as the important quantity to describe skyrmions or antiskyrmions , respectively .
still , these objects have an internal magnetic structure given by the magnetization @xmath14 .
in particular , different kinds of dzyaloshinskii - moriya interactions ( dmi ) may stabilize different types of skyrmions . in this appendix.
Please generate the next two sentences of the article | , we show exemplary magnetic structures for * bulk dmi given by the hamiltonian @xmath98 $ ] which stabilizes bloch - like skyrmions ( cf .
[ fig::bdmi ] and movie `` ` sk_density_vs_time_bulkdmi.avi ` '' ) , * interfacial dmi given by the hamiltonian @xmath99 $ ] which stabilizes nel - like skyrmions ( cf . |
3,616 | Suppose that you have an abstract for a scientific paper: production of @xmath0mesons in charged - current @xmath1interactions on plastic scintillator ( ch ) is measured using minervaexposed to the low - energy numi beam at fermilab .
timing information is used to isolate a sample of 885 charged - current events containing a stopping @xmath0which decays at rest . the differential cross section in @xmath0kinetic energy , @xmath2 ,
is observed to be relatively flat between 0 and 500 mev .
its shape is in good agreement with the prediction by the genieneutrino event generator when final - state interactions are included , however the data rate is lower than the prediction by 15% . 0=1 0=1 0=0 .
And you have already written the first three sentences of the full article: the energy spectrum of mesons produced in neutrino - nucleus interactions is modified by strong interactions with the residual nucleus .
recent high - statistics measurements of charged - current @xmath3production by miniboone @xcite and minerva @xcite have shown tension with available models @xcite .
a study of @xmath0production is complementary because of differences in the nuclear interaction due to strangeness conservation ..
Please generate the next two sentences of the article | previous measurements of neutrino - induced charged - current @xmath0production have been carried out in bubble chambers with very limited statistics @xcite .
we report the first high - statistics measurement of this process based on a sample of 1755 selected event candidates , of which 885 are estimated to be charged - current @xmath0events with @xmath4 mev . at neutrino energies below 2 gev , |
3,617 | Suppose that you have an abstract for a scientific paper: the nature of the progenitor systems of type ia supernovae is still unclear .
one way to distinguish between the single - degenerate scenario and double - degenerate scenario for their progenitors is to search for the surviving companions . using a technique that couples the results from multi - dimensional hydrodynamics simulations with calculations of the structure and evolution of main - sequence- and helium - rich surviving companions , the color and magnitude of main - sequence- and helium - rich surviving companions
are predicted as functions of time .
the surviving companion candidates in galactic type ia supernova remnants and nearby extragalactic type ia supernova remnants are discussed .
we find that the maximum detectable distance of main - sequence surviving companions ( helium - rich surviving companions ) is @xmath0 mpc ( @xmath1 mpc ) , if the apparent magnitude limit is 27 in the absence of extinction , suggesting that the large and small magellanic clouds and the andromeda galaxy are excellent environments in which to search for surviving companions .
however , only five ia snrs have been searched for surviving companions , showing little support for the standard channels in the singe - degenerate scenario . to better understand the progenitors of type ia supernovae
, we encourage the search for surviving companions in other nearby type ia supernova remnants . .
And you have already written the first three sentences of the full article: thermonuclear explosions of carbon - oxygen ( co ) white dwarfs ( wds ) , which lead to type ia supernovae ( sne ia ) , could be triggered by the merger of two wds ( the double - degenerate scenario ( dds ) @xcite ) or by the accretion of matter from a non - degenerate star through roche - lobe overflow ( the single - degenerate scenario ( sds ) @xcite ) . in the sds , the companion to the co - wd could be a main - sequence ( ms ) , red giant ( rg ) , or helium - rich ( he ) star . in the dds , the companion could be another co wd or he wd . based on current studies , both scenarios are not ruled out by observations , but are also not proven by them . if both scenarios lead to sn ia , it is still unclear which channel(s ) in the sds and dds dominate(s ) the sne ia , and by what fraction @xcite .
recent multi - dimensional hydrodynamics simulations of sn impact on the non - degenerate binary companions in the sds suggest that the companions should survive the sn impact and could be detectable . therefore , one of the direct methods to distinguish between the sds and dds is to search for the surviving companions ( scs ) in sn ia remnants ( ia snrs ) .
* hereafter p10 ) and ( * ? ? ?.
Please generate the next two sentences of the article | * hereafter p12a ) examine the effects of a sn impact on the non - degenerate binary companions in the sds for ms , rg , and he star binary companions via multi - dimensional hydrodynamics simulations .
these simulations include the symmetry - breaking effects of orbital motion , rotation of the binary companion , and roche - lobe overflow ( rlof ) , all of which allow a better description of sn - driven shock compression , heating , and stripping of scs . examined a similar sn impact on ms and he stars with the sph approach using companion models from more sophisticated one - dimensional binary evolutions . |
3,618 | Suppose that you have an abstract for a scientific paper: we use the floquet scattering theory to study the correlation properties of the nonadiabatic pumped dc current and heat flow through a time - dependent quantum well .
electrons can transit through the quasibound state to the oscillator induced floquet states leading to resonant tunneling effect .
virtual electron scattering processes can produce pumped heat flow , pumped shot noise and pumped heat flow noise , with presence of time and spatial reversal symmetry . when one of the floquet levels matches the quasibound level there strikes a fano " resonance . .
And you have already written the first three sentences of the full article: quantum pumping is a transport phenomenon originally proposed by thouless@xcite and first realized by switkes _
et al_.@xcite it proposed that directed current can be induced by time - dependent modulation of external and internal parameters without bias in a quantum phase coherent nanoscale conductor .
theoretical and experimental research of quantum pumping has become a very important and active direction in mesoscopic physics ..
Please generate the next two sentences of the article | it is also significant in the field of quantum dynamic theory . by scale of the modulation frequency
the quantum pump can be categorized into the adiabatic and nonadiabatic ones , with the former frequency much smaller than the characteristic tunneling times and vice the latter@xcite . |
3,619 | Suppose that you have an abstract for a scientific paper: using yang and yang s particle - hole description , we present a thorough derivation of the thermodynamic bethe ansatz equations for a general @xmath0 fermionic system in one - dimension for both the repulsive and attractive regimes under the presence of an external magnetic field .
these equations are derived from sutherland s bethe ansatz equations by using the spin - string hypothesis .
the bethe ansatz root patterns for the attractive case are discussed in detail .
the relationship between the various phases of the magnetic phase diagrams and the external magnetic fields is given for the attractive case .
we also give a quantitative description of the ground state energies for both strongly repulsive and strongly attractive regimes . .
And you have already written the first three sentences of the full article: exactly solvable models of interacting fermions in one - dimension ( 1d ) have attracted theoretical interest for more than half a century . before 1950 , it was not clear how to treat the schrdinger equation for a large system of interacting fermions .
the first important breakthrough was achieved by tomonaga @xcite who showed that fermionic interactions in 1d can mediate new collective degrees of freedom that are approximately bosonic in nature . in 1963
, luttinger @xcite introduced an exactly solvable many - fermion model in 1d which consists of two types of particles , one with positive momentum and the other with negative momentum ..
Please generate the next two sentences of the article | however , luttinger s model suffers from several flaws which include the assumption that the fermions are spinless and massless , and more importantly an improperly filled negative energy dirac sea .
mattis and lieb @xcite expanded on luttinger s work by correctly filling the negative energy states with `` holes '' . before that , lieb and liniger @xcite solved the 1d interacting bose gas with @xmath1-function interactions using bethe s hypothesis @xcite . |
3,620 | Suppose that you have an abstract for a scientific paper: by analyzing the real space nonequilibrium dynamics of polymers , we elucidate the physics of driven translocation and propose its dynamical scaling scenario analogous to that in the surface growth phenomena .
we provide a detailed account of the previously proposed tension - propagation formulation and extend it to cover the broader parameter space relevant to real experiments ; in addition to a near - equilibrium regime , we identify three distinct nonequilibrium regimes reflecting the steady - state property of a dragged polymer with the finite extensibility .
finite size effects are also pointed out .
these elements are shown to be crucial for the appropriate comparison with experiments and simulations . .
And you have already written the first three sentences of the full article: macromolecules can pass through a nanoscopic hole which is much smaller in space dimension than the bulk coil size .
given the chain - like architecture , this fact itself may not be surprising , but the way how it goes threading is interesting . today
, this mode of molecular transport , called translocation , finds its great potentiality in the multidisciplinary field of nano - technology and biological sciences @xcite , e.g. , in inventing nano - pore based rapid dna sequencing devices . in typical situations , a polymer ( with @xmath0 segments ) passes through driven by the force @xmath1 acting at the pore site ..
Please generate the next two sentences of the article | the corresponding setup has been realized in most of experiments , where the charged polymers ( dnas ) are driven by the electric field , and the voltage drop is concentrated in the pore @xcite . from the technological design perspective , one of the most important measure is the translocation time @xmath2 , i.e. , an average passage time for a polymer to go through . for this reason ,
there have been considerable experimental attempts to quantify the translocation time . |
3,621 | Suppose that you have an abstract for a scientific paper: using published measurements of dielectronic recombination ( dr ) resonance strengths and energies for c v to c iv and o viii to o vii , we have calculated the dr rate coefficient for these ions .
our derived rates are in good agreement with multiconfiguration , intermediate - coupling and multiconfiguration , fully - relativistic calculations as well as with most @xmath0 coupling calculations .
our results are not in agreement with the recommended dr rates commonly used for modeling cosmic plasmas .
we have used theoretical radiative recombination ( rr ) rates in conjunction with our derived dr rates to produce a total recombination rate for comparison with unified rr+dr calculations in @xmath0 coupling .
our results are not in agreement with undamped , unified calculations for c v but are in reasonable agreement with damped , unified calculations for o viii .
for c v , the burgess general formula ( gf ) yields a rate which is in very poor agreement with our derived rate .
the burgess & tworkowski modification of the gf yields a rate which is also in poor agreement .
the merts et al .
modification of the gf yields a rate which is in fair agreement . for
o viii the gf yields a rate which is in fair agreement with our derived rate .
the burgess & tworkowski modification of the gf yields a rate which is in good agreement . and the merts et al .
modification yields a rate which is in very poor agreement .
these results suggest that for @xmath1 dr it is not possible to know _ a priori _ which formula will yield a rate closer to the true dr rate .
we describe the technique used to obtain dr rate coefficients from laboratory measurements of dr resonance strengths and energies . for use in plasma modeling
, we also present easy - to - use fitting formulae for the experimentally derived dr rates . .
And you have already written the first three sentences of the full article: carbon and oxygen are two of the most abundant elements in the universe and lines from these elements provide valuable plasma diagnostics for almost all classes of cosmic sources .
essential for many of these diagnostics are accurate electron - ion recombination rate coefficients , particularly of dielectronic recombination ( dr ) , which for most ions in electron - ionized plasmas is the dominant means of electron capture ( arnaud & rothenflug 1985 ) .
producing accurate theoretical dr rate coefficients is , however , theoretically and computationally challenging . in the past ,.
Please generate the next two sentences of the article | semi - empirical expressions such as the burgess ( 1965 ) formula along with modified versions by burgess & tworkowski ( 1976 ) and merts et al .
( 1976 ) were developed to calculate dr rates . |
3,622 | Suppose that you have an abstract for a scientific paper: we propose a fast method to determine the local curvature in two - dimensional ( 2d ) systems with arbitrary shape .
the curvature information , combined with elastic constants obtained for a planar system , provides an accurate estimate of the local stability in the framework of continuum elasticity theory .
relative stabilities of graphitic structures including fullerenes , nanotubes and schwarzites , as well as phosphorene nanotubes , calculated using this approach , agree closely with _
ab initio _ density functional calculations
. the continuum elasticity approach can be applied to all 2d structures and is particularly attractive in complex systems with known structure , where the quality of parameterized force fields has not been established . .
And you have already written the first three sentences of the full article: layered structures including graphite , hexagonal boron nitride , black phosphorus , transition metal dichalcogenides such as mos@xmath0 , and oxides including v@xmath0o@xmath1 are very common in nature .
the possibility to form stable two - dimensional ( 2d ) structures by mechanical exfoliation of these structures appears very attractive for a variety of applications .
the most prominent example of such 2d systems , graphitic carbon , is the structural basis not only of graphene,@xcite but also fullerenes , nanotubes , tori and schwarzites . even though the structural motif in all of these systems may be the same , their mechanical and electronic properties depend sensitively on the local morphology ..
Please generate the next two sentences of the article | not only does the natural abundance of structural allotropes and isomers reflect their net energetic stability , but also the relative chemical reactivity of specific sites in a given structure correlates well with the local curvature and local stability .
this relationship has been well established for the reactive sites in the c@xmath2 fullerene,@xcite used to induce structural collapse leading to chemical unzipping of carbon nanotubes , and to destroy collapsed carbon nanotubes.@xcite and the gaussian curvature @xmath3 on the surface of ( a ) a sphere , ( b ) a cylinder and ( c ) in a saddle point . |
3,623 | Suppose that you have an abstract for a scientific paper: strongly interacting one - dimensional quantum systems often behave in a manner that is distinctly different from their higher - dimensional counterparts . when a particle attempts to move in a one - dimensional environment it will unavoidably have to interact and push other particles in order to execute a pattern of motion , irrespective of whether the particles are fermions or bosons .
a present frontier in both theory and experiment are mixed systems of different species and/or particles with multiple internal degrees of freedom . here
we consider trapped two - component bosons with short - range inter - species interactions much larger than their intra - species interactions and show that they have novel energetic and magnetic properties . in the strongly interacting regime , these systems have energies that are fractions of the basic harmonic oscillator trap quantum and have spatially separated ground states with manifestly ferromagnetic wave functions . furthermore , we predict excited states that have perfect antiferromagnetic ordering .
this holds for both balanced and imbalanced systems , and we show that it is a generic feature as one crosses from few- to many - body systems . .
And you have already written the first three sentences of the full article: the interest in one - dimensional ( 1d ) quantum systems with several interacting particles arguably began back in 1931 when bethe solved the famous heisenberg model of ferromagnetism @xcite , but it was only in the 1960s that people realized that the techniques invented by bethe could be used to solve a host of different many - body models @xcite .
it was subsequently realized that many 1d systems have universal low - energy behaviour and can be described by the paradigmatic tomonaga - luttinger - liquid ( tll ) theory @xcite .
this opened up the field of one - dimensional physics , which has remained a large subfield of condensed - matter physics ever since @xcite ..
Please generate the next two sentences of the article | recently , there has been a great revival of interest in 1d systems due to the realization of 1d quantum gases in highly controllable environments using cold atomic gases @xcite .
this development implies that one may now experimentally realize 1d systems with bosons or fermions and explore the intricate nature of their quantum behaviour . |
3,624 | Suppose that you have an abstract for a scientific paper: we present optical data which shows that g " , the optical counterpart of the @xmath0-ray pulsar geminga , pulses in b with a period of 0.237 seconds .
the similarity between the optical pulse shape and the @xmath0-ray light curve indicates that a large fraction of the optical emission is non - thermal in origin - contrary to recent suggestions based upon the total optical flux .
the derived magnitude of the pulsed emission is @xmath1 . whilst it is not possible to give an accurate figure for the pulsed fraction ( due to variations in the sky background ) we can give an upper limit of @xmath2 for the unpulsed fraction . .
And you have already written the first three sentences of the full article: the nature of the bright @xmath0-ray source geminga remained elusive from the first observations using sas - b ( @xcite ) until its recognition as a pulsar with a period of 0.237 seconds in @xmath0 rays ( @xcite @xcite ) and in x - rays ( @xcite ) . based upon colour considerations an optical candidate was proposed , g " with a m@xmath3 of 25.5 ( @xcite ) .
this star had a measurable proper motion ( @xcite ) indicating a probable distance of about 100 pc and thereby making a probable association with a neutron star .
subsequent hubble space telescope observations have given a distance based upon parallax of @xmath4 pc ( @xcite ) ..
Please generate the next two sentences of the article | optical observations in b showed geminga to be fainter than 26th magnitude ( @xcite ) - a result confirmed by hst observations ( @xcite ) . in v geminga is brighter at 25.4 .
this aspect of the spectrum has been explained by a proton cyclotron feature causing either preferential emission in v or absorption in b and i ( @xcite ) superimposed on a thermal continuum . |
3,625 | Suppose that you have an abstract for a scientific paper: we evaluate in perturbative qcd , up to order @xmath0 , the mass of the @xmath1 .
we use the so - called @xmath2-mass in order to improve the convergence of the perturbative series .
our result is @xmath3 .
non - perturbative effects are discussed .
a comparison with potential models seems to be consistent with non - perturbative contributions of the order @xmath4 . +
pacs numbers : 12.38.aw , 12.38.bx , 14.40.lb , 14.40.nd = 10000 = 5 pt = 24 pt 0.25 cm .
And you have already written the first three sentences of the full article: the discovery of the @xmath1 meson ( the lowest pseudoscalar @xmath5 state of the @xmath6 system ) has been reported in 1998 by the cdf collaboration in the 1.8 tev @xmath7 collisions at the fermilab tevatron @xcite .
the mass has been measured to be @xmath8 gev .
the fact that the mass of the quarks of quark antiquark systems built up by @xmath9 and @xmath10 quarks is much larger than the typical binding energy suggests that these systems are non - relativistic , i.e. that the heavy - quark velocity @xmath11 is small ..
Please generate the next two sentences of the article | the typical scales of these systems are the binding energy @xmath12 and the momentum transfer @xmath13 ; moreover , because of the non - relativistic nature of the system , @xmath14 ( for the purpouses of this discussion @xmath15 and @xmath11 can be identified with the mass and the velocity of the lightest component of the bound state respectively ) .
let us call @xmath16 the scale at which non - perturbative effects become important . |
3,626 | Suppose that you have an abstract for a scientific paper: in an ongoing infrared imaging survey of quasars at keck observatory , we have discovered that the @xmath0 quasar sdss j233646.2 - 010732.6 comprises two point sources with a separation of 167 .
resolved spectra show that one component is a standard quasar with a blue continuum and broad emission lines ; the other is a broad absorption line ( bal ) quasar , specifically , a bal qso with prominent absorption from and metastable , making it a member of the `` felobal '' class .
the number of known felobals has recently grown dramatically from a single example to more than a dozen , including a gravitationally lensed example and the binary member presented here , suggesting that this formerly rare object may be fairly common .
additionally , the presence of this bal quasar in a relatively small separation binary adds to the growing evidence that the bal phenomenon is not due to viewing a normal quasar at a specific orientation , but rather that it is an evolutionary phase in the life of many , if not all , quasars , and is particularly associated with conditions found in interacting systems .
# 1 # 1 .
And you have already written the first three sentences of the full article: the current tally of gravitationally lensed quasars now stands at nearly 70 ( kochanek et al .
the various searches which have contributed to this total have naturally also discovered examples of the apparently rarer phenomenon of binary quasars , of which only @xmath1 systems have been documented ( mortlock , webster , & francis 1999 ; kochanek et al .
2002 ) . while the gravitationally lensed quasars have been intensively studied , binary quasars have not received nearly as much attention , even though binary quasars may provide invaluable insight into various aspects of the quasar phenomenon . of particular importance are the cases where the pair members exhibit strikingly different characteristics , perhaps making it possible to deduce what aspects of the agn environment are responsible for presently little - understood quasar behavior such as radio - loudness , broad or narrow absorption lines , or very red colors ..
Please generate the next two sentences of the article | in addition , physically close binaries also supply limits , statistically at least , on the timescales involved because once within @xmath2 galaxy radius ( @xmath3kpc ) , dynamical considerations limit the binary lifetimes ( mortlock et al .
1999 ) . in an ongoing infrared imaging survey of quasars at keck observatory |
3,627 | Suppose that you have an abstract for a scientific paper: iras 06562@xmath00337 has been the recent subject of a classic debate : proto - planetary nebula or young stellar object ?
we present the first 2@xmath1 image of iras 06562@xmath00337 , which reveals an extended diffuse nebula containing approximately 70 stars inside a 30@xmath2 radius around a bright , possibly resolved , central object .
the derived stellar luminosity function is consistent with that expected from a single coeval population , and the brightness of the nebulosity is consistent with the predicted flux of unresolved low - mass stars .
the stars and nebulosity are spatially coincident with strong co line emission .
we therefore identify iras 06562@xmath00337 as a new young star cluster embedded in its placental molecular cloud .
the central object is likely a herbig be star , @xmath3 , which may be seen in reflection .
we present medium resolution , high s / n , 1997 epoch optical spectra of the central object .
comparison with previously published spectra shows new evidence for time variable permitted and forbidden line emission , including , , [ ] , and [ ] .
we suggest the origin is a dynamic stellar wind in the extended , stratified atmosphere of the massive central star in iras 06562@xmath00337 . .
And you have already written the first three sentences of the full article: garcia - lario , manchado , sahu , and pottasch ( 1993 , hereafter gmsp ) present the first detailed analysis of iras 06562@xmath00337 .
they argue that it is a proto - planetary nebula ( ppn ) undergoing final mass - loss episodes .
their time - series of optical spectra , obtained over a 5 year period , show the onset of forbidden line emission and the possible evolution of the central star toward hotter temperatures ..
Please generate the next two sentences of the article | they derive a zanstra temperature of 2@xmath410@xmath5 k , with a slight increase over a two year interval .
the effective temperature of the exciting star , t@xmath6 @xmath7 3.6@xmath410@xmath5 k , also showed a slight increase in two years . |
3,628 | Suppose that you have an abstract for a scientific paper: a vector field on a riemannian manifold is called geodesic if its integral curves are reparametrized geodesics .
we classify compact khler manifolds admitting nontrivial real - holomorphic geodesic gradient vector fields that satisfy an additional integrability condition .
they are all biholomorphic to bundles of complex projective spaces .
0.5 un champ de vecteurs sur une varit riemannienne est dit godsique si ses courbes intgrales sont godsiques non paramtrs . on classifie des
varits khlriennes compactes qui admettent des gradients godsiques rels -.64ptholomorphes -.64ptnon -.64pttriviaux -.64ptsatisfaisant -.64pt -.64ptune -.64ptcondition -.64ptadditionnelle -.64ptdintgrabilit .
elles sont toutes biholomorphes fibrs en espaces projectifs complexes
. [ section ] [ theorem]lemma [ theorem]corollary [ theorem]proposition [ theorem]claim [ theorem]definition [ theorem]remark [ theorem]example [ theorem]notation .
And you have already written the first three sentences of the full article: we say that a vector field on a riemannian manifold is geodesic if its integral curves are reparametrized geodesics .
the present paper discusses@xmath0 we observe ( remark [ dppdm ] ) that for @xmath1 and @xmath2 , where @xmath3 and @xmath4 are the maximum and minimum level sets of @xmath5 , one then has @xmath6 and every @xmath7 satisfying ( [ ddm ] ) is realized by some @xmath8 with ( [ trp ] ) .
one of our three main results , theorem [ cpbdl ] , classifies the triples ( [ trp ] ) such that @xmath9 here @xmath10 , while @xmath11 sends each @xmath12 to the unique point nearest @xmath13 in @xmath14 ..
Please generate the next two sentences of the article | ( in case ( [ trp ] ) @xmath15 always are disk - bundle projections , and their vertical distributions @xmath16 span a vector subbundle of @xmath17 , cf
. section [ cc ] ; however , ( [ trp ] ) does not imply ( [ spn ] ) see remark [ nintg ] . ) as a consequence of theorem [ cpbdl ] , in every triple with ( [ trp ] ) and ( [ spn ] ) , @xmath18 the remaining two main results of the paper , theorems [ tgimm ] and [ dicho ] , deal with the general case of ( [ trp ] ) , that is , do not assume ( [ spn ] ) . according to theorem [ tgimm ] , whenever @xmath19 is a leaf of either ( obviously integrable ) vertical distribution @xmath20 , the other projection @xmath21 maps @xmath22 onto the image @xmath23 of some totally geodesic holomorphic immersion @xmath24 inducing on @xmath25 a multiple of the fubini - study metric , with @xmath26 given by @xmath27 . |
3,629 | Suppose that you have an abstract for a scientific paper: we study non - spinning @xmath0-balls and boson stars in 4-dimensional anti - de sitter ( ads ) space - time .
we use an exponential scalar field potential that appears in gauge - mediated supersymmetry ( susy ) breaking in the minimal supersymmetric extension of the standard model ( mssm ) .
we investigate the dependence of the charge and mass of these non - topological solitons on the negative cosmological constant , the frequency that appears in the periodic time - dependence as well as on the ratio between the susy breaking scale and the planck mass .
next to fundamental solutions without nodes in the scalar field function we also construct radially excited solutions . in the second part of the paper we put the emphasis on the holographic interpretation of these solutions in terms of bose - einstein condensates of scalar glueballs that are described by a strongly coupled quantum field theory ( qft ) on the boundary of global ads .
pacs numbers : 04.40.-b , 11.25.tq .
And you have already written the first three sentences of the full article: solitons play an important role in many areas of physics . as classical solutions of non - linear field theories
, they are localized structures with finite energy , which are globally regular . in general
, one can distinguish between topological and non - topological solitons ..
Please generate the next two sentences of the article | while topological solitons @xcite possess a conserved quantity , the topological charge , that stems ( in most cases ) from the spontaneous symmetry breaking of the theory , non - topological solitons @xcite have a conserved noether charge that results from a symmetry of the lagrangian .
the standard example of non - topological solitons are @xmath0-balls @xcite , which are solutions of theories with self - interacting complex scalar fields . |
3,630 | Suppose that you have an abstract for a scientific paper: the monitored drift tube ( mdt ) chambers for the muon spectrometer of the atlas detector at the large hadron collider ( lhc ) consist of 34 layers of pressurised drift tubes on either side of a space frame carrying an optical deformation monitoring system .
the chambers have to provide a track position resolution of @xmath0 m with a single - tube resolution of at least @xmath1 m and a sense wire positioning accuracy of @xmath2 m ( rms ) .
the feasibility was demonstrated with the full - scale prototype of one of the largest mdt chambers with 432 drift tubes of 3.8 m length .
for the atlas muon spectrometer , 88 chambers of this type have to be built .
the first chamber has been completed with a wire positioning accuracy of @xmath3 m ( rms ) .
drift tubes , drift chambers , muon spectrometer , atlas detector .
And you have already written the first three sentences of the full article: the muon spectrometer of the atlas experiment @xcite will be operated in the toroidal magnetic field of a superconducting air - core magnet system with 36 tm bending power.it is designed to provide stand - alone muon momentum resolution of @xmath4 for transverse momenta between 6 gev and 1 tev over a pseudo - rapidity range of @xmath5 .
this requires very accurate track sagitta measurement with three layers of muon chambers and high - precision optical alignment monitoring systems .
precision drift chambers , the monitored drift tube ( mdt ) chambers , have been developed to provide a track position resolution of @xmath0 m over an active area of 5500 m@xmath6 . ] ] ] ] ] ] lcc + parameter & x - ray fit & design value + @xmath7-pitch @xmath8m@xmath9 $ ] & @xmath10 & @xmath11 + @xmath12-pitch @xmath8m@xmath9 $ ] & @xmath13 & @xmath14 + @xmath15 @xmath16mm@xmath9 $ ] & @xmath17 & @xmath18 + @xmath19 @xmath8m@xmath9 $ ] & @xmath20 & @xmath21 + + parameter & x - ray fit & design value + @xmath7-pitch @xmath8m@xmath9 $ ] & @xmath22 & @xmath11 + @xmath12-pitch @xmath8m@xmath9 $ ] & @xmath13 & @xmath14 + @xmath15 @xmath16mm@xmath9 $ ] & @xmath23 & @xmath24 + @xmath19 @xmath8m@xmath9 $ ] & @xmath25 & @xmath21 + & & + [ -2 mm ] + parameter & x - ray fit & design value + @xmath7-pitch @xmath8m@xmath9 $ ] & @xmath26 & @xmath27 + @xmath12-pitch @xmath8m@xmath9 $ ] & @xmath28 & @xmath14 + @xmath15 @xmath16mm@xmath9 $ ] & @xmath29 & @xmath30 + @xmath19 @xmath8m@xmath9 $ ] & @xmath31 & @xmath21 + + parameter & x - ray fit & design value + @xmath7-pitch @xmath8m@xmath9 $ ] & @xmath32 & @xmath27 + @xmath12-pitch @xmath8m@xmath9 $ ] & @xmath28 & @xmath14 + @xmath15 @xmath16mm@xmath9 $ ] & @xmath33 & @xmath30 + @xmath19 @xmath8m@xmath9 $ ] & @xmath34 & @xmath21 + lccc + & high voltage end & readout end & center + @xmath7-coord . @xmath8m@xmath9 $ ] & @xmath35 & @xmath36 & 15.0 + @xmath12-coord . @xmath8m@xmath9 $ ] & @xmath37 & @xmath38 &....
Please generate the next two sentences of the article | @xmath8m@xmath9 $ ] & 14.3 & 15.3 & 13.2 + @xmath12-coord . @xmath8m@xmath9 $ ] & 10.5 & 14.1 & 7.7 + combined @xmath8m@xmath9 $ ] & & 10.5 + ] ] ] ] of the measured @xmath7 coordinates of the wires in the 6 tube layers ( distances between layers compressed ) with respect to the expected wire grid at the readout end of the bos 98 prototype chamber .
the uncompensated cross plate deformations during assembly of each layer are indicated . |
3,631 | Suppose that you have an abstract for a scientific paper: effects of presence of ions , at moderate to high concentrations , on dynamical properties of water molecules are investigated through classical molecular dynamics simulations using two well known non - polarizable water models .
simulations reveal that the presence of magnesium chloride ( mgcl@xmath0 ) induces perturbations in the hydrogen bond network of water leading to the formation of bulk - like domains with defect sites on boundaries of such domains : water molecules at such defect sites have less number of hydrogen bonds than those in bulk water .
reorientational autocorrelation functions for dipole vectors of such defect water molecules are computed at different concentrations of ions and compared with system of pure water .
earlier experimental and simulation studies indicate significant differences in reorientational dynamics for water molecules in the first hydration shell of many dissolved ions .
results of this study suggest that defect water molecules , which are beyond the first hydration shells of ions , also experience significant slowing down of reorientation times as a function of concentration in the case of mgcl@xmath0 . however , addition of cesium chloride(cscl ) to water does not perturb the hydrogen bond network of water significantly even at higher concentrations .
this difference in behavior between mgcl@xmath0 and cscl is consistent with the well - known hofmeister series . .
And you have already written the first three sentences of the full article: effects of simple inorganic salts on the molecular properties of water are at the heart of a vast number of interesting and complex processes such as the stability of proteins and nucleic acids @xcite and environmentally relevant processes @xcite . understanding the effect of dissolved ions on the structural and dynamical properties of water is essential in this regard . the hofmeister effect , which includes highly ion - specific effects on aggregation dynamics of proteins @xcite and other biologically relevant processes @xcite has been of significant interest lately .
spectroscopic techniques have been instrumental in probing the cooperative ion hydration mechanism and consequent long - range structural and dynamical effects of certain salts , or ion combinations , on water @xcite .
earlier experiments suggested that the effect of ions on dynamical properties of water is largely restricted to their first hydration shell @xcite ..
Please generate the next two sentences of the article | however , recent experiments , using a combination of femtosecond time resolved infrared ( fs - ir ) and dielectric relaxation spectroscopy , have shown the existence of a fraction of reorientationally slow water molecules @xcite well beyond the first hydration shells of dissolved mgso@xmath1 ions . in these experiments ,
two sub - populations of water molecules were identified for various salts : one with reorientation timescales comparable to pure water ( @xmath22.6 ps ) and the other showing characteristically slower reorientations ( @xmath210 ps ) . |
3,632 | Suppose that you have an abstract for a scientific paper: we review a novel approach to evaluate the ground - state properties of many - body lattice systems based on an exact probabilistic representation of the dynamics and its long time approximation via a central limit theorem .
the choice of the asymptotic density probability used in the calculation is discussed in detail . .
And you have already written the first three sentences of the full article: the real- or imaginary - time dynamics of systems described by a finite hamiltonian matrix , representing bosonic or fermionic degrees of freedom , admits an exact probabilistic representation in terms of a proper collection of independent poisson processes @xcite . for a lattice system
, the poisson processes are associated to the links of the lattice and the probabilistic representation leads to an optimal algorithm @xcite which coincides with the green function quantum monte carlo method in the limit when the latter becomes exact @xcite . in the recent ref .
we have exploited the above probabilistic representation to derive analytical expressions for the matrix elements of the evolution operator in the long time limit . in this way ,.
Please generate the next two sentences of the article | the ground - state energy as well as the expectation of a generic operator in the ground state of a lattice system without sign problem are obtained as the solution of a simple scalar equation .
the result is based on the application of a central limit theorem to the rescaled multiplicities of the values assumed by the potential and hopping energies in the configurations dynamically visited by the system . as a consequence |
3,633 | Suppose that you have an abstract for a scientific paper: qcd sum rules are used to calculate the @xmath0 dependence of the @xmath1 coupling @xmath2 in the spacelike region @xmath3 .
we study the borel sum rule for the three point function of one pseudoscalar and two nucleon currents up to order four in the operator product expansion .
the borel transform is performed with respect to the nucleon momenta , whereas the momentum @xmath0 of the pseudoscalar vertex is kept fixed at spacelike values .
the results can be well fitted using a monopole form with a cutoff mass of about @xmath4 . .
And you have already written the first three sentences of the full article: the pion nucleon form factor @xmath2 plays a very important , but not less controversial role in the framework of @xmath5 and @xmath6 dynamics . in general ,
meson baryon form factors are used in one boson exchange potentials ( obep ) for the @xmath6 force in order to account for the microscopic , i.e. quark and gluon structure of the mesons and baryons at a given vertex , and therefore provide a natural cutoff description for the interaction potential at short distances .
most of the realistic obep fit the data with a monopole form for the @xmath1 form factor @xmath7 with a large monopole mass @xmath8 @xcite ..
Please generate the next two sentences of the article | on the other hand almost all other hadronic theories advocate a much softer form factor with @xmath9 : chiral soliton and quark models for the nucleon @xcite , the goldberger - treiman discrepancy between @xmath10 and @xmath11 @xcite , general considerations on the structure of the @xmath1 vertex @xcite , charge exchange reactions @xcite , threshold @xmath12 production @xcite , deep inelastic lepton nucleon scattering ( sullivan process ) @xcite .
more recent studies within the obep , which either include the @xmath13 resonance @xcite , use a different form of the scalar exchange potential @xcite or consider a correlated @xmath14exchange @xcite also indicate a softer cutoff mass ( @xmath15 ) . for these reasons it seems highly desirable to perform a calculation of @xmath2 , which does not suffer from the ambiguities of the model and parameterization schemes mentioned above and |
3,634 | Suppose that you have an abstract for a scientific paper: the pure penguin process @xmath0 is one of the most important probes of physics beyond the standard model .
recently babar and belle have measured the unexpectedly large transverse polarization in the decays @xmath0 , which may single out new physics effects beyond the standard model .
we study the possibility that the phenomenon could serve as an important probe of anomalous tensor interactions . we find that a spin flipped tensor interaction with a small strength and a phase could give a possible solution to the polarization puzzle . + * pacs numbers 13.25.hw , 12.60.jv * ( 0,0 ) looking for signals of physics beyond the standard model is one of the most important missions of high energy physics .
it is well known that flavor - changing neutral currents induced in @xmath1 decays are one of the best probes of new physics beyond the standard model because they arise only through loop effects in the standard model ( sm ) . to this end , the decays @xmath0 are of particular interests , since they are pure penguin processes and have interesting polarization phenomena as well as relatively clear experiment signature . within the sm
, it is expected that both @xmath2 and @xmath3 are mainly longitudinally polarized , while its transverse polarization is suppressed by the power of @xmath4 . however , last year both babar and belle had observed rather small longitudinal polarizations in the decays @xmath5 due to @xmath6 , both groups have measured unexpectedly large transverse polarizations in the @xmath7 decays . this summer babar collaboration has again reported their full angular analysis of the the decay @xmath8
@xcite @xmath9 which has confirmed their previous measurements and called urgent theoretical explanations . the final states @xmath2 and @xmath10 are fast moving in the @xmath1 meson frame and any spin flip of fast flying quark will be suppressed by power of @xmath11 .
the charge interaction currents structure of the sm is left - handed , therefore , will result in the dominance....
And you have already written the first three sentences of the full article: the work of c.s.k . was supported by grant no . r02 - 2003 - 000 - 10050 - 0 from brp of the kosef .
y.d . is supported in part by nfsc under contract no.10305003 , henan provincial foundation for prominent young scientists under contract no.0312001700 and in part by the project sponsored by srf for rocs , sem .
this work is also supported by grant no ..
Please generate the next two sentences of the article | f01 - 2004 - 000 - 10292 - 0 of kosef - nsfc international collaborative research grant . |
3,635 | Suppose that you have an abstract for a scientific paper: lkca 15 hosts a pre - transitional disk as well as at least one accreting protoplanet orbiting in its gap .
previous disk observations have focused mainly on the outer disk , which is cleared inward of @xmath050au .
the planet candidates , on the other hand , reside at orbital radii around 15au , where disk observations have been unreliable until recently . here we present new @xmath1-band imaging polarimetry of lkca 15 with sphere irdis , yielding the most accurate and detailed scattered - light images of the disk to date down to the planet - hosting inner regions .
we find what appear to be persistent asymmetric structures in the scattering material at the location of the planet candidates , which could be responsible at least for parts of the signals measured with sparse - aperture masking .
these images further allow us to trace the gap edge in scattered light at all position angles and search the inner and outer disks for morphological substructure .
the outer disk appears smooth with slight azimuthal variations in polarized surface brightness , which may be due to shadowing from the inner disk or a two - peaked polarized phase function .
we find that the near - side gap edge revealed by polarimetry matches the sharp crescent seen in previous adi imaging very well . finally , the ratio of polarized disk to stellar flux is more than six times larger in @xmath1-band than in the @xmath2 bands .
= 1 .
And you have already written the first three sentences of the full article: transitional disks have properties that can be interpreted as intermediate between the protoplanetary and debris disk phases , with an optically thick outer disk and typically a wide ( tens of au ) gap within ( e.g. , * ? ? ?
* ; * ? ? ?
one possible origin for such gaps is dynamical clearing by forming planets ..
Please generate the next two sentences of the article | the transitional disk host lkca 15 has emerged as a benchmark target for this scenario .
lkca 15 is a k5-type star at a distance of @xmath0140pc located in the taurus - auriga star - forming region @xcite . |
3,636 | Suppose that you have an abstract for a scientific paper: the phase diagram of a system constituted of neutrons , protons , @xmath0-hyperons and electrons is evaluated in the mean - field approximation in the complete three - dimensional space given by the baryon , lepton and strange charge .
it is shown that the phase diagram at sub - saturation densities is strongly affected by the electromagnetic interaction , while it is almost independent of the electric charge at supra - saturation density . as a consequence ,
stellar matter under the condition of strangeness equilibrium is expected to experience a first as well as a second - order strangeness - driven phase transition at high density , while the liquid - gas phase transition is expected to be quenched .
an rpa calculation indicates that the presence of this critical point might have sizable implications for the neutrino propagation in core - collapse supernovae . .
And you have already written the first three sentences of the full article: supernova explosions following the gravitational collapse of a massive star ( @xmath1 ) are among the most fascinating events in the universe as they radiate as much energy as the sun is expected to emit over its whole life span @xcite .
nuclear physics is an essential ingredient in the numerical simulations which aim to describe these events , since realistic astrophysical descriptions of the collapse and post - bounce evolution rely on the accuracy of the implementation of weak processes and equation(s ) of state ( eos ) @xcite .
determining the eos constitutes a particularly difficult task since phenomenology ranges from a quasi - ideal un - homogeneous gas to strongly interacting uniform matter and , potentially , deconfined quark - matter ..
Please generate the next two sentences of the article | the situation is even more difficult if phase transitions are experienced , since mean - field models fail in such situations @xcite . the coulomb - quenched liquid - gas ( lg ) phase transition taking place at densities smaller than the nuclear saturation density ( @xmath2 @xmath3 ) is , probably , the most notorious and best understood case @xcite . at highest densities
, a quark - gluon plasma is expected , but predictions on the exact location of the transition are strongly model dependent @xcite . in the intermediate density domain |
3,637 | Suppose that you have an abstract for a scientific paper: we present deep hubble space telescope ( hst ) nicmos 2 band observations of the central 56@xmath057 ( [email protected] ) region around r136 in the starburst cluster 30 dor ( ngc 2070 ) located in the large magellanic cloud .
our aim is to derive the stellar initial mass function ( imf ) down to @xmath11 m@xmath2 in order to test whether the imf in a massive metal
poor cluster is similar to that observed in nearby young clusters and the field in our galaxy .
we estimate the mean age of the cluster to be 3 myr by combining our photometry with previously obtained hst wfpc2 optical and band photometry and comparing the stellar locus in the color magnitude diagram with main sequence and pre main sequence isochrones . the color
magnitude diagrams show the presence of differential extinction and possibly an age spread of a few myr .
we convert the magnitudes into masses adopting both a single mean age of 3 myr isochrone and a constant star formation history from 2 to 4 myr .
we derive the imf after correcting for incompleteness due to crowding .
the faintest stars detected have a mass of 0.5 m@xmath2 and the data are more than 50% complete outside a radius of 5 pc down to a mass limit of 1.1 m@xmath2 for 3 myr old objects .
we find an imf of @xmath3 over the mass range 1.120 m@xmath2 only slightly shallower than a salpeter imf .
in particular , we find no strong evidence for a flattening of the imf down to 1.1 m@xmath2 at a distance of 5 pc from the center , in contrast to a flattening at 2 m@xmath2 at a radius of 2 pc , reported in a previous optical hst study .
flattening at 2 m@xmath2 at a radius of 2 pc previously found .
we examine several possible reasons for the different results including the possible presence of mass segregation and the effects of differential extinction , particularly for the pre
main sequence sources .
if the imf determined here applies to the whole cluster , the cluster would be massive enough to remain bound and evolve into a relatively low mass....
And you have already written the first three sentences of the full article: the shape of the stellar initial mass function ( imf ) and whether it is universal or not are key issues in astrophysics . for clusters within 2 kpc , there is no compelling evidence for variations in the stellar imf ( e.g. * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ) or the brown dwarf imf ( e.g. * ? ? ?
* ) . however , these clusters only span a limited range in total cluster mass ( @xmath4 m@xmath2 ) and all have a metallicity similar to the solar value . |
3,638 | Suppose that you have an abstract for a scientific paper: we study repeated games where players use an exponential learning scheme in order to adapt to an ever - changing environment .
if the game s payoffs are subject to random perturbations , this scheme leads to a new stochastic version of the replicator dynamics that is quite different from the `` aggregate shocks '' approach of evolutionary game theory .
irrespective of the perturbations magnitude , we find that strategies which are dominated ( even iteratively ) eventually become extinct and that the game s strict nash equilibria are stochastically asymptotically stable .
we complement our analysis by illustrating these results in the case of congestion games . and . .
And you have already written the first three sentences of the full article: ever since it was introduced in @xcite , the notion of a nash equilibrium and its refinements have remained among the most prominent solution concepts of noncooperative game theory . in its turn , not only has noncooperative game theory found applications in such diverse topics as economics , biology and network design , but it has also become the standard language to actually _ describe _ complex agent interactions in these fields . still , the issue of why and how players may arrive to equilibrial strategies in the first place remains an actively debated question .
after all , the complexity of most games increases exponentially with the number of players and , hence , identifying a game s equilibria quickly becomes prohibitively difficult .
accordingly , as was first pointed out by aumann in @xcite , a player has no incentive to play his component of a nash equilibrium unless he is convinced that all other players will play theirs . and.
Please generate the next two sentences of the article | if the game in question has multiple nash equilibria , this argument gains additional momentum : in that case , even players with unbounded deductive capabilities will be hard - pressed to choose a strategy . from this point of view
, rational individuals would appear to be more in tune with aumann s notion of a correlated equilibrium where subjective beliefs are also taken into account @xcite . |
3,639 | Suppose that you have an abstract for a scientific paper: quality of microarray gene expression data has emerged as a new research topic . as in other areas ,
microarray quality is assessed by comparing suitable numerical summaries across microarrays , so that outliers and trends can be visualized , and poor quality arrays or variable quality sets of arrays can be identified .
since each single array comprises tens or hundreds of thousands of measurements , the challenge is to find numerical summaries which can be used to make accurate quality calls . to this end ,
several new quality measures are introduced based on probe level and probeset level information , all obtained as a by - product of the low - level analysis algorithms rma / fitplm for affymetrix genechips .
quality landscapes spatially localize chip or hybridization problems .
numerical chip quality measures are derived from the distributions of _ normalized unscaled standard errors _ and of _ relative log expressions . _
quality of chip batches is assessed by _ residual scale factors . _
these quality assessment measures are demonstrated on a variety of datasets ( spike - in experiments , small lab experiments , multi - site studies ) .
they are compared with affymetrix s individual chip quality report . *
_ to be published in technometrics ( with discussion ) _ * * julia brettschneider @xmath0 , franois collin , benjamin m.bolstad , terence p.speed * * quality assessment for * + + keywords : quality control , microarrays , affymetrix chips , relative log expression , normalized unscaled standard errors , residual scale factors . .
And you have already written the first three sentences of the full article: with the introduction of microarrays biologist have been witnessing entire labs shrinking to matchbox size .
this paper invites quality researchers to join scientists on their _ fantastic journey _ into the world of microscopic high - throughput measurement technologies . building a biological organism as laid out by the genetic code
is a multi - step process with room for variation at each step ..
Please generate the next two sentences of the article | the first steps , as described by the _ dogma of molecular biology , _ are genes ( and dna sequence in general ) , their transcripts and proteins .
substantial factors contributing to their variation in both structure and abundance include cell type , developmental stage , genetic background and environmental conditions . |
3,640 | Suppose that you have an abstract for a scientific paper: the circular noise is important in connection to mach s principle , and also as a possible probe of the unruh effect . in this letter
the power spectrum of the detector following the trocheries - takeno motion in the minkowski vacuum is analytically obtained in the form of an infinite series .
a mean distribution function and corresponding energy density are obtained for this particular detected noise .
the analogous of a non constant temperature distribution is obtained . and
in the end , a brief discussion about the equilibrium configuration is given .
key words : circular unruh effect the non inertial vacuum , and the noise associated to it , has been extensively studied .
it is called fulling - davies - unruh effect , after the discoverers @xcite .
the more simple situation of proper constant acceleration , is already very well understood .
for instance , a free scalar field can be quantized in rindler coordinates .
the vacuum obtained in these coordinates is unitary inequivalent to the minkowski vacuum .
the monopole type detector introduced by dewitt @xcite , can give a meaning to these vacua .
a detector at rest in rindler coordinates is equivalent to an accelerated one in minkowski space . as a consequence of poincar invariance , a detector in inertial motion in vacuum ,
does not get excited .
this can also be understood in the detailed balance context of @xcite .
the authors used the ddc @xcite formalism to obtain the einstein coefficients for spontaneous excitation and emition . for non inertial motion
the balance of the coefficients is upset , resulting in the unruh effect .
the thermal character of the noise in the kms sense , and the verification of other consistencies are reviewed in @xcite .
in @xcite it is shown the connection between the absorptions of particles and the noise to which the detector is submitted .
the rotational motion is different . besides its own importance connected to the concept of inertia ,
this motion is of....
And you have already written the first three sentences of the full article: the author acknowledges the brazilian agencies funpe and finatec for partial support , and an anonymous referee for improvements .
99 unruh w g 1976 _ phys .
* 14 * 870 ; davies p c w 1975 _ j. phys . a _ * 8 * 609 ; fulling s a 1973 _ phys . rev.
Please generate the next two sentences of the article | . d _ * 10 * 2850 dewitt b s 1979 in _ general relativity _
s. w. hawking and w. israel ( cambridge university press ) p. 680 |
3,641 | Suppose that you have an abstract for a scientific paper: the presence of a light @xmath0 squark ( @xmath1gev ) and gluino ( @xmath2gev ) might explain the observed excess in @xmath3-quark production at the tevatron .
though provocative , this model is not excluded by present data .
the light supersymmetric particles can induce large flavor - changing effects in radiative decays of @xmath4 mesons .
we analyse the decays @xmath5 and @xmath6 in this scenario and derive restrictive bounds on the flavor - changing quark - squark - gluino couplings . clns 02/1790 + slac - pub-9230 + hep - ph/0205274 + may 24 , 2002 * constraints on light bottom squarks from + radiative
b - meson decays * thomas becher + _ stanford linear accelerator center + stanford university , stanford , ca 94309 , usa _
+ stephan braig , matthias neubert + _ newman laboratory of elementary - particle physics , cornell university + ithaca , ny 14853 , usa _ + alexander l. kagan + _ fermi national accelerator laboratory + batavia , il 60510 , usa _ .
And you have already written the first three sentences of the full article: the measured @xmath3-quark production cross section at hadron colliders exceeds next - to - leading order ( nlo ) qcd predictions by more than a factor of two .
while it is conceivable that this discrepancy is due to higher - order corrections , the disagreement is surprising since nlo calculations have been reliable for other processes in this energy range .
berger et al . have analysed @xmath3-quark production in the context of the minimal supersymmetric standard model ( mssm ) and find that the excess in the cross section could be attributed to gluino pair - production followed by gluino decay into pairs of @xmath3 quarks and @xmath0 squarks , if both the gluino and the @xmath0 squark are sufficiently light @xcite ..
Please generate the next two sentences of the article | in order to reproduce the transverse - momentum distribution of the @xmath3 quarks , the masses of the gluino and light @xmath0-squark mass eigenstate should be in the range @xmath716gev and @xmath85.5gev .
the masses of all other supersymmetric ( susy ) particles are assumed to be large , of order several hundred gev , so as to have evaded detection at lep2 . |
3,642 | Suppose that you have an abstract for a scientific paper: using state - of - the - art first - principles calculations we study the properties of the ferromagnetic heusler compounds niysi where y stands for v , cr or mn .
nicrsi and nimnsi contrary to nivsi are half - metallic at their equilibrium lattice constant exhibiting integer values of the total spin magnetic moment and thus we concentrate on these two alloys .
the minority - spin gap has the same characteristics as for the well - known nimnsb alloy being around @xmath01 ev .
upon tetragonalization the gap is present in the density of states even for expansion or contraction of the out - of - plane lattice parameter by 5% .
the cr - cr and mn - mn interactions make ferromagnetism extremely stable and the curie temperature exceeds 1000 k for nimnsi .
surface and interfaces with gap , zns and si semiconductors are not half - metallic but in the case of nicrsi the ni - based contacts present spin - polarization at the fermi level over 90% .
finally , we show that there are two cases of defects and atomic - swaps .
the first - ones which involve the cr(mn ) and si atoms induce states at the edges of the gap which persists for a moderate - concentration of defects .
defects involving ni atoms induce states localized within the gap completely destroying the half - metallicity . based on single - impurity calculations we associate these states to the symmetry of the crystal . .
And you have already written the first three sentences of the full article: magnetoelectronics , also known as spintronics , is probably the field with the most rapid growth in materials science bringing to the center of scientific research new phenomena.@xcite for researchers dealing with ab - initio calculations one of the most interesting concept in spintronics is the half - metallicity.@xcite research has been focused initially on the explanation of the origin of the half - metallicity and afterwards on the prediction of new half - metallic materials with potential applications in spintronics devices .
half - metals are hybrids between normal metals and semiconductors : the majority - spin band is crossed by the fermi level as in a normal metal while the fermi level falls within a gap in the minority - spin band as in semiconductors leading to a perfect 100% spin - polarization at the fermi level,@xcite maximizing the efficiency of magnetoelectronic devices.@xcite de groot and his collaborators in 1983 were the first to predict the existence of half - metallicity in the case of the intermetallic semi - heusler alloy nimnsb,@xcite and the origin of the gap seems to be well understood .
@xcite there exist several ab - initio calculations on nimnsb reproducing the initial results of de groot and collaborators,@xcite and galanakis _ et al ..
Please generate the next two sentences of the article | _ showed that the gap arises from the hybridization between the @xmath1 orbitals of the ni and mn atoms.@xcite moreover in the latter reference it was shown that the total spin moment for the heusler alloys of the nimnsb type follows a slater - pauling behavior being in @xmath2 the total number of valence electrons in the unit cell minus 18 since there are exactly nine occupied minority - spin states.@xcite theoretical calculations for the interfaces of these materials with the semiconductors are few and all results agree that in general the half - metallicity is lost both at the surfaces@xcite and the interfaces with binary semiconductors.@xcite wijs and de groot have argued than in the case of the nimnsb / cds ( 111 ) contacts the sb / s interface keeps half - metallicity when the s atoms sit exactly on top of sb.@xcite moreover taking into account also the reconstruction at the surfaces and interfaces can have an important effect on their properties.@xcite finally we should note that several other aspects of nimnsb have been studied using first - principles calculations like the exchange constants and curie temperatures,@xcite the quasiparticle states@xcite and the dynamical effects,@xcite the defects and doping,@xcite the structural stability,@xcite the effect of spin - orbit coupling,@xcite the fit of model hamiltonians to describe nimnsb,@xcite orbital magnetism,@xcite the pressure and thermal expansion effects,@xcite the temperature effect@xcite and the magneto - optical properties.@xcite the half - metallic character of nimnsb in single crystals has been well - established experimentally .
infrared absorption@xcite and spin - polarized positron - annihilation@xcite gave a spin - polarization of @xmath0100% at the fermi level . |
3,643 | Suppose that you have an abstract for a scientific paper: we consider the problem of convergence in stratified isothermal shearing boxes with zero net magnetic flux .
we present results with the highest resolution to - date up to 200 grid - point per pressure scale height that show no clear evidence of convergence .
rather , the maxwell stresses continue to decrease with increasing resolution .
we propose some possible scenarios to explain the lack of convergence based on multi - layer dynamo systems . .
And you have already written the first three sentences of the full article: the magneto - rotational instability ( mri ) and magneto - rotational turbulence ( mrt ) provide an elegant framework to study the origin of enhanced angular momentum transport in accretion discs .
much effort has been devoted to understanding the nonlinear development of the mri and the processes that control the saturation amplitude of the instability , since , ultimately this controls the transport efficiency .
because of the difficulties inherent in approaching a strongly nonlinear problem analytically , much of the work on mrt has relied on numerical simulations with all their attendant idealizations and approximations . by far the most popular is the shearing - box approximation in which the computational domain is restricted to a region of small radial extent at a large radius in the disc . under reasonable assumptions.
Please generate the next two sentences of the article | this can be mapped into a cartesian layer with shearing - periodic boundary conditions in the radial direction . because the shearing - box approximation conserves vertical magnetic flux it is important to distinguish two types of simulations : those with finite initial ( vertical ) flux and those with zero initial flux .
if the flux is finite there is a linear instability with a well defined growth rate and wavelength of maximum growth whose values are determined by the amount of flux @xcite . in the nonlinear regime |
3,644 | Suppose that you have an abstract for a scientific paper: we study a system of polar dipolar fermions in a two - dimensional optical lattice and show that multi - band fermi - hubbard model is necessary to discuss such system . by taking into account both on - site , and long - range interactions between different bands , as well as occupation - dependent inter- and intra - band tunneling
, we predict appearance of novel phases in the strongly - interacting limit . .
And you have already written the first three sentences of the full article: creation of ultracold hetero - nuclear molecules opens the path towards experimental realization of strongly - interacting dipolar many - body systems .
depending on the constituent atoms , in moderate electric field these molecules can have large dipole moment of @xmath0 debye in their vibrational ground states @xcite .
in particular , fermionic molecules in presence of an optical lattice can be used to simulate various quantum phases , such as quantum magnetism and phases of @xmath1 like models @xcite , various charge density wave orders @xcite , bond - order solids @xcite etc ..
Please generate the next two sentences of the article | one should also stress that in the strongly correlated regime , both in bosonic and fermionic systems the standard descriptions of single - band hubbard model ceases to be valid .
the effect of non - standard terms become important leading to novel phases like pair - superfluidity etc @xcite . while most of the works have dealing with higher bands concentrated on bosonic systems , in this paper , we study dipolar fermions confined in 2d optical lattice @xmath2 + \frac{m\omega^2}{2}z^2 $ ] , where @xmath3 is the lattice depth , @xmath4 is the lattice constant , @xmath5 is the mass of the molecule , and @xmath6 is the frequency of harmonic potential in @xmath7 direction . |
3,645 | Suppose that you have an abstract for a scientific paper: we discuss non - conformal gauge theories from type iib d3-branes embedded in orbifolded space - times .
such theories can be obtained by allowing some non - vanishing logarithmic twisted tadpoles . in certain cases with @xmath0 supersymmetry correlation functions in the planar limit
are the same as in the parent @xmath1 supersymmetric theories .
in particular , the effective action in such theories perturbatively is not renormalized beyond one loop in the planar limit . in the @xmath1 as well as
such @xmath0 theories quantum corrections in the d3-brane gauge theories are encoded in the corresponding classical higher dimensional field theories whose actions contain the twisted fields with non - vanishing tadpoles .
we argue that this duality can be extended to the non - perturbative level in the @xmath1 theories .
we give some evidence that this might also be the case for @xmath0 theories as well .
= 10000 epsf .
And you have already written the first three sentences of the full article: in t hooft s large @xmath2 limit @xcite gauge theories are expected to be drastically simplified .
thus , in this limit the gauge theory diagrams are organized in terms of riemann surfaces , where each extra handle on the surface suppresses the corresponding diagram by @xmath3 .
the large @xmath2 expansion , therefore , resembles perturbative expansion in string theory . in the case of four - dimensional gauge theories.
Please generate the next two sentences of the article | this connection can be made precise in the context of type iib string theory in the presence of a large number @xmath2 of d3-branes @xcite .
thus , we consider a limit where @xmath4 , @xmath5 and @xmath6 , while keeping @xmath7 fixed , where @xmath8 is the type iib string coupling . |
3,646 | Suppose that you have an abstract for a scientific paper: glimpse imaging using the infrared array camera ( irac ) on the _ spitzer space telescope _ indicates that star formation is ongoing in the rcw 49 giant region .
a photometric comparison of the sources in rcw 49 to a similar area to its north finds that at least 300 stars brighter than 13th magnitude in band [ 3.6 ] have infrared excesses inconsistent with reddening due to foreground extinction .
these are likely young stellar objects ( ysos ) more massive than 2.5 @xmath0 suggesting that thousands more low - mass stars are forming in this cloud .
some of the ysos are massive ( b stars ) and therefore very young , suggesting that a new generation of star formation is occurring , possibly triggered by stellar winds and shocks generated by the older ( 2 - 3 myr ) central massive cluster .
the _ spitzer _
irac camera has proven to be ideally suited for distinguishing young stars from field stars , and the glimpse survey of the galactic plane will likely find thousands of new star formation regions . .
And you have already written the first three sentences of the full article: rcw 49 is one of the most luminous and massive regions in the galaxy . at its center
lies the westerlund 2 ( hereafter w2 ; westerlund 1960 ) compact cluster which contains over a dozen ob stars and a wolf - rayet star ; another wolf - rayet star lies several arc minutes away in the extended nebula ( moffat & vogt 1975 ; moffat , shara , & potter 1991 ; carraro & munari 2004 ; van der hucht 2001 ) .
the age of the w2 cluster is estimated to be 2 - 3 myr ( piatti et al . 1998 ) . as discussed in churchwell et al ..
Please generate the next two sentences of the article | ( 2004 ; hereafter , c04 ) , distance estimates range from @xmath1 kpc and we follow their adoption of 4.2 kpc . at this distance
, we estimate the cluster luminosity is 1.4@xmath2 @xmath3 based on the iras flux and a relationship derived between far - infrared and bolometric luminosity @xcite . |
3,647 | Suppose that you have an abstract for a scientific paper: new high - resolution @xmath0 band imaging of the brightest cluster galaxy ( bcg ) in abell 85 ( holm 15a ) was obtained using the gemini multi object spectrograph .
these data were taken with the aim of deriving an accurate surface brightness profile of the bcg of abell 85 , in particular its central region .
the new gemini data show clear evidence of a previously unreported nuclear emission that is evident as a distinct light excess in the central kiloparsec of the surface brightness profile .
we find that the light profile is never flat nor does it present a downward trend towards the center of the galaxy .
that is , the new gemini data show a different physical reality from the featureless , `` evacuated core '' recently claimed for the abell 85 bcg . after trying different models ,
we find that the surface brightness profile of the bcg of abell 85 is best fit by a double srsic model . .
And you have already written the first three sentences of the full article: within the current framework of hierarchical structure formation ( e.g. white & rees 1978 ) galaxy clusters are formed through the successive mergers of galaxies , galaxy groups , and subclusters .
galaxy clusters form , thus , the largest gravitationnally bound structures in the universe .
interestingly , x - ray observations have shown that most of the baryonic mass of galaxy clusters resides not in galaxies but in their hot intracluster gas ( e.g. jones & forman 1984 ) abell 85 is a rich galaxy cluster located at a redshift of @xmath1 with 305 confirmed cluster members ( durret et al ..
Please generate the next two sentences of the article | abell 85 is a bright x - ray source that has been extensively studied using several x - ray satellites ( e.g. markevitch et al .
1998 ; lima neto et al . 2001 ; sivakoff et al . 2008 ) . |
3,648 | Suppose that you have an abstract for a scientific paper: spontaneous phase separation instabilities with the formation of various types of charge and spin pairing ( pseudo)gaps in @xmath0 hubbard model including the _ next nearest neighbor coupling _ are calculated with the emphasis on the two - dimensional ( square ) lattices generated by @xmath1- and @xmath2-site betts unit cells . the exact theory yields insights into the nature of quantum critical points , continuous transitions , dramatic phase separation instabilities and electron condensation in spatially inhomogeneous systems .
the picture of coupled anti - parallel ( singlet ) spins and paired charged holes suggests full bose condensation and coherent pairing in real space at zero temperature of electrons complied with the bose - einstein statistics .
separate pairing of charge and spin degrees at distinct condensation temperatures offers a new route to superconductivity different from the bcs scenario .
the conditions for spin liquid behavior coexisting with unsaturated and saturated nagaoka ferromagnetism due to spin - charge separation are established .
the phase separation critical points and classical criticality found at zero and finite temperatures resemble a number of inhomogeneous , coherent and incoherent nanoscale phases seen near optimally doped high-@xmath3 cuprates , pnictides and cmr nanomaterials .
= 1.7 cm .
And you have already written the first three sentences of the full article: [ intro ] a key element for understanding the complexity and perplexity in high-@xmath3 cuprates , manganites and colossal magnetoresistance ( cmr ) nanomaterials is the experimental observation of phase separation ( ps ) instabilities at the nanoscale signaled by spin - charge separation and quantum phase transitions ( qpts ) @xcite .
a new guiding principle for the search of new materials with enhanced tc is the proximity to quantum critical points ( qcps ) for spontaneous first order qpts attributed to intrinsic spatial inhomogeneities ( see ref .
@xcite and references therein ) ..
Please generate the next two sentences of the article | strong quantum fluctuations dominate thermal fluctuations and affect the classical properties well above absolute zero temperature @xcite .
the inhomogeneous concentrated system in equilibrium can be well approximated as a quantum gas of decoupled clusters , which do not interact directly but through the grand canonical ensemble , with different electron number per cluster . |
3,649 | Suppose that you have an abstract for a scientific paper: abstract we introduce the class of piecewise convex transformations , and study their complexity .
we apply the results to the complexity of polygonal billiards on surfaces of constant curvature . .
And you have already written the first three sentences of the full article: the following situation frequently occurs in geometric dynamics .
there is a phase space @xmath0 , a transformation @xmath1 ; and there is a finite decomposition @xmath2 . let @xmath3 be the corresponding alphabet .
a phase point @xmath4 is regular if every element of the orbit @xmath5 belongs to a unique atom of @xmath6 ..
Please generate the next two sentences of the article | suppose that @xmath7 , etc .
the corresponding word @xmath8 is the _ code _ of @xmath9 . |
3,650 | Suppose that you have an abstract for a scientific paper: for the first time a complete set of the most recent direct data on primary cosmic ray spectra is used as input into calculations of muon flux at sea level in wide energy range @xmath0 gev .
computations have been performed with the corsika / qgsjet and corsika / venus codes .
the comparison of the obtained muon intensity with the data of muon experiments shows , that measurements of primary nuclei spectra conform to sea level muon data only up to several tens of gev and result in essential deficit of muons at higher energies . as it follows from our examination , uncertainties in muon flux measurements and in the description of nuclear cascades development
are not suitable to explain this contradiction , and the only remaining factor , leading to this situation , is underestimation of primary light nuclei fluxes .
we have considered systematic effects , that may distort the results of the primary cosmic ray measurements with the application of the emulsion chambers .
we suggest , that re - examination of these measurements is required with the employment of different hadronic interaction models .
also , in our point of view , it is necessary to perform estimates of possible influence of the fact , that sizable fraction of events , identified as protons , actually are antiprotons .
study of these cosmic ray component begins to attract much attention , but today nothing definite is known for the energies @xmath1 gev . in any case , to realize whether the mentioned , or some other reasons are the sources of disagreement of the data on primaries with the data on muons , the indicated effects should be thoroughly analyzed . _
accepted for publication in _ .
And you have already written the first three sentences of the full article: a muon component of cosmic rays plays an important role in many fields of astroparticle physics .
it provides a basis for verification of our knowledge on primary cosmic ray ( pcr ) spectrum behaviour , high - energy hadronic interactions and for solution of neutrino physics problems . in view of this
, a question of interconsistency of information , gained in the last two decades on primary and muon fluxes , and on high - energy hadronic interactions presents great importance . in well known works of volkova et al ..
Please generate the next two sentences of the article | ( 1979 ) @xcite , dar ( 1983 ) @xcite , butkevich et al .
( 1989 ) @xcite , lipari ( 1993 ) @xcite , honda et al . |
3,651 | Suppose that you have an abstract for a scientific paper: coordinate transformations are derived from global minkowski coordinates to the fermi coordinates of an observer moving in a circle in minkowski space - time .
the metric for the fermi coordinates is calculated directly from the tensor transformation rule .
the behavior of ideal clocks is examined from the observer s reference frame using the fermi coordinates .
a complicated relation exists between fermi coordinate time and proper time on stationary clocks ( in the fermi frame ) and between proper time on satellite clocks that orbit the observer .
an orbital sagnac - like effect exists for portable clocks that orbit the fermi coordinate origin .
the coordinate speed of light is isotropic but varies with fermi coordinate position and time .
the magnitudes of these kinematic effects are computed for parameters that are relevant to the global positioning system ( gps ) and are found to be small ; however , for future high - accuracy time transfer systems , these effects may be of significant magnitude . .
And you have already written the first three sentences of the full article: during the past several decades there have been significant advances in the accuracy of satellite - based navigation and time transfer systems @xcite .
the most recent example of such a system is the global positioning system ( gps ) , which is run by the u. s. department of defense @xcite .
the gps is based on a network of 24 atomic clocks in space , from which a user can receive signals and compute his position and time ..
Please generate the next two sentences of the article | the order of magnitude of the accuracy of the gps currently is ten meters and twenty nanoseconds @xcite .
future navigation and time transfer systems are being contemplated that will have several orders of magnitude better position accuracy and sub - nanosecond time accuracy @xcite . over satellite to ground distances , precise measurements must be interpreted within the framework of a relativistic theory @xcite . |
3,652 | Suppose that you have an abstract for a scientific paper: we report on optical identifications of x - ray sources in the vicinity of the r cra association .
we identify 11 low - mass pre - main - sequence stars as counterparts of 9 x - ray sources .
we also find x - ray emission from coordinates consistent with the position of 3 bright late - b stars , although the emission may come from lower mass companions .
the x - ray - selected stars lie along a narrow locus in the luminosity - temperature diagram at an age of about 7 myr , which is considerably older than the estimated ages of the higher mass stars or of the ir - excess stars .
we determine the physical characteristics of these stars , including masses , ages , and lithium abundances .
we estimate that the complete membership of the r cra association amounts to about 90 stars , mostly older naked t tauri stars , and that the population is consistent with the standard imf . .
And you have already written the first three sentences of the full article: the r cra association , at a distance of about 130 pc ( marraco & rydgren 1981 ) , is one of the nearest star - forming associations to the sun .
the association is projected against a prominent dark cloud 18@xmath0 below the galactic plane ( see figure 1 of knacke _
et al_. 1973 ) ..
Please generate the next two sentences of the article | the total mass of the cloud is estimated to be between 3000 and 10,000 m@xmath1 ( dame _ et al_. 1987 ; loren 1979 ) .
et al_. ( 1994 ) comment that the morphology of the cloud bears a resemblance to the @xmath2 oph cloud . however , the number of known and suspected members of the stellar association is only 10% of that known or suspected in @xmath2 oph . |
3,653 | Suppose that you have an abstract for a scientific paper: broadcasting and gossiping are fundamental communication tasks in networks . in broadcasting ,
one node of a network has a message that must be learned by all other nodes . in gossiping
, every node has a ( possibly different ) message , and all messages must be learned by all nodes .
we study these well - researched tasks in a very weak communication model , called the _ beeping model_. communication proceeds in synchronous rounds . in each round
, a node can either listen , i.e. , stay silent , or beep , i.e. , emit a signal .
a node hears a beep in a round , if it listens in this round and if one or more adjacent nodes beep in this round .
all nodes have different labels from the set @xmath0 .
our aim is to provide fast deterministic algorithms for broadcasting and gossiping in the beeping model .
let @xmath1 be an upper bound on the size of the network and @xmath2 its diameter .
let @xmath3 be the size of the message in broadcasting , and @xmath4 an upper bound on the size of all input messages in gossiping .
for the task of broadcasting we give an algorithm working in time @xmath5 for arbitrary networks , which is optimal .
for the task of gossiping we give an algorithm working in time @xmath6 for arbitrary networks .
* keywords : * algorithm , broadcasting , gossiping , deterministic , graph , network , beep . at the time of writing this paper
we were unaware of the paper + a. czumaj , p. davis , communicating with beeps , arxiv:1505.06107 [ cs.dc ] which contains the same results for broadcasting and a stronger upper bound for gossiping in a slightly different model . .
And you have already written the first three sentences of the full article: * the background and the problem . * broadcasting and gossiping are fundamental communication tasks in networks . in broadcasting ,
one node of a network , called the _ source _ , has a message that must be learned by all other nodes . in gossiping
, every node has a ( possibly different ) input message , and all messages must be learned by all nodes ..
Please generate the next two sentences of the article | we study these well - researched tasks in a very weak communication model , called the _ beeping model_. communication proceeds in synchronous rounds . in each round
, a node can either listen , i.e. , stay silent , or beep , i.e. , emit a signal . |
3,654 | Suppose that you have an abstract for a scientific paper: an algorithm based on the ehrlich - aberth root - finding method is presented for the computation of the eigenvalues of a t - palindromic matrix polynomial .
a structured linearization of the polynomial represented in the dickson basis is introduced in order to exploit the symmetry of the roots by halving the total number of the required approximations .
the rank structure properties of the linearization allow the design of a fast and numerically robust implementation of the root - finding iteration .
numerical experiments that confirm the effectiveness and the robustness of the approach are provided .
_ ams classification : _
65f15 generalized eigenvalue problem , root - finding algorithm , rank - structured matrix .
And you have already written the first three sentences of the full article: the design of effective numerical methods for solving structured generalized eigenvalue problems has recently attracted a great deal of attention .
palindromic matrix polynomials arise in many applications @xcite .
an @xmath0 matrix polynomial of degree @xmath1 @xmath2 , @xmath3 , @xmath4 , @xmath5 , is said to be t - palindromic if @xmath6 for @xmath7 ..
Please generate the next two sentences of the article | it is well - known @xcite , @xcite that the palindromic structure induces certain spectral symmetries : in particular if @xmath8 is an eigenvalue of @xmath9 then @xmath10 is also an eigenvalue of @xmath9 .
numerical solution methods are generally asked to preserve these symmetries . |
3,655 | Suppose that you have an abstract for a scientific paper: + local - susceptibility measurements via the nmr shifts of @xmath0p and @xmath1v nuclei in the high - pressure phase of ( vo)@xmath2p@xmath2o@xmath3 confirmed the existence of a unique alternating antiferromagnetic chain with a zero - field spin gap of 34 k. the @xmath0p nuclear spin - lattice relaxation rate scales with the uniform spin susceptibility below about 15 k which shows that the temperature dependence of both the static and dynamical spin susceptibilities becomes identical at temperatures not far below the spin - gap energy .
magnetic excitations of a low - dimensional quantum antiferromagnet have been one of the current topics among the condensed matter physicists .
vanadyl pyrophosphate ( vo)@xmath2p@xmath2o@xmath3 had long been believed as a prototype of a spin-@xmath4 two - leg ladder which has a magnetic lattice intermediate between one and two spatial dimensions @xcite . the ladder model , however , has been rejected by an observation of a dominant magnetic interaction perpendicular to the supposed ladder axis via the inelastic neutron scattering ( ins ) measurements @xcite .
a dimerized ( alternating ) chain model has now been becoming accepted as an alternative starting point , although a mechanism of the major exchange interaction between distant pairs of v@xmath5 spins via po@xmath6 tetrahedra is still under study @xcite .
the ins experiments has also revealed the existence of the mode with a gap nearly twice the gap of the lowest excited triplet which can not be explained by a simple alternating - chain model .
this mode has first been assigned as a bound state of two magnons possibly formed via interchain couplings @xcite , but it was difficult to account for the intensity comparable to the fundamental mode .
recent nmr @xcite and high - field magnetization @xcite studies have suggested on this issue that the two structurally - distinguishable chains of v atoms , which were thought to be magnetically identical , have different spin - gap energies .
this gives a....
And you have already written the first three sentences of the full article: .
Please generate the next two sentences of the article | |
3,656 | Suppose that you have an abstract for a scientific paper: the complete classification of hexapods also known as stewart gough platforms of mobility one is still open . to tackle this problem , we can associate to each hexapod of mobility one an algebraic curve , called the configuration curve . in this paper
we establish an upper bound for the degree of this curve , assuming the hexapod is general enough .
moreover , we provide a construction of hexapods with curves of maximal degree , which is based on liaison , a technique used in the theory of algebraic curves . .
And you have already written the first three sentences of the full article: this paper is devoted to the study of mechanical devices called _ hexapods _ , which are also known as _
stewart gough platforms_. as described in @xcite , the geometry of this kind of mechanical manipulators is defined by the coordinates of the @xmath0 platform points @xmath1 and of the @xmath0 base points @xmath2 in one of their possible configurations .
a hexapod is called _ planar _ if both base points and platform points are coplanar , otherwise _ non - planar_. all pairs of points @xmath3 are connected by a rigid body , called _ leg _ , so that for all possible configurations the distance @xmath4 is preserved ( see fig ..
Please generate the next two sentences of the article | [ figure : hexapod ] ) .
we say that a hexapod is _ movable _ , or admits a _ self - motion _ if , once we fix the position of the base points @xmath5 , the platform points @xmath6 are allowed to move in an ( at least ) one - dimensional set of configurations respecting the constraints given by the legs . in this case , each @xmath7 moves on the sphere with center @xmath8 and radius @xmath9 . |
3,657 | Suppose that you have an abstract for a scientific paper: we present a molecular dynamics study on atomic self - diffusion in frank - kasper type dodecagonal quasicrystals .
it is found that the quasicrystal - specific flip mechanism for atomic diffusion as predicted by kalugin and katz@xcite , indeed occurs in this system .
however , in order to be effective , this mechanism needs to be catalyzed by other defects such as half - vacancies if the structure is truly three - dimensional . for this reason ,
flip diffusion is difficult to distinguish from standard vacancy diffusion . in a quasi - two - dimensional setup ,
however , the flips may occur without other defects .
activation energies and flip frequencies are also determined . .
And you have already written the first three sentences of the full article: quasicrystals are by now well - established in solid state physics .
they exhibit non - crystallographic symmetries together with a number of unusual physical properties .
recent reviews may be found in refs ..
Please generate the next two sentences of the article | @xcite .
there has recently been much interest in atomic self - diffusion in quasicrystals , mostly triggered by a paper by kalugin and katz@xcite where a diffusion mechanism specific to quasicrystals was proposed . |
3,658 | Suppose that you have an abstract for a scientific paper: we note that detector depth can influence the decay path length available for the primary and secondary particles that are the source of atmospheric neutrinos . as a consequence
there is a location dependent modulation to the neutrino flux , which could be as large as 5 - 10% in some directions . .
And you have already written the first three sentences of the full article: estimates for the ambient neutrino flux are an important input parameter to experiments analyzing underground neutrino interactions and upward going muons to understand the time evolution of a neutrino beam .
different directions provide neutrino fluxes with varying source distance so observation of the angular distribution is an essential tool in the study of neutrino oscillations .
since the overall flux normalization is uncertain , experiments frequently place a greater emphasis on the shape of the distribution than the absolute event rate ..
Please generate the next two sentences of the article | this note points out _ depth dependent _ effects that can also provide a directional modulation .
these effects are modest , but predominantly effect the higher end of the neutrino spectrum . |
3,659 | Suppose that you have an abstract for a scientific paper: we present mond fits to 15 rotation curves of lsb galaxies .
good fits are readily found , although for a few galaxies minor adjustments to the inclination are needed .
reasonable values for the stellar mass - to - light ratios are found , as well as an approximately constant value for the total ( gas and stars ) mass - to - light ratio .
we show that the lsb galaxies investigated here lie on the one , unique tully - fisher relation , as predicted by mond .
the scatter on the tully - fisher relation can be completely explained by the observed scatter in the total mass - to - light ratio .
we address the question of whether mond can fit any arbitrary rotation curve by constructing a plausible fake model galaxy .
while mond is unable to fit this hypothetical galaxy , a normal dark halo fit is readily found , showing that dark matter fits are much less selective in producing fits .
the good fits to rotation curves of lsb galaxies support mond , especially as these are galaxies with large mass discrepancies deep in the mond regime . .
And you have already written the first three sentences of the full article: the inability of the visible mass components in disk galaxies to account for the observed rotation curves is usually interpreted as evidence for the existence of an additional , invisible mass component .
other theories suggest that this mass discrepancy is an indication of a breakdown of classical newtonian dynamics .
it is difficult to evaluate these theories , as only a few make specific and testable predictions ..
Please generate the next two sentences of the article | one of the exceptions is the modified newtonian dynamics ( mond ) , advocated by milgrom ( 1983 , 1989 ) and sanders ( 1990 , 1996 ) .
this theory postulates that newton s law of gravity should be modified for very small accelerations , with the result that any need for dark matter disappears . |
3,660 | Suppose that you have an abstract for a scientific paper: we have calculated the free energy up to two loop to compare @xmath0 with @xmath1 in iib matrix model .
it turns out that @xmath0 has smaller free energy than @xmath1 .
we have also discussed the generation of the gauge group by considering @xmath2-coincident fuzzy tori and found that in this case u(1 ) gauge group is favored .
this means that if the true vacuum is four - dimensional , it is not a simple fuzzy space considered here .
@xmath3 [ cols= " < " , ] + + + fuzzy torus in matrix model + subrata bal@xmath4 , masanori hanada@xmath5 , hikaru kawai@xmath6 , fukuichiro kubo@xmath7 @xmath4 _ theoretical physics laboratory , riken ( the institute of physical and chemical research ) , + wako , saitama 351 - 0198 , japan _ + @xmath7 _ department of physics , kyoto university , kyoto 606 - 8502 , japan _ .
And you have already written the first three sentences of the full article: iib matrix model @xcite is a candidate of the constructive definition of superstring theory .
it is defined by the action @xmath8[a_\mu , a_\nu ] + \frac{1}{2}\bar{\psi}\gamma^\mu[a_\mu,\psi ] \right ) , \label{eq : action}\end{aligned}\ ] ] where @xmath9 and @xmath10 are @xmath11 hermitian matrices .
@xmath9 is a ten - dimensional vector and @xmath10 is a ten - dimensional majorana - weyl fermion ..
Please generate the next two sentences of the article | one of the important aspects of this model is the dynamical generation of the spacetime and the gauge group . in this model
the eigenvalue distribution represents spacetime geometry . from this point of view , if a four - dimensional eigenvalue distribution has smaller free energy than the other configurations , the spacetime will be compactified to four - dimensions . on the other hand |
3,661 | Suppose that you have an abstract for a scientific paper: a fundamental aspect in performance engineering of wireless networks is optimizing the set of links that can be concurrently activated to meet given signal - to - interference - and - noise ratio ( sinr ) thresholds .
the solution of this combinatorial problem is the key element in scheduling and cross - layer resource management .
previous works on link activation assume single - user decoding receivers , that treat interference in the same way as noise . in this paper
, we assume multiuser decoding receivers , which can cancel strongly interfering signals . as a result , in contrast to classical spatial reuse , links being close to each other are more likely to be active simultaneously .
our goal here is to deliver a comprehensive theoretical and numerical study on optimal link activation under this novel setup , in order to provide insight into the gains from adopting interference cancellation .
we therefore consider the optimal problem setting of successive interference cancellation ( sic ) , as well as the simpler , yet instructive , case of parallel interference cancellation ( pic ) .
we prove that both problems are np - hard and develop compact integer linear programming formulations that enable us to approach the global optimum solutions .
we provide an extensive numerical performance evaluation , indicating that for low to medium sinr thresholds the improvement is quite substantial , especially with sic , whereas for high sinr thresholds the improvement diminishes and both schemes perform equally well . .
And you have already written the first three sentences of the full article: in wireless networking , determining the sets of links that can be active simultaneously is a cornerstone optimization task of combinatorial nature . for a link to be active , a given signal - to - interference - and - noise ratio ( sinr ) threshold
must be met at the receiver , according to the physical connectivity model @xcite . within this domain
, previous analyses assume that the communication system employs single - user decoding ( sud ) receivers that treat interference as additive noise . for interference - limited scenarios ,.
Please generate the next two sentences of the article | it is very unlikely that all links can be active at the same time .
hence , it is necessary to construct transmission schedules that orthogonalize link transmissions along some dimension of freedom , such as time . |
3,662 | Suppose that you have an abstract for a scientific paper: electroweak baryogenesis provides a very attractive scenario to explain the origin of the baryon asymmetry .
the mechanism of electroweak baryogenesis makes use of the baryon number anomaly and relies on physics that can be tested experimentally .
it is today understood that , if the higgs mass is not larger than 120 gev , this mechanism may be effective within supersymmetric extensions of the standard model . in this work ,
we reconsider the question of baryon number generation at the electroweak phase transition within the context of the minimal supersymmetric extension of the standard model .
we derive the relevant diffusion equations , give a consistent definition of the sources , and compare our results with those appearing in the recent literature on this subject . .
And you have already written the first three sentences of the full article: electroweak baryogenesis @xcite provides a predictive framework for the computation of the baryon asymmetry of the universe @xcite .
perhaps the most attractive feature of this mechanism is that it relies on anomalous baryon number violation processes which are present in the standard model @xcite . at temperatures far above the electroweak phase transition scale ,
these anomalous processes are unsuppressed and , in the absence of any @xmath0 asymmetry , they lead to the erasure of any baryon or lepton number generated at high energy scales @xcite . these baryon number violation processes are , instead , exponentially suppressed in the electroweak symmetry broken phase , at temperatures far below the electroweak phase transition @xcite . at the electroweak phase transition , non - equilibrium processes may generate a non - vanishing baryon number which may efficiently diffuse into the broken phase @xcite ..
Please generate the next two sentences of the article | the generated baryon number depends on the cp - violating currents present in the model .
the mechanism of electroweak baryogenesis may become effective if the cp - violating sources are strong and , at the electroweak phase transition temperature , the baryon number violation processes in the broken phase are sufficiently suppressed , leading to a baryon number density in the broken phase consistent with observations . |
3,663 | Suppose that you have an abstract for a scientific paper: the time evolution of a system where a uniform and classical su(3 ) color electric field and quantum fields of quarks are dynamically coupled with each other is studied focusing on non - perturbative pair creation and its back reaction .
we characterize the color direction of the electric field in a gauge invariant way , and investigate its dependence .
momentum distributions of created quarks show plasma oscillation as well as quantum effects such as the pauli blocking and interference .
pressure of the system is also calculated , and we show that pair creation moderates degree of anisotropy of pressure . furthermore , enhancement of pair creation and induction of chiral charge under a color magnetic field which is parallel to the electric field are discussed .
ut - komaba/10 - 1 .
And you have already written the first three sentences of the full article: study of non - perturbative pair creation from a classical electric field , which is known as the schwinger mechanism @xcite , has a long history and wide range of applications ( see ref .
@xcite for a recent review ) .
one of those applications can be found in studies of relativistic heavy - ion collisions , where the schwinger mechanism has been used as a mechanism of matter formation from a color flux tube @xcite ..
Please generate the next two sentences of the article | the color flux - tube model assumes that a strong color electric field is formed in a beam direction just after two nuclei collide and pass through each other @xcite .
formation of longitudinal color electric fields is also predicted in the framework of color glass condensate @xcite . |
3,664 | Suppose that you have an abstract for a scientific paper: i review radiatively inefficient accretion flow models for the @xmath0 black hole ( bh ) in the galactic center .
i argue for a concordance model of sgr a * : both theory and observations suggest that hot ambient gas around the bh is accreted at a rate @xmath1 , much less than the canonical bondi rate .
i interpret _ chandra _ observations of sgr a * in the context of such a model : ( 1 ) the extended quiescent x - ray emission is due to thermal bremsstrahlung from gas in the vicinity of the bondi accretion radius , and ( 2 ) the @xmath2 second long x - ray flares are due to synchrotron or inverse - compton emission by non - thermal electrons accelerated in the inner @xmath3 schwarzschild radii of the accretion flow . .
And you have already written the first three sentences of the full article: the case for a @xmath0 black hole ( bh ) coincident with the radio source sagittarius a * in the galactic center ( gc ) is now compelling ( e.g. , schdel et al .
2002 ; ghez et al .
this only emphasizes the long - standing puzzle that the luminosity from the gc is remarkably low given the presence of a massive black hole ..
Please generate the next two sentences of the article | the resolution of this puzzle must lie in how gas from the ambient medium accretes onto the central bh . in these proceedings
i review accretion models and their application to sgr a*. a unique feature of the galactic center is our ability to constrain the dynamics of gas quite close to the black hole ( relative to other systems ) , thus providing additional boundary conditions on , and much less freedom for , theoretical models . |
3,665 | Suppose that you have an abstract for a scientific paper: we analyze the temporal structure of long ( @xmath0 ) and short ( @xmath1 ) batse bursts .
we find that : ( i ) in many short bursts @xmath2 ( where @xmath3 is the shortest pulse ) .
this indicates that short bursts arise , like long ones , in internal shocks .
( ii ) in long bursts there is an excess of long intervals between pulses ( relative to a lognormal distribution ) .
this excess can be explained by the existence of _ quiescent times _ , long periods with no signal above the background that arise , most likely , from periods with no source activity .
the lognormal distribution of the intervals ( excluding the _ quiescent times _ ) is similar and correlated with the distribution of the pulses width , in agreement with the predictions of the internal shock model . .
And you have already written the first three sentences of the full article: the variability of grbs provided the main evidence for the internal - external shocks scenario .
external shocks can not produce efficiently such variability @xcite .
internal shocks can produce such temporal structure provided that there are two time scale within the inner engine " - a short time scale that produces the variability and a long time scale that determines the duration of the burst ..
Please generate the next two sentences of the article | so far variability was shown only for long bursts .
it is an open question whether short bursts arise in internal shocks as well . using a new algorithm @xcite we study their variability . |
3,666 | Suppose that you have an abstract for a scientific paper: we present a detailed analysis of the @xmath0ray emission from hess j1745 - 303 with the data obtained by the _ fermi _ gamma - ray space telescope in the first @xmath1 months observation .
the source can be clearly detected at the level of @xmath2 and @xmath3 in @xmath4 gev and @xmath5 gev respectively .
different from the results obtained by the _
compton _
gamma - ray observatory , we do not find any evidence of variability .
most of emission in @xmath5 gev is found to coincide with the region c of hess j1745 - 303 .
a simple power - law is sufficient to describe the gev spectrum with a photon index of @xmath6 .
the power - law spectrum inferred in the gev regime can be connected to that of a particular spatial component of hess j1745 - 303 in @xmath7 tev without any spectral break .
these properties impose independent constraints for understanding the nature of this dark particle accelerator " . .
And you have already written the first three sentences of the full article: recent surveys of the central region of our galaxy with the * h*igh * e*nergy * s*teroscopic * s*ystem ( h.e.s.s . ) have uncovered a number of @xmath0ray sources in the tev regime ( aharonian et al .
2002 , 2005a , 2005b , 2006a ) .
different from the cases of pulsar wind nebulae ( pwne ) and young supernova remnants ( snrs ) , some of these sources have no non - thermal x - ray counterpart yet been identified . among them , hess j1745 - 303 is one of the most enigmatic objects ..
Please generate the next two sentences of the article | hess j1745 - 303 was firstly discovered by the h.e.s.s .
galactic plane survey ( aharonian et al . |
3,667 | Suppose that you have an abstract for a scientific paper: we have developed a linear scaling algorithm for calculating maximally - localized wannier functions ( mlwfs ) using atomic orbital basis .
an o(n ) ground state calculation is carried out to get the density matrix ( dm ) . through a projection of the dm onto atomic orbitals and a subsequent o(n ) orthogonalization
, we obtain initial orthogonal localized orbitals .
these orbitals can be maximally localized in linear scaling by simple jacobi sweeps .
our o(n ) method is validated by applying it to water molecule and wurtzite zno .
the linear scaling behavior of the new method is demonstrated by computing the mlwfs of boron nitride nanotubes . .
And you have already written the first three sentences of the full article: wannier function@xcite is a powerful tool in the study of the chemical bonding , dielectric properties , excited electronic states , electron transport , and many body correlations in materials . in particular , the modern theory of bulk polarization
relates the vector sum of the centers of the wannier functions to the macroscopic polarization of a crystalline insulator.@xcite however , the intrinsic nonuniqueness in the wannier function definition , and the difficulty in defining their centers within a periodic cell calculation , limited their practical use .
fortunately , an elegant method has been recently proposed by marzari and vanderbilt to obtain a unique set of maximally - localized wannier functions ( mlwfs).@xcite by transforming the occupied electronic manifold into a set of mlwfs , it becomes possible to obtain an enhanced understanding of chemical bonding properties and electric polarization via an analysis of the mlwfs . beside the above points ,.
Please generate the next two sentences of the article | the mlwfs are now also being used as a very accurate minimal basis for a variety of algorithmic or theoretical developments , with recent applications ranging from linear - scaling approaches@xcite to the construction of effective hamiltonians for the study of ballistic transport,@xcite strongly - correlated electrons,@xcite self - interaction corrections , metal - insulator transitions,@xcite and photonic lattices.@xcite in the seminal work of marzari and vanderbilt , first a ground state calculation was carried out to obtain the occupied delocalized canonical orbitals , then a sequence of unitary transformations were performed to obtain mlwfs which minimize the spread function.@xcite using the exponential representation for the unitary transformation , berghold _
et al._@xcite derived an iterative scheme to obtain mlwfs in large supercells of arbitrary symmetry . |
3,668 | Suppose that you have an abstract for a scientific paper: in this paper , we define the notion of a mapping on soft classes and study several properties of images and inverse images of soft sets supported by examples and counterexamples .
finally , these notions have been applied to the problem of medical diagnosis in medical expert systems.*keywords :* soft set ; soft class ; mapping on soft classes ; image of soft set ; inverse image of a soft set ; medical diagnosis in medical expert systems . _ _ .
And you have already written the first three sentences of the full article: to solve complicated problems in economics , engineering and environment , we can not successfully use classical methods because of different kinds of incomplete knowledge , typical for those problems .
there are four theories : theory of probablity , fuzzy set theory ( fst ) @xcite , interval mathematics and rough set theory ( rst ) @xcite , which we can consider as mathematical tools for dealing with imperfect knowledge .
all these tools require the pre - specification of some parameter to start with , e.g. probablity density function in probablity theory , membership function in fst and an equivalence relation in rst ..
Please generate the next two sentences of the article | such a requirement , seen in the backdrop of imperfect or incomplete knowledge , raises many problems . at the same time
, incomplete knowledge remains the most glaring characteristic of humanistic systems |
3,669 | Suppose that you have an abstract for a scientific paper: a recent calculation by chay and rey has shown that instantons may make a significant contribution to the lepton energy spectrum near its endpoint . using an ansatz borrowed from the study of high energy baryon number violating processes
, we investigate whether these corrections could spoil the relation between the nonperturbative contributions to this spectrum and to the photon energy spectrum in radiative @xmath0 decays .
we find , in general , that this universality may well fail unless the spectrum is smeared over a region which is considerably larger than had previously been thought necessary .
this result affects the possibility of performing a reliable measurement of @xmath1 using inclusive decays . .
And you have already written the first three sentences of the full article: there has been considerable recent interest in the study of the endpoint spectra of charmless semileptonic and radiative @xmath0 meson decays .
this effort is motivated by the fact that in order to remove overwhelming backgrounds due to decays to charmed states , stringent cuts must be applied to the data , which restrict the experimental analysis to within a few hundred mev of the kinematic endpoint .
hence it is crucial to understand in as much detail as possible the theoretical shape of the lepton or photon energy spectrum in the endpoint region , if one is to use these processes to extract reliably short - distance couplings such as kobayashi - maskawa matrix elements ..
Please generate the next two sentences of the article | the current theoretical analysis makes use of the operator product expansion ( ope ) and the heavy quark effective theory ( hqet ) @xcite . within this context
one may compute a variety of corrections to the simple free quark decay picture , both perturbative @xmath2 and nonperturbative @xmath3 in origin . |
3,670 | Suppose that you have an abstract for a scientific paper: we consider andreev - majorana ( am ) bound states with zero energy on surfaces , interfaces and vortices in different phases of the @xmath0-wave superfluids . we discuss the chiral superfluid @xmath1he - a , and time reversal invariant phases : superfluid @xmath1he - b , planar and polar phases .
the am zero modes are determined by topology in bulk , and they disappear at the quantum phase transition from the topological to non - topological state of the superfluid . the topology demonstrates the interplay of dimensions .
in particular , the zero - dimensional weyl points in chiral superfluids ( the berry phase monopoles in momentum space ) give rise to the one - dimensional fermi arc of am bound states on the surface and to the one - dimensional flat band of am modes in the vortex core .
the one - dimensional nodal line in the polar phase produces the two - dimensional flat band of am modes on the surface .
the interplay of dimensions also connects the am states in superfluids with different dimensions .
for example , the topological properties of the spectrum of bound states in the three - dimensional @xmath1he - b is connected to the properties of the spectrum in the two - dimensional planar phase ( thin film ) . .
And you have already written the first three sentences of the full article: majorana fermions are ubiquitous for superconductors and fermionic superfluids .
the bogoliubov- de gennes equation for fermionic bogoliubov - nambu quasiparticles can be brought to a real form by unitary transformation .
this implies the linear relation between the particle and antiparticle field operators , which is the hallmark of a majorana fermion ..
Please generate the next two sentences of the article | the fermionic statistics and cooper pair correlations give rise to majorana fermions , irrespective of geometry , dimensionality , symmetry and topology @xcite .
the role of topology is to protect gapless majorana fermions , which play the major role at low temperature , when the gapped degrees of freedom are frozen out . for some combinations of geometry , dimensionality and symmetry |
3,671 | Suppose that you have an abstract for a scientific paper: a bouncing cosmology with an initial matter - dominated phase of contraction during which scales which are currently probed with cosmological observations exit the hubble radius provides a mechanism alternative to inflation for producing a nearly scale - invariant spectrum of cosmological perturbations . in this review article
i first discuss the evolution of cosmological fluctuations in the matter bounce scenario , and then discuss various attempts at realizing such a scenario .
observational signatures which will allow the matter bounce to be distinguished from the inflationary paradigm are also discussed . .
And you have already written the first three sentences of the full article: the idea that instead of originating from a big bang singularity , the universe has emerged from a cosmological bounce has a long history ( see @xcite for a review with an extensive list of references to the original literature ) . the group of professor novello has made a lot of important contributions to the research on this topic .
however , it was realized only fairly recently @xcite that a bouncing cosmology with a matter - dominated phase of contraction during which scales which are probed today in cosmological observations exit the hubble radius can provide an alternative to the current inflationary universe paradigm of cosmological structure formation . in this review article
, we provide an overview of this matter bounce " scenario of structure formation , and we discuss some recent efforts at obtaining a non - singular bouncing cosmological background ( see also @xcite for reviews comparing the matter bounce with inflation and other alternatives to inflation ) ..
Please generate the next two sentences of the article | inflationary cosmology @xcite ( see also @xcite ) has become the paradigm of early universe cosmology not only because it addresses some of the conceptual problems of standard big bang cosmology such as the horizon , flatness and entropy problems , but because it provided the first causal mechanism for generating the primordial fluctuations which could have developed into the structures we see today on large scales @xcite ( see also @xcite ) .
more specifically , it predicted a roughly scale - invariant spectrum of cosmological fluctuations which in simple models of inflation have a slight red tilt and which are gaussian and nearly adiabatic . |
3,672 | Suppose that you have an abstract for a scientific paper: the fluctuations of 5d self - gravitating non - abelian kinks which arise from the breaking of the @xmath0 symmetric theory are analyzed within the context of brane - worlds . while tensor and vector sectors of these fluctuations behave like its counterparts in the standard abelian @xmath1 kinks , the mixing between the field excitations of the non - abelian kink and the scalar components of the metric makes the pure scalar sector of the theory very interesting .
the spectrum of these scalar fluctuations , which includes gravitationally trapped massless modes on the core of the wall associated to the broken symmetries , is discussed for the two classes of kinks that break @xmath2 to its maximal subgroups . .
And you have already written the first three sentences of the full article: the central idea in brane - world scenarios is that matter and its interactions , as we know them , must be localized on the brane .
domain wall spacetimes , providing regularizations of the randall - sundrum brane - world @xcite preserve the property of produce effective 4d gravity on the brane @xcite .
in addition , while it has been shown that fermion fields may be localized on the brane _ via _ their interaction with the scalar field from which the wall is made of @xcite , gauge field localization has been somewhat more elusive @xcite ..
Please generate the next two sentences of the article | a lot of work has been done on the topic of localization in brane - worlds in which the field theoretic domain walls considered arise in abelian @xmath1-symmetric theories , although it is also possible to consider ( besides the @xmath1 symmetry ) continuos internal symmetry walls with interesting localization properties .
there are well known examples of domain walls in flat space - time that arise in a @xmath0 symmetric theory @xcite in which the full @xmath0 symmetry is not restored at the core of the wall @xcite . |
3,673 | Suppose that you have an abstract for a scientific paper: over the years , ensemble methods have become a staple of machine learning .
similarly , generalized linear models ( _ glms _ ) have become very popular for a wide variety of statistical inference tasks .
the former have been shown to enhance out - of - sample predictive power and the latter possess easy interpretability .
recently , ensembles of glms have been proposed as a possibility . on the downside
, this approach loses the interpretability that glms possess .
we show that minimum description length ( _ mdl_)-motivated compression of the inferred ensembles can be used to recover interpretability without much , if any , downside to performance and illustrate on a number of standard classification data sets . .
And you have already written the first three sentences of the full article: ensemble classifiers have become very popular for classification and regression tasks .
they offer the potential advantages of robustness via bootstrapping , feature prioritization , and good out - of - sample performance characteristics ( @xcite ) .
however , they suffer from lack of interpretability , and oftentimes features are reported as `` word bags '' - e.g. by feature importance ( @xcite ) ..
Please generate the next two sentences of the article | generalized linear models , a venerable statistical toolchest , offer good predictive performance across a range of prediction and classification tasks , well - understood theory ( advantages and modes of failure ) and implementation considerations and , most importantly , excellent interpretability . until recently ,
there has been little progress in bringing together ensemble learning and glms , but some recent work in this area ( e.g. @xcite ) has resulted in publicly - available implementations of glm ensembles . |
3,674 | Suppose that you have an abstract for a scientific paper: the algebraic translational surface is a typical modeling surface in computer aided design and architecture industry . in this paper
, we give a necessary and sufficient condition for that algebraic surface having a standard parametric representation and our proof is constructive .
if the given algebraic surface is translational , then we can compute a standard parametric representation for the surface .
* keywords : * translational surface , rational parametrization , reparametrization .
And you have already written the first three sentences of the full article: in computer aided geometric design and geometric modeling , we often use some common surface to construct a complex model .
these common surfaces are generally called basic modeling surfaces , and they should have some advantages such as simple and widely used .
the simple surfaces refer the ones with low degree , for instance , quadratic surfaces @xcite and cubic surfaces @xcite ..
Please generate the next two sentences of the article | the widely used surface refer the ones common in industrial design , for instance , ruled surfaces @xcite , swept surfaces @xcite and translational surfaces @xcite . then a primary task is to have a well study for these basic modeling surfaces .
certainly , how to represent these surface is the first problem in studying surface . |
3,675 | Suppose that you have an abstract for a scientific paper: we investigate the bulk orbital angular momentum ( am ) in a two - dimensional hole - doped topological superconductor ( sc ) which is composed of a hole - doped semiconductor thin film , a magnetic insulator , and an @xmath0-wave sc and is characterized by the chern number @xmath1 . in the topological phase , @xmath2 is strongly reduced from the intrinsic value by the non - particle - hole - symmetric edge states as in the corresponding chiral @xmath3-wave scs when the spin - orbit interactions ( sois ) are small , while this reduction of @xmath2 does not work for the large sois . here
@xmath4 and @xmath5 are the bulk orbital am and the total number of particles at zero temperature , respectively . as a result ,
@xmath2 is discontinuous or continuous at the topological phase transition depending on the strengths of the sois .
we also discuss the effects of the edge states by calculating the radial distributions of the orbital am . .
And you have already written the first three sentences of the full article: orbital angular momentum ( am ) is one of the most fundamental quantities in classical and quantum mechanics . in condensed matter physics ,
the bulk orbital am in chiral superconductors ( scs ) has been intensively studied @xcite .
a chiral sc is an exotic sc whose cooper pairs carry nonzero orbital am @xmath6 , and hence the time - reversal symmetry is spontaneously broken ..
Please generate the next two sentences of the article | @xmath7he - a is the only material experimentally established as a chiral superfluid , whose pairing symmetry is chiral @xmath8 wave @xcite .
also , sr@xmath9ruo@xmath10 is widely believed to be a chiral @xmath8-wave sc @xcite . |
3,676 | Suppose that you have an abstract for a scientific paper: finite - temperature properties of weakly doped antiferromagnets as modeled by the two - dimensional @xmath0-@xmath1 model and relevant to underdoped cuprates are investigated by numerical studies of small model systems at low doping .
two numerical methods are used : the worldline quantum monte carlo method with a loop cluster algorithm and the finite - temperature lanczos method , yielding consistent results .
thermodynamic quantities : specific heat , entropy and spin susceptibility reveal a sizeable perturbation induced by holes introduced into a magnetic insulator , as well as a pronounced temperature dependence .
the diamagnetic susceptibility introduced by coupling of the magnetic field to the orbital current reveals an anomalous temperature dependence , changing character from diamagnetic to paramagnetic at intermediate temperatures . .
And you have already written the first three sentences of the full article: anomalous normal - state properties of superconducting cuprates @xcite have stimulated intense theoretical investigations of models of strongly correlated electrons describing the interplay between antiferromagnetic ( afm ) ordering of reference ( undoped ) insulating substances and the itinerant character of charge carriers introduced by doping .
for the understanding of superconductivity the most challenging regime is that of intermediate ( optimum ) doping .
however , even the apparently simplest region of weak doping is not fully understood theoretically ..
Please generate the next two sentences of the article | recently , the attention in experimental and theoretical investigations of cuprates has been given to characterization and understanding of different doping regimes @xcite . in a simple picture
, weak doping should correspond to the regime where properties vary linearly with the concentration of holes , i.e. one can deal with a semiconductor - like model where charge carriers ( holes ) are independent and well defined quasiparticles . |
3,677 | Suppose that you have an abstract for a scientific paper: regular expressions ( res ) , because of their succinctness and clear syntax , are the common choice to represent regular languages . however , efficient pattern matching or word recognition depend on the size of the equivalent nondeterministic finite automata ( nfa ) .
we present the implementation of several algorithms for constructing small @xmath0-free nfasfrom reswithin the * fado*system , and a comparison of regular expression measures and nfasizes based on experimental results obtained from uniform random generated res . for this analysis ,
nonredundant resand reduced resin star normal form were considered . .
And you have already written the first three sentences of the full article: regular expressions ( res ) , because of their succinctness and clear syntax , are the common choice to represent regular languages .
equivalent deterministic finite automata ( dfa ) would be the preferred choice for pattern matching or word recognition as these problems can be solved efficiently by dfas .
however , minimal dfascan be exponentially bigger than res ..
Please generate the next two sentences of the article | nondeterministic finite automata ( nfa ) obtained from rescan have the number of states linear with respect to ( w.r.t ) the size of the res . because nfaminimization is a pspace - complete problem other methods
must be used in order to obtain small nfas usable for practical purposes . |
3,678 | Suppose that you have an abstract for a scientific paper: we report on the discovery of @xmath0 100 mev @xmath1 rays from the binary system psr b1259@xmath263/ls 2883 using the large area telescope ( lat ) on board _
fermi_. the system comprises a radio pulsar in orbit around a be star .
we report on lat observations from near apastron to @xmath3 days after the time of periastron , @xmath4 , on 2010 december 15 .
no -ray emission was detected from this source when it was far from periastron .
faint @xmath1-ray emission appeared as the pulsar approached periastron . at @xmath5d , the @xmath0 100
mev @xmath1-ray flux increased over a period of a few days to a peak flux 2030 times that seen during the pre - periastron period , but with a softer spectrum . for the following month
, it was seen to be variable on daily time scales , but remained at @xmath6 before starting to fade at @xmath7d .
the total @xmath1-ray luminosity observed during this period is comparable to the spin - down power of the pulsar .
simultaneous radio and x - ray observations of the source showed no corresponding dramatic changes in radio and x - ray flux between the pre - periastron and post - periastron flares . we discuss possible explanations for the observed -ray - only flaring of the source . .
And you have already written the first three sentences of the full article: the pulsar system psr b1259@xmath263 was discovered at parkes in 1989 and comprises a 47.76 ms radio pulsar orbiting a massive star ( ls 2883 ) in a highly elliptical ( @xmath8 ) orbit with a period of @xmath9 years @xcite .
recent optical spectroscopy @xcite yields an updated distance estimate to this source of @xmath10 kpc , in reasonable agreement with the dispersion measure ( dm ) derived distance of 2.7 kpc using the ne2001 model @xcite , so we adopt @xmath11 kpc .
the companion shows evidence for an equatorial disk in its optical spectrum , and has generally been classified as a be star @xcite ..
Please generate the next two sentences of the article | the pulsar comes within @xmath12 au of its companion star at periastron , which is roughly the size of the equatorial disk @xcite .
the orbital plane of the pulsar is believed to be highly inclined with respect to this disk and so the pulsar crosses the disk plane twice each orbit , just before and just after periastron @xcite . |
3,679 | Suppose that you have an abstract for a scientific paper: we apply a previously developed gibbs sampling framework to the foreground corrected 3-yr wmap polarization data and compute the power spectrum and residual foreground template amplitude posterior distributions .
we first analyze the co - added q- and v - band data , and compare our results to the likelihood code published by the wmap team .
we find good agreement , and thus verify the numerics and data processing steps of both approaches .
however , we also analyze the q- and v - band separately , allowing for non - zero eb cross - correlations and including two individual foreground template amplitudes tracing synchrotron and dust emission . in these analyses ,
we find tentative evidence of systematics : the foreground tracers correlate with each of the q- and v - band sky maps individually , although not with the co - added qv map ; there is a noticeable negative eb cross - correlation at @xmath0 in the v - band map ; and finally , when relaxing the constraints on eb and bb , noticeable differences are observed between the marginalized band powers in the q- and v - bands . further studies of these features are imperative , given the importance of the low-@xmath1 ee spectrum on the optical depth of reionization @xmath2 and the spectral index of scalar perturbations @xmath3 . .
And you have already written the first three sentences of the full article: one of the most remarkable results in the 3-yr data release from the wilkinson microwave anisotropy probe ( wmap ) experiment @xcite was the detection of large - scale e - mode polarization at millimeter wavelengths .
this was interpreted as the theoretically predicted signature of reionization , and allowed the wmap team to set new and tighter constraints on the optical depth of reionization @xmath2 . in turn ,
the well - known degeneracy between @xmath2 and the spectral index of primordial scalar perturbations @xmath3 was broken ..
Please generate the next two sentences of the article | the final outcome was a claimed detection of @xmath4 at a statistical significance of almost @xmath5 @xcite .
one should bear in mind , however , the great potential for systematics effects in both the temperature and polarization measurements . |
3,680 | Suppose that you have an abstract for a scientific paper: we present a new direct proof of a topological representation theorem for oriented matroids in the general rank case .
our proof is based on an earlier rank 3 version .
it uses hyperline sequences and the generalized schnflies theorem . as an application
, we show that one can read off oriented matroids from arrangements of embedded spheres of codimension one , even if wild spheres are involved .
* keywords : * oriented matroid , pseudosphere arrangement , chirotope , lawrence representation , hyperline sequences , generalized schnflies theorem . .
And you have already written the first three sentences of the full article: when studying vector configurations or central hyperplane configurations , point sets on a sphere or great hypersphere arrangements , vector spaces or their duals , points on grassmannians , polytopes and their corresponding cellular decompositions in projective space , etc .
, an abstraction of an important equivalence class of matrices often plays a central role : an oriented matroid .
the theory of oriented matroids ( see @xcite ) provides us with a multitude of definitions for an oriented matroid that can be viewed as reflecting the variety of objects that a matrix can represent ..
Please generate the next two sentences of the article | these definitions via circuit or cocircuit axioms ( @xcite , p. 103 ) , sphere systems ( @xcite , p. 227 ) , gramann plcker relations ( chirotope axioms ) ( @xcite , p. 126 , p. 138 , @xcite ) , hull systems ( @xcite ) , to mention just a few of them , differ a lot with respect to their motivational aspects , their algorithmical efficiency or their relation to the actual application .
each definition provides in general an additional insight for the motivating problem . in the research monograph on oriented matroids , @xcite , |
3,681 | Suppose that you have an abstract for a scientific paper: we consider collider signatures of the exceptional supersymmetric ( susy ) standard model ( e@xmath0ssm ) .
this @xmath1 inspired susy model is based on the sm gauge group together with an extra @xmath2 gauge symmetry under which right handed neutrinos have zero charge .
to ensure anomaly cancellation and gauge coupling unification the low energy matter content of the e@xmath0ssm involve extra exotic matter beyond the mssm .
we discuss the collider signatures associated with the production of new particles predicted by the e@xmath0ssm and consider the implications of this model for dark matter and higgs phenomenology . since exotic quarks in the e@xmath0ssm can be either diquarks or leptoquarks they may provide spectacular new physics signals at the lhc . .
And you have already written the first three sentences of the full article: softly broken supersymmetry ( susy ) provides a very attractive framework for physics beyond the standard model ( bsm ) , in which the hierarchy problem is solved and the unification of gauge couplings can be realised @xcite .
despite these attractive features , the minimal supersymmetric standard model ( mssm ) suffers from the @xmath3 problem .
the superpotential of the mssm contains the bilinear term @xmath4 , where @xmath5 and @xmath6 are the higgs doublet superfields . in order to get the correct pattern of electroweak ( ew ) symmetry breaking the parameter @xmath3 is required to be in the tev region . at the same time.
Please generate the next two sentences of the article | the incorporation of the mssm into supergravity ( sugra ) or grand unified theories ( gut ) implies that @xmath3 should be of the order of gut or planck scales .
an elegant solution to this problem arises within @xmath1 inspired susy models . at high energies |
3,682 | Suppose that you have an abstract for a scientific paper: we report on a limited search for pure - rotational molecular hydrogen emission associated with young , pre - main - sequence stars .
we looked for @xmath0 @xmath1 and @xmath2 emission in the mid - infrared using the texas echelon - cross - echelle spectrograph ( texes ) at nasa s 3 m infrared telescope facility .
the high spectral and spatial resolution of our observations lead to more stringent limits on narrow line emission close to the source than previously achieved .
one star , ab aur , shows a possible ( 2@xmath3 ) detection , but further observations are required to make a confident statement .
our non - detections suggest that a significant fraction , perhaps all , of previously reported emission towards these objects could be extended on scales of 5 or more . .
And you have already written the first three sentences of the full article: formation of a circumstellar disk is recognized as a natural step in the process of star formation and a vital step toward forming planets .
currently our knowledge of protoplanetary disk properties at anthropically interesting distances of 1 - 30 au is relatively limited .
the best spectroscopic constraints on disk temperature and density structure are dominated by material either within 0.5 au of the central source ( najita et al ..
Please generate the next two sentences of the article | 1996 ; carr , mathieu , & najita 2001 ) or at radii @xmath450 au ( dutrey , guilloteau , & simon 1994 ) .
this radial sampling results from the tracers utilized to date : dust emission and scattering and co ro - vibrational and rotational emission . using rotational lines as a tracer may allow study of disks at radii of 1 - 50 au . |
3,683 | Suppose that you have an abstract for a scientific paper: we study the origin of the bi - stability jump in the terminal velocity of the winds of supergiants near spectral type b1 .
observations show that here the ratio @xmath0 drops steeply from about 2.6 at types earlier than b1 to a value of @xmath0=1.3 at types later than b2 . to this purpose
, we have calculated wind models and mass - loss rates for early - type supergiants in a @xmath1 grid covering the range between @xmath2 and @xmath3 .
these models show the existence of a jump in mass loss around @xmath4 for normal supergiants , with increasing by about a factor five from @xmath5 to 22 500 k for constant luminosity .
the wind efficiency number @xmath6 also increases drastically by a factor of 2 - 3 near that temperature .
we argue that the jump in mass loss is accompanied by a decrease of the ratio @xmath0 , which is the observed bi - stability jump in terminal velocity . using self - consistent models for two values of @xmath1
, we have derived @xmath0 = 2.4 for = 30 000 k and @xmath0 = 1.2 for = 17 500 k. this is within 10 percent of the observed values around the jump . up to now , a theoretical explanation of the observed bi - stability jump was not yet provided by radiation driven wind theory .
to understand the origin of the bi - stability jump , we have investigated the line acceleration for models around the jump in detail .
these models demonstrate that _
@xmath7 increases around the bi - stability jump due to an increase in the line acceleration of fe iii _ below _ the sonic point_. this shows that the mass - loss rate of b - type supergiants is very sensitive to the abundance and the ionization balance of iron .
furthermore , we show that the elements c , n and o are important line drivers in the _ supersonic _ part of the wind .
the _ subsonic _ part of the wind is dominated by the line acceleration due to fe .
therefore , cno - processing is expected _ not _ to have a large impact on but it might have impact on the terminal velocities . finally , we....
And you have already written the first three sentences of the full article: in this paper we investigate the origin and the consequences of the _ bi - stability jump _ of the stellar winds of early - type stars near spectral type b1 .
this bi - stability jump is observed as a steep decrease in the terminal velocity of the winds from @xmath8 for supergiants of types earlier than b1 to @xmath9 for supergiants of types later than b1 ( lamers et al .
we will show that this jump in the wind velocity is accompanied by a jump in the mass - loss rate with @xmath7 increasing by about a factor of five for supergiants with between 27 500 and 22 500 k. the theory of radiation driven winds predicts that the mass - loss rates and terminal velocities of the winds of early - type stars depend smoothly on the stellar parameters , with @xmath10 and @xmath11 ( castor et al ..
Please generate the next two sentences of the article | 1975 , abbott 1982 , pauldrach et al .
1986 , kudritzki et al . |
3,684 | Suppose that you have an abstract for a scientific paper: local electronic structures of nanometer - sized patches of epitaxial graphene and its interface layer with sic(0001 ) have been studied by atomically resolved scanning tunneling microscopy and spectroscopy .
localized states belonging to the interface layer of a graphene / sic system show to have an essential influence on the electronic structure of graphene .
giant enhancement of inelastic tunneling , reaching 50% of the total tunneling current , has been observed at the localized states on a nanometer - sized graphene monolayer surrounded by defects . .
And you have already written the first three sentences of the full article: epitaxially grown graphene on sic offers one of the most promising platforms for applications in high speed electronic devices that might replace silicon in future.@xcite however , the quality of the two - dimensional electron gas in epitaxial graphene on sic still falls behind the electronic quality of mechanically exfoliated graphene.@xcite while the maximum charge carrier mobility of epitaxial graphene on si(0001 ) is in the order of 1000 @xmath0/vs at room temperature,@xcite the mobility reaches two orders of magnitude higher values in exfoliated graphene.@xcite therefore a great deal of interest is focused on the understanding the differences between the electronic structure of exfoliated and epitaxial graphene and the consequences for potential applications .
since the crystallographic quality of both graphene layers seems to be equivalent,@xcite the interaction with the substrate remains the biggest unknown .
this is mainly because of the complicated structure and electronic properties of the carbon rich graphene / sic interface layer , which are still not fully understood.@xcite in this paper , we present a local study of electronic and vibrational properties of nanometer - sized areas of a graphene monolayer grown on sic(0001 ) and its @xmath1 interface layer by scanning tunneling microscopy ( stm ) . local scanning tunneling spectroscopy ( sts ) and inelastic electron tunneling spectroscopy ( iets ) measurements have revealed unexpected phenomena in epitaxial graphene that could not be observed in spatially averaged measurements , which are usually reported in literature ..
Please generate the next two sentences of the article | localized states of the interface layer protruding through the first graphene layer have caused giant enhancement of inelastic tunneling of electrons from graphene particularly on the places with localized electron states of the graphene / sic interface layer .
the inelastic phonon contribution for the out of plane graphene acoustic phonon at 70 mv has reached a gigantic 50% of the total tunneling current . |
3,685 | Suppose that you have an abstract for a scientific paper: based on the sheaf logic approach to set theoretic forcing , a hierarchy of quantum variable sets is constructed which generalizes and simplifies the analogous construction developed by takeuti on boolean valued models of set theory . over this model two alternative proofs of takeuti s correspondence , between self adjoint operators and the real numbers of the model , are given .
this approach results to be more constructive showing a direct relation with the gelfand representation theorem , revealing also the importance of these results with respect to the interpretation of quantum mechanics in close connection with the deutsch - everett multiversal interpretation .
finally , it is shown how in this context the notion of genericity and the corresponding generic model theorem can help to explain the emergence of classicality also in connection with the deutsch - everett perspective . .
And you have already written the first three sentences of the full article: the advent of quantum mechanics ( qm ) and the problems linked to its ontological nature changed our conception of physical reality in a radical way , problems that before had concerned just philosophers of science became central to the physics debate .
notions like observable , observer and measurement , which had not been problematic to the conception of physical theories , became fundamental and subject of numerous controversies .
furthermore , the classical realist conception of physical objects as independent bearers of properties , on which the ontology of classical theories was based , was also challenged ; becoming evident the interpretational difficulties of the theory , a problem which physics had never affronted before ..
Please generate the next two sentences of the article | + today , more than one hundred years after max planck formulated the quantum hypothesis , we still do not have a settled agreement about what quantum reality is or if there is something as a quantum reality at all .
nevertheless , the theory has been incredibly successful in its predictive role . for this reason |
3,686 | Suppose that you have an abstract for a scientific paper: an algebraic soft - decision decoder for hermitian codes is presented .
we apply koetter and vardy s soft - decision decoding framework , now well established for reed - solomon codes , to hermitian codes .
first we provide an algebraic foundation for soft - decision decoding
. then we present an interpolation algorithm finding the @xmath0-polynomial that plays a key role in the decoding . with some simulation results ,
we compare performances of the algebraic soft - decision decoders for hermitian codes and reed - solomon codes , favorable to the former .
hermitian codes , algebraic soft - decision decoding , interpolation algorithm , grbner bases . .
And you have already written the first three sentences of the full article: sudan and guruswami s list decoding of reed - solomon codes @xcite has developed into algebraic soft - decision decoding by koetter and vardy @xcite . as reed - solomon codes are widely used in coding applications ,
algebraic soft - decision decoding is regarded as one of the most important developments for reed - solomon codes .
hence there have been many subsequent works to make the decoding method efficient and practical @xcite ..
Please generate the next two sentences of the article | engineers have proposed fast electronic circuits implementing the algebraic soft - decision decoder @xcite .
one may say that the algebraic soft - decision decoding of reed - solomon codes is now in a mature state for deployment in applications @xcite . |
3,687 | Suppose that you have an abstract for a scientific paper: we use hydrodynamic simulations with adaptive grid refinement to study the dependence of hot gas flows in x - ray luminous giant elliptical galaxies on the efficiency of heat supply to the gas .
we consider a number of potential heating mechanisms including type ia supernovae and sporadic nuclear activity of a central super - massive black hole . as a starting point for this research
we use an equilibrium hydrostatic recycling model @xcite .
we show that a compact cooling inflow develops , if the heating is slightly insufficient to counterbalance radiative cooling of the hot gas in the central few kiloparsecs .
an excessive heating in the centre , instead , drives a convectively unstable outflow .
we model the onset of the instability and a quasi - steady convective regime in the core of the galaxy in two - dimensions assuming axial symmetry . provided the power of net energy supply in the core
is not too high , the convection remains subsonic .
the convective pattern is dominated by buoyancy driven large - scale mushroom - like structures . unlike in the case of a cooling inflow , the x - ray surface brightness of an ( on average ) isentropic convective core does not display a sharp maximum at the centre . a hybrid model , which combines a subsonic peripheral cooling inflow with an inner convective core , appears to be stable .
we also discuss observational implications of these results .
[ firstpage ] hydrodynamics instabilities cooling flows galaxies : ism ism dark matter .
And you have already written the first three sentences of the full article: extended thermal x - ray emission from the hot ( @xmath0 k ) interstellar medium ( ism ) in giant elliptical galaxies is usually interpreted in terms of a ` cooling flow ' scenario [ see loewenstein for a recent review ] .
it implies that radiative cooling of optically thin hot plasma drives a subsonic inflow towards the centre of a potential well formed by the stellar component and a massive dark halo .
galactic cooling flows and cooling flows in clusters of galaxies are essentially different owing to a difference in the origin of the two media ..
Please generate the next two sentences of the article | the intracluster medium is mostly primordial , cools from its high virial temperature and is accreted by the central galaxy , which provides a focus for the flow .
in contrast , the ism in elliptical galaxies is constantly replenished by mass loss from evolved stars . |
3,688 | Suppose that you have an abstract for a scientific paper: current analytic and semi - analytic dark matter halo models distinguish between the central galaxy in a halo and the satellite galaxies in halo substructures .
it is expected that galaxy properties are correlated with host halo mass , and that central galaxies tend to be the most luminous , massive , and reddest galaxies in halos while the satellites around them are fainter and bluer .
using a recent halo - model description of the color dependence of galaxy clustering ( skibba & sheth 2008 ) , we investigate the colors of central and satellite galaxies predicted by the model and compare them to those of two galaxy group catalogs constructed from the sloan digital sky survey ( yang et al .
2007 , berlind et al .
2006a ) . in the model , the environmental dependence of galaxy color is determined by that of halo mass , and the predicted color mark correlations were shown to be consistent with sdss measurements .
the model assumes that satellites tend to follow a color - magnitude sequence that approaches the red sequence at bright luminosities ; the model s success suggests that bright satellites tend to be ` red and dead ' while the star formation in fainter ones is in the process of being quenched . in both the model and the sdss group catalogs
, we find that at fixed luminosity or stellar mass , central galaxies tend to be bluer than satellites .
in contrast , at fixed group richness or halo mass , central galaxies tend to be redder than satellites , and galaxy colors become redder with increasing mass .
we also compare the central and satellite galaxy color distributions , as a function of luminosity and as a function of richness , in the model and in the two group catalogs . except for faint galaxies and small groups , the model and both group catalogs are in very good agreement .
[ firstpage ] methods : analytical - methods : statistical - galaxies : clusters : general - galaxies : formation - galaxies : evolution - galaxies : clustering - galaxies : halos - large scale structure....
And you have already written the first three sentences of the full article: in standard @xmath0cdm cosmological models , cold dark matter halos form from the gravitational collapse of dark matter particles , and they assemble hierarchically , such that smaller halos merge to form larger and more massive halos . according to the current paradigm of galaxy formation , galaxies form within halos , due to the cooling of hot gas .
halos and galaxies evolve simultaneously , and the evolution of a galaxy is affected by its host halo .
if the halo is accreted by a larger halo , the galaxy will be affected by it as well , and may interact or merge with the galaxies within the new host halo ..
Please generate the next two sentences of the article | such ` satellite ' galaxies in halo substructures no longer accrete hot gas , which instead is only accreted by the ` central ' galaxy in the halo .
the central galaxy consequently continues to grow , while other massive galaxies may merge into it , and therefore it is expected to be the most luminous and most massive galaxy in the halo . for these reasons , current analytic and semi - analytic models distinguish between central and satellite galaxies , which at a given time are at different stages of evolution , or may have evolved differently . |
3,689 | Suppose that you have an abstract for a scientific paper: we show that strong electromagnon peaks can be found in absorption spectra of non - collinear magnets exhibiting a linear magnetoelectric effect .
the frequencies of these peaks coincide with the frequencies of antiferromagnetic resonances and the ratio of the spectral weights of the electromagnon and antiferromagnetic resonance is related to the ratio of the static magnetoelectric constant and magnetic susceptibility . using a kagom lattice antiferromagnet as an example
, we show that frustration of spin ordering gives rise to magnetoelastic instabilities at strong spin - lattice coupling , which transform a non - collinear magnetoelectric spin state into a collinear multiferroic state with a spontaneous electric polarization and magnetization .
the kagom lattice antiferromagnet also shows a ferroelectric incommensurate - spiral phase , where polarization is induced by the exchange striction mechanism . .
And you have already written the first three sentences of the full article: the recent renewal of interest in multiferroic materials led to discovery of many novel compounds where electric polarization is induced by ordered magnetic states with broken inversion symmetry.@xcite the electric polarization in multiferroics is very susceptible to changes in spin ordering produced by an applied magnetic field , which gives rise to dramatic effects such as the magnetically - induced polarization flops and colossal magnetocapacitance.@xcite magnetoelectric interactions also couple spin waves to polar phonon modes and make possible to excite magnons by an oscillating electric field of light , which gives rise to the so - called electromagnon peaks in photoabsorption.@xcite electromagnons were recently observed in two groups of multiferroic orthorombic manganites , @xmath0mno@xmath1 ( @xmath0 = gd , tb , dy , eu@xmath2y@xmath3 ) and @xmath0mn@xmath4o@xmath5 ( @xmath0 = y , tb ) .
@xcite ferroelectricity in @xmath0mno@xmath1 appears in a non - collinear antiferromagnetic state with the cycloidal spiral ordering and the magnetoelectric coupling originates from the so - called inverse dzyaloshinskii - moriya mechanism .
@xcite in ref ..
Please generate the next two sentences of the article | [ ] it was noted that the same mechanism can couple magnons to photons and that an oscillating electric field of light can excite rotations of the spiral plane .
however , the selection rule for the electromagnon polarization resulting from this coupling does not agree with recent experimental data@xcite and , moreover , the inverse dzyaloshinskii - moriya mechanism of relativistic nature is too weak to explain the strength of the electromagnon peaks in @xmath0mno@xmath1 . |
3,690 | Suppose that you have an abstract for a scientific paper: in this letter we study the problem of scalar particle production in external electric field in de sitter geometry . the total probability is calculated using the previously obtained result in ref.@xcite for transition amplitude in external electric field on de sitter space .
then we make a graphical study of the total probability in terms of the ratio mass of the particle / expansion factor .
our results show that the probability depend of the direction in which the particles are emitted and that the probability becomes maxim when particles are emitted on the direction of the electric field . in the minkowski limit we obtain that the probability is vanishing . .
And you have already written the first three sentences of the full article: the problem of particle production in electric field on de sitter geometry received a lot of attention in the literature @xcite . this problem can be studied using nonperturbative methods @xcite and the main results are related to the number density of produced particles .
more recent studies suggest that this effect could also appear as a perturbative phenomenon @xcite .
this is because in de sitter qed these processes are no longer forbidden by the simultaneous energy - momentum conservation as in flat space case ..
Please generate the next two sentences of the article | the cosmological mechanism of particle creation based on nonperturbative methods use the approximation of the out field at late times to obtain the density number of produced particles . in the case of scalar pair production
it was shown that the results are valid only when the mass of the particle is larger than the expansion parameter @xmath0 @xcite , and this corresponds to weak gravitational fields . |
3,691 | Suppose that you have an abstract for a scientific paper: we present a study of the effects of simultaneous charge- and spin - frustration on the two - dimensional strongly correlated quarter - filled band on an anisotropic triangular lattice .
the broken - symmetry states that dominate in the weakly frustrated region near the rectangular lattice limit are the well known antiferromagnetic state with in - phase lattice dimerization along one direction , and the wigner crystal state with the checkerboard charge order . for moderate to strong frustration , however , the dominant phase is a novel spin - singlet paired - electron crystal ( pec ) , consisting of pairs of charge - rich sites separated by pairs of charge - poor sites .
the pec , with coexisting charge - order and spin - gap in two dimension , is the quarter - filled band equivalent of the valence bond solid ( vbs ) that can appear in the frustrated half - filled band within antiferromagnetic spin hamiltonians .
we discuss the phase diagram as a function of on - site and intersite coulomb interactions as well as electron - phonon coupling strength .
we speculate that the spin - bonded pairs of the pec can become mobile for even stronger frustration , giving rise to a paired - electron liquid .
we discuss the implications of the pec concept for understanding several classes of quarter - filled band materials that display unconventional superconductivity , focusing in particular on organic charge transfer solids .
our work points out the need to go beyond quantum spin liquid ( qsl ) concepts for highly frustrated organic charge - transfer solids such as @xmath0-(bedt - ttf)@xmath1cu@xmath1(cn)@xmath2 and etme@xmath2sb[pd(dmit)@xmath1]@xmath1 , which we believe show frustration - induced charge disproportionation at low temperatures .
we discuss possible application to layered cobaltates and @xmath4-filled band spinels . .
And you have already written the first three sentences of the full article: strong coulomb electron - electron ( e - e ) interactions can drive transitions from metallic to exotic insulating states , the most well known of which are the mott - hubbard semiconductor ( mhs ) and the wigner crystal ( wc ) .
the mhs is a characteristic of systems with carrier concentration per site @xmath5 and is driven by strong onsite e - e repulsion , the hubbard @xmath6 interaction . depending upon the lattice structure the critical @xmath6
at which the metal - insulator ( mi ) transition occurs , @xmath7 , can be 0@xmath8 or finite @xcite ..
Please generate the next two sentences of the article | in contrast , the wc occurs in systems with @xmath9 , and is characterized by charge - ordering ( co ) , _ i.e. _ , a periodic arrangement of _ single _ charge carriers on the lattice .
the wc is driven by strong onsite as well as inter - site coulomb interactions @xcite . |
3,692 | Suppose that you have an abstract for a scientific paper: employing concrete examples from nuclear physics it is shown that low energy nuclear reactions can and have been induced by all of the four fundamental interactions ( i ) ( stellar ) gravitational , ( ii ) strong , ( iii ) electromagnetic and ( iv ) weak .
differences are highlighted through the great diversity in the rates and similarity through the nature of the nuclear reactions initiated by each . .
And you have already written the first three sentences of the full article: we show below through physical examples that low energy nuclear reactions have been induced by _ all _ of the four fundamental interactions : gravitational , strong , electromagnetic and weak .
* gravity * : gravitational interactions are well known to cause nuclear reactions and fusion in a star . were it not for nuclear activity
, a star would be dynamically unstable and undergo gravitational collapse@xcite ..
Please generate the next two sentences of the article | in fact , standard theory predicts the collapse of a star when the nuclear fuel is exhausted as the star can no longer counteract the inward compression due to gravitation . *
nuclear * : a laboratory example of low energy strong interaction fusion is provided by a fast discharge in fine deuterated polymer fibers . in such fibers , |
3,693 | Suppose that you have an abstract for a scientific paper: we study the birational representation of @xmath0 proposed by kajiwara - noumi - yamada ( kny ) in the case of @xmath1 and @xmath2 . it is shown that the equation can be lifted to an automorphism of a family of @xmath3 surfaces and therefore the group of cremona isometries is @xmath4 ( @xmath5 ) .
the equation can be decomposed into two mappings which are conjugate to the @xmath6-@xmath7 equation .
it is also shown that the subgroup of cremona isometries which commute with the original translation is isomorphic to @xmath8 .
graduate school of mathematical sciences , university of tokyo , komaba 3 - 8 - 1 , meguro - ku , tokyo 153 - 8914 , japan + .
And you have already written the first three sentences of the full article: since the singularity confinement criterion was introduced as a discrete analogue of the painlev test @xcite , many discrete analogues of painlev equations have been proposed and extensively studied @xcite .
discrete painlev equations have been considered as 2-dimensional non - autonomous birational dynamical systems which satisfy this criterion and which have limiting procedures to the ( continuous ) painlev equations . in recent years
it was shown by sakai that all of these ( from the point of view of symmetries ) are obtained by studying rational surfaces in connection with extended affine weyl groups @xcite ..
Please generate the next two sentences of the article | on the other hand , recently kajiwara _ et al _ ( kny ) @xcite have proposed a birational representation of the extended weyl groups @xmath9 on the field of rational functions @xmath10 , which is expected to provide higher order discrete painlev equations ( however , this representation is not always faithful , for example it is not faithful in the case where @xmath11 or @xmath12 equals @xmath13 and in the case of @xmath14 ) . in the case of @xmath1 and @xmath15 ,
the actions of the translations can be considered to be 2-dimensional non - autonomous discrete dynamical systems and therefore to correspond to discrete painlev equations . |
3,694 | Suppose that you have an abstract for a scientific paper: we perform a numerical analysis of superfluid turbulence produced by thermal counterflow in he ii by using the vortex filament model .
counterflow in a low aspect ratio channel is known to show the transition from laminar flow to the two turbulent states ti and tii .
the present understanding is that the ti has the turbulent superfluid and the laminar normal fluid but both fluids are turbulent in the tii state .
this work studies the vortex tangle in the ti state .
solid boundary condition is applied to walls of a square channel , and the velocity field of the normal fluid is prescribed to be a laminar poiseuille profile .
an inhomogeneous vortex tangle , which concentrates near the solid boundaries , is obtained as the statistically steady state .
it is sustained by its characteristic space - time oscillation .
the inhomogeneity of the vortex tangle shows the characteristic dependence on temperature , which is caused by two competitive effects , namely the profile of the counterflow velocity and the mutual friction . .
And you have already written the first three sentences of the full article: a thermal counterflow in he ii is internal convection of two fluids , namely the normal fluid and the superfluid .
when the counterflow velocity exceeds a critical value , a self - sustaining tangle of quantized vortices appears to form superfluid turbulence . in low aspect ratio channels ,
superfluid turbulence makes the mysterious transition ..
Please generate the next two sentences of the article | the increase in the counterflow velocity is observed to change the laminar state to the first turbulent state ti , and next to the second turbulent state tii @xcite .
melotte and barenghi suggested that the transition from the ti to tii state is caused by the transition of the normal fluid from laminar to turbulent @xcite . |
3,695 | Suppose that you have an abstract for a scientific paper: the high quantum efficiency of photosynthetic complexes has inspired researchers to explore new routes to utilize this process for photovoltaic devices .
quantum coherence has been demonstrated to play a crucial role within this process .
herein , we propose a three - dipole system as a model of a new photocell type which exploits the coherence among its three dipoles .
we have proved that the efficiency of such a photocell is greatly enhanced by quantum coherence .
we have also predicted that the photocurrents can be enhanced by about 49.5% in such a coherent coupled dipole system compared with the uncoupled dipoles .
these results suggest a promising novel design aspect of photosynthesis - mimicking photovoltaic devices . .
And you have already written the first three sentences of the full article: long - lived quantum coherence been observed in photosynthesis after laser excitation @xcite .
it has attracted much attention on how quantum coherence could be enhanced in complex biological environment and how it may play a key role in efficient exciton transports @xcite .
it is well known that the photon - to - charge conversion quantum efficiency of photosynthesis in plants , bacteria , and algae can be almost 100% under certain conditions ..
Please generate the next two sentences of the article | while photosynthesis converts sunlight into chemical energy , solar cell converts sunlight into electric energy . according to shockley and queisser ,
the efficiency of photovoltaic energy conversion is limited to 33% , based on the energy band gap and solar spectrum , due to the radiative recombination of electron - hole pairs , thermalization , and unabsorbed photons @xcite . |
3,696 | Suppose that you have an abstract for a scientific paper: the mathematical problem of localizing modular functors to neighborhoods of points is shown to be closely related to the physical problem of engineering a local hamiltonian for a computationally universal quantum medium . for genus
@xmath0 surfaces , such a local hamiltonian is mathematically defined .
braiding defects of this medium implements a representation associated to the jones polynomial and this representation is known to be universal for quantum computation . _
dedicated to my teachers and collaborators : alexei kitaev , greg kuperberg , kevin walker , and zhenghan wang .
their work has been the inspiration for this lecture . _ .
And you have already written the first three sentences of the full article: reality has the habit of intruding on the prodigies of purest thought and encumbering them with unpleasant embellishments .
so it is astonishing when the chthonian hammer of the engineer resonates precisely to the gossamer fluttering of theory .
such a moment may soon be at hand in the practice and theory of quantum computation ..
Please generate the next two sentences of the article | the most compelling theoretical question , @xmath1localization , " is yielding an answer which points the way to a solution of quantum computing s ( qc ) most daunting engineering problem : reaching the accuracy threshold for fault tolerant computation .
after shor s discovery [ s1 ] of a polynomial time factoring algorithm in the quantum model qc , skeptics properly questioned whether a unitary evolution could ever be induced to process information fault tolerantly . |
3,697 | Suppose that you have an abstract for a scientific paper: equilibrium charge distribution on a thin , straight conductor has been actively discussed in recent years , starting with griffiths and li @xcite , who suspected a uniform distribution , and culminating with maxwell s insightful words @xcite as reported by jackson @xcite .
the present work addresses the electrostatic problem of a thin , curved , cylindrical conductor , or a conducting _ filament _ , and shows that the corresponding linear charge density slowly tends to uniformity as the inverse of the logarithm of a characteristic parameter which is the ratio of the diameter to the smaller of the length and minimum radius of curvature of the filament .
an alternative derivation of this result directly based on energy minimization is developed .
these results are based on a general asymptotic analysis of the electric field components and potential near a charge filament in the limit of vanishing diameter whereby the divergent parts of these quantities are explicitly calculated .
it is found that the divergent parts of the radial and azimuthal electric field components , as well as the electric potential , are determined by the local charge density while the axial component is determined by the local dipole density . for a straight filament ,
these results reduce to those for conducting needles discussed in the literature . for curved filaments ,
the configuration of charges and fields is no longer azimuthally symmetric , and there is an additional length scale in the problem arising from the finite radius of curvature of the filament .
remarkably , the basic uniformity result survives the added complications , which include an azimuthal variation in the surface charge density of the filament . as with the variations of linear charge density along the filament ,
the azimuthal variations vanish with the characteristic parameter , only more rapidly .
these uniformity results yield an asymptotic formula for the capacitance of a curved filament that generalizes maxwell s original result
. the....
And you have already written the first three sentences of the full article: a paper of griffiths and li in this journal @xcite has triggered a lively discussion on the electrostatic equilibrium distribution of charge on a thin , straight , cylindrical conductor .
while suspecting that as the diameter - to - length ratio of the conductor approaches zero the charge distribution on it tends to uniformity at all points sufficiently far from the ends , they encountered certain puzzling aspects of the problem in their numerical studies .
in particular , they identified an apparent contradiction in the strict limit of zero diameter , posing the question that `` if the charge density _ were _ constant , on a truly one - dimensional needle , how could the force on an off - center point be zero ? '' contributions by good @xcite and andrews @xcite followed the work of griffiths and li , offering further evidence of the uniformity conjecture of the latter , as well as alternative methods of analyzing the problem ..
Please generate the next two sentences of the article | however , it fell to jackson @xcite to provide a clear resolution of the equilibrium paradox quoted above by carefully considering the limit of vanishing diameter - to - length ratio and the crucial role of the slow , inverse - logarithmic approach of charge density to uniformity in that limit .
a subsequent paper by jackson @xcite reported on his discovery that the problem in question had already been considered by none other than james clerk maxwell ! maxwell , treating `` the electrical capacity of a long narrow cylinder '' more than 130 years ago @xcite , had derived the inverse - logarithmic approach to uniformity noted by andrews and highlighted by jackson , and had eloquently summarized the behavior of electrostatic charges on a thin , straight conductor . |
3,698 | Suppose that you have an abstract for a scientific paper: spin dimer systems are a promising playground for the detailed study of quantum phase transitions . using the magnetic field as the tuning parameter it is in principle possible to observe a crossover from the characteristic scaling near critical points to the behavior of a finite temperature phase transition . in this work
we study two - dimensional coupled spin dimer systems by comparing numerical quantum monte carlo simulations with analytical calculations of the susceptibility , the magneto - caloric effect , and the helicity modulus .
the magneto - caloric behavior of the magnetization with temperature can be used to determine the critical fields with high accuracy , but the critical scaling does not show the expected logarithmic corrections .
the zeros of the cooling rate are an excellent indicator of the competition between quantum criticality and vortex physics , but they are not directly associated with the quantum phase transition or the finite temperature berezinsky - kosterlitz - thouless transition .
the results give a unified picture of the full quantum and finite temperature phase diagram . .
And you have already written the first three sentences of the full article: the study of quantum phase transitions ( qpt ) remains a very active topic in many fields of physics , spurred by experimental progress to create novel tunable interacting systems .
qpt occur in quite different materials , including heavy fermion compounds , * ? ? ?
* unconventional superconductors , * ? ? ?.
Please generate the next two sentences of the article | * mott insulators , * ? ? ?
* coupled spin systems , * ? ? ? |
3,699 | Suppose that you have an abstract for a scientific paper: large - scale practical applications of fullerene ( c@xmath0 ) in nanodevices could be significantly facilitated if the commercially - available micrometer - scale raw c@xmath0 powder were further processed into a one - dimensional ( 1d ) nanowire - related polymer displaying covalent bonding as molecular interlinks and resembling traditional important conjugated polymers .
however , there has been little study thus far in this area despite the abundant literature on fullerene .
here we report the synthesis and characterization of such a c@xmath0-based nanowire polymer , ( -c@xmath0tmb-)@xmath1 , where tmb=1,2,4-trimethylbenzene , which displays a well - defined crystalline structure , exceptionally large length - to - width ratio and excellent thermal stability .
the material is prepared by first growing the corresponding nanowire through a solution phase of c@xmath0 followed by a topochemical polymerization reaction in the solid state .
gas chromatography , mass spectrometry and @xmath2c nuclear magnetic resonance evidence is provided for the nature of the covalent bonding mode adopted by the polymeric chains . theoretical analysis based on detailed calculations of the reaction energetics and structural analysis provides an in - depth understanding of the polymerization pathway .
the nanopolymer promises important applications in biological fields and in the development of optical , electrical , and magnetic nanodevices . .
And you have already written the first three sentences of the full article: two important forms of carbon , fullerene ( c@xmath0 ) and carbon nanotubes , are closely related to each other by their structural commonality of the sp@xmath3 framework .
carbon nanotubes have been widely investigated for the last decade or so as one - dimensional ( 1d ) nanomaterial @xcite .
in contrast , fullerene 1d nanostructures , such as c@xmath0 nanowires , presently represent laboratory curiosities @xcite ..
Please generate the next two sentences of the article | c@xmath0 nanowires are highly interesting nanomaterials because of the physical properties associated with their high surface area , low - dimensionality and quantum confinement effects @xcite . in comparison with carbon nanotubes
, however , c@xmath0 nanowires are mechanically fragile and electrically non - conducting on account of the large intermolecular spaces in the crystalline lattice although an individual c@xmath0 molecule is extremely hard , almost incompressible and electronically fully conjugated across all the carbon atoms @xcite . |
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