id
int64 0
203k
| input
stringlengths 66
4.29k
| output
stringlengths 0
3.83k
|
|---|---|---|
12,500 |
Suppose that you have an abstract for a scientific paper: we present the recent results from the star experiment on charged and neutral particle measurements at the forward rapidity in d+au collisions at @xmath0 = 200 gev and au+au collisions at @xmath0 = 62.4 gev .
the nuclear modification factor for charged and neutral hadrons in d+au collisions are presented .
measurements of @xmath1 and @xmath2 production at forward rapidity and the variation of net baryon density as a function of collision centrality are discussed .
we have also studied the limiting fragmentation of photons and charged particles in au+au collisions .
the photons and charged particles separately follow the energy independent limiting fragmentation behaviour .
however they have been observed to follow a different centrality dependence of limiting fragmentation . .
And you have already written the first three sentences of the full article: the star experiment at the relativistic heavy ion collider ( rhic ) at the brookhaven national laboratory has a unique capability of precise measurement of charged and neutral hadrons and photon multiplicity at forward rapidity . through this capability
we can carry out a systematic study of various aspects of particle production in relativistic heavy ion collisions .
the study of nuclear modification factor ( @xmath3 ) as a function of transverse momentum ( @xmath4 ) and pseudorapidity ( @xmath5 ) can reveal interesting information on the mechanism of particle production . a @xmath3(@xmath4 ) of unity.
Please generate the next two sentences of the article
|
will indicate the absence of nuclear effects such as shadowing , multiple scattering ( cronin effect ) and gluon saturation . in a color glass condensate picture ( cgc ) of particle production
it is expected that the nuclear modification factor will decrease with the increase in rapidity @xcite .
|
12,501 |
Suppose that you have an abstract for a scientific paper: we consider the possibility of observing continuous third - harmonic generation using a strongly driven , single - band one - dimensional metal . in the absence of scattering ,
the quantum efficiency of frequency tripling for such a system can be as high as 93% . combining the floquet quasi - energy spectrum with the keldysh green s function technique
, we derive the semiclassical master equation for a one - dimensional band of strongly and rapidly driven electrons in the presence of weak scattering by phonons . the power absorbed from the driving field is continuously dissipated by phonon modes , leading to a quasi - equilibrium in the electron distribution .
we use the kronig - penney model with varying effective mass to establish growth parameters of an inas / inp nanowire near optimal for third harmonic generation at terahertz frequency range . .
And you have already written the first three sentences of the full article: when electrons in a crystal band are driven by an external time - independent electric field , they move periodically across the brillouin zone , creating characteristic bloch oscillations . the frequency of the oscillations , @xmath0 , where @xmath1 is the unit cell size , coincides with the energy separation between neighboring states localized on a wannier - stark ladder @xcite .
the effect has been observed for electrons / holes in semiconducting superlattices@xcite , for atoms trapped in a periodic optical potential@xcite , and for light propagating in a periodic array of waveguides , with gradient of the temperature or of the refraction index working as an effective electric field@xcite .
combining the effects of a strong , time - periodic driving field , with the nonlinearity of the bloch oscillations leads to higher harmonic generation of the driving frequency@xcite ..
Please generate the next two sentences of the article
|
this effect has recently been observed in bulk zno crystals strongly driven by a few - cycle pulsed infrared laser@xcite .
the application of the infrared field in short , 100-femtosecond , pulses was necessary to ensure that the absorbed energy could be transferred to the lattice and dissipated . in this work , we suggest that frequency multiplication due to periodically - driven bloch oscillations could also be observed in a steady - state setting , e.g. , a periodically modulated nanowire ( or an array of such nanowires ) continuously driven by high - amplitude terahertz radiation ( see fig .
|
12,502 |
Suppose that you have an abstract for a scientific paper: we survey agglomerative hierarchical clustering algorithms and discuss efficient implementations that are available in r and other software environments .
we look at hierarchical self - organizing maps , and mixture models .
we review grid - based clustering , focusing on hierarchical density - based approaches .
finally we describe a recently developed very efficient ( linear time ) hierarchical clustering algorithm , which can also be viewed as a hierarchical grid - based algorithm . .
And you have already written the first three sentences of the full article: agglomerative hierarchical clustering has been the dominant approach to constructing embedded classification schemes .
it is our aim to direct the reader s attention to practical algorithms and methods both efficient ( from the computational and storage points of view ) and effective ( from the application point of view ) .
it is often helpful to distinguish between _ method _ , involving a compactness criterion and the target structure of a 2-way tree representing the partial order on subsets of the power set ; as opposed to an _ implementation _ , which relates to the detail of the algorithm used ..
Please generate the next two sentences of the article
|
as with many other multivariate techniques , the objects to be classified have numerical measurements on a set of variables or attributes .
hence , the analysis is carried out on the rows of an array or matrix .
|
12,503 |
Suppose that you have an abstract for a scientific paper: using nuclear magnetic resonance techniques , we experimentally investigated the effects of applying a two bit phase error detection code to preserve quantum information in nuclear spin systems .
input states were stored with and without coding , and the resulting output states were compared with the originals and with each other . the theoretically expected result , net reduction of distortion and conditional error probabilities to second order , was indeed observed , despite imperfect coding operations which increased the error probabilities by approximately 5% .
systematic study of the deviations from the ideal behavior provided quantitative measures of different sources of error , and good agreement was found with a numerical model .
theoretical questions in quantum error correction in bulk nuclear spin systems including fidelity measures , signal strength and syndrome measurements are discussed . .
And you have already written the first three sentences of the full article: recent progress in experimental implementation of quantum algorithms has demonstrated in principle that quantum computers could solve specific problems in fewer steps than any classical machine @xcite .
these first generation quantum computers were 2-spin molecules in solution .
they were initialized , manipulated and measured at room - temperature using bulk nuclear magnetic resonance ( nmr ) spectroscopy techniques @xcite ..
Please generate the next two sentences of the article
|
classical redundancy in the ensemble and the discrete nature of the answers ensured that the correct answers were obtained despite gate imperfections and moderate rates of decoherence .
however , the accumulation of errors would be detrimental in larger quantum computers and for longer computations in the future , and methods to protect quantum information will be needed .
|
12,504 |
Suppose that you have an abstract for a scientific paper: hadronic transitions of @xmath0 ( @xmath1 , 1 , 2 ) are searched for using a sample of @xmath2 @xmath3 events collected with the besiii detector at the bepcii storage ring .
the @xmath4 is reconstructed with @xmath5 and @xmath6 final states .
no signals are observed in any of the three @xmath7 states in either @xmath4 decay mode . at the 90% confidence level ,
the upper limits are determined to be @xmath8 , @xmath9 , and @xmath10 . the upper limit of @xmath11 is lower than the existing theoretical prediction by almost an order of magnitude . the branching fractions of @xmath12 , @xmath13 , @xmath14 and @xmath15 ( @xmath1 , 1 , 2 ) are measured for the first time . .
And you have already written the first three sentences of the full article: heavy quarkonia , both @xmath16 and @xmath17 bound states , have provided good laboratories for the study of the strong interaction @xcite . for the hadronic transitions between the heavy quarkonium states , yan @xcite characterized it as the emission of two soft gluons from the heavy quarks and the conversion of gluons into light hadrons .
based on this scheme , a series of decay rates , such as the e1-e1 hadronic transition , e1-m1 hadronic transition , m1-m1 hadronic transition have been calculated @xcite . it has been shown that the multipole expansion can make quite successful predictions for many hadronic transitions between the heavy quarkonia @xcite
. however , most of these studies are for the transitions among the @xmath18 states ; the hadronic transitions of @xmath19 states are seldom explored . using a sample of @xmath20 , cleo measured for the first time the transition rate of @xmath21-wave bottomonium @xmath22 @xcite , and the results are consistent with the theoretical predictions @xcite . for the hadronic transition of the @xmath21-wave charmonium states ,.
Please generate the next two sentences of the article
|
there is only an upper limit of 2.2% at the 90% confidence level ( c.l . ) on the @xmath23 transition rate recently reported by the babar experiment @xcite .
the most promising process @xmath24 , which is dominated by an e1-m1 transition , is calculated in the multipole expansion formalism , and a transition rate @xmath25% is predicted @xcite . in this article , we search for @xmath0 with @xmath4 decays into @xmath5 and @xmath6 , where the @xmath26 is reconstructed in @xmath27 and @xmath28 in @xmath29 final states .
|
12,505 |
Suppose that you have an abstract for a scientific paper: a regression modeling method of space weather prediction is proposed .
it allows forecasting dst index up to 6 hours ahead with about @xmath0 correlation .
it can also be used for constructing phenomenological models of interaction between the solar wind and the magnetosphere . with its help
two new geoeffective parameters were found : latitudinal and longitudinal flow angles of the solar wind .
it was shown that dst index remembers its previous values for 2000 hours . .
And you have already written the first three sentences of the full article: the humankind studies space weather for more than 4000 years starting from the first mentions of auroras in ancient chinese literature . the term `` space weather '' itself exists for almost a century .
the official definition adopted by cospar states that `` space weather describes the physical processes induced by solar activity that have impact on our terrestrial and space environment , on ground based and space technological systems , and on human activities and health . ''
the first part of this definition actually covers two spatial scales of space weather , because when we speak about space weather in space , e.g. in connection with spacecraft failures , we usually mean some local parameters of the environment , and when we speak about space weather on the earth , e.g. in connection with human health , we usually mean some integral characteristics like the geomagnetic indices.
Please generate the next two sentences of the article
|
. since this article centers on the variations of the geomagnetic field , the latter meaning will be used .
the second part of this definition indicates practical manifestations of space weather .
|
12,506 |
Suppose that you have an abstract for a scientific paper: on montre la conjecture de breuil concernant la rduction modulo @xmath0 des reprsentations triangulines @xmath1 et des reprsentations @xmath2 de @xmath3 qui leur sont associes par la correspondance de langlands @xmath0-adique .
lingrdient principal de la dmonstration est ltude de certaines reprsentations lisses irrductibles de @xmath4 via des modles construits en utilisant les @xmath5-modules .
we prove breuil s conjecture concerning the reduction modulo @xmath0 of trianguline representations @xmath1 and of the representations @xmath2 of @xmath3 associated to them by the @xmath0-adic langlands correspondence .
the main ingredient of the proof is the study of some smooth irreducible representations of @xmath4 through models built using the theory of @xmath5-modules . .
And you have already written the first three sentences of the full article: cet article sinscrit dans le cadre de la correspondance de langlands @xmath0-adique .
dans ses articles @xcite , breuil a dfini une correspondance qui une reprsentation @xmath0-adique @xmath1 de dimension @xmath6 qui est cristalline ou semi - stable , associe une reprsentation @xmath2 de @xmath7 .
le fait que @xmath2 est non - nul , irrductible et admissible a t dmontr par colmez pour les reprsentations semi - stables dans @xcite puis par breuil et lauteur pour les reprsentations cristallines dans @xcite ..
Please generate the next two sentences of the article
|
la correspondance a ensuite t tendue aux reprsentations triangulines par colmez dans @xcite .
dans @xcite , breuil a par ailleurs dfini une correspondance en caractristique @xmath0 et conjectur quelle tait compatible avec la premire . lobjet
|
12,507 |
Suppose that you have an abstract for a scientific paper: upon hydrogen bond formation , electronic charge density is transferred between the donor and acceptor , impacting processes ranging from hydration to spectroscopy . here
we use ab initio path integral simulations to elucidate the role of nuclear quantum effects in determining the charge transfer in a range of hydrogen bonded species in the gas and liquid phase .
we show that the quantization of the nuclei gives rise to large changes in the magnitude of the charge transfer as well as its temperature dependence .
we then explain how a single geometric parameter determines the charge transfer through the hydrogen bond .
these results thus demonstrate that nuclear quantum effects are vital for the accurate description of charge transfer and offer a physically transparent way to understand how hydrogen bonding gives rise to it . .
And you have already written the first three sentences of the full article: the transfer of electronic charge density through a hydrogen bond manifests in effects ranging from the stabilization and spectroscopy of hydrated ions and aqueous solutions @xcite to the charging of polar residues in proteins @xcite , and has even been implicated in explaining the observed zeta potential at hydrophobic interfaces @xcite . however , defining the amount of charge transfer ( ct ) remains a subject of significant debate , since partitioning the electron density and assigning it to particular atoms or molecules is not uniquely defined .
this has led to the introduction of a number of approaches to calculate the charge transfer and charge transfer energy , with different approaches exhibiting both different quantitative and qualitative behavior @xcite .
for example , methods based on natural bond orbitals suggest that without ct the 0 k water dimer would adopt a different structure @xcite ..
Please generate the next two sentences of the article
|
however , studies using other methods suggest a much less substantial role of ct in stabilizing the water dimer hydrogen bond @xcite .
previous ct studies of hydrogen bonded systems have analyzed minimum energy structures @xcite or those obtained from simulations that treat the nuclei classically @xcite .
|
12,508 |
Suppose that you have an abstract for a scientific paper: we present secondary eclipse observations of the highly irradiated transiting brown dwarf kelt-1b .
these observations represent the first constraints on the atmospheric dynamics of a highly irradiated brown dwarf , the atmospheres of irradiated giant planets at high surface gravity , and the atmospheres of brown dwarfs that are dominated by external , rather than internal , energy . using the spitzer space telescope , we measure secondary eclipse depths of @xmath0% at 3.6@xmath1 m and @xmath2% at 4.5@xmath3 m .
we also find tentative evidence for the secondary eclipse in the @xmath4 band with a depth of @xmath5% .
these measured eclipse depths are most consistent with an atmosphere model in which there is a strong substellar hotspot , implying that heat redistribution in the atmosphere of kelt-1b is low .
while models with a more mild hotspot or even with dayside heat redistribution are only marginally disfavored , models with complete heat redistribution are strongly ruled out .
the eclipse depths also prefer an atmosphere with no tio inversion layer , although a model with tio inversion is permitted in the dayside heat redistribution case , and we consider the possibility of a day - night tio cold trap in this object . for the first time
, we compare the irac colors of brown dwarfs and hot jupiters as a function of effective temperature .
importantly , our measurements reveal that kelt-1b has a @xmath6-[4.5]$ ] color of @xmath7 , identical to that of isolated brown dwarfs of similarly high temperature .
in contrast , hot jupiters generally show redder @xmath6-[4.5]$ ] colors of @xmath80.4 , with a very large range from @xmath80 to @xmath81 .
evidently , despite being more similar to hot jupiters than to isolated brown dwarfs in terms of external forcing of the atmosphere by stellar insolation , kelt-1b appears to have an atmosphere most like that of other brown dwarfs .
this suggests that surface gravity is very important in controlling the atmospheric systems of substellar mass bodies . .
And you have already written the first three sentences of the full article: among substellar objects , the relationship between giant planets and brown dwarfs is unclear . the generally acknowledged dividing line between these two classes of objects
is based on mass .
specifically , objects above the minimum mass to burn deuterium are defined to be brown dwarfs , whereas objects less massive than this limit are defined to be planets ..
Please generate the next two sentences of the article
|
the deuterium burning limit is roughly @xmath813@xmath9 , although in detail this depends on one s definition of `` burning deuterium , '' and on the detailed composition of the object @xcite .
lcc @xmath10&mass ( @xmath11 ) & @xmath12 + @xmath13&radius ( @xmath14 ) & @xmath15 + @xmath16&effective temperature ( k ) & @xmath17 + @xmath18&period ( days ) & @xmath19 + @xmath20&mass ( @xmath9 ) & @xmath21 + @xmath22&radius ( @xmath23 ) & @xmath24 + @xmath25&eccentricity & @xmath26 + @xmath27&argument of periastron ( degress ) & @xmath28 + @xmath29 & & @xmath30 + @xmath31 & & @xmath32 + @xmath33&surface gravity & @xmath34 + @xmath35&equilibrium temperature ( k ) & @xmath36 + @xmath37&incident flux ( 10@xmath38 erg s@xmath39 @xmath40 ) & @xmath41 + @xmath42&radius of the planet in stellar radii & @xmath43 + @xmath44&semi - major axis in stellar radii & @xmath45 + @xmath46&inclination ( degrees ) & @xmath47 + @xmath48&impact parameter & @xmath49 + @xmath50&transit depth & @xmath51 + @xmath52&fwhm duration ( days ) & @xmath53 + @xmath54&ingress / egress duration ( days ) & @xmath55 + @xmath56&total duration ( days ) & @xmath57 + [ tab : kelt-1b.finalfinal.median ] on the one hand , distinguishing between objects below and above 13@xmath9 is clearly arbitrary , particularly since after roughly a billion years deuterium burning is over and any evidence of this initial internal energy source is largely gone , i.e. , an old @xmath850@xmath9 object that never fused deuterium would be difficult to distinguish from one that did @xcite .
|
12,509 |
Suppose that you have an abstract for a scientific paper: new scalar structure functions with different sign - symmetry properties are defined .
these structure functions possess different scaling exponents even when their order is the same .
their scaling properties are investigated for second and third orders , using data from high - reynolds - number atmospheric boundary layer .
it is only when structure functions with disparate sign - symmetry properties are compared can the extended self - similarity detect two different scaling ranges that may exist , as in the example of convective turbulence . .
And you have already written the first three sentences of the full article: a problem of broad interest is the advection and diffusion of passive scalars in a turbulent flow .
the classical paradigm of a passive scalar is the temperature field @xmath0 when the heating is small .
the temperature increments @xmath1 have been studied in the literature @xcite in search of scaling in the intermediate range of scales that are unaffected directly by either the stirring mechanism or diffusive and viscous effects . for examples of early and recent experimental studies , see @xcite and @xcite , respectively ..
Please generate the next two sentences of the article
|
the following two types of moments of @xmath2 , the so - called structure functions of order @xmath3 , have been employed : @xmath4 here , @xmath5 is the separation vector between two spatial positions , and @xmath6 defines a suitable ensemble average . for convenience we will call ( [ sn ] ) the _ normal _ structure functions and ( [ snabs ] ) the _ absolute _ structure functions . when @xmath7 is small compared to the large scale @xmath8 , both structure functions are homogeneous , i.e. , independent of @xmath9 .
clearly , ( [ sn ] ) and ( [ snabs ] ) coincide for even @xmath3 .
|
12,510 |
Suppose that you have an abstract for a scientific paper: results from an analysis of the intrinsic uv absorption in the seyfert 1 galaxy ngc 3783 are presented .
we focus on two new results that demonstrate techniques for deriving important constraints on the physical conditions and geometry of the absorbers .
first , using variability in the spectrum , the emission - line profile is separated into distinct kinematic components and the effect on the interpretation of covering factors and column densities is demonstrated .
second , measurements of the 2s2p @xmath0p metastable levels of c@xmath1 derived from the c iii*1175 - 76 absorption multiplet are presented .
new calculations of the metastable level populations are given and shown to provide a powerful diagnostic of the density ( and thus location ) and temperature in an absorber .
# 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: recent surveys with high - resolution uv spectra have shown that mass outflow is common in seyfert 1 galaxies , appearing as blueshifted absorption in more than half of observed objects ( crenshaw et al .
detailed studies are needed to determine the physical conditions ( density , ionization structure , total gas column ) and geometry of the absorbers . here
, we focus on constraints derived on the absorbers in the uv spectrum of ngc 3783 to demonstrate some techniques that can be used to probe mass outflow in agns ..
Please generate the next two sentences of the article
|
since the background agn light that the absorption features are imprinted on is comprised of distinct emission sources with different flux distributions , sizes , and geometries , the most general treatment of absorption features should take into account the different covering factors associated with each source .
the lyman series lines in the averaged stis and _ fuse _ spectra were used to separate the individual covering factors of the continuum and emission line sources in ngc 3783 ( gabel et al .
|
12,511 |
Suppose that you have an abstract for a scientific paper: we report on the search for neutrino - induced particle - showers , so - called cascades , in the icecube-@xmath0 detector .
the data for this search was collected between april 2008 and may 2009 when the first @xmath0 icecube strings were deployed and operational .
three complementary searches were performed , each optimized for different energy regimes .
the analysis with the lowest energy threshold ( @xmath1 ) targeted atmospheric neutrinos .
a total of @xmath2 events were found , consistent with the expectation of @xmath3 atmospheric muons and @xmath4 atmospheric neutrino events .
the two other analyses targeted a harder , astrophysical neutrino flux .
the analysis with an intermediate threshold of @xmath5 lead to the observation of @xmath6 cascade - like events , again consistent with the prediction of @xmath7 atmospheric neutrino and @xmath8 atmospheric muon events .
we hence set an upper limit of @xmath9 ( @xmath10 c.l . ) on the diffuse flux from astrophysical neutrinos of all neutrino flavors , applicable to the energy range @xmath5 to @xmath11 , assuming an @xmath12 spectrum and a neutrino flavor ratio of @xmath13 at the earth .
the third analysis utilized a larger and optimized sample of atmospheric muon background simulation , leading to a higher energy threshold of @xmath14 .
three events were found over a background prediction of @xmath15 atmospheric muon events and @xmath16 events from the flux of conventional and prompt atmospheric neutrinos . including systematic errors this corresponds to a @xmath17 excess with respect to the background - only hypothesis .
our observation of neutrino event candidates above @xmath14 complements icecube s recently observed evidence for high - energy astrophysical neutrinos . .
And you have already written the first three sentences of the full article: one century after the discovery of cosmic rays the search for their sources is still ongoing .
astrophysical objects which are either confirmed or expected to be able to accelerate hadrons to the observed energies include supernova remnants@xcite , active galactic nuclei ( agn ) , gamma - ray bursts ( grbs ) , and shocks in star formation regions of galaxies .
the cosmic - ray nuclei interact with ambient matter and radiation fields close to their source@xcite ..
Please generate the next two sentences of the article
|
charged pions produced in these interactions decay into neutrinos . therefore , the detection of high - energy neutrinos from such objects provides a unique possibility to identify individual astrophysical objects as cosmic - ray sources .
however , low fluxes and small interaction probabilities make the detection of high - energy neutrinos challenging . to date
|
12,512 |
Suppose that you have an abstract for a scientific paper: we investigate , using a chiral effective model , the quark spectrum in the critical region of the chiral transition focusing on the effect of the possible mesonic excitations in the quark - gluon plasma phase .
we find that there appears a novel three - peak structure in the quark spectra .
we elucidate the mechanism of the appearance of the multi - peak structure with the help of a yukawa model with an elementary boson . .
And you have already written the first three sentences of the full article: it is an intriguing problem with a rather long history to explore the possible existence of hadronic excitations in the quark - gluon plasma ( qgp ) phase@xcite .
the existence of the hadronic ( mesonic ) excitations in the light - quark sector was first predicted as being the soft mode associated to the chiral transition@xcite .
the recent lattice qcd simulations also suggest the existence of the mesonic bound states in heavy - quark sector in the qgp phase@xcite . in this work.
Please generate the next two sentences of the article
|
, we investigate the effect of these bosonic excitations on the quark quasi - particle picture in the qgp phase@xcite .
we first explore how the soft mode of the chiral transition@xcite affects the quark spectrum in the qgp phase using the nambu - jona - lasinio(njl ) model , and show that a novel three - peak structure is formed in the quark spectrum near the critical temperature @xmath0@xcite .
|
12,513 |
Suppose that you have an abstract for a scientific paper: we analyze the quantum properties of the light generated by a three - level laser with a closed cavity and coupled to a vacuum reservoir .
the three - level atoms available in the cavity are pumped from the bottom to the top level by means of electron bombardment and we carry out our analysis by putting the noise operators associated with the vacuum reservoir in normal order .
the maximum quadrature squeezing of the light generated by the laser , operating far below threshold , is found to be @xmath0 below the coherent - state level .
we have also established that the quadrature squeezing of the output light is equal to that of the cavity light and has the same value in any frequency interval .
this implies that the quadrature squeezing of the laser light is an intrinsic property of the individual photons .
keywords : stimulated emission , photon statistics , quadrature squeezing , noiselessvacuum reservoir .
And you have already written the first three sentences of the full article: a three - level laser is a quantum optical system in which light is generated by three - level atoms inside a cavity usually coupled to a vacuum reservoir . in one model of a such laser ,
three - level atoms initially prepared in a coherent superposition of the top and bottom levels are injected into a cavity and then removed after they have decayed due to spontaneous emission [ 1,2 ] . in another model ,
the top and bottom levels of the three - level atoms injected into a cavity are coupled by coherent light [ 3,4 ] ..
Please generate the next two sentences of the article
|
the statistical and squeezing properties of the light generated by three - level lasers have been investigated by several authors [ 5 - 11 ] .
it is found that a three - level laser in either model generates squeezed light under certain conditions .
|
12,514 |
Suppose that you have an abstract for a scientific paper: the boltzmann equation for inelastic maxwell models is used to determine the navier - stokes transport coefficients of a granular binary mixture in @xmath0 dimensions .
the chapman - enskog method is applied to solve the boltzmann equation for states near the ( local ) homogeneous cooling state .
the mass , heat , and momentum fluxes are obtained to first order in the spatial gradients of the hydrodynamic fields , and the corresponding transport coefficients are identified .
there are seven relevant transport coefficients : the mutual diffusion , the pressure diffusion , the thermal diffusion , the shear viscosity , the dufour coefficient , the pressure energy coefficient , and the thermal conductivity .
all these coefficients are _ exactly _ obtained in terms of the coefficients of restitution and the ratios of mass , concentration , and particle sizes .
the results are compared with known transport coefficients of inelastic hard spheres obtained analytically in the leading sonine approximation and by means of monte carlo simulations .
the comparison shows a reasonably good agreement between both interaction models for not too strong dissipation , especially in the case of the transport coefficients associated with the mass flux .
* key words * : navier - stokes transport coefficients ; granular mixtures ; inelastic maxwell models ; boltzmann equation . running title : inelastic maxwell mixtures .
And you have already written the first three sentences of the full article: the evaluation of the transport coefficients from the boltzmann equation for inelastic hard spheres ( ihs ) is quite involved .
in fact , to get explicit results one usually considers the leading order in a sonine polynomial expansion of the velocity distribution function .
these difficulties increase when one considers multicomponent systems since not only the number of transport coefficients is larger than for a single gas but they are also functions of more parameters such as composition , masses , sizes , and the coefficients of restitution . as in the elastic case , a possible way to partially overcome these problems.
Please generate the next two sentences of the article
|
is to consider other interaction models that simplify the complex mathematical structure of the boltzmann collision integrals for ihs .
for this reason , the so - called inelastic maxwell models ( imm ) have been widely used in the past few years as a toy model to characterize the influence of the inelasticity of collisions on the physical properties of granular fluids . the imm share with elastic maxwell molecules the property that the collision rate is velocity independent but , on the other hand , their collision rules are the same as for ihs . in this sense , although these imm do not correspond to any microscopic potential interaction , it has been shown by several authors @xcite that the cost of sacrificing physical realism is in part compensated by the amount of exact analytical results .
|
12,515 |
Suppose that you have an abstract for a scientific paper: a model vlasov poisson system is simulated close the point of marginal stability , thus assuming only the wave - particle resonant interactions are responsible for saturation , and shown to obey the power
law scaling of a second - order phase transition .
the set of critical exponents analogous to those of the ising universality class is calculated and shown to obey the widom and rushbrooke scaling and josephson s hyperscaling relations at the formal dimensionality @xmath0 below the critical point at nonzero order parameter .
however , the two - point correlation function does not correspond to the propagator of euclidean quantum field theory , which is the gaussian model for the ising universality class .
instead it corresponds to the propagator for the fermionic _ vector _ field and to the _ upper critical dimensionality _ @xmath1 .
this suggests criticality of collisionless vlasov - poisson systems as representative of the _ universality class _ of critical phenomena of _ a fermionic _ quantum field description . .
And you have already written the first three sentences of the full article: [ intro ] the remarkable property of critical phenomena is the universal scaling appearing in vast variety of systems ; e.g. , magnets and gases follow simple power laws for the order parameter , specific heat capacity , susceptibility , compressibility , etc . @xcite . in thermodynamic systems ,
phase transitions take place at a critical temperature @xmath2 when the coefficients that characterize the linear response of the system to external perturbations _
diverge_. then long range order appears , causing a transition to a new phase due to collective behavior of the entire system @xcite ..
Please generate the next two sentences of the article
|
the condition for nonlinear saturation in the test case of the bump on tail instability in plasmas @xcite is @xmath3 @xcite , where @xmath4 is the linear growth rate of a weakly unstable langmuir wave according to the landau theory @xcite , @xmath5 is the frequency of oscillations for particles trapped by the wave .
these trapped particles generate a long range order of the wavelength @xmath6 , the saturated amplitude @xmath7 can be considered as the order parameter , and the condition of saturation can be rewritten as a power law , typical for the second - order phase transitions , @xmath8 .
|
12,516 |
Suppose that you have an abstract for a scientific paper: two - particle correlation triggered by high- particles allows us to study hard scattering phenomena when full jet reconstruction is challenging .
an analysis of the first alice pp data where charged and neutral particles isolated or not are used as trigger particles is presented . the two - particle correlation between the trigger ( @xmath0 ) and the associate ( @xmath1 ) particles
is studied as a function of the imbalance parameter @xmath2=-@xmath3 and interpreted in terms of jet fragmentation function .
two - particle correlation measurements provide a suitable tool to study the jet properties in proton - proton and heavy - ion collisions @xcite where the full jet reconstruction is challenging and even impossible for jet- below about 50 gev / c .
such a measurement can be further improved if the trigger particle is isolated . ultimately , selecting a direct photon as the trigger particle would provide the optimum choice since the direct photon sets the reference of the @xmath4 type of hard scattering kinematics and balances the jet emitted in the opposite azimuthal direction .
in addition , while purely hadronic observables are strongly biased with respect to surface emission , photons can sample the entire collision volume .
however , identifying direct photons is quite challenging because of their scarcity and the overwhelming contribution of hadron decay - photons , mainly from @xmath5 .
applying isolation criteria ( select trigger particles spatially isolated ) is the traditional approach to enrich the data sample with hadrons sampling a large fraction of the parton momentum from which they fragment .
we have studied the two - particle correlation with the alice experiment @xcite at lhc in proton - proton collisions at @xmath6@xmath7 tev .
the experimental technique consists in tagging events with a leading trigger and measuring the distribution of charged hadrons associated to this leading trigger from the same event .
such a measurement requires to reconstruct charged....
And you have already written the first three sentences of the full article: .
Please generate the next two sentences of the article
| |
12,517 |
Suppose that you have an abstract for a scientific paper: we present the results of a new , comprehensive investigation of the radio spectral index of the crab nebula supernova remnant .
new data at 74 mhz are combined with data at 327 mhz , 1.5 ghz and 5 ghz .
in contrast to previous claims , little spatial variation in the spectral index is seen . in particular ,
between 327 mhz and 5 ghz we see no evidence of spectral steepening near the edge of the nebula , the `` jet '' or the ionized filaments .
the rms limits on any spectral index variations in these regions amount to no more than 0.01 .
we believe that earlier reports of large steepening were the result of correlator bias and image registration problems .
an elongated feature was detected 1 northwest of the pulsar which may be a continuation of the well - known wisp - like structures seen closer to the center of the nebula . at 74 mhz , we see for the first time evidence of free - free absorption by the thermal material in the crab nebula s filaments .
apart from some possible renewed acceleration occurring in the wisps , the dominant accelerator of relativistic electrons in the crab nebula is the pulsar itself .
4m@xmath0 # 1@xmath1 # 1#2 # 1 # 2 # 3.#4 # 1 # 2 # 3.#4 .
And you have already written the first three sentences of the full article: the crab nebula supernova remnant ( snr ) is one of the strongest radio sources in the sky and has long been an object of intense scrutiny by radio astronomers .
nevertheless , a number of controversies with important physical implications continue to surround the details of its radio continuum spectrum . while there is general agreement that the crab s integrated spectrum has a slope @xmath2 @xmath3 from 10 mhz to the synchrotron break frequency near 10@xmath4 ghz ( strom & greidanus 1992 , kovalenko , pynzar & udaltsov 1994 ) , there is considerable dispute over the details of its spatial distribution ( wilson 1972 , swinbank 1980 , velusamy , roshi & venugopal 1992 , bietenholz & kronberg 1992 , hereafter bk92 ) .
since the spectral index serves as a useful measure of the energy distribution of the relativistic electrons which generate the synchrotron emission , claims of _ spatial variations _ in spectral index across the nebula therefore must be interpreted in terms of differences in the underlying physical processes which influence the energy of the particles ..
Please generate the next two sentences of the article
|
the following are the three main areas where small variations in the radio spectral index , @xmath5 , have been reported : in the first instance , bk92 report spectral index variations in the vicinity of the pulsar , similar to the wisps found in the optical ( scargle 1969 , hester 1995 ) .
although they can be seen as weak arcsecond - width features in the total intensity images , these structures are most prominent in the spectral index images .
|
12,518 |
Suppose that you have an abstract for a scientific paper: we study the spindown of isolated neutron stars from initially rapid rotation rates , driven by two factors : ( i ) gravitational wave emission due to r - modes and ( ii ) magnetic braking . in the context of isolated neutron stars ,
we present the first study including self - consistently the magnetic damping of r - modes in the spin evolution .
we track the spin evolution employing the rns code , which accounts for the rotating structure of neutron stars for various equations of state .
we find that , despite the strong damping due to the magnetic field , r - modes alter the braking rate from pure magnetic braking for @xmath0 g . for realistic values of the saturation amplitude @xmath1 , the r - mode can also decrease the time to reach the threshold central density for quark deconfinement . within a phenomenological model
, we assess the gravitational waveform that would result from r - mode driven spindown of a magnetized neutron star . to contrast with the persistent signal during the spindown phase
, we also present a preliminary estimate of the transient gravitational wave signal from an explosive quark - hadron phase transition , which can be a signal for the deconfinement of quarks inside neutron stars . .
And you have already written the first three sentences of the full article: neutron stars are highly compact stars of typical radius @xmath2 km and mass @xmath3 made mostly of degenerate neutron - rich matter at densities up to several times nuclear matter saturation density @xmath4 g / cc . by tracking their long - term thermal and rotational evolution
, we can learn about the nature of matter under the crust .
for example , @xcite have proposed that the thermal history of the neutron star in cas a may be indicating the recent onset of neutron superfluidity deep in its interior ..
Please generate the next two sentences of the article
|
recently , @xcite have shown how rotational evolution is linked to a reorganization of particle composition in the stellar interior , leading to switching on of exotic neutrino emission processes .
a neutron star is a complex system with intertwined physical properties that can change on relatively short astrophysical timescales . in this paper
|
12,519 |
Suppose that you have an abstract for a scientific paper: we recently argued that the dynamics of strongly coupled field theories in black hole backgrounds is related via the ads / cft correspondence to two new classes of ads black hole solutions : black funnels , and black droplets suspended above a second disconnected horizon .
the funnel solutions are dual to black holes coupling strongly to a field theory plasma . in contrast , the droplet solutions describe black holes coupling only weakly .
we continue our investigation of these solutions and construct a wide variety of examples from the ads c - metric in four bulk spacetime dimensions .
the solutions we find are dual to field theories on spatially compact universes with killing horizons .
( 0,0)(0,0 ) ( 350 , 320)dcpt-09/59 ( 350,305)nsf - kitp-09 - 165 .
And you have already written the first three sentences of the full article: the ads / cft correspondence @xcite provides a unique window into the dynamics of a class of strongly coupled gauge field theories . for large @xmath0 gauge theories , the dynamics in the planar limit
is expected to be effectively classical , with @xmath1 controlling the quantum corrections . for a class of superconformal field theories arising as world - volume theories on d - branes or m - branes ,
the ads / cft correspondence identifies this classical dynamics of the single trace sector with that of classical string theory in a higher dimensional spacetime ..
Please generate the next two sentences of the article
|
furthermore , if the field theory is strongly coupled then one can truncate to the zero mode sector of the string theory , viz .
, classical gravity in this higher dimensional spacetime .
|
12,520 |
Suppose that you have an abstract for a scientific paper: our input is a bipartite graph @xmath0 where each vertex in @xmath1 has a preference list strictly ranking its neighbors .
the vertices in @xmath2 ( similarly , in @xmath3 ) are called _ residents _ ( resp . , _ hospitals _ ) : each resident seeks to be matched to a hospital while each hospital @xmath4 seeks @xmath5 many residents to be matched to it .
the gale - shapley algorithm computes a stable matching in @xmath6 in linear time .
we consider the problem of computing a _ popular _ matching in @xmath6 a matching @xmath7 is popular if @xmath7 can not lose an election to any other matching where vertices cast votes for one matching versus another .
our main contribution is to show that a max - size popular matching in @xmath6 can be computed by the _ 2-level gale - shapley _ algorithm in linear time .
this is a simple extension of the classical gale - shapley algorithm and we prove its correctness via linear programming . .
And you have already written the first three sentences of the full article: we study the one - to - many matching problem , also known as the hospitals / residents problem .
formally , this is given by a set of residents @xmath2 and a set of hospitals @xmath3 , where every hospital @xmath4 has a capacity @xmath5 .
every resident seeks to get matched to a hospital and every hospital @xmath4 seeks to get matched to @xmath8 residents ..
Please generate the next two sentences of the article
|
moreover , every resident @xmath9 has a strict ranking @xmath10 over hospitals that are acceptable to @xmath11 and every hospital @xmath4 has a strict ranking @xmath12 over residents that are acceptable to @xmath4 .
the set of mutually acceptable pairs is given by @xmath13 .
|
12,521 |
Suppose that you have an abstract for a scientific paper: we have found evidence for interaction between a standing and a traveling shock in the jet of the blazar cta 102 .
our result is based in the study of the spectral evolution of the turnover frequency - turnover flux density ( @xmath0 ) plane .
the radio / mm light curves were taken during a major radio outburst in april 2006 . .
And you have already written the first three sentences of the full article: the blazar cta102 ( z=1.037 ) shows a curved jet which exhibits apparent velocities up to 15.4c ( ( * ? ? ?
* lister et al . 2009 ) ) .
the analysis of single - dish light curves and 43@xmath1 vlbi observations of ( * ? ? ?.
Please generate the next two sentences of the article
|
* hovatta et al . ( 2009 ) ) and ( * ? ? ?
* jorstad et al .
|
12,522 |
Suppose that you have an abstract for a scientific paper: the core polarization effect for the electric quadrupole moment of the neutron - rich @xmath0al , @xmath1al and @xmath2al isotopes in the vicinity of the island of inversion are investigated by means of the microscopic particle - vibration coupling model in which the skyrme hartee - fock - bogoliubov and quasiparticle - random - phase approximation are used to calculate the single - quasiparticle wave functions and the excitation modes .
it is found that the polarization charge for the proton @xmath3 hole state in @xmath1al is quite sensitive to coupling to the neutrons in the @xmath4-shell associated with the pairing correlations , and that the polarization charge in @xmath2al becomes larger due to the stronger collectivity of the low - lying quadrupole vibrational mode in the neighboring @xmath5si nucleus . .
And you have already written the first three sentences of the full article: the nuclear structure far from the @xmath6-stability line has been studied very actively with the development of the new - generation radioactive - isotope beam techniques together with of the microscopic nuclear models applicable to drip - line nuclei carried out by the high performance computers .
the ground state properties and the dynamical properties such as low - energy excitation modes and giant resonances in the medium - mass to the heavier nuclei have been successfully described by the self - consistent mean - field theory or the nuclear density - functional theory ( dft ) @xcite .
the nuclear dft has been applied to the exotic modes of excitation in unstable nuclei @xcite , and developed towards description of nuclei in the whole chart . along this line ,.
Please generate the next two sentences of the article
|
the self - consistent random - phase approximation ( rpa ) including the pairing correlation and the nuclear deformation has been recently developed by several groups @xcite .
presently , the small excitation energy of the @xmath7 state and large transition probability @xmath8 in @xmath9 mg has been discussed in connection with the breaking of the spherical magic number @xmath10 in neutron - rich systems @xcite .
|
12,523 |
Suppose that you have an abstract for a scientific paper: we study a new mechanism for hadronic helicity flip in high energy hard exclusive reactions .
the mechanism proceeds in the limit of perfect chiral symmetry , namely without any need to flip a quark helicity .
the fundamental feature of the new mechanism is the breaking of rotational symmetry of the hard collision by a scattering plane in processes involving independent quark scattering .
we show that in the impulse approximation there is no evidence for of the helicity violating process as the energy or momentum transfer @xmath0 is increased over the region @xmath1 . in the asymptotic region
@xmath2 gev@xmath3 , a saddle point approximation with doubly logarithmic accuracy yields suppression by a fraction of power of @xmath0 .
chirally odd " exclusive wave functions which carry non zero orbital angular momentum and yet are leading order in the high energy limit , play an important role .
hadron helicity violation in exclusive processes : + quantitative calculations in leading order qcd * thierry gousset * .
And you have already written the first three sentences of the full article: the theory of hard elastic scattering in quantum chromodynamics ( qcd ) has evolved considerably over many years of work .
currently there exist two self - consistent perturbative descriptions , each with a specific factorization method for separating the hard scattering from non - perturbative wave functions . a well - known procedure using the `` quark - counting '' diagrams has been given by lepage and brodsky @xcite .
a consequence , and direct test , of the factorization defining this mechanism is the hadron helicity conservation rule @xcite @xmath4 where the @xmath5 s are the helicities of the participating hadrons in the reaction @xmath6 ..
Please generate the next two sentences of the article
|
the fact that this rule is badly violated in almost every case tested suggests two alternatives .
one possibility , advocated by isgur and llewellyn - smith @xcite , is that the energy and momentum transfer ( @xmath0 ) in the data is not large enough for the formalism to apply .
|
12,524 |
Suppose that you have an abstract for a scientific paper: using a large sample of spectroscopically confirmed lyman break galaxies at @xmath0 , we establish for the first time an empirical relationship between reddening ( @xmath1 ) , neutral gas covering fraction ( @xmath2 ) , and the escape of ionizing ( lyman continuum , lyc ) photons at high redshift .
our sample includes 933 galaxies at @xmath0 , 121 of which have very deep spectroscopic observations ( @xmath3hrs ) in the rest - frame far - uv ( @xmath4 ) with the low resolution imaging spectrograph on the keck telescope .
based on the high covering fraction of outflowing optically - thick @xmath5 indicated by the composite spectra of these galaxies , we conclude that photoelectric absorption , rather than dust attenuation , dominates the depletion of lyc photons . by modeling the composite spectra as the combination of an unattenuated stellar spectrum including nebular continuum emission with one that is absorbed by @xmath5 and reddened by a line - of - sight extinction
, we derive an empirical relationship between @xmath1 and @xmath2 .
galaxies with redder uv continua have larger covering fractions of @xmath5 characterized by higher line - of - sight extinctions .
the absolute escape fraction of ly@xmath6 correlates inversely with @xmath2 , consistent with the escape of ly@xmath6 through gas- and dust - free lines - of - sight .
gas covering fractions based on low - ionization interstellar absorption lines systematically underpredict those deduced from the @xmath5 lines , suggesting that much of the outflowing material in these galaxies may be metal - poor .
we develop a model which connects the ionizing escape fraction with @xmath1 , and which may be used to estimate the ionizing escape fraction for an ensemble of high - redshift galaxies .
alternatively , direct measurements of the escape fraction for the composite spectra allow us to constrain the intrinsic ionizing - to - non - ionizing flux density ratio to be @xmath7 , a value that favors stellar population models that include weaker....
And you have already written the first three sentences of the full article: significant efforts have focused on determining the sources responsible for cosmic reionization .
studies suggesting the apparent minor role of quasars in keeping the universe ionized at @xmath8 ( e.g. , @xcite but see @xcite ) have led the community to assess the contribution of star - forming galaxies to the ionizing photon budget at high redshift ( e.g. , @xcite ) .
these investigations have advocated broadly for the important role of hitherto undetected uv - faint galaxies with their high number densities as inferred from the steep faint - end slopes of the uv luminosity functions and their assumed large lyman continuum ( lyc ) escape fractions in dominating the ionizing background ..
Please generate the next two sentences of the article
|
however , the direct detection of lyman continuum radiation , possible only at modest redshifts ( @xmath9 ) where the transmissivity of the inter - galactic medium ( igm ) allows such measurements , remains elusive .
locally , only a handful of objects have been detected with lyc emission @xcite .
|
12,525 |
Suppose that you have an abstract for a scientific paper: we consider mean curvature flow of an initial surface that is the graph of a function over some domain of definition in @xmath0
. if the graph is not complete then we impose a constant dirichlet boundary condition at the boundary of the surface .
we establish longtime - existence of the flow and investigate the projection of the flowing surface onto @xmath0 , the shadow of the flow .
this moving shadow can be seen as a weak solution for mean curvature flow of hypersurfaces in @xmath0 with a dirichlet boundary condition .
furthermore , we provide a lemma of independent interest to locally mollify the boundary of an intersection of two smooth open sets in a way that respects curvature conditions . .
And you have already written the first three sentences of the full article: a family @xmath1 of hypersurfaces of @xmath2 is said to move by mean curvature flow if there is a map @xmath3 such that @xmath4 is an immersion for all @xmath5 with @xmath6 and @xmath7 solves @xmath8 where @xmath9 is a @xmath10-dimensional manifold , @xmath11 is the mean curvature of @xmath12 and @xmath13 its normal , such that @xmath14 is the mean curvature vector .
if @xmath15 for a family of functions @xmath16 , then @xmath12 moves by mean curvature flow if and only if @xmath17 solves the graphical mean curvature flow equation , which is the parabolic partial differential equation @xmath18 graphical mean curvature flow was studied in @xcite by ecker and huisken .
they proved long - time existence for the mean curvature flow of entire graphs and showed that the solution stays graphical for all time ..
Please generate the next two sentences of the article
|
more recently , sez trumper and schnrer proved in @xcite a long - time existence result for complete graphs .
starting from an open set @xmath19 and a proper function @xmath20 , they showed the existence of a solution @xmath17 to graphical mean curvature flow with initial data @xmath21 , where @xmath22 is defined on an open set @xmath23 for @xmath24 .
|
12,526 |
Suppose that you have an abstract for a scientific paper: multiple scattering theory is applied to low - energy electron collisions with a complex target formed of two molecular scatterers .
the total t - matrix is expressed in terms of the t - matrix for each isolated molecule .
we apply the approach to elastic electron-(h@xmath0o)@xmath0 collisions . following the method developed in our previous work on crystalline ice @xcite ,
we impose a cut - off on the dipole outside the r - matrix sphere and an energy dependent cut - off on the angular momentum components of the monomer t - matrix .
an r - matrix calculation of electron - dimer collisions is performed in order to evaluate the accuracy of the multiple scattering approach .
the agreement between the two calculations is very good . .
And you have already written the first three sentences of the full article: in biological systems , water is present in a wide range of environments . as a highly polar molecule
, water tends to trap low - energy electrons ( lees ) and is expected to play an important role in lee - induced processes @xcite .
electron collisions with water vapour being the simplest to study , extensive experimental @xcite and theoretical @xcite work has been carried out . in the more complicated condensed phase systems , experimental studies of electron scattering from amorphous solid water , porous amorphous solid water and crystalline ice.
Please generate the next two sentences of the article
|
have been reported @xcite . in water clusters ,
formation of ( h@xmath0o)@xmath1 by attachment of slow electrons has also been investigated @xcite in order to elucidate the mechanism of electron solvation . to our knowledge ,
|
12,527 |
Suppose that you have an abstract for a scientific paper: we investigate the behaviors of entanglement entropy in the holographical insulator / superconductor phase transition .
we calculate the holographic entanglement entropy for two kinds of geometry configurations in a completely back - reacted gravitational background describing the insulator / superconductor phase transition . the non - monotonic behavior of the entanglement entropy is found in this system . in the belt geometry case ,
there exist four phases characterized by the chemical potential and belt width . .
And you have already written the first three sentences of the full article: the ads / cft correspondence @xcite provides a powerful theoretical method to study the strongly coupled systems in various fields of physics .
one of the most widely investigated objects is the holographic superconductor ( superfluid ) @xcite .
the physical picture is that some gravity background will become unstable as one tunes some parameter , such as temperature for black hole and chemical potential for ads soliton , to develop some kind of hair " ..
Please generate the next two sentences of the article
|
this condensation of the hair " induces the symmetry breaking , which results in the non - vanishing vacuum expectation value of the dual operator in the field theory side . on the other hand , as a measurement of how a given quantum system is entangled or strongly correlated , the entanglement entropy is also considered as a useful tool for keeping track of the degrees of freedom of strongly coupled systems . dividing a quantum system into a subsystem @xmath0 and its complement , the entanglement entropy of @xmath0 is known as the famous von neumann entropy @xmath1 where @xmath2 is the reduced density matrix for @xmath0 by tracing over its complement of the total density matrix .
however , the calculation of entanglement entropy for a given system is found to be very difficult except for the case in @xmath3 dimensions . inspired by the bekenstein - hawking entropy of black hole and motivated by the development of ads / cft correspondence , the authors in refs .
|
12,528 |
Suppose that you have an abstract for a scientific paper: we investigate adding two sterile neutrinos to resolve the apparent tension existing between short - baseline neutrino oscillation results and cpt - conserving , four - neutrino oscillation models .
for both ( 3 + 1 ) and ( 3 + 2 ) models , the level of statistical compatibility between the combined dataset from the null short - baseline experiments bugey , chooz , ccfr84 , cdhs , karmen , and nomad , on the one hand ; and the lsnd dataset , on the other , is computed .
a combined analysis of all seven short - baseline experiments , including lsnd , is also performed , to obtain the favored regions in neutrino mass and mixing parameter space for both models .
finally , four statistical tests to compare the ( 3 + 1 ) and the ( 3 + 2 ) hypotheses are discussed .
all tests show that ( 3 + 2 ) models fit the existing short - baseline data significantly better than ( 3 + 1 ) models . .
And you have already written the first three sentences of the full article: there currently exist three experimental signatures for neutrino oscillations .
the two signatures seen originally in solar and atmospheric neutrinos have been verified by several experiments , including experiments carried out with accelerator and nuclear reactor sources .
the results on atmospheric neutrinos can be explained by @xmath0 disappearance due to oscillations @xcite , while those on solar neutrinos can be explained by @xmath1 oscillations @xcite ..
Please generate the next two sentences of the article
|
the third signature is @xmath2 appearance in a @xmath3 beam , observed by the short - baseline , accelerator - based lsnd experiment at los alamos @xcite .
this signature is strong from a statistical point of view , being a 3.8@xmath4 excess , but further confirmation by an independent experiment is necessary .
|
12,529 |
Suppose that you have an abstract for a scientific paper: most of the super massive black hole mass ( ) estimates based on stellar kinematics use the assumption that galaxies are axisymmetric oblate spheroids or spherical . here
we use fully general triaxial orbit - based models to explore the effect of relaxing the axisymmetric assumption on the previously studied galaxies 32 and ngc 3379 .
we find that 32 can only be modeled accurately using an axisymmetric shape viewed nearly edge - on and our black hole mass estimate is identical to previous studies .
when the observed 5 kinematical twist is included in our model of ngc 3379 , the best shape is mildly triaxial and we find that our best - fitting black hole mass estimate doubles with respect to the axisymmetric model . this particular black hole mass estimate is still within the errors of that of the axisymmetric model and consistent with the relationship .
however , this effect may have a pronounced impact on black hole demography , since roughly a third of the most massive galaxies are strongly triaxial .
[ firstpage ] black hole physics , galaxies : elliptical and lenticular , cd - galaxies : kinematics and dynamics - galaxies : individual : ngc 3379 , m32 galaxies : structure , galaxies : nuclei .
And you have already written the first three sentences of the full article: the masses of super massive black holes in the centers of galaxies are known to correlate with several properties of the host galaxy .
the most well known correlation is with the stellar velocity dispersion of the galaxy ( , e.g. , * ? ? ?
the black hole is thought to play an important role in the evolution of its host ( e.g. agn feedback ) , as the properties of galaxies are tightly linked to ..
Please generate the next two sentences of the article
|
therefore it is important to be able to measure the accurately and understand whether the scatter in the relations is due to measurement error , or if it is intrinsic .
most of the estimates upon which these relationships are based were derived using dynamical ( edge - on ) axisymmetric ( or spherical ) dynamical models ( see @xcite for a review ) .
|
12,530 |
Suppose that you have an abstract for a scientific paper: this paper studies convergence behavior of latent mixing measures that arise in finite and infinite mixture models , using transportation distances ( i.e. , wasserstein metrics ) .
the relationship between wasserstein distances on the space of mixing measures and @xmath0-divergence functionals such as hellinger and kullback leibler distances on the space of mixture distributions is investigated in detail using various identifiability conditions .
convergence in wasserstein metrics for discrete measures implies convergence of individual atoms that provide support for the measures , thereby providing a natural interpretation of convergence of clusters in clustering applications where mixture models are typically employed .
convergence rates of posterior distributions for latent mixing measures are established , for both finite mixtures of multivariate distributions and infinite mixtures based on the dirichlet process . .
And you have already written the first three sentences of the full article: a notable feature in the development of hierarchical and bayesian nonparametric models is the role of mixing measures , which help to combine relatively simple models into richer classes of statistical models @xcite . in recent years
the mixture modeling methodology has been significantly extended by many authors taking the mixing measure to be random and infinite - dimensional via suitable priors constructed in a nested , hierarchical and nonparametric manner .
this results in rich models that can fit more complex and high - dimensional data ( see , e.g. , @xcite for several examples of such models , as well as a recent book @xcite ) ..
Please generate the next two sentences of the article
|
the focus of this paper is to analyze convergence behavior of the posterior distribution of latent mixing measures as they arise in several mixture models , including finite mixtures and the infinite dirichlet process mixtures .
let @xmath1 denote a discrete probability measure .
|
12,531 |
Suppose that you have an abstract for a scientific paper: we extract constraints on the parameter space of the mw model by comparing the cross - sections for dijet , top - pair , dijet - pair , @xmath0 and @xmath1 productions at the lhc with the strongest available experimental limits from atlas or cms at 8 or 13 tev .
overall we find that masses below 1 tev have not been excluded for color octet scalars as it is often claimed in the literature .
the constraints that can be placed on coupling constants are typically weaker than those from existing theoretical considerations , with the exception of the parameter @xmath2 . .
And you have already written the first three sentences of the full article: the search for new physics at the lhc has covered enormous ground so far , constraining the parameters of many possible new particles that appear in a variety of extensions of the standard model ( sm ) .
there are still exceptions , models that have not been carefully confronted with the lhc data , amongst them an extension of the scalar sector of the sm with a color octet electroweak doublet scalar .
this model was introduced some time ago by manohar and wise ( mw ) @xcite , and it is motivated by minimal flavor violation @xcite ..
Please generate the next two sentences of the article
|
there are several phenomenological papers concerning lhc studies of the mw model available , but all of them predate the lhc .
the original mw paper already gave analytic expressions for the pair production of the new scalars through the dominant gluon fusion channel , finding production cross - sections that vary many orders of magnitude , between @xmath3 fb and @xmath4 fb for @xmath5 between @xmath6 and @xmath7 tev respectively at lhc14 @xcite .
|
12,532 |
Suppose that you have an abstract for a scientific paper: we analyze the complexity of the quantum optimization algorithm based on adiabatic evolution for the np - complete set partition problem .
we introduce a cost function defined on a logarithmic scale of the partition residues so that the total number of values of the cost function is of the order of the problem size .
we simulate the behavior of the algorithm by numerical solution of the time - dependent schr " odinger equation as well as the stationary equation for the adiabatic eigenvalues .
the numerical results for the time - dependent quantum evolution indicate that the complexity of the algorithm scales exponentially with the problem size .
this result appears to contradict the recent numerical results for complexity of quantum adiabatic algorithm applied to a different np - complete problem ( farhi et al , _ science _ 292 , p.472 ( 2001 ) ) . .
And you have already written the first three sentences of the full article: most common computationally intensive tasks encountered in practice may be formulated as combinatorial optimization problems ( cops ) , many of which are found to belong to the algorithmic class _ nondeterministic - polynomial complete _ ( np - complete ) @xcite .
the np - complete problems are computationally hard - they are characterized ( in the worst cases ) by exponential scaling of the running time or memory requirements with the problem size .
a special property of the class is that any np - complete problem can be converted into any other np - complete problem in polynomial time on a classical computer ; therefore , it is sufficient to find a deterministic algorithm that can be guaranteed to solve all instances of just one of the np - complete problems within a polynomial time bound ..
Please generate the next two sentences of the article
|
an instance of a cop of size @xmath0 may be encoded using bit strings @xmath1 , @xmath2 , with a corresponding value of the cost function ( or `` energy '' ) @xmath3 for each string . the objective is to find the bit string(s ) with the minimum cost ( and the corresponding cost value ) . in quantum computation ,
bits @xmath4 are replaced by spin-@xmath5 _ qubits _ ; the qubit states @xmath6 and @xmath7 are eigenstates of the @xmath8 component of the @xmath9-th spin , respectively .
|
12,533 |
Suppose that you have an abstract for a scientific paper: one - photon and two - photon wavepackets of entangled two - photon states in spontaneous parametric down - conversion ( spdc ) fields are calculated and measured experimentally . for type - ii spdc ,
measured one - photon and two - photon wavepackets agree well with theory . for type - i spdc ,
the measured one - photon wavepacket agree with the theory .
however , the two - photon wavepacket is much bigger than the expected value and the visibility of interference is low .
we identify the sources of this discrepancy as the spatial filtering of the two - photon bandwidth and non - pair detection events caused by the detector apertures and the tuning curve characteristics of the type - i spdc . .
And you have already written the first three sentences of the full article: the two - photon state generated via spontaneous parametric down - conversion ( spdc ) is one of the most well - known examples of two - particle entangled states .
the spdc process can be briefly explained as a spontaneous splitting or decay of a pump photon into a pair of daughter photons ( typically called signal and idler photons ) in a nonlinear optical crystal @xcite .
this spontaneous decay or splitting only occurs when energies and momentum of the interacting photons satisfy the conservation condition , which is known as the phase matching condition ..
Please generate the next two sentences of the article
|
signal and idler photons have the same polarization in type - i phase matching and have orthogonal polarization in type - ii phase matching . if the phase matching is perfect , assuming monochromatic plane wave pump , it is not hard to see that the state of spdc should be written as @xmath0 ( @xmath1 ) are the frequency and the wave vectors of the signal , idler , and the pump , respectively , and @xmath2 is the creation operator for the signal photon .
the @xmath3 functions in state ( [ eq : perfect ] ) ensure that the signal and the idler photons satisfy the phase matching condition , i.e. , there is only one energy or wave vector for the idler photon corresponding to a given energy or wave vector for the signal photon . in other words ,
|
12,534 |
Suppose that you have an abstract for a scientific paper: the magnetic field - induced superconductor insulator metal transition ( simt ) in partially deuterated @xmath0-(bedt - ttf)@xmath1cu[n(cn)@xmath1]br , which is just on the mott boundary , has been observed using the infrared magneto - optical imaging spectroscopy . the infrared reflectivity image on the sample surface revealed that the metallic ( or superconducting ) and insulating phases coexist and they have different magnetic field dependences .
one of the magnetic field dependence is simt that appeared on part of the sample surface .
the simt was concluded to originate from the balance of the inhomogenity in the sample itself and the disorder of the ethylene end groups resulting from fast cooling . .
And you have already written the first three sentences of the full article: a family of @xmath0-(bedt - ttf)@xmath3 ( bedt - ttf = bis(ethylenedithio)-tetrathiafulvalene , @xmath4 = cu[n(cn)@xmath1]br , cu[n(cn)@xmath1]cl , cu(ncs)@xmath1 , etc . ) salts is a charge - transfer group with quasi - two - dimensional electronic properties .
@xcite these salts have attractive physical properties , including a range of antiferromagnetic insulating ( afi ) to superconducting ( sc ) ground states depending on the pressure , @xcite deuteration , @xcite cooling rate , @xcite and magnetic field strength .
@xcite in these salts , the @xmath0-(bedt - ttf)@xmath1cu[n(cn)@xmath1]br ( abbreviated @xmath5 $ ] hereafter ) is in the sc state in the vicinity of a sc afi boundary , named the mott boundary ..
Please generate the next two sentences of the article
|
@xcite additionally , a perfectly deuterated salt ( @xmath6 $ ] ) formed under slow cooling conditions is believed to exist on the mott boundary . in the case of the fast cooling conditions , the ground state changes to be in the afi phase because the disorder originating from the mixing of the eclipsed and staggered conformations of the ethylene end groups in the bedt - ttf molecules of the sample affects the ground state characteristics .
@xcite in intermediate materials in which the deuterium is randomly distributed in the ethylene groups , the ground state is on the boundary between the sc and afi phases . in these cases , a partial sc state in the material
|
12,535 |
Suppose that you have an abstract for a scientific paper: a summary of neutrino oscillation results is given along with a discussion of neutrino mass generation mechanisms , including high and low - scale seesaw , with and without supersymmetry , as well as recent attempts to understand flavor .
i argue that if the origin of neutrino masses is intrinsically supersymmetric , it may lead to clear tests at the lhc .
finally , i briefly discuss thermal leptogenesis and dark matter . .
And you have already written the first three sentences of the full article: the discovery of neutrino oscillations provides the first evidence of physics beyond the standard model ( sm ) , marking the beginning of a new era in particle physics .
thanks to their brilliant confirmation by reactor and accelerator experiments , oscillations constitute the only viable explanation for the observed flavor conversion of `` celestial '' neutrinos @xcite , requiring both neutrino mass and mixing , as expected in theories without conserved lepton number @xcite . even in its simplest @xmath0 unitary form ,
the lepton mixing matrix @xmath1 @xcite differs from the quark mixing matrix in that each @xmath2 factor carries a physical phase : one is the km - analogue and appears in oscillations , while the other two are majorana phases and appear in lepton number ( l)-violating processes ..
Please generate the next two sentences of the article
|
current experiments are insensitive to cp violation , so that oscillations depend only on the three mixing angles @xmath3 and on the two squared - mass splittings @xmath4 and @xmath5 characterizing solar and atmospheric transitions .
setting @xmath6 in the analysis of atmospheric and accelerator data , and @xmath7 to infinity in the solar and reactor data analysis one obtains the neutrino oscillation parameters , as summarized in figs .
|
12,536 |
Suppose that you have an abstract for a scientific paper: we study the compressed sensing ( cs ) signal estimation problem where an input signal is measured via a linear matrix multiplication under additive noise . while this setup usually assumes sparsity or compressibility in the input signal during recovery ,
the signal structure that can be leveraged is often not known _ a priori_. in this paper , we consider _ universal _ cs recovery , where the statistics of a stationary ergodic signal source are estimated simultaneously with the signal itself .
inspired by kolmogorov complexity and minimum description length , we focus on a maximum _ a posteriori _ ( map ) estimation framework that leverages universal priors to match the complexity of the source .
our framework can also be applied to general linear inverse problems where more measurements than in cs might be needed .
we provide theoretical results that support the algorithmic feasibility of universal map estimation using a markov chain monte carlo implementation , which is computationally challenging .
we incorporate some techniques to accelerate the algorithm while providing comparable and in many cases better reconstruction quality than existing algorithms .
experimental results show the promise of universality in cs , particularly for low - complexity sources that do not exhibit standard sparsity or compressibility .
compressed sensing , map estimation , markov chain monte carlo , universal algorithms . .
And you have already written the first three sentences of the full article: since many systems in science and engineering are approximately linear , linear inverse problems have attracted great attention in the signal processing community . an input signal @xmath0
is recorded via a linear operator under additive noise : @xmath1 where @xmath2 is an @xmath3 matrix and @xmath4 denotes the noise .
the goal is to estimate @xmath5 from the measurements @xmath6 given knowledge of @xmath2 and a model for the noise @xmath7 ..
Please generate the next two sentences of the article
|
when @xmath8 , the setup is known as compressed sensing ( cs ) and the estimation problem is commonly referred to as recovery or reconstruction ; by posing a sparsity or compressibility requirement on the signal and using this requirement as a prior during recovery , it is indeed possible to accurately estimate @xmath5 from @xmath6 @xcite . on the other hand , we might need more measurements than the signal length when the signal is dense or the noise is substantial .
wu and verd @xcite have shown that independent and identically distributed ( i.i.d . )
|
12,537 |
Suppose that you have an abstract for a scientific paper: quandle homology was defined from rack homology as the quotient by a subcomplex corresponding to the idempotency , for invariance under the type i reidemeister move .
similar subcomplexes have been considered for various identities of racks and moves on diagrams .
we observe common aspects of these identities and subcomplexes ; a quandle identity gives rise to a @xmath0-cycle , the abelian extension with a @xmath0-cocycle that vanishes on the @xmath0-cycle inherits the identity , and a subcomplex is constructed from the identity .
specific identities are examined among small connected quandles . .
And you have already written the first three sentences of the full article: quandle homology @xcite was defined from rack homology @xcite as the quotient by a subcomplex corresponding to the idempotency , for invariance under the type i reidemeister move .
similar subcomplexes have been considered for various identities of racks and moves on diagrams .
typically a certain change of knot diagrams requires a condition for quandle @xmath0-cocycles to satisfy to obtain desired cocycle invariant , and the condition leads to a subcomplex ..
Please generate the next two sentences of the article
|
for example , for defining quandle cocycle invariants for unoriented knots , a good involution was defined in @xcite , and a corresponding condition for cocycles and a subcomplex were defined . for a telephone cord move for racks , a condition for rack @xmath0-cocycles and a subcomplex
were defined in @xcite .
|
12,538 |
Suppose that you have an abstract for a scientific paper: excess microwave emission observed in the inner galaxy ( inner @xmath0 kpc ) is consistent with synchrotron emission from highly relativistic @xmath1 pairs produced by dark matter particle annihilation .
more conventional sources for this emission , such as free - free ( thermal bremsstrahlung ) , thermal dust , spinning dust , and the softer galactic synchrotron traced by low - frequency surveys , have been ruled out . the total power observed in the range @xmath2 is between @xmath3 and @xmath4 , depending on the method of extrapolation to the galactic center , where bright foreground emission obscures the signal .
the inferred electron energy distribution is diffusion hardened , and is in qualitative agreement with the energy distribution required to explain the gamma ray excess in the inner galaxy at @xmath5 as inverse - compton scattered starlight .
we investigate the possibility that this population of electrons is produced by dark matter annihilation of @xmath6 particles , with cross section @xmath7 , and an @xmath8 dark matter mass profile truncated in the inner galaxy , and find this scenario to be consistent with current data . .
And you have already written the first three sentences of the full article: it is almost universally accepted that the majority of matter in the universe is non - baryonic .
existence of this `` dark matter '' is supported by several kinds of evidence : galaxy rotation curves , gravitational lensing of background objects by galaxy clusters , the small value of @xmath9 determined from big bang nucleosynthesis , and @xmath10 from the cosmic microwave background ( cmb ) anisotropy .
the gravitational effects of dark matter are observed , but in spite of numerous investigations with particle accelerators and direct detection experiments , no direct signature of dark matter interaction with ordinary matter has ever been found . supersymmetry theory ( susy ).
Please generate the next two sentences of the article
|
provides a candidate dark matter particle : a linear combination of higgsino , z - ino , and photino states commonly known as the neutralino , @xmath11 , the lightest stable supersymmetric particle ( see jungman , kamionkowski , & griest 1996 for a review ) .
direct detection of neutralinos is difficult because of their very weak interactions with ordinary matter , but if the neutralino is a majorana fermion ( and therefore is its own anti - particle , @xmath12 ) , it self - annihilates and produces some combination of w and z bosons , mesons , @xmath1 pairs , and @xmath13-rays ( see gunn
|
12,539 |
Suppose that you have an abstract for a scientific paper: exploring two - dimensional ( 2d ) materials with magnetic ordering is a focus of current research .
it remains a challenge to achieve tunable magnetism in a material of one - atom - thickness without introducing extrinsic magnetic atoms or defects . here ,
based on first - principles calculations , we propose that tunable ferromagnetism can be realized in the recently synthesized holey 2d c@xmath0n ( @xmath12d - c@xmath0n ) monolayer via purely electron doping that can be readily achieved by gating .
we show that owing to the prominent van hove singularity in the band structure , the material exhibits ferromagnetism even at a small doping level .
remarkably , over a wide doping range of 4@xmath210@xmath3/@xmath4 to 8@xmath210@xmath3/@xmath4 , the system becomes half - metallic , with carriers fully spin - polarized .
the estimated curie temperature can be up to 320 k. besides gating , we find that the magnetism can also be effectively tuned by lattice strain .
our result identifies @xmath12d - c@xmath0n as the first material with single - atom - thickness that can host gate - tunable room - temperature half - metallic magnetism , suggesting it as a promising platform to explore nanoscale magnetism and flexible spintronic devices . .
And you have already written the first three sentences of the full article: two - dimensional ( 2d ) materials have been attracting tremendous interest since the discovery of graphene in 2004.@xcite many new 2d materials have been realized to date.@xcite in this family of 2d materials , graphene still stands out in that it is completely flat with only one - atom - thickness .
other monolayer materials such as silicene or phosphorene have buckled structures with atoms displaced perpendicular to the 2d plane ; while materials like transition metal dichalcogenides consist of multiple atomic layers . the single - atom - thickness endows graphene with superior properties.@xcite representing the ultimate limit of a material s thickness , it enables devices that are more compact in size ; and the atomic thickness also makes the material more susceptible to external control , e.g. , the carrier density in graphene can be tuned up to @xmath5/@xmath4 by gating.@xcite meanwhile , it is much desired to realize various symmetry - breaking phases in 2d materials .
2d materials with magnetic ordering are of particular interest , because such nanoscale magnetism is not only fascinating from a scientific point of view , it is also of great value for important applications such as magnetic information storage and spintronics devices.@xcite extensive efforts have been devoted in this direction , mostly by doping non - magnetic 2d materials with magnetic atoms or by creating certain structural defects.@xcite however , the induced magnetism is usually weak , and it is very difficult to control the distribution of dopants or defects in experiment . moreover , acting as extrinsically introduced scattering centers , these dopants or defects would strongly scatter the carriers and deteriorate the material s transport properties . it would become much better if we could generate magnetism without introducing extrinsic dopants or defects , which could avoid the above - mentioned severe disadvantages ..
Please generate the next two sentences of the article
|
it was predicted that the 2d mon@xmath0 is an intrinsic magnetic material with its magnetic ordering tunable by strain.@xcite but monolayer mon@xmath0 has not been experimentally realized yet .
another interesting proposal is to achieve tunable ferromagnetism in monolayer gase via gate controlled hole - doping.@xcite the resulting spin - polarization can be large , however , the magnetic transition ( curie ) temperature is still low ( @xmath6 k ) , not high enough for practical applications . it hence remains a challenge to find a dopant - free 2d material with room - temperature magnetism .
|
12,540 |
Suppose that you have an abstract for a scientific paper: in this work , we have presented a simple analytical approximation scheme for generic non - linear fbsdes . by treating the interested system as the linear decoupled fbsde perturbed with non - linear generator and feedback terms
, we have shown that it is possible to carry out a recursive approximation to an arbitrarily higher order , where the required calculations in each order are equivalent to those for standard european contingent claims .
we have also applied the perturbative method to the pde framework following the so - called four step scheme . the method is found to render the original non - linear pde into a series of standard parabolic linear pdes . due to the equivalence of the two approaches ,
it is also possible to derive approximate analytic solution for the non - linear pde by applying the asymptotic expansion to the corresponding probabilistic model .
two simple examples are provided to demonstrate how the perturbation works and show its accuracy relative to known numerical techniques .
the method presented in this paper may be useful for various important problems which have eluded analytical treatment so far .
*p * * keywords :* bsde , fbsde , four step scheme , asymptotic expansion , malliavin derivative , non - linear pde , cva .
And you have already written the first three sentences of the full article: in this paper , we propose a simple analytical approximation for backward stochastic differential equations ( bsdes ) .
these equations were introduced by bismut ( 1973 ) @xcite for the linear case and later by pardoux and peng ( 1990 ) @xcite for the general case , and have earned strong academic interests since then .
they are particularly relevant for the pricing of contingent claims in constrained or incomplete markets , and for the study of recursive utilities as presented by duffie and epstein ( 1992 ) @xcite ..
Please generate the next two sentences of the article
|
for a recent comprehensive study with financial applications , one may consult yong and zhou ( 1999 ) @xcite , ma and yong ( 2000 ) @xcite and references therein .
the importance of bsdes , or more specifically non - linear fbsdes which have non - linear generators coupled with some state processes satisfying the forward sdes , has risen greatly in recent years also among practitioners .
|
12,541 |
Suppose that you have an abstract for a scientific paper: studies of dust scattering properties in astrophysical objects with milky way interstellar dust are reviewed .
such objects are reflection nebulae , dark clouds , and the diffuse galactic light ( dgl ) .
to ensure their basic quality , studies had to satisfy four basic criteria to be included in this review .
these four criteria significantly reduced the scatter in dust properties measurements , especially in the case of the dgl .
determinations of dust scattering properties were found to be internally consistent for each object type as well as consistent between object types .
the 2175 bump is seen as an absorption feature .
comparisons with dust grain models find general agreement with significant disagreements at particular wavelengths ( especially in the far - ultraviolet ) . finally , unanswered questions and future directions are enumerated . .
And you have already written the first three sentences of the full article: the scattering properties of dust provide a unique view into the physical properties of dust grains .
this view is different from other probes of dust grains ( eg
. , extinction , polarization due to differential extinction , abundances ) as it allows their absorption and scattering properties to be separated ..
Please generate the next two sentences of the article
|
the scattering properties of dust grains are indicators of the size and composition of dust grains .
the scattering of photons by dust grains can be described by a single scattering albedo , @xmath0 , and a scattering phase function , @xmath1 , where @xmath2 is the scattering angle . in most studies ,
|
12,542 |
Suppose that you have an abstract for a scientific paper: les chanes de galton - watson , ou processus de branchements , font partie de la formation traditionnelle des tudiants en probabilit .
le thorme de base concerne ltude de la survie du modle en fonction de la fcondit : sauf cas dgnr , la survie nest possible que si le taux de fcondit dpasse @xmath0 .
la preuve classiquement enseigne est essentiellement analytique , reposant sur les fonctions gnratrices et des arguments de convexit . on se
propose ici , sinspirant des travaux de bezuidenhout et grimmett , de donner une preuve plus conforme lintuition probabiliste . .
And you have already written the first three sentences of the full article: sinspirant dun article de grimmett et marstrand sur certaines proprits de la percolation en dimension @xmath1 , bezuidenhout et grimmett ont dmontr dans un article clbre que le processus de contact steint au point critique .
leur technique de preuve a souvent t utilise pour tudier la croissance des modles de population .
le prsent texte se veut une introduction leurs ides , dans le cadre de lexemple simple du processus de galton - watson . on montrera.
Please generate the next two sentences of the article
|
ici quun processus de galton - waltson non dgnr ne peut steindre que si sa fertilit dpasse strictement 1 .
la preuve classiquement enseigne
|
12,543 |
Suppose that you have an abstract for a scientific paper: in this article we present our implementation of a hybrid monte carlo algorithm for lattice gauge theory using two degenerate flavours of wilson - dirac fermions on a fermi gpu .
we find that using registers instead of global memory speeds up the code by almost an order of magnitude . to map the array variables to scalars , so that the compiler puts them in the registers , we use code generators .
our final program is more than 10 times faster than a generic single cpu . .
And you have already written the first three sentences of the full article: lattice gauge theory @xcite is a formulation of gauge theory on a euclidean space - time lattice @xmath0 .
@xmath0 consists of @xmath1 points @xmath2 ordered in some fashion and @xmath3 links @xmath4 where @xmath5 is the number of space - time dimensions .
this formulation of gauge theory is amenable to computer simulations ..
Please generate the next two sentences of the article
|
lattice gauge theory simulations can perform non - perturbative computations for static observables in quantum chromodynamics ( qcd ) .
the expectation value of an observable @xmath6 can be obtained by evaluating a euclidean path integral as = d_i d|_i o e^-|_i ( d^(u)+ m_i)_i -s_g(u ) .
|
12,544 |
Suppose that you have an abstract for a scientific paper: the evolutionary properties and spatial distribution of i zwicky 18 stellar populations are analyzed by means of hst / acs deep and accurate photometry .
the comparison of the resulting colour - magnitude diagrams with stellar evolution models indicates that stars of all ages are present in all the system components , including objects possibly up to 13 gyr old , intermediate age stars and very young ones .
the colour - magnitude diagrams show evidence of thermally pulsing asymptotic giant branch and carbon stars .
classical and ultra - long period cepheids , as well as long period variables have been measured .
about 20 objects could be unresolved star clusters , and are mostly concentrated in the north - west ( nw ) portion of the main body ( mb ) . if interpreted with simple stellar population models , these objects indicate a particularly active star formation over the past hundred myr in izw 18 .
the stellar spatial distribution shows that the younger ones are more centrally concentrated , while old and intermediate age stars are distributed homogeneously over the two bodies , although more easily detectable at the system periphery .
the oldest stars are best visible in the secondary body ( sb ) and in the south east ( se ) portion of the mb , where crowding is less severe , but are present also in the rest of the mb , although measured with larger uncertainties .
the youngest stars are a few myr old , are located predominantly in the mb and mostly concentrated in its nw portion .
the se portion of the mb appears to be in a similar , but not as young evolutionary stage as the nw , while the sb stars are older than at least 10 myr .
there is then a sequence of decreasing age of the younger stars from the secondary body to the se portion of the mb to the nw portion .
all our results suggest that izw18 is not atypical compared to other bcds . .
And you have already written the first three sentences of the full article: i zwicky 18 ( also mrk 116 or ugca 166 , hereafter izw18 ) is the most intriguing blue compact dwarf ( bcd ) galaxy in the local universe .
it became famous right after its discovery , when @xcite measured from its emission - line spectrum an oxygen abundance [ o / h]= 1.14 dex , only 7@xmath0 of the solar value , indicating an almost unprocessed gas content .
the first studies on its color and composition @xcite emphasized its almost primordial evolutionary status ..
Please generate the next two sentences of the article
|
izw18 shows very blue colors , u@xmath1b@xmath2 and b@xmath1v@xmath3 @xcite , suggesting the presence of a very young stellar population , with a current star formation rate ( sfr ) much higher than the past mean value .
the total mass of izw18 from the rotation curve at a radius of 10@xmath412@xmath5 is estimated to be @xmath6 m@xmath7 ( e.g. , * ? ? ?
|
12,545 |
Suppose that you have an abstract for a scientific paper: a summary is presented for 130 galaxies observed with the @xmath0 pacs instrument to measure fluxes for the [ cii ] 158 emission line .
sources cover a wide range of active galactic nucleus to starburst classifications , as derived from polycyclic aromatic hydrocarbon ( pah ) strength measured with the @xmath1 infrared spectrograph .
redshifts from [ cii ] and line to continuum strengths ( equivalent width of [ cii ] ) are given for the full sample , which includes 18 new [ cii ] flux measures .
calibration of @xmath2)$ ] as a star formation rate ( sfr ) indicator is determined by comparing [ cii ] luminosities with mid - infrared [ neii ] and [ neiii ] emission line luminosities ; this gives the same result as determining sfr using bolometric luminosities of reradiating dust from starbursts : log sfr = log @xmath2)$ ] - 7.0 , for sfr in m@xmath3 yr@xmath4 and @xmath5)$ ] in l@xmath3 .
we conclude that @xmath5)$ ] can be used to measure sfr in any source to a precision of @xmath6 50% , even if total source luminosities are dominated by an agn component . the line to continuum ratio at 158 , ew([cii ] ) , is not significantly greater for starbursts ( median ew([cii ] ) = 1.0 ) compared to composites and agn ( median ew([cii ] ) = 0.7 ) , showing that the far infrared continuum at 158 scales with [ cii ] regardless of classification .
this indicates that the continuum at 158 also arises primarily from the starburst component within any source , giving log sfr = log @xmath7(158 ) - 42.8 for sfr in m@xmath3 yr@xmath4 and @xmath7(158 ) in erg s@xmath4 . .
And you have already written the first three sentences of the full article: to discover and understand dusty galaxies at the highest redshifts , the emission of [ cii ] 158 is the single most important atomic line feature because it is the strongest far - infrared line in most sources @xcite and also provides the best opportunity for high redshift determinations and source diagnostics using submillimeter and millimeter spectroscopic observations .
already , for example , [ cii ] has been measured with the atacama large millimeter array ( alma ) in sources with 4 @xmath8 z @xmath6 6 @xcite , demonstrating that large scale star formation extends to high redshifts .
the [ cii ] line should be a diagnostic of star formation because it is primarily associated with the photodissociation region ( pdr ) surrounding starbursts @xcite . the objective of our studies is to compare characteristics of [ cii ] emission with classifications and luminosities of sources determined from mid - infrared spectra , so that [ cii ] can be used alone as a quantitative diagnostic when no other spectroscopy is available ..
Please generate the next two sentences of the article
|
this is especially important for dusty sources at high redshifts , when the rest frame far - infrared can be observed in submillimeter and millimeter wavelengths , but other rest frame wavelengths are not observationally accessible .
our observations consist of a sample of 130 sources which include a wide range of active galactic nucleus ( agn ) through starburst ( sb ) classifications , using [ cii ] observations made with the photodetector array camera and spectrometer ( pacs ; poglitsch et al . 2010 ) on the @xmath0 space observatory @xcite .
|
12,546 |
Suppose that you have an abstract for a scientific paper: many radioactive nuclei relevant for gamma - ray astrophysics are synthesized during explosive events , such as classical novae and supernovae .
a review of recent results of explosive nucleosynthesis in these scenarios will be presented , with a special emphasis on the ensuing gamma - ray emission from individual nova and supernova explosions .
the influence of the dynamic properties of the ejecta on the gamma - ray emission features , as well as the still remaining uncertainties in nova and supernova modelling will also be reviewed . .
And you have already written the first three sentences of the full article: in this paper i will review the sites of explosive nucleosynthesis relevant for gamma - ray astronomy .
two main types of explosion are responsible for the emission of gamma - rays in the galaxy : supernovae , both thermonuclear and gravitational ( core - collapse ) and classical novae .
thermonuclear supernovae , or supernovae of type ia , are exploding white dwarfs in close binary systems , which do not leave a remnant after the explosion ..
Please generate the next two sentences of the article
|
core collapse supernovae ( supernovae of type ii , ib / c ) are exploding massive stars ( m@xmath0 ) , which leave as remnant either a black hole or a neutron star .
typical velocities of supernovae ejecta are some @xmath1 km s@xmath2 , energies involved @xmath3 erg and ejected masses some m@xmath4 .
|
12,547 |
Suppose that you have an abstract for a scientific paper: the stability and conservation properties of a recently proposed polymerization model are studied . the achiral
( racemic ) solution is linearly unstable once the relevant control parameter ( here the fidelity of the catalyst ) exceeds a critical value .
the growth rate is calculated for different fidelity parameters and cross - inhibition rates .
a chirality parameter is defined and shown to be conserved by the nonlinear terms of the model .
finally , a truncated version of the model is used to derive a set of two ordinary differential equations and it is argued that these equations are more realistic than those used in earlier models of that form . .
And you have already written the first three sentences of the full article: the chirality of molecules in living organisms must have been fixed at an early stage in the development of life .
all life that we know is based on rna and dna molecules with dextrarotatory sugars .
there is growing evidence that the rna world ( woese , 1967 ; crick , 1968 ; orgel , 1968 ; see also wattis & coveney 1999 ) must have been preceded by a simpler pre - rna world made up of achiral constituents ( bada , 1995 , nelson _.
Please generate the next two sentences of the article
|
et al . , _ 2000 ) .
an alternative carrier of genetic code are peptide nucleic acids or pna ( nielsen , 1993 )
|
12,548 |
Suppose that you have an abstract for a scientific paper: we review the cross sections for low - energy @xmath0 reactions in the framework of chiral perturbation theory .
charged pion compton scattering , @xmath1 , is considered up to one - loop order where the pion s internal structure enters through the difference of the electric and magnetic pion polarizability , @xmath2 .
the ongoing compass experiment aims at measuring this important structure constant with high statistics using the primakoff effect . in the same way
, the reaction @xmath3 serves as a test of the qcd chiral anomaly ( via the @xmath4-coupling constant @xmath5 ) .
furthermore , we calculate the total cross sections for neutral and charged pion - pair production , @xmath6 and @xmath7 , which are governed by the chiral @xmath8-interaction . finally , we investigate the radiative ( correction ) process @xmath9 and calculate the corresponding two - photon mass spectrum .
this information will be useful for analyzing the @xmath10 primakoff scattering events with photons in the final state .
25.cm 17.cm -2.2 cm
-0.6 cm -0.6 cm # 1#2 # 2 cm n. kaiser and j.m .
friedrich + pacs : 12.20.ds , 12.39.fe , 13.60.fz , 13.75.lb .
And you have already written the first three sentences of the full article: the pions @xmath11 are the goldstone bosons of spontaneous chiral symmetry breaking in qcd : @xmath12 .
their low - energy dynamics can therefore be calculated systematically ( and accurately ) with chiral perturbation theory in form of a loop - expansion based on an effective chiral lagrangian .
the very accurate two - loop prediction @xcite for the isospin - zero s - wave @xmath8-scattering length @xmath13 has recently been confirmed in the e865 @xcite and na48/2 @xcite experiments by analyzing the @xmath14 invariant mass distribution of the rare kaon decay mode @xmath15 ..
Please generate the next two sentences of the article
|
one particular implication of that good agreement between theory and experiment is that the quark condensate @xmath16 constitutes the leading order parameter @xcite of spontaneous chiral symmetry breaking ( considering the two - flavor sector of qcd ) . as a consequence
, one can assert that more than @xmath17 of the ( squared ) pion mass , @xmath18mev/@xmath19 , must stem from the term linear in the light quark mass multiplied with the quark condensate @xmath20 @xcite .
|
12,549 |
Suppose that you have an abstract for a scientific paper: background : : mixed - symmetry @xmath0 states in vibrational nuclei are characterized by a sign change between dominant proton and neutron valence - shell components with respect to the fully symmetric @xmath0 state .
the sign can be measured by a decomposition of proton and neutron transition radii with a combination of inelastic electron and hadron scattering [ c. walz _ et al .
_ , phys .
rev .
lett . * 106 * , 062501 ( 2011 ) ] . for the case of @xmath1zr ,
a difference could be experimentally established for the neutron components , while about equal proton transition radii were indicated by the data .
purpose : : determination of the ground - state ( g.s . ) transition strength of the mixed - symmetry @xmath2 state and verification of the expected vanishing of the proton transition radii difference between the one - phonon @xmath0 states in @xmath1zr .
method : : differential cross sections for the excitation of one - phonon @xmath0 and @xmath3 states in @xmath1zr have been measured with the ( @xmath4 ) reaction at the s - dalinac in a momentum transfer range @xmath5 @xmath6 .
results : : transition strengths @xmath7 , @xmath8 and @xmath9 weisskopf units are determined from a comparison of the experimental cross sections to quasiparticle - phonon model ( qpm ) calculations . it is shown that a model - independent plane wave born approximation ( pwba ) analysis can fix the ratio of @xmath10 transition strengths to the @xmath11 states with a precision of about 1% .
the method furthermore allows to extract their proton transition radii difference . with the present data @xmath12 fm is obtained .
conclusions : : electron scattering at low momentum transfers can provide information on transition radii differences of one - phonon @xmath0 states even in heavy nuclei .
proton transition radii for the @xmath11 states in @xmath1zr are found to be identical within uncertainties .
....
And you have already written the first three sentences of the full article: collectivity , isospin symmetry and shell structure are generic features of the nuclear many - body quantum system .
collective nuclear valence - shell excitations are a key to understand how these features coexist , interplay and compete . in vibrational nuclei ,
the development of predominantly proton - neutron symmetric collective nuclear structures at low excitation energies is governed by the strong residual proton - neutron interaction ..
Please generate the next two sentences of the article
|
their existence implies - due to quantum - mechanical orthogonality - the formation of collective states with , at least partial antisymmetry with respect to the contribution of proton and neutron valence - space components to their wave functions .
such excited states are said to have mixed symmetry @xcite .
|
12,550 |
Suppose that you have an abstract for a scientific paper: we analyse non ideal quantum measurements described as scattering processes providing an estimator of the measured quantity .
the sensitivity is expressed as an equivalent input noise .
we address the von neumann problem of chained measurements and show the crucial role of preamplification . .
And you have already written the first three sentences of the full article: active systems are fundamental elements in high precision measurements in particular measurement on quantum systems .
amplifiers are used either for amplifying the signal to a macroscopic level or to make the system work around its optimal working point with the help of feedback loops .
the analysis of sensitivity limits in these devices rises many questions related to fundamental processes as well as experimental constraints ..
Please generate the next two sentences of the article
|
how does the active feedback act on the quantum system ?
how does the coupling with the environment influence the sensitivity of the measurement ? how are these process related to the fluctuation dissipation theorem ?
|
12,551 |
Suppose that you have an abstract for a scientific paper: the scattering of the electron by a domain wall in a nano - wire is calculated perturbatively to the lowest order .
the resistance is calculated by use of landauer s formula .
the result is shown to agree with the result of the linear response theory if the equilibrium is assumed in the four - terminal case . .
And you have already written the first three sentences of the full article: the electronic transport properties in nano - size ferromagnetic structures has been drawing growing interest recently . of most interest would be the magnetoresistance effect , namely , the change of the resistance by application of a magnetic field .
the magnetoresistance in nano - structures is due to the rearrangement of the magnetization , namely the creation and motion of domain walls , driven by the external field .
recently high - sensitivity measurements on magnetic nano - structures such as wires and contacts has become possible and intensive experimental studies of the magnetoresistance due to a single domain wall have begun@xcite @xcite ..
Please generate the next two sentences of the article
|
these recent experiments have evoked a renewal of interest in theories of the scattering of the electron by a domain wall@xcite @xcite , although the first theoretical study of this problem goes back to more than 25 years ago@xcite .
the scattering mechanism is due to the non - adiabatic deviation of the electron spin from the local magnetization as the electron goes through the wall . in the case of a wall with thickness @xmath0 ( @xmath1 being the fermi wave length )
|
12,552 |
Suppose that you have an abstract for a scientific paper: we study one loop corrections to @xmath0 supersymmetric @xmath1 pure gauge theory .
we calculate divergent contributions of the 1pi graphs contain the non - anti - commutative parameter @xmath2 up to one loop corrections .
we find the disagreement between component formalism and superspace formalism is because of the field redefinition in component case .
we modify gaugino field redefinition and lagrangian .
we show extra terms of lagrangian have been generated by @xmath3 redefinition and are necessary for the renormalisation of the theory .
finally we prove @xmath4 supersymmetric gauge theory is renormalisable up one loop corrections using standard method of renormalisation # 1@xmath5 .3 in * * .3 in * a. f. kord @xmath6 , m. haddadi moghaddam @xmath7 * .3 in .
And you have already written the first three sentences of the full article: theories defined on non - anti - commutative superspace have been studied extensively during last ten years @xcite .
superspace in such non - anti - commutative theories is a superspace whose fermionic supercoordinates are not anticommutative .
one could construct a field theory in non - anti - commutative superspace in terms of superfields with the star - product where lagrangian is deformed from the original theory by the non - anti - commutative parameters ..
Please generate the next two sentences of the article
|
recently some renormalisability aspects of the non - anti - commutative field theories have been studies .
it has been shown non - anti - commutative field theories are not power - counting renormalisable ; however it has been discussed that they could be renormalisable if some additional terms have been added to the lagrangian in order to divergences to all orders @xcite-@xcite .
|
12,553 |
Suppose that you have an abstract for a scientific paper: we investigate pairing and quantum phase transitions in the one - dimensional two - component fermi atomic gas in an external field .
the phase diagram , critical fields , magnetization and local pairing correlation are obtained analytically via the exact thermodynamic bethe ansatz solution . at zero temperature , bound pairs of fermions with opposite spin states form a singlet ground state when the external field @xmath0 .
a completely ferromagnetic phase without pairing occurs when the external field @xmath1 . in the region
@xmath2 we observe a mixed phase of matter in which paired and unpaired atoms coexist .
the phase diagram is reminiscent of that of type ii superconductors . for temperatures below the degenerate temperature and in the absence of an external field , the bound pairs of fermions form hard - core bosons obeying generalized exclusion statistics . .
And you have already written the first three sentences of the full article: recent achievements in manipulating quantum gases of ultracold atoms have opened up exciting possibilities for the experimental study of many - body quantum effects in low - dimensional systems @xcite .
experimental observation of superfluidity and phase separation in imbalanced fermi atomic gases @xcite have stimulated great interest in exploring exotic quantum phases of matter with two mismatched fermi surfaces .
the pairing of fermionic atoms with mismatched fermi surfaces may lead to a breached pairing phase @xcite and a nonzero momentum pairing phase of fulde - ferrell - larkin - ovchinnikov ( fflo ) states @xcite . in general the nature of pairing and superfluidity in strongly interacting systems.
Please generate the next two sentences of the article
|
is both subtle and intriguing @xcite .
pairing is well known to be a momentum space phenomenon , in which two fermions with opposite spin states form a bound pair which behaves like a boson .
|
12,554 |
Suppose that you have an abstract for a scientific paper: a new spectral method is built resorting to @xmath0 jacobi polynomials .
we describe the origin and the properties of these polynomials .
this choice of polynomials is motivated by their orthogonality properties with the respect to the weight @xmath1 used in spherical geometry .
new results about jacobi - gauss - lobatto quadratures are proven , leading to a discrete jacobi transform .
numerical tests for poisson problems in a sphere are presented using the c++ library lorene .
spectral methods , jacobi polynomials , numerical relativity .
And you have already written the first three sentences of the full article: amongst the various techniques used to discretize partial differential equations , spectral methods , introduced by d. gottlieb and s. orszag in the seventies @xcite , offer high accuracy at a low computational cost .
their principle is to approximate solutions of pdes by truncated fourier series or high degree polynomials .
these methods have an infinite order of convergence , because the error between the exact and discrete solutions is only limited by the regularity of the exact solution ..
Please generate the next two sentences of the article
|
spectral methods resort to fourier series in the case of periodic boundary conditions ; whereas polynomial approximations use orthogonal polynomials ( such as chebyshev or legendre polynomials ) .
these methods also employ quadrature formulas to compute integrals in variationnal formulations of pdes . in the present work ,
|
12,555 |
Suppose that you have an abstract for a scientific paper: we present two reduced - rank channel estimators for large - scale multiple - input , multiple - output ( mimo ) systems and analyze their mean square error ( mse ) performance . taking advantage of the channel s
transform domain sparseness , the estimators yield outstanding performance and may offer additional mean angle - of - arrival ( aoa ) information . it is shown that , for the estimators to be effective , one has to select a proper predetermined unitary basis ( transform ) and be able to determine the dominant channel rank and the associated subspace .
further mse analysis reveals the relations among the array size , channel rank , signal - to - noise ratio ( snr ) , and the estimators performance .
it provides rationales for the proposed rank determination and mean aoa estimation algorithms as well . an angle alignment operation included in one of our channel models is proved to be effective in further reducing the required rank , shifting the dominant basis vectors range ( channel spectrum ) and improving the estimator s performance when a suitable basis is used .
we also draw insightful analogies among mimo channel modeling , transform coding , parallel spatial search , and receive beamforming .
computer experiment results are provided to examine the numerical effects of various estimator parameters and the advantages of the proposed channel estimators and rank determination method .
channel estimation , channel rank , channel spatial correlation , massive mimo , transform - domain approach . .
And you have already written the first three sentences of the full article: we consider a cellular mobile network in which each base station ( bs ) is equipped with a large - scale antenna array whose size @xmath0 is much greater than the number of single - antenna mobile users it serves .
such a large - scale ( distributed ) multiple - input , multiple - output ( mimo ) system or a massive mimo system for short has the potentiality of achieving transmission rate much higher than those offered by current cellular systems with enhanced reliability and drastically improved power efficiency .
it takes advantage of the so - called channel - hardening effect @xcite which implies that the channel vectors seen by different users tend to be mutually orthogonal and frequency - independent @xcite . as a result ,.
Please generate the next two sentences of the article
|
linear receivers are near - optimal in the uplink and simple multiuser ( mu ) precoders are sufficient to guarantee satisfactory downlink performance .
we consider a single cell within such a network whose bs array size @xmath1 , @xmath2 being the number of single antenna mobile users within its coverage range , and refer to this system as a distributed massive mimo system . to estimate a massive mimo channel
|
12,556 |
Suppose that you have an abstract for a scientific paper: in preparation for an experimental study of magnetorotational instability ( mri ) in liquid metal , we present non - ideal axisymmetric magnetohydrodynamic simulations of the nonlinear evolution of mri in the experimental geometry .
the simulations adopt fully insulating boundary conditions .
no - slip conditions are imposed at all boundaries .
a clear linear phase is observed with reduced linear growth rate .
mri results in an inflowing jet " near the midplane and enhances the angular momentum transport at saturation . .
And you have already written the first three sentences of the full article: the magnetorotational instability ( mri ) is probably the main cause of turbulence and accretion in sufficiently ionized astrophysical disks @xcite , which has inspired searches for mri in taylor - couette flow .
experiments on magnetized couette flow aiming to observe mri have been performed @xcite .
those experiments have demonstrated mri - like modes , but not yet for background flows that approximate keplerian disks ..
Please generate the next two sentences of the article
|
@xcite observed nonaxisymmetric modes and enhanced transport in a spherical experiment , but with a hydrodynamically linearly unstable background state .
@xcite demonstrated unsteady behavior in a very low - rm experiment with a strong toroidal as well as axial field ; the relationship between the experimental results and linear instabilities is still controversial @xcite , but if these are indeed the linear modes , then the corresponding ratio of toroidal to axial field in a thin ( thickness @xmath0 ) disk would have to be @xmath1 , where @xmath2 is the radius of the accretion disk .
|
12,557 |
Suppose that you have an abstract for a scientific paper: we have employed laser guide star ( lgs ) adaptive optics ( ao ) on the keck ii telescope to obtain near - infrared ( nir ) images in the extended groth strip ( egs ) deep galaxy survey field .
this is a continuation of our center for adaptive optics treasury survey ( cats ) program of targeting @xmath0 galaxies where existing images with the _ hubble space telescope _ ( hst ) are already in hand .
our ao field has already been imaged by the advanced camera for surveys ( acs ) and the near infared camera and multiobject spectrograph ( nicmos ) .
our ao images at 2.2@xmath1 m ( @xmath2 ) are comparable in depth to those from hst , have strehl ratios up to 0.4 , and fwhm resolutions superior to that from nicmos . by sampling the field with the lgs at different positions ,
we obtain better quality ao images than with an immovable natural guide star . as examples of the power of adding lgs ao to hst data we study the optical to nir colors and color gradients of the bulge and disk of two galaxies in the field with @xmath3 . .
And you have already written the first three sentences of the full article: although the bulges of disk - dominated galaxies can appear to be the remnants of long - ago mergers , their kinematics may point to close ties with ongoing formation processes in the disk ( for reviews , see * ? ? ?
* ; * ? ? ?
* and references therein ) ..
Please generate the next two sentences of the article
|
the strong correlation of bulge and disk color seen in local galaxies @xcite suggests a shared history , with similar ages and metallicities in their stellar populations .
so it is important to probe bulge and disk colors at significant look - back times .
|
12,558 |
Suppose that you have an abstract for a scientific paper: we present alma observations of the fw tau system , a close binary pair of m5 stars with a wide - orbit ( 300au projected separation ) substellar companion .
the companion is extremely faint and red in the optical and near - infrared , but boasts a weak far - infrared excess and optical / near - infrared emission lines indicative of a primordial accretion disk of gas and dust .
the component - resolved 1.3 mm continuum emission is found to be associated only with the companion , with a flux ( @xmath0mjy ) that indicates a dust mass of 12@xmath1 . while this mass reservoir is insufficient to form a giant planet , it is more than sufficient to produce an analog of the kepler-42 exoplanetary system or the galilean satellites .
the mass and geometry of the disk - bearing fw tau companion remains unclear .
near - infrared spectroscopy shows deep water bands that indicate a spectral type later than m5 , but substantial veiling prevents a more accurate determination of the effective temperature ( and hence mass ) .
both a disk - bearing `` planetary - mass '' companion seen in direct light or a brown dwarf tertiary viewed in light scattered by an edge - on disk or envelope remain possibilities . .
And you have already written the first three sentences of the full article: over the past decade , direct imaging surveys have discovered a small but significant number of faint , apparently planetary - mass ( @xmath220 @xmath3 ) companions that orbit their primary star hosts ( @xmath40.21.5@xmath5 ) at ultrawide separations ( @xmath6100au , extending to thousands of au ) @xcite .
these planetary mass companions ( pmcs ) represent intriguing analogs to the recent discoveries of smaller separation planets , like hr 8799 bcde @xcite , beta pic b @xcite , hd 95086 b @xcite , gj 504 b @xcite , and lkca15 b @xcite .
the large orbital separations of the pmcs are markedly different from the planets in our own solar system and the vast population of exoplanets detected with the radial velocity and transit methods , so it is not clear whether pmcs formed via similar processes ..
Please generate the next two sentences of the article
|
planets at orbital radii of @xmath2100 au can feasibly be formed via traditional methods like core accretion @xcite and class ii disk instability @xcite . at wider radii ,
the most plausible process is likely disk fragmentation at the class 0/i stage(e.g .
|
12,559 |
Suppose that you have an abstract for a scientific paper: millisecond dips in the rxte / pca light curve of sco x-1 were reported recently ( chang et al .
2006 ) , which were interpreted as the occultation of x - rays from sco x-1 caused by trans - neptunian objects ( tno ) of hundred - meter size .
inconclusive signatures of possible instrumental effects in many of these dip events related to high - energy cosmic rays were later found ( jones et al .
2006 ) and the tno interpretation became shaky .
here we report more detailed analysis aiming at distinguishing true occultation events from those related to cosmic rays . based on some indicative criteria derived from housekeeping data and two - channel spectral information , we suggest that about 10% of the dips are probable events of occultation .
the total number of tnos of size from 60 m to 100 m is estiamted to be about @xmath0 accordingly .
limited by the coarser time resolution of standard data modes of rxte / pca , however , definite results can not be obtained .
adequately configured observations with rxte or other new instruments in the future are very much desired .
[ firstpage ] occultations kuiper belt solar system : formation stars : neutron x - rays : binaries . .
And you have already written the first three sentences of the full article: the outer solar system beyond the orbit of neptune is a relatively unfamiliar world to the human being , and yet it is believed to contain debris of the primordial solar disk and therefore carries much information about the early solar system . although the existence of objects in the outer solar system was proposed long time ago @xcite , except for pluto discovered by c. w. tombaugh in 1930 , the first of such objects was not found until 1992 @xcite . since then
several surveys have been performed and about 1000 tnos have been discovered ( http://cfa-www.harvard.edu/cfa/ps/lists/tnos.html ) . the differential size distribution of the observed tnos , which are all larger than about 100 km in diameter , follows a power law like @xmath1 with @xmath2 ( e.g. @xcite ) .
the size distribution , in addition to representing a major population property of tnos , provides important constraints on the theory of how our planetary system was formed . in coagulation models of planet formation with collisional disruption cascade ,.
Please generate the next two sentences of the article
|
for example , the power - law size distribution does not simply extend towards smaller size but turns flatter ( a smaller @xmath3 ) below a certain break radius ( e.g. @xcite ) .
the magnitude of the break radius depends on the initial mass in the trans - neptunian region , the epoch of neptune s formation , and the tensile strength of these small bodies .
|
12,560 |
Suppose that you have an abstract for a scientific paper: the possible @xmath0 protonic superfluidity is investigated in neutron star matter , and the corresponding energy gap as a function of baryonic density is calculated on the basis of bcs gap equation .
we have discussed particularly the influence of hyperon degrees of freedom on @xmath0 protonic superfluidity .
it is found that the appearance of hyperons leads to a slight decrease of @xmath0 protonic pairing energy gap in most density range of existing @xmath0 protonic superfluidity .
however , when the baryonic density @xmath10.377 ( or 0.409 ) @xmath2 for tm1 ( or tma ) parameter set , @xmath0 protonic pairing energy gap is significantly larger than the corresponding values without hyperons . and the baryonic density range of existing @xmath0 protonic superfluidity is widen due to the appearance of hyperons . in our results , the hyperons not only change the eos and bulk properties but also change the size and baryon density range of @xmath0 protonic superfluidity in neutron star matter . .
And you have already written the first three sentences of the full article: the dense neutron star(ns ) matter shows us an interesting subject to study the properties of nucleon matter with the density higher than nuclear saturation density @xmath3 .
there , it has pointed that the various new degrees of freedom , such as hyperons , quarks and their mixed phases , realize according to the density@xcite .
it is well known that ns matter has the properties of the strong degeneracy and exists the attractive interaction between two baryons , which are the conditions for the occurrence of superfluid states in fermi systems ..
Please generate the next two sentences of the article
|
thus , ns is already considered as the key laboratories of various superfluidity in nuclear matter@xcite . in recent years
, many studies have been focussing on @xmath0 protonic superfluidity .
|
12,561 |
Suppose that you have an abstract for a scientific paper: we consider an ensemble of globally coupled phase oscillators whose interaction is transmitted at finite speed .
this introduces time delays , which make the spatial coordinates relevant in spite of the infinite range of the interaction .
we show that one - dimensional arrays synchronize in an asymptotic state where all the oscillators have the same frequency , whereas their phases are distributed in spatial structures that in the case of periodic boundaries can propagate , much as in coupled systems with local interactions . .
And you have already written the first three sentences of the full article: standard models for studying collective complex behavior in natural systems consist typically of ensembles of interacting dynamical elements @xcite .
such kind of models has proven to be extremely versatile in the mathematical description , both analytical and numerical , of a wide variety of phenomena within the scopes of physics , biology , and other branches of science @xcite . according to the range of the involved interactions
, these models can be divided into two well distinct classes ..
Please generate the next two sentences of the article
|
local interactions which are paradigmatically represented in reaction - diffusion systems @xcite give rise to macroscopic evolution in which space variables play a relevant role , such as spatial structures and propagation phenomena . on the other hand , with global interactions where the coupling range is of the order of , or larger than , the system size space becomes irrelevant and collective behavior is observed to develop in time , typically , in the form of synchronization @xcite .
an essential model of globally coupled elements is given by a set of @xmath0 identical oscillators described , in the so - called phase approximation , by phase variables @xmath1 ( @xmath2 ) .
|
12,562 |
Suppose that you have an abstract for a scientific paper: the decay rate for a particle in a metastable cubic potential is investigated in the quantum regime by the euclidean path integral method in semiclassical approximation .
the imaginary time formalism allows one to monitor the system as a function of temperature .
the family of classical paths , saddle points for the action , is derived in terms of jacobian elliptic functions whose periodicity sets the energy - temperature correspondence .
the period of the classical oscillations varies monotonically with the energy up to the sphaleron , pointing to a smooth crossover from the quantum to the activated regime .
the softening of the quantum fluctuation spectrum is evaluated analytically by the theory of the functional determinants and computed at low @xmath0 up to the crossover . in particular , the negative eigenvalue , causing an imaginary contribution to the partition function , is studied in detail by solving the lam equation which governs the fluctuation spectrum . for a heavvy particle mass , the decay rate shows a remarkable temperature dependence mainly ascribable to a low lying soft mode and , approaching the crossover , it increases by a factor five over the predictions of the zero temperature theory . just beyond the peak value ,
the classical arrhenius behavior takes over .
a similar trend is found studying the quartic metastable potential but the lifetime of the latter is longer by a factor ten than in a cubic potential with same parameters .
some formal analogies with noise - induced transitions in classically activated metastable systems are discussed . .
And you have already written the first three sentences of the full article: occuring in a broad class of natural phenomena metastability has been intensively studied in different research fields ranging from condensed matter to chemical physics , from particle and nuclear physics to cosmology . while the mathematics of the metastable phase in statistical physics was elaborated by langer @xcite forty years ago , the thorough extension of the formalism to the quantum field theory came in the seventies of the last century @xcite .
as the semiclassical approximation is known to be appropriate @xcite to deal with quantum tunneling , the path integral method in the euclidean version @xcite has emerged as the fundamental tool for quantitative theories of the decay rate @xmath1 of a metastable state .
the latter is given in semiclassical theory by @xmath2 \label{eq:100}\end{aligned}\ ] ] where @xmath3 and @xmath4 depend on the specific shape of the potential ..
Please generate the next two sentences of the article
|
in the path integral approach , @xmath4 is the euclidean action calculated at the classical path around which the action varies the least while @xmath3 is obtained by summing over the quantum fluctuations paths . in quadratic approximation
the quantum fluctuations are decoupled and their contribution can be evaluated by the theory of the functional determinants which implements the path integral method @xcite .
|
12,563 |
Suppose that you have an abstract for a scientific paper: the extreme ultraviolet variability experiment ( eve ) on the solar dynamics observatory obtains extreme - ultraviolet ( euv ) spectra of the full - disk sun at a spectral resolution of @xmath01 and cadence of 10s .
such a spectral resolution would normally be considered to be too low for the reliable determination of electron density ( n@xmath1 ) sensitive emission line intensity ratios , due to blending .
however , previous work has shown that a limited number of fexxi features in the 90160 wavelength region of eve do provide useful n@xmath1-diagnostics at relatively low flare densities ( n@xmath1 @xmath2 10@xmath310@xmath4@xmath5 ) . here
we investigate if additional highly ionised fe line ratios in the eve 90160 range may be reliably employed as n@xmath1-diagnostics .
in particular , the potential for such diagnostics to provide density estimates for high n@xmath1 ( @xmath010@xmath6@xmath5 ) flare plasmas is assessed .
our study employs eve spectra for x - class flares , combined with observations of highly active late - type stars from the extreme ultraviolet explorer ( euve ) satellite plus experimental data for well - diagnosed tokamak plasmas , both of which are similar in wavelength coverage and spectral resolution to those from eve .
several ratios are identified in eve data which yield consistent values of electron density , including fexx 113.35/121.85 and fexxii 114.41/135.79 , with confidence in their reliability as n@xmath1-diagnostics provided by the euve and tokamak results .
these ratios also allow the determination of density in solar flare plasmas up to values of @xmath010@xmath6@xmath5 .
[ firstpage ] stars : coronae stars : flares sun : corona sun : flares .
And you have already written the first three sentences of the full article: electron density ( n@xmath1 ) is a fundamental physical parameter of a plasma , and one of the main ways for determining this quantity in remote astrophysical sources is via emission line intensity ratios which are sensitive to variations in n@xmath1 . in the case of the high temperature solar transition region and corona ,
many of the emission lines lie at extreme - ultraviolet ( euv ) wavelengths ( @xmath01001200 ) , and for more than half a century numerous researchers have worked on the calculation of theoretical line ratio n@xmath1-diagnostics involving euv transitions ( see , for example , @xcite ; @xcite ; @xcite ) .
such diagnostics have generally been used in conjunction with medium to high spectral resolution solar observations obtained with rocket - borne or satellite - based instrumentation , required to adequately resolve and hence reliably measure the relevant emission lines ..
Please generate the next two sentences of the article
|
examples include the s082a instrument on board the skylab space station , which had a resolution of @xmath00.1 @xcite , the solar euv rocket telescope and spectrograph ( serts ) at 0.050.08resolution @xcite , the coronal diagnostic spectrometer ( cds ) on the solar and heliospheric observatory ( soho ) satellite at @xmath00.4resolution @xcite and the euv imaging spectrometer ( eis ) on the hinode satellite at @xmath00.07resolution @xcite .
the solar dynamics observatory ( sdo ) , launched on 2010 february 11 , contains a number of instruments including the extreme ultraviolet variability experiment ( eve ) , which obtains a full - disk euv spectrum every 10s using its megs - a component , albeit at a relatively low resolution of @xmath01 @xcite .
|
12,564 |
Suppose that you have an abstract for a scientific paper: we study the possible decay of a coherently oscillating scalar field , interpreted as dark matter , into light fermions . specifically , we consider a scalar field with sub - ev mass decaying into a fermi sea of neutrinos .
we recognize the similarity between our scenario and inflationary preheating where a coherently oscillating scalar field decays into standard model particles . like the case of fermionic preheating
, we find that pauli blocking controls the dark matter decay into the neutrino sea .
the radius of the fermi sphere depends on the expansion of the universe leading to a time varying equation of state of dark matter .
this makes the scenario very rich and we show that the decay rate might be different at different cosmological epochs .
we categorize this in two interesting regimes and then study the cosmological perturbations to find the impact on structure formation .
we find that the decay may help alleviating some of the standard problems related to cold dark matter . .
And you have already written the first three sentences of the full article: dark matter has become an extremely interesting area of research in both cosmology and particle physics . from the particle physics point of view
it can be thermal wimps , axions , kaluza klein states , etc .
though supersymmetric ( susy ) models predict its mass to be of the order the electro - weak scale , there are viable models of dark matter where its mass can be as low as sub - ev , for example axion - like dark matter ..
Please generate the next two sentences of the article
|
especially the direct and indirect search for dark matter has narrowed down the parameter space of these well studied candidates to a large extent .
hence it is highly likely that dark matter is of much more exotic nature than thought of .
|
12,565 |
Suppose that you have an abstract for a scientific paper: recently it has been suggested that the fragmentation boundary in smoothed particle hydrodynamic ( sph ) and fargo simulations of self - gravitating accretion discs with @xmath0 cooling do not converge as resolution is increased .
furthermore , this recent work suggests that by carefully optimising the artificial viscosity parameters in these codes it can be shown that fragmentation may occur for much longer cooling times than earlier work suggests .
if correct , this result is intriguing as it suggests that gas giant planets could form , via direct gravitational collapse , reasonably close to their parent stars .
this result is , however , slightly surprising and there have been a number of recent studies suggesting that the result is likely an indication of a numerical problem with the simulations .
one suggestion , in particular , is that the sph results are influenced by the manner in which the cooling is implemented .
we extend this work here and show that if the cooling is implemented in a manner that removes a known numerical artefact in the shock regions , the fragmentation boundary converges to a value consistent with earlier work and that fragmentation is unlikely for the long cooling times suggested by this recent work .
we also investigate the optimisation of the artificial viscosity parameters and show that the values that appear optimal are likely introducing numerical problems in both the sph and fargo simulations .
we therefore conclude that earlier predictions for the cooling times required for fragmentation are likely correct and that , as suggested by this earlier work , fragmentation can not occur in the inner parts ( @xmath1 au ) of typical protostellar discs .
[ firstpage ] accretion , accretion discs - gravitation - instabilities - stars ; formation - stars ; .
And you have already written the first three sentences of the full article: if a disc around a central object is sufficiently massive , its own self - gravity may play an important role in its evolution through the growth of the gravitational instability @xcite .
an infinitesimally thin disc is susceptible to the growth of an axisymmetric gravitational instability if the @xmath2 parameter @xcite @xmath3 where @xmath4 is the sound speed in the disc , @xmath5 is the local epicyclic frequency ( equal to the angular velocity , @xmath6 , in a keplerian disc ) , @xmath7 is the gravitational constant , and @xmath8 is the disc surface density . global , non - axisymmetric perturbations can , however , grow for @xmath2 values greater than @xmath9 , with simulations suggesting that the stability criteria in global discs is @xmath10 @xcite .
it is now , however , quite well understood that the @xmath2 parameter alone does not determine the ultimate evolution of a self - gravitating accretion disc ..
Please generate the next two sentences of the article
|
the evolution is determined by both the value of @xmath2 and by the rate at which the disc is able to lose energy @xcite .
the current picture is that for long cooling times , the disc will settle into a state of marginal stability @xcite in which the instability acts to transport angular momentum outwards , allowing mass to accrete onto the central object @xcite . for short cooling times , however , the disc may become sufficiently unstable to fragment and form bound objects @xcite .
|
12,566 |
Suppose that you have an abstract for a scientific paper: we propose a means to discriminate between the two basic variants of little higgs models , the product group and simple group models , at the next generation of colliders .
it relies on a special coupling of light pseudoscalar particles present in little higgs models , the pseudo - axions , to the @xmath0 and the higgs boson , which is present only in simple group models .
we discuss the collider phenomenology of the pseudo - axion in the presence of such a coupling at the lhc , where resonant production and decay of either the higgs or the pseudo - axion induced by that coupling can be observed for much of parameter space . the full allowed range of parameters , including regions where the observability is limited at the lhc , is covered by a future ilc , where double scalar production would be a golden channel to look for . .
And you have already written the first three sentences of the full article: little higgs models @xcite have been proposed as a solution to the hierarchy problem , the vast difference between the scales of electroweak symmetry breaking and the scale where quantum effects of gravity can no longer be neglected .
the higgs boson emerges as a pseudo - goldstone boson of spontaneously broken chiral symmetries of a strongly interacting theory in the multi - tev regime .
the quadratically divergent contributions to the higgs mass are canceled unlike in supersymmetry by particles of like statistics , chiral multiplet partners of the standard model ( sm ) fermions ..
Please generate the next two sentences of the article
|
the collective breaking of these symmetries generates a quadratically - divergent correction to the higgs mass only at two - loop order , such that the models remain weakly interacting at the tev scale , thereby satisfying electroweak precision data constraints .
ideas about possible uv completions exist @xcite , but we ignore them in this paper and take little higgs models as low - energy effective theories .
|
12,567 |
Suppose that you have an abstract for a scientific paper: the spectrum width can be narrowed to a certain degree by decreasing the coupling strength for the two - level emitter coupled to the propagating surface plasmon . but the width can not be narrowed any further because of the loss of the photon out of system by spontaneous emission from the emitter . here we propose a new scheme to construct a narrow - band source via a one - dimensional waveguide coupling with a three - level @xmath0-type emitter .
it is shown that the reflective spectrum width can be narrowed avoiding the impact of the loss .
this approach opens up the possibility of plasmonic ultranarrow single - photon source . _
introduction. _ in recent years , the coupling between one - dimensional waveguide and optical emitters has attracted considerable attentions because of their wide application in many aspects@xcite .
the two - level emitter within the waveguide acts as a perfect mirror for the light field at resonance@xcite .
the @xmath0-type three - level emitter system(@xmath0ls ) can realize electromagnetically induced transparency ( eit ) mechanism to control behavior of the probe photon by applying a classical control light beam in the system@xcite .
similarly , two separated two - level emitters system can also obtain eit - like transmission spectrum by adjusting the distance between the two emitters@xcite .
as one of important applications of eit , cavity - linewidth narrowing has shown great potential in many different areas such as laser stabilization@xcite , high - resolution spectroscopy@xcite , enhanced light matter interaction , and compressed optical energy@xcite . in this letter
, we shall investigate the linewidth narrowing effect in the system of optical emitter coupling the nanowire surface plasmons . as we have known , in the two - level emitter coupling with spps systems(tls ) , the linewidth of the reflection peak is proportional to @xmath1 , where @xmath2 is the coupling strength , and @xmath3 is the group velocity of the photons and can be simplified....
And you have already written the first three sentences of the full article: in the following , we shall investigate the linewidth narrowing effect of the @xmath0ls .
first of all , we study the single - photon reflective properties under the resonant control field ( @xmath53 ) . and our emphasis is still put on the change of linewidth with the coupling strength , as shown in fig.3 . here
the reflective spectrum appears a multiple peak - dip - peak structure ( eit - like reflective spectrum ) because of the interference between the two transitions ..
Please generate the next two sentences of the article
|
this is different from a single peak structure in the two - level system .
but with the coupling strength decreasing , the two peaks is becoming declining and narrowing .
|
12,568 |
Suppose that you have an abstract for a scientific paper: we present keck 10-meter / lris spectra of candidate red giants in the halo of m31 , located at a projected radius of @xmath0 kpc on the minor axis .
these spectroscopic targets have been selected using a combination of @xmath1-based and morphological screening to eliminate background galaxies .
radial velocity measurements are used to separate m31 halo giants from foreground milky way dwarf stars , m31 disk stars , and residual background galaxies .
the metallicity of each m31 halo giant is measured using standard photometric and spectroscopic techniques , the latter based on the strength of the ca ii triplet .
the various [ fe / h ] estimates are in rough agreement with one another .
the data reveal a large spread ( @xmath2 dex ) in [ fe / h ] in m31 s halo ; there is no strong radial [ fe / h ] gradient .
lris and hires spectra are also presented for red giants in five dwarf spheroidal satellites of m31 : andi , andiii , andv , andvi , and andvii . there appears to be a significant metallicity spread in andvi and possibly in andi .
the new radial velocity data on these outer dwarfs are used to constrain the total mass of m31 : the best estimate is under @xmath3 , somewhat less than the best estimate for the milky way . .
And you have already written the first three sentences of the full article: this paper describes two ongoing observational programs at keck unified by a common goal : to investigate the metallicity , structure , and dynamics of m31 s extended stellar halo .
the first is a low - resolution spectroscopic survey of field red giant stars in m31 s outer halo ( @xmath4@xmath550 kpc ) , while the second aims to combine low- , intermediate- , and high - resolution spectroscopy of giants in dwarf spheroidal ( dsph ) companions of m31 located at @xmath6@xmath5300 kpc .
such dwarfs have long been thought of as basic building blocks in the process of galaxy formation ..
Please generate the next two sentences of the article
|
the metallicity distribution of our target stars serves as as a fossil record of the formation of m31 s halo .
moreover , these stars are good tracers for investigating the internal dynamics of the dwarfs as well as the global dynamics of the m31 subgroup , and hence the dark matter distribution within the local group .
|
12,569 |
Suppose that you have an abstract for a scientific paper: let @xmath0 be an unrooted tree .
the _ chromatic symmetric function _
@xmath1 , introduced by stanley , is a sum of monomial symmetric functions corresponding to proper colorings of @xmath0 .
the _ subtree polynomial _
@xmath2 , first considered under a different name by chaudhary and gordon , is the bivariate generating function for subtrees of @xmath0 by their numbers of edges and leaves .
we prove that @xmath3 , where @xmath4 is the hall inner product on symmetric functions and @xmath5 is a certain symmetric function that does not depend on @xmath0 . thus the chromatic symmetric function is a stronger isomorphism invariant than the subtree polynomial . as a corollary
, the path and degree sequences of a tree can be obtained from its chromatic symmetric function . as another application ,
we exhibit two infinite families of trees ( _ spiders _ and some _ caterpillars _ ) , and one family of unicyclic graphs ( _ squids _ ) whose members are determined completely by their chromatic symmetric functions . .
And you have already written the first three sentences of the full article: let @xmath6 be a simple graph with vertices @xmath7 and edges @xmath8 , and let @xmath9 denote the positive integers .
a _ ( proper ) coloring _ of @xmath6 is a function @xmath10 such that @xmath11 whenever the vertices @xmath12 are adjacent .
stanley ( @xcite ; see also @xcite ) defined the _ chromatic symmetric function _ of @xmath6 as @xmath13.
Please generate the next two sentences of the article
|
the sum over all colorings @xmath14 , where @xmath15 are countably infinitely many commuting indeterminates .
this definition is invariant under permutations of @xmath16 , so @xmath17 is a symmetric function , homogeneous of degree @xmath18 .
|
12,570 |
Suppose that you have an abstract for a scientific paper: quantum repeaters represent one possible way to achieve long - distance quantum key distribution .
collins et al . in [ phys .
rev .
lett .
98 , 060502 ( 2007 ) ] proposed multiplexing as method to increase the repeater rate and to decrease the requirement in memory coherence time . motivated by the experimental fact that long - range connections are practically demanding ,
in this paper we extend the original quantum repeater multiplexing protocol to the case of short - range connection .
we derive analytical formulas for the repeater rate and we show that for short connection lengths it is possible to have most of the benefits of a full - range multiplexing protocol . then we incorporate decoherence of quantum memories and we study the optimal matching for the bell - state measurement protocol permitting to minimize memory requirements . finally , we calculate the secret key rate and we show that the improvement via finite - range multiplexing is of the same order of magnitude as via full - range multiplexing . .
And you have already written the first three sentences of the full article: quantum key distribution ( qkd ) @xcite allows two parties to share a secret key which might be used for applications in cryptography .
the preferred quantum systems used for transmitting information are photons
. these can be generated , distributed and measured fairly easily with standard technology ..
Please generate the next two sentences of the article
|
however , photons are usually transmitted through optical fibers and due to absorption the maximal distance where qkd is feasible is around 150 km @xcite . in order to overcome this problem the concept of quantum repeaters
can be used @xcite . for increasing the final repeater rate and the final fidelity many variations of the original protocol
|
12,571 |
Suppose that you have an abstract for a scientific paper: we study quantum correlations beyond entanglement in two mode gaussian states of continuous variable systems , by means of the measurement - induced disturbance ( mid ) and its ameliorated version ( amid ) . in analogy with the recent studies of the gaussian quantum discord , we define a gaussian amid by constraining the optimization to all bi - local gaussian positive operator valued measurements .
we solve the optimization explicitly for relevant families of states , including squeezed thermal states .
remarkably , we find that there is a finite subset of two mode gaussian states , comprising pure states , where non - gaussian measurements such as photon counting are globally optimal for the amid and realize a strictly smaller state disturbance compared to the best gaussian measurements . however , for the majority of two mode gaussian states the unoptimized mid provides a loose overestimation of the actual content of quantum correlations , as evidenced by its comparison with gaussian discord .
this feature displays strong similarity with the case of two qubits .
upper and lower bounds for the gaussian amid at fixed gaussian discord are identified .
we further present a comparison between gaussian amid and gaussian entanglement of formation , and classify families of two mode states in terms of their gaussian amid , gaussian discord , and gaussian entanglement of formation .
our findings provide a further confirmation of the genuinely quantum nature of general gaussian states , yet they reveal that non - gaussian measurements can play a crucial role for the optimized extraction and potential exploitation of classical and nonclassical correlations in gaussian states . .
And you have already written the first three sentences of the full article: one of the seminal findings triggering the development of quantum information theory is that there exist nonlocal correlations among subparts of quantum systems that do not emerge in a classical scenario .
these nonclassical correlations , commonly identified with entanglement , can be exploited to manipulate and transmit information in novel and enhanced ways @xcite going beyond the possibilities of classical physics .
consequently , an increasing interest in their study has risen in recent years @xcite ..
Please generate the next two sentences of the article
|
interestingly , signatures of correlations having no classical counterpart can be traced even in separable ( non - entangled ) states , but their nature is rather different from entanglement @xcite .
in fact , while entanglement is a consequence of the superposition principle , more general forms of nonclassical correlations arise essentially from the noncommutativity of quantum observables . when speaking about composite systems , separable states are often perceived as essentially classical . however , _
|
12,572 |
Suppose that you have an abstract for a scientific paper: in the context of holographic qcd we analyze sakai - sugimoto s chiral model at finite baryon density and zero temperature .
the baryon number density is introduced through compact d4 wrapping @xmath0 at the tip of d8-@xmath1 .
each baryon acts as a chiral point - like source distributed uniformly over @xmath2 , and leads a non - vanishing @xmath3 potential on the brane . for fixed baryon charge density @xmath4
we analyze the energy density and pressure using the canonical formalism .
the baryonic matter with point like sources is always in the spontaneously broken phase of chiral symmetry , whatever the density .
the point - like nature of the sources and large @xmath5 cause the matter to be repulsive as all baryon interactions are omega mediated . through the induced dbi action on d8-@xmath1 , we study the effects of the fixed baryon charge density @xmath4 on the pion and vector meson masses and couplings .
issues related to vector dominance in matter in the context of holographic qcd are also discussed . * the chiral model of sakai - sugimoto at finite baryon density
* + keun - young kim@xmath6 , sang - jin sin @xmath7 and ismail zahed@xmath6 + @xmath6 _ department of physics and astronomy , suny stony - brook , ny 11794 _
+ @xmath8 _ department of physics , bk21 division , hanyang university , seoul 133 - 791 , korea _ + .
And you have already written the first three sentences of the full article: dense hadronic matter is of interest to a number of fundamental problems that range from nuclear physics to astrophysics .
qcd at finite baryon density is notoriously difficult : ( 1 ) the introduction of a chemical potential causes most lattice simulations to be numerically noisy owing to the sign problem ; ( 2 ) the baryon - baryon interaction is strong making most effective approaches limited to subnuclear matter densities . in the limit of a large number of colors @xmath5
, qcd is an effective theory of solely mesons where baryons appear as chiral skyrmions ..
Please generate the next two sentences of the article
|
dense matter in large @xmath5 is a skyrmion crystal with spontaneous breaking of chiral symmetry at low density , and restored or stripped ( overhauser ) chiral symmetry at high density .
while some of these aspects can be studied qualitatively using large @xmath5 motivated chiral models @xcite , they still lack a first principle understanding . the ads / cft approach has provided a framework for discussing large @xmath5 gauge theories at strong coupling @xmath9 from first principles @xcite .
|
12,573 |
Suppose that you have an abstract for a scientific paper: recently , an excess of gev gamma ray near the galactic centre has been reported .
the spectrum obtained can be best fitted with the annihilation of @xmath0 gev dark matter particles through @xmath1 channel . in this letter ,
i show that this annihilation model can also solve the mysteries of heating source in x - ray plasma and the unexpected high gamma - ray luminosity .
the cross section constrained by these observations give excellent agreements with both the predicted range by using fermi - lat data and the canonical thermal relic abundance cross section .
[ firstpage ] dark matter .
And you have already written the first three sentences of the full article: recently , high energy gamma ray observations reveal some excess emissions near the galactic centre .
these excess emissions can not be easily explained by standard physical processes
. one potential origin of such emissions is due to an unusual population of millisecond pulsars @xcite ..
Please generate the next two sentences of the article
|
however , @xcite point out that the large diffuse signal of gamma ray disfavours the possibility of pulsar emissions . even including both known sources and unidentified sources , the millisecond pulsars can only account no more than 10 percent of the gev excess @xcite .
in fact , the majority of discussions of the gev excess is now focused on the annihilation of dark matter particles @xcite .
|
12,574 |
Suppose that you have an abstract for a scientific paper: we consider a scheduler for the downlink of a wireless channel when only partial channel - state information is available at the scheduler .
we characterize the network stability region and provide two throughput - optimal scheduling policies .
we also derive a _
deterministic _ bound on the mean packet delay in the network .
finally , we provide a throughput - optimal policy for the network under qos constraints when real - time and rate - guaranteed data traffic may be present .
this work has been submitted to the ieee for possible publication .
copyright may be transferred without notice , after which this version may no longer be accessible . .
And you have already written the first three sentences of the full article: scheduling has always been an indispensable part of resource allocation in wireless networks . the seminal work of tassiulas _ et al . _
@xcite , and later @xcite , @xcite considered the case where both channel states and queue lengths are fully available to the scheduler .
it was shown that the maxweight algorithm , which serves the longest connected queue , is throughput - optimal ..
Please generate the next two sentences of the article
|
subsequently , the maxweight algorithm was found to be throughput - optimal in many other settings as well ( @xcite-@xcite and the references therein ) using tools from lyapunov optimization . some other works ( see @xcite , @xcite , @xcite ) also approach the scheduling problem using convex optimization and dual decomposition techniques . @xcite
even considers the role of imperfect queue length information on network throughput , showing that the stability region does not reduce .
|
12,575 |
Suppose that you have an abstract for a scientific paper: we propose a simple model with spin and orbit angular momentum coupling in a spin-1 bose - einstein condensate , where three internal atomic states are raman coupled by a pair of co - propagating laguerre - gaussian beams .
the resulting raman transition imposes a transfer of orbital angular momentum between photons and the condensate in a spin - dependent way . focusing on a regime where the single - particle ground state is nearly three - fold degenerate ,
we show that the weak interatomic interaction in the condensate produces a rich phase diagram , and that a many - body rabi oscillation between two quantum phases can be induced by a sudden quench of the quadratic zeeman shift .
we carried out our calculations using both a variational method and a full numerical method , and found excellent agreement . .
And you have already written the first three sentences of the full article: a promising platform to quantum simulate such novel phenomena of condensed matter physics as topological insulators @xcite and superconductors @xcite is the spin - orbit coupled cold atomic systems @xcite which have drawn great attention in recent years .
raman dressed coupling between atomic pseudo - spin and its linear momentum was first realized by lin and co - workers @xcite in a two - component ( spin-1/2 ) @xmath0rb condensate , and were soon generalized to spin-1/2 degenerate fermi gases of @xmath1k @xcite and @xmath2li @xcite . in this scheme ,
photon recoil associated with the raman transition facilitated by two counter - propagating laser beams changes the center - of - mass momentum of the atom when it jumps from one spin state to the other ..
Please generate the next two sentences of the article
|
very recently , the same spin - orbit coupling ( soc ) scheme was achieved in a spin-1 condensate @xcite . in general , the physics becomes richer in larger spin systems @xcite simply because more spin states are involved and more control knobs can be utilized . when the two laser beams that induce the raman transition are made to co - propagating , but possess different orbital angular momenta ( e.g. , in the form of laguerre - gaussian , or lg , beams ) @xcite , the raman transition will be accompanied by a transfer of the orbital angular momentum ( oam ) , instead of the linear momentum , to the atom
this situation has been achieved in experiment where this transfer of oam from photon to the atom was exploited to create spin textures in a spinor condensate @xcite .
|
12,576 |
Suppose that you have an abstract for a scientific paper: carbon - enhanced metal - poor ( cemp ) stars in the halo components of the milky way are explored , based on accurate determinations of the carbon - to - iron ( [ c / fe ] ) abundance ratios and kinematic quantities for over 30000 calibration stars from the sloan digital sky survey ( sdss ) . using our present criterion that low - metallicity stars exhibiting [ c / fe ] ratios ( `` carbonicity '' ) in excess of [ c / fe]@xmath0 are considered cemp stars , the global frequency of cemp stars in the halo system for [ fe / h ]
@xmath1 is 8% ; for [ fe / h ] @xmath2 it is 12% ; for [ fe / h ] @xmath3 it is 20% .
we also confirm a significant increase in the level of carbon enrichment with declining metallicity , growing from @xmath4[c / fe]@xmath5 @xmath6 at [ fe / h ] @xmath7 to @xmath4[c / fe]@xmath5 @xmath8 at [ fe / h ] @xmath9 .
the nature of the carbonicity distribution function ( cardf ) changes dramatically with increasing distance above the galactic plane , @xmath10z@xmath10 . for @xmath10z@xmath10 @xmath11 kpc ,
relatively few cemp stars are identified . for distances
@xmath10z@xmath10 @xmath12 kpc , the cardf exhibits a strong tail towards high values , up to [ c / fe ] @xmath13 + 3.0 .
we also find a clear increase in the cemp frequency with @xmath10z@xmath10 . for stars with @xmath14 [ fe / h ] @xmath151.5 , the frequency grows from 5% at @xmath10z@xmath10 @xmath16 kpc to 10% at @xmath10z@xmath10 @xmath17 kpc . for stars with [ fe / h ] @xmath152.0
, the frequency grows from 8% at @xmath10z@xmath10 @xmath16 kpc to 25% at @xmath10z@xmath10 @xmath17 kpc . for stars with @xmath14 [ fe / h ] @xmath151.5 , the mean carbonicity is @xmath4[c / fe]@xmath5 @xmath18 for 0 kpc @xmath19 @xmath10z@xmath10 @xmath19 10 kpc , with little dependence on @xmath10z@xmath10 ; for [ fe / h ] @xmath152.0 , @xmath4[c / fe]@xmath5 @xmath20 , again roughly independent of @xmath10z@xmath10 .
based on a statistical separation of the halo components in velocity space , we find evidence for a significant....
And you have already written the first three sentences of the full article: the milky way provides astronomers with a unique opportunity to explore the formation and evolution of large spiral galaxies , as well as the nature of their stellar populations and recognized structures .
the key to this understanding comes from the availability , for large numbers of individual stars , of the powerful combination of six - dimensional phase - space information ( location and velocity ) and chemical abundances .
metal - poor stars , in particular , shed light on the early stages of galaxy formation and chemical evolution , as they represent the fossil record of the first generations of stars that formed shortly after the big bang ..
Please generate the next two sentences of the article
|
although theory suggests that the bulge of the galaxy may harbor numerous ancient ( though not necessarily the most metal - poor ) stars ( e.g. , tumlinson 2010 ) , the vast majority of presently recognized metal - poor stars are found in the halo system of the galaxy . according to carollo et al .
( 2007 ; c07 ) and carollo et al . ( 2010 ; c10 ) , the inner and outer halos possess different peak metallicities ( [ fe / h]@xmath23 @xmath24 ; [ fe / h]@xmath25 @xmath26 ) , as well as different spatial distributions , with the inner halo exhibiting a flatter density profile than the nearly spherical outer halo . their analysis of the kinematics of a local sample of calibration stars from the sloan digital sky survey ( sdss : york et al .
|
12,577 |
Suppose that you have an abstract for a scientific paper: stripe width variation in ultrathin magnetic films is a well known phenomenon still not well understood .
we analyze this problem considering a 2d heisenberg model with ferromagnetic exchange interactions , dipolar interactions and perpendicular anisotropy , relevant e.g. in fe / cu(001 ) films . by extending a classic result of yafet & gyorgy ( yg ) and
using monte carlo simulations we calculate the complete zero temperature phase diagram of the model . through this calculation
we analyze the correlation between domain walls structure and stripe width variation , as the perpendicular anisotropy changes .
in particular , we found evidences that the recently detected canted state becomes the ground state of the system close to the spin reorientation transition ( srt ) for any value of the exchange to dipolar couplings ratio .
far away of the srt the canted ground state is replaced by a saturated stripes state , in which in plane magnetization components are only present inside the walls .
we find that the domain wall structure strongly depends on the perpendicular anisotropy : close to srt it is well described by yg approximation , but a strong departure is observed in the large anisotropy limit .
moreover , we show that stripe width variation is directly related to domain wall width variation with the anisotropy . .
And you have already written the first three sentences of the full article: pattern formation in ferromagnetic thin films with perpendicular anisotropy and its thermodynamical description have been the subject of intense experimental @xcite , theoretical @xcite and numerical @xcite work in the last 20 years .
magnetic order in ultrathin ferromagnetic films is very complex due to the competition between exchange and dipolar interactions on different length scales , together with a strong influence of shape and magnetocrystalline anisotropies of the sample .
these in turn are very susceptible to the growth conditions of the films @xcite . among the different magnetization patterns that have been observed in these systems , striped order ( i.e. , modulated patterns of local perpendicular magnetization with a well defined half - wavelength or stripe width @xmath0 ) at low temperatures is an ubiquitous phenomenon ..
Please generate the next two sentences of the article
|
one intriguing fact is the strong variation displayed by the equilibrium stripe width @xmath0 in many of these systems , when either the temperature or the film thickness is changed@xcite .
the origin of such variation is still controversial , but recent results suggest that a key point to understand it is the role played by the interfaces ( i.e. , the domain walls ) between stripes@xcite . thus , a starting point to study this problem is to compare the energies of striped patterns with different domain wall configurations .
|
12,578 |
Suppose that you have an abstract for a scientific paper: the structural and dynamic properties of silica melts under high pressure are studied using molecular dynamics ( md ) computer simulation .
the interactions between the ions are modeled by a pairwise - additive potential , the so - called chik potential , that has been recently proposed by carr _
et al_. the experimental equation of state is well - reproduced by the chik model . with increasing pressure ( density ) ,
the structure changes from a tetrahedral network to a network containing a high number of five- and six - fold si - o coordination . in the partial static structure factors , this change of the structure with increasing density
is reflected by a shift of the first sharp diffraction peak towards higher wavenumbers @xmath0 , eventually merging with the main peak at densities around 4.2g/@xmath1 .
the self - diffusion constants as a function of pressure show the experimentally - known maximum , occurring around a pressure of about 20gpa . .
And you have already written the first three sentences of the full article: under ambient conditions , amorphous silica ( sio@xmath2 ) forms a disordered tetrahedral network .
tetrahedral units with silicon atoms in the centre are connected to each other via the oxygen atoms at the four corners of each tetrahedron . under compression ,
the network structure of sio@xmath2 may change significantly . from experiments on silica glasses.
Please generate the next two sentences of the article
|
@xcite , it is known that the sio coordination changes for pressures of the order of 1520gpa . then , the network structure is dominated by five- and six - fold coordinated sio units . albeit of great interest for geoscience ,
experimental studies of pure silica melts under ( high ) pressure are very rare @xcite .
|
12,579 |
Suppose that you have an abstract for a scientific paper: colliding high energy hadrons either produce new particles or scatter elastically with their quantum numbers conserved and no other particles produced .
we consider the latter case here .
although inelastic processes dominate at high energies , elastic scattering contributes considerably ( 18 - 25@xmath0 ) to the total cross section .
its share first decreases and then increases at higher energies .
small - angle scattering prevails at all energies .
some characteristic features are seen that provide informationon the geometrical structure of the colliding particles and the relevant dynamical mechanisms .
the steep gaussian peak at small angles is followed by the exponential ( orear ) regime with some shoulders and dips , and then by a power - law drop .
results from various theoretical approaches are compared with experimental data .
phenomenological models claiming to describe this process are reviewed .
the unitarity condition predicts an exponential fall for the differential cross section with an additional substructure to occur exactly between the low momentum transfer diffraction cone and a power - law , hard parton scattering regime under high momentum transfer .
data on the interference of the coulomb and nuclear parts of amplitudes at extremely small angles provide the value of the real part of the forward scattering nuclear amplitude .
the real part of the elastic scattering amplitude and the contribution of inelastic processes to the imaginary part of this amplitude ( the so - called overlap function ) at nonforward transferred momenta are also discussed .
problems related to the scaling behavior of the differential cross section are considered .
the power - law regime at highest momentum transfer is briefly described .
* elastic scattering of hadrons * if only you knew what trash gives rise + to verses that are nt ashamed uprise + a. akhmatova + @xmath1 * 1 introduction . * * 2 the main relations . * * 3 where do we stand now ? * * 4....
And you have already written the first three sentences of the full article: hadron interactions are strong and , in principle , should be described by quantum chromodynamics ( qcd ) .
however , experimental data show that their main features originate from the non - perturbative sector of qcd .
only comparatively rare processes with large transferred momenta can be treated theoretically rather successfully by perturbative methods due to the well - known property of the asymptotical freedom of qcd ..
Please generate the next two sentences of the article
|
hence , in the absence of methods for a rigorous solution of qcd equations , our understanding of the dynamics of the main bulk of strong interactions is severely limited by model building or some rare rigorous relations .
in fact , our approach to high - energy hadronic processes at present is at best still in its infancy .
|
12,580 |
Suppose that you have an abstract for a scientific paper: the aharon - vaidman ( av ) game exemplifies the advantage of using simple quantum systems to outperform classical strategies .
we present an experimental test of this advantage by using a three - state quantum system ( qutrit ) encoded in a spatial mode of a single photon passing through three slits .
the preparation of a particular state is controlled as the photon propagates through the slits by varying the number of open slits and their respective phases .
the measurements are achieved by placing detectors in the specific positions in the near and far fields after the slits .
this set of tools allowed us to perform tomographic reconstructions of generalized qutrit states , and to implement the quantum version of the av game with compelling evidence of the quantum advantage . .
And you have already written the first three sentences of the full article: the aharon - vaidman game @xcite is a conceptually simple example of how quantum mechanics can be both beneficial and counter - intuitive . in the classical analog ,
alice puts a particle in one of three boxes such that when bob , who in next turn is allowed to check only two of them , is most likely to find it .
alice who can either accept or not accept a particular game trial wins whenever she accepts a trial in which bob has also discovered the particle ..
Please generate the next two sentences of the article
|
hence , it is obvious that alice will not use the box that bob does not have access to and therefore her chance to win is @xmath0 .
however , the result of the game can be totally different when the particle is described by laws of quantum mechanics and alice prepares it in equal superposition of being in each of the boxes .
|
12,581 |
Suppose that you have an abstract for a scientific paper: we consider two - player random extensive form games where the payoffs at the leaves are independently drawn uniformly at random from a given feasible set @xmath0 .
we study the asymptotic distribution of the subgame perfect equilibrium outcome for binary - trees with increasing depth in various random ( or deterministic ) assignments of players to nodes .
we characterize the assignments under which the asymptotic distribution concentrates around a point .
our analysis provides a natural way to derive from the asymptotic distribution a novel solution concept for two - player bargaining problems with a solid strategic justification . .
And you have already written the first three sentences of the full article: a subgame perfect equilibrium is one of the fundamental solution concepts in game theory .
its characterization is very simple : a strategy profile is a subgame perfect equilibrium if it constitutes a nash equilibrium of every subgame of the original game . in extensive form games with perfect information ,
subgame perfect equilibrium coincides with backward - induction and can be easily determined . in this work.
Please generate the next two sentences of the article
|
we study the distribution of the subgame perfect equilibrium outcome in random two - player extensive form games . in these games there
are two potential natural degrees of randomness that may be considered .
|
12,582 |
Suppose that you have an abstract for a scientific paper: we show effects of the event - by - event fluctuation of the initial conditions ( ic ) in hydrodynamic description of high - energy nuclear collisions on some observables .
such ic produce not only fluctuations in observables but , due to their bumpy structure , several non - trivial effects appear .
they enhance production of isotropically distributed high-@xmath0 particles , making @xmath1 smaller there . also , they reduce @xmath1 in the forward and backward regions where the global matter density is smaller , so where such effects become more efficacious
. they may also produce the so - called _ ridge effect _ in the two large-@xmath0 particle correlation . .
And you have already written the first three sentences of the full article: hydrodynamics is one of the main tools for studying the collective flow in high - energy nuclear collisions . in this approach
, it is assumed that , after a complex process involving microscopic collisions of nuclear constituents , at a certain early instant a hot and dense matter is formed , which would be in local thermal equilibrium .
after this instant , the system would expand hydrodynamically , following the well known set of differential equations ..
Please generate the next two sentences of the article
|
the initial conditions ( ic ) for the hydrodynamic expansion are usually parametrized as smooth distributions of thermodynamic quantities and four - velocity .
however , since our systems are small , important _ event - by - event fluctuations _ are expected in the ic of the real collisions . moreover
|
12,583 |
Suppose that you have an abstract for a scientific paper: we review recent results on near - horizon static black hole solutions and entropy in @xmath0-corrected @xmath1 sugra in @xmath2 , focusing on actions connected to heterotic string compactified on @xmath3 .
comparison with @xmath4-perturbative results , results obtained by using simple gauss - bonnet @xmath0-correction , osv conjecture and microscopic stringy description ( for small black holes ) shows that situation in @xmath2 is , in a sense , even more interesting then in @xmath5 . .
And you have already written the first three sentences of the full article: bosonic part of the lagrangian for the @xmath1 supergravity action in five dimensions is given by @xmath6 where @xmath7 and @xmath8 .
also , @xmath9 a bosonic field content of the theory is the following .
we have weyl multiplet which contains the fnfbein @xmath10 , the two - form auxiliary field @xmath11 , and the scalar auxiliary field @xmath12 ..
Please generate the next two sentences of the article
|
there are @xmath13 vector multiplets enumerated by @xmath14 , each containing the one - form gauge field @xmath15 ( with the two - form field strength @xmath16 ) , and the scalar @xmath17 .
scalar fields @xmath18 , which are belonging to the hypermultiplet , can be gauge fixed and the convenient choice is given by @xmath19 , @xmath20 .
|
12,584 |
Suppose that you have an abstract for a scientific paper: we observed ar lac , an eclipsing rs cvn binary star , with the chandra high energy grating spectrometer for a total of 100 ks divided into six intervals covering both quadratures and eclipses .
we repeated observations at each phase .
at least two flares were seen , in which the flux increased by factors of two and four .
the flares occurred near eclipse phases and compromised detection of eclipse modulation .
the quadrature fluxes were the most stable , but they also show non - repeating trends .
quadrature line profiles are broadened relative to eclipse profiles , presumably due to orbital velocity doppler shifted emission from each binary component .
the spectrum appears to be iron poor and neon rich , similar to hr 1099 , but not as extreme as ii pegasi .
we will examine line strengths , widths , and positions vs. phase , and present preliminary differential emission measure models and abundance determinations using the aped emissivity database .
this work is supported by nasa contract nas8 - 38249 ( hetg ) and sao sv1 - 61010 ( cxc ) to mit . .
And you have already written the first three sentences of the full article: rs cvn binaries were first noted for their sinusoidal optical light curve variability , interpreted as large scale analogs of sunspots ( hall , 1976 ) .
subsequent studies showed them to have optical ( hydrogen and calcium ; huenemoerder & ramsey 1984 ) and ultraviolet ( carbon , silicon , oxygen , nitrogen ; simon and linsky 1980 ) emission lines also analogous to the solar chromosphere and transition region .
they were later found to be luminous in x - rays ( walter & bowyer , 1981 ) , extending the solar analogy to the corona , but with 1000 times the activity level . eclipsing systems like.
Please generate the next two sentences of the article
|
ar lac permit us to study coronal phenomena for stars of known mass , size , and rotational velocity .
emission line spectroscopy provides temperature and density diagnostics , which together with geometrical constraints , can provide insights regarding sizes of magnetic loops .
|
12,585 |
Suppose that you have an abstract for a scientific paper: the dark - matter candidates of particle physics invariably possess electromagnetic interactions , if only via quantum fluctuations . taken en masse , dark matter
can thus engender an index of refraction which deviates from its vacuum value .
its presence is signaled through frequency - dependent effects in the propagation and attenuation of light .
we discuss theoretical constraints on the expansion of the index of refraction with frequency , the physical interpretation of the terms , and the particular observations needed to isolate its coefficients .
this , with the advent of new opportunities to view gamma - ray bursts at cosmological distance scales , gives us a new probe of dark matter and a new possibility for its direct detection .
as a first application we use the time delay determined from radio afterglow observations of distant gamma - ray bursts to realize a direct limit on the electric - charge - to - mass ratio of dark matter of @xmath0 at 95% cl .
some twenty - three percent of the universe s energy budget is in dark matter @xcite , yet , despite its abundance , little is known of its properties .
a number of methods have been proposed for the detection of dark matter .
such studies typically rely , for direct searches , on dark - matter nucleus scattering , and , for indirect searches , on two - body annihilation of dark - matter to standard model ( sm ) particles ; constraints follow from the nonobservation of the aftermath of particular two - body interactions .
in contrast , we probe dark matter in bulk to infer constraints on its particulate nature .
we search for dark matter by studying the modification of the properties of light upon passage through it .
one can study either polarization @xcite or propagation effects ; we focus here on the latter .
the resulting constraints are most stringent if dark matter consists of sufficiently low mass particles , be they , e.g. , warm thermal relics or axion - like particles , that its number density greatly....
And you have already written the first three sentences of the full article: from the publicly available data , we consider the gamma - ray bursts ( grb ) with known redshifts and detected radio afterglows through march , 2009 . tables 14 collect the grbs with these properties which satisfy certain criteria .
we demand that the energy of the initially detected gamma - ray burst in its rest frame be compatible with the energy range of the fermi gamma - burst monitor .
this excludes the x - ray flashes grb 080109a and grb 020903a . to determine whether an observation of the radio flux is indeed a detected radio afterglow , we demand that the radio flux detection be within the error box of the location of the observed grb , that it not be a site of previously observed radio activity , and that it be significantly non - zero ..
Please generate the next two sentences of the article
|
we use the criterion employed by ref .
@xcite and thus require that the radio observation be nonzero by three standard deviations or more to be termed a detection .
|
12,586 |
Suppose that you have an abstract for a scientific paper: we study the 2d @xmath0 gauge theory descriptions of little strings on type ii ns5-branes .
the iib strings on @xmath1 ns5-branes are described by the @xmath2 gauge theories , whose higgs branch cfts on @xmath3 instanton moduli spaces are relevant .
the iia strings are described by @xmath2 @xmath4 quiver theories , whose coulomb branch cfts are relevant .
we study new @xmath5 quiver gauge theories for the iia strings , which make it easier to study some infrared observables .
in particular , we show that the elliptic genera of the iia / iib strings precisely map to each other by t - duality .
addtoresetequationsection + + * little strings and t - duality * jungmin kim@xmath6 , seok kim@xmath6 , kimyeong lee@xmath7 _ @xmath6department of physics and astronomy & center for theoretical physics , + seoul national university , seoul 151 - 747 , korea .
_ + _ @xmath7school of physics , korea institute for advanced study , seoul 130 - 722 , korea . _
+ e - mails : [email protected] , [email protected] , [email protected] .
And you have already written the first three sentences of the full article: little string theories with @xmath8 supercharges @xcite are obtained by decoupling limits of the type ii strings near @xmath1 ns5-branes .
they are non - local theories without gravity . depending on whether we start from type iia or iib ns5-branes , the system has @xmath9 or @xmath10 super - poincare symmetry , respectively
. since ns5-branes are one of the most difficult nonperturbative objects to study in string theory , it would be very desirable to have better understanding on these strings . also , the type iia little string theory has interesting low energy limit given by interacting @xmath9 superconformal field theories ..
Please generate the next two sentences of the article
|
little strings have similarities with critical strings , and also differences .
the fact that it does not contain gravity would be the main difference , with far - reaching implications .
|
12,587 |
Suppose that you have an abstract for a scientific paper: long - lived , spatially localized , and temporally oscillating nonlinear excitations are predicted by numerical simulation of coupled gross - pitaevskii equations .
these oscillons closely resemble the time - periodic breather solutions of the sine - gordon equation but decay slowly by radiating bogoliubov phonons .
their time - dependent profile is closely matched with solutions of the sine - gordon equation , which emerges as an effective field theory for the relative phase of two linearly coupled bose fields in the weak - coupling limit .
for strong coupling the long - lived oscillons persist and involve both relative and total phase fields . the oscillons decay via bogoliubov phonon radiation that is increasingly suppressed for decreasing oscillon amplitude .
possibilities for creating oscillons are addressed in atomic gas experiments by collision of oppositely charged bose - josephson vortices and direct phase imprinting . .
And you have already written the first three sentences of the full article: oscillons are localized and oscillating concentrations of energy in a nonlinear field that decay very slowly over many of their oscillation periods @xcite .
they are thought to be relevant in the dynamics of cosmological phase transitions @xcite and inflation scenarios @xcite , where they provide localized stores of energy .
in contrast to cosmic strings @xcite or other topological defects that can only be destroyed by annihilation , isolated oscillons can decay by radiation over long time scales . closely related to oscillons.
Please generate the next two sentences of the article
|
are breathers , which are time - periodic localized solutions of a nonlinear field equation @xcite .
breathers only exist when resonance between the breather frequency and extended linear waves is avoided .
|
12,588 |
Suppose that you have an abstract for a scientific paper: we compare the existing observational data on type ia supernovae with the evolutions of the universe predicted by a one - parameter family of tachyon models which we have introduced recently in paper @xcite . among the set of the trajectories of the model which are compatible with the data
there is a consistent subset for which the universe ends up in a new type of soft cosmological singularity dubbed big brake .
this opens up yet another scenario for the future history of the universe besides the one predicted by the standard @xmath0cdm model . .
And you have already written the first three sentences of the full article: the discovery of cosmic acceleration @xcite has stimulated the study of different models of dark energy @xcite which may be responsible for such a phenomenon .
models of dark energy include those based on different perfect fluids , having negative pressure , on minimally and non - minimally coupled scalar fields and on fields having non - standard kinetic terms kinetic , tachyons .
the latter ones include as a subclass the models based on different forms of the born - infeld - type action , which is often associated with the tachyons arising in the context of string theory @xcite ..
Please generate the next two sentences of the article
|
tachyonic models with relatively simple potentials were confronted with observational data in @xcite . compared to the standard klein - gordon scalar field cosmological models the dynamics of tachyon models can be much richer due to the non - linearity of the dependence of the tachyon lagrangians on the kinetic term of the tachyon field . in a recent paper @xcite a particular one - parameter family of tachyon models was considered , which has revealed some unexpected features . at some values of the parameter of the model a long period of accelerated quasi - de sitter expansion
is followed by a period of cosmic deceleration culminating , after a finite time , in an encounter with a cosmological singularity of a new type , which was named _ big brake_. this singularity is characterized by an infinite negative value of the second time derivative of the cosmological radius of the universe , while its first time derivative and the hubble variable vanish , and the radius itself acquires a finite value .
|
12,589 |
Suppose that you have an abstract for a scientific paper: despite its size and complexity , the human cortex exhibits striking anatomical regularities , suggesting there may simple meta - algorithms underlying cortical learning and computation .
we expect such meta - algorithms to be of interest since they need to operate quickly , scalably and effectively with little - to - no specialized assumptions .
this note focuses on a specific question : how can neurons use vast quantities of _ unlabeled _ data to speed up learning from the comparatively rare labels provided by reward systems ? as a partial answer , we propose randomized co - training as a biologically plausible meta - algorithm satisfying the above requirements . as evidence
, we describe a biologically - inspired algorithm , correlated nystrm views ( ` xnv ` ) that achieves state - of - the - art performance in semi - supervised learning , and sketch work in progress on a neuronal implementation .
although staggeringly complex , the human cortex has a remarkably regular structure @xcite .
for example , even expert anatomists find it difficult - to - impossible to distinguish between slices of tissue taken from , say , visual and prefrontal areas .
this suggests there may be simple , powerful meta - algorithms underlying neuronal learning .
consider one problem such a meta - algorithm should solve : taking advantage of massive quantities of unlabeled data .
evolution has provided mammals with neuromodulatory systems , such as the dopamenergic system , that assign labels ( e.g. pleasure or pain ) to certain outcomes .
however , these labels are rare ; an organism s interactions with its environment are typically indifferent .
nevertheless , mammals often generalize accurately from just a few good or bad outcomes .
our problem is therefore to understand how organisms , and more specifically individual neurons , use unlabeled data to learn quickly and accurately .
next , consider some properties a semi - supervised _ neuronal _ learning algorithm should have
. it should....
And you have already written the first three sentences of the full article: the perceptron was introduced in the 50s as a simple model of how neurons learn @xcite .
it has been extremely influential , counting both deep learning architectures and support vector machines amongst its descendants .
unfortunately however , the perceptron and related models badly misrepresent important features of neurons ..
Please generate the next two sentences of the article
|
in particular , they treat outputs symmetrically ( @xmath3 ) rather than asymmetrically ( 0/1 ) .
this is crucial since spikes ( 1s ) are more metabolically expensive than silences ( 0s ) .
|
12,590 |
Suppose that you have an abstract for a scientific paper: most of the calculations in standard sphere decoders are redundant , in the sense that they either calculate quantities that are never used or calculate some quantities more than once . a new method , which is applicable to lattices as well as finite constellations , is proposed to avoid these redundant calculations while still returning the same result .
pseudocode is given to facilitate immediate implementation .
simulations show that the speed gain with the proposed method increases linearly with the lattice dimension . at dimension 60 ,
the new algorithms avoid about 75 % of all floating - point operations . .
And you have already written the first three sentences of the full article: lattice is represented with its _ generator matrix _ @xmath0 , whose entries are real numbers .
let @xmath1 and @xmath2 denote the number of rows and columns of @xmath0 respectively with @xmath3 .
the rows of @xmath0 , which are @xmath4 , are called _ basis vectors _ and are assumed to be linearly independent vectors in @xmath5 ..
Please generate the next two sentences of the article
|
the lattice of dimension @xmath1 is defined as the set of points @xmath6 this paper is about methods to find the _
closest point _ in a lattice to a given vector @xmath7 , hereafter called _ received vector , _ which requires minimization of the metric @xmath8 over all lattice points @xmath9 with @xmath10 . in 1981
|
12,591 |
Suppose that you have an abstract for a scientific paper: the absolute position of the compact radio source at the dynamical center of the galaxy , sgr a@xmath0 , was known only to an accuracy of @xmath1 in spite of its accurate location with respect to near - ir stellar sources to within 30 milliarcsecond ( mas ) . to remedy this poor positional accuracy ,
we have selected 15 high - resolution , high - frequency vla observations of sgr a@xmath0 carried out in the last 13 years and determined the weighted average position with the average epoch 1992.4 to be at @xmath2 , @xmath3[1950 ] = @xmath4 293076@xmath5 , @xmath6 , or @xmath2 , @xmath7[2000 ] = @xmath8 400383@xmath5 , @xmath9 which agrees with earlier published values to within the @xmath1 error bars of the earlier measurements . an accurate absolute position of sgr a@xmath0 can be useful for its identification with sources at other wavelengths , particularly , in soft and hard x - rays with implications for the models of a massive black hole at the galactic center .
submitted to the editor of the apj letters on february 4 , 1999 i v i .
And you have already written the first three sentences of the full article: recent advances in infrared and x - ray array technologies have greatly increased the spatial coverage and resolutions in near - ir and x - ray observations , providing powerful tools to compare high - resolution radio , ir and x - ray images of the complex region of the galactic center .
sgr a@xmath0 is a bright compact radio source which is considered to be the strongest candidate for a 2.5@xmath10 black hole at the dynamical center of the galaxy ( eckart and genzel 1997 ; ghez et al .
this source is surrounded by diffuse ionized gas as well as clusters of hot and cool stars seen in near - ir wavelengths ..
Please generate the next two sentences of the article
|
detailed comparison of radio and near - ir images was recently made with a new approach by menten et al .
( 1997 ) , who detected a number of sio ( 0.7 cm ) and h@xmath11o ( 1.3 cm ) masers associated with known compact stellar sources seen in the diffraction limited 2.2 @xmath12 m infrared images .
|
12,592 |
Suppose that you have an abstract for a scientific paper: water is a complex structured liquid of hydrogen - bonded molecules that displays a surprising array of unusual properties , also known as water anomalies , the most famous being the density maximum at about @xmath0c .
the origin of these anomalies is still a matter of debate , and so far a quantitative description of water s phase behavior starting from the molecular arrangements is still missing .
here we provide its simple physical description from microscopic data obtained through computer simulations .
we introduce a novel structural order parameter , which quantifies the degree of translational order of the second shell , and show that this parameter alone , which measures the amount of locally favored structures , accurately characterizes the state of water .
a two - state modeling of these microscopic structures is used to describe the behavior of liquid water over a wide region of the phase diagram , correctly identifying the density and compressibility anomalies , and being compatible with the existence of a second critical point in the deeply supercooled region .
furthermore , we reveal that locally favored structures in water not only have translational order in the second shell , but also contain five - membered rings of hydrogen - bonded molecules .
this suggests their mixed character : the former helps crystallization , whereas the latter causes frustration against crystallization . .
And you have already written the first three sentences of the full article: the anomalous thermodynamic and kinetic behavior of water is known to play a fundamental role not only in many physical and chemical processes in materials science , but also in biological , geological and terrestrial processes in nature @xcite .
for this reason , a lot of effort has been devoted to rationalizing water s anomalous behavior in a coherent and simple physical picture , but no consensus has yet emerged .
one of the breakthroughs in this endeavor was the discovery of water s polyamorphism , i.e. the existence of amorphous coexisting phases in the supercooled region of the phase diagram ..
Please generate the next two sentences of the article
|
distinct states have indeed been found in glassy water , called low - density ( lda ) , high - density ( hda ) and very high - density ( vhda ) @xcite amorphous ices , which can interconvert with each other by the application of pressure .
it is believed that the transition between the amorphous ices connects to a liquid - liquid first - order phase transition line above the glass transition temperature ( @xmath1 ) , and terminates at a critical point @xcite , but the fundamental nature of this transition is still being debated @xcite .
|
12,593 |
Suppose that you have an abstract for a scientific paper: we present a simple mass model for the lensing galaxy in the gravitationally lensed quasar 0957 + 561 .
we represent the galaxy as a softened power - law sphere ( spls ) , a generalization of the singular isothermal sphere with three parameters @xmath0 , the central density , @xmath1 , the angular core radius , and @xmath2 , the radial index which is defined such that mass increases as @xmath3 at large radius . as in previous studies we approximate the galaxy cluster surrounding the lensing galaxy by means of a quadratic potential described by its convergence @xmath4 and shear @xmath5 .
a feature of the model is that it does not require a large central compact mass .
we fit the model to a recent high resolution vlbi map of the two images of 0957 + 561 .
the data provide a number of independent constraints and the model - fit has six degrees of freedom , which is a significant improvement over previous models .
although the reduced @xmath6 of the best - fit model is only 4.3 , nevertheless we obtain a tight constraint on the radial index , @xmath7 , at the 95% confidence level .
thus , the galaxy has mass increasing slightly more rapidly than isothermal ( @xmath8 ) out to at least @xmath9 kpc .
since the light from the galaxy follows a de vaucouleurs profile , we deduce that the mass - to - light ratio of the galaxy increases rapidly with increasing radius .
we also obtain an upper limit on the core radius , namely @xmath10 or linear core radius @xmath11 pc .
we use the model to calculate the hubble constant @xmath12 as a function of the time delay @xmath13 between the two images .
we obtain @xmath14 once @xmath13 is measured , this will provide an upper bound on @xmath12 since @xmath4 can not be negative .
in addition , the model degeneracy due to @xmath4 can be eliminated if the one - dimensional velocity dispersion @xmath15 of the lensing galaxy is measured . in this case
we find that @xmath16 we find that these results are virtually unchanged when we investigate the....
And you have already written the first three sentences of the full article: although the magnification tensor is symmetric , the relative magnification tensor is not and thus will have four independent components .
it is customary to refer to the relative magnification tensor in terms of its eigenvalues @xmath69 and corresponding eigenvector position angles @xmath70 ( _ e.g. _ fgs ) . with unresolved images ,
it is not possible to measure the full relative magnification tensor ..
Please generate the next two sentences of the article
|
however , the flux ratio of the two images gives the magnitude of the determinant of @xmath71 $ ] .
observational constraints [ obscons ] image positions and magnifications [ imdat ] the highest - resolution images of 0957 + 561 have been obtained by means of radio vlbi . shortly after the discovery of the source , vlbi observations ( @xcite ) revealed similar core - jet structure in the radio components a and b , reinforcing the lensing hypothesis for the system .
|
12,594 |
Suppose that you have an abstract for a scientific paper: the quantification of quantum coherence has attracted a growing attention , and based on various physical contexts , several coherence measures have been put forward . an interesting question is whether these coherence measures give the same ordering when they are used to quantify the coherence of quantum states . in this paper
, we consider the two well - known coherence measures , the @xmath0 norm of coherence and the relative entropy of coherence , to show that there are the states for which the two measures give a different ordering .
our analysis can be extended to other coherence measures , and as an illustration of the extension we further consider the formation of coherence to show that the @xmath0 norm of coherence and the formation of coherence , as well as the relative entropy of coherence and the coherence of formation , do not give the same ordering too . .
And you have already written the first three sentences of the full article: quantum coherence is considered to be one of the most important resources in quantum physics .
it has many significant applications in various subjects , such as quantum optics @xcite , quantum information @xcite , quantum biology @xcite , and thermodynamics @xcite .
however , a general criterion to quantify the coherence of quantum states in information theoretic terms has only been proposed recently @xcite , although the topic has ever been attempted in early papers @xcite ..
Please generate the next two sentences of the article
|
the general criterion has triggered the community s great interest @xcite , and based on the criterion , various concrete measures of coherence have been given .
the @xmath0 norm of coherence and the relative entropy of coherence , which satisfy the general criterion of quantifying the coherence of quantum states , were first suggested as two coherence measures based on distance in ref.@xcite . the coherence measure based on skew information @xcite , and the coherence measure based on entanglement @xcite
|
12,595 |
Suppose that you have an abstract for a scientific paper: we predict and theoretically investigate the new coherent effect of nonlinear quantum optics spatial propagation of rabi oscillations ( rabi waves ) in one - dimensional quantum dot ( qd ) chain .
qd - chain is modeled by the set of two - level quantum systems with tunnel coupling between neighboring qds .
the space propagation of rabi waves in the form of traveling waves and wave packets is considered .
it is shown , that traveling rabi waves are quantum states of qd - chain dressed by radiation .
the dispersion characteristics of traveling rabi waves are investigated and their dependence on average number of photons in wave is demonstrated .
the propagation of rabi wave packets is accompanied by the transfer of the inversion and quantum correlations along the qd - chain and by the transformation of quantum light statistics .
the conditions of experimental observability are analyzed .
the effect can find practical use in quantum computing and quantum informatics . .
And you have already written the first three sentences of the full article: rabi oscillations are periodical transitions of a two - level quantum system between its stationary states under the action of an oscillatory driving field , see e.g. @xcite .
the phenomenon was theoretically predicted by rabi on nuclear spins in radio - frequency magnetic field @xcite and was firstly observed by torrey @xcite .
afterwards , rabi oscillations were discovered in various physical systems , such as electromagnetically driven atoms@xcite ( including the case of rydberg atomic states @xcite ) , semiconductor quantum dots ( qds ) @xcite , and different types of solid - state qubits ( superconducting charge qubits based on josephson junctions @xcite , spin - qubits @xcite , semiconductor charge - qubits @xcite ) . in real physical systems the ideal picture @xcite of rabi effect can be essentially modified by additional features , such as the time - domain modulation of the field - matter coupling constant @xcite , the phonon - induced dephasing @xcite and the local - field effects @xcite ..
Please generate the next two sentences of the article
|
new phenomena appear in rabi oscillators with broken inversion symmetry @xcite and in systems of two coupled rabi oscillators @xcite . in spatially extensive samples with a large number of oscillators
the propagation effects come into play . as a result ,
|
12,596 |
Suppose that you have an abstract for a scientific paper: we report on an ongoing investigation into a seismic calibration of solar models designed for estimating the main - sequence age and a measure of the chemical abundances of the sun
. only modes of low degree are employed , so that with appropriate modification the procedure could be applied to other stars .
we have found that , as has been anticipated , a separation of the contributions to the seismic frequencies arising from the relatively smooth , glitch - free , background structure of the star and from glitches produced by helium ionization and the abrupt gradient change at the base of the convection zone renders the procedure more robust than earlier calibrations that fitted only raw frequencies to glitch - free asymptotics . as in the past , we use asymptotic analysis to design seismic signatures that are , to the best of our ability , contaminated as little as possible by those uncertain properties of the star that are not directly associated with age and chemical composition . the calibration itself , however , employs only numerically computed eigenfrequencies .
it is based on a linear perturbation from a reference model .
two reference models have been used , one somewhat younger , the other somewhat older than the sun .
the two calibrations , which use bison data , are more - or - less consistent , and yield a main - sequence age @xmath0gy , coupled with a formal initial heavy - element abundance @xmath1 .
the error analysis has not yet been completed , so the estimated precision must be taken with a pinch of salt . .
And you have already written the first three sentences of the full article: the only way by which the age of the sun can be estimated to a useful degree of precision is by accepting the basic tenets of solar - evolution theory and measuring those aspects of the structure of the sun that are predicted by the theory to be indicators of age .
the structure measurements must be carried out seismologically , and evidently one expects greatest reliability of the results when all the available helioseismic data are employed . however , the most relevant modes are those of lowest degree , because it is they that penetrate most deeply into the energy - generating core where the relic helium - abundance variation records the integrated history of nuclear transmutation .
moreover , it is also only they that can be measured in other stars ..
Please generate the next two sentences of the article
|
therefore , there has been some interest in calibrating theoretical stellar models using only low - degree modes .
the prospect was first discussed in detail by ( * ? ? ?
|
12,597 |
Suppose that you have an abstract for a scientific paper: we use the theory of poset resolutions to give an alternate construction for the minimal free resolution of an arbitrary stable monomial ideal in the polynomial ring whose coefficients are from a field .
this resolution is recovered by utilizing a poset of eliahou - kervaire admissible symbols associated to a stable ideal .
the structure of the poset under consideration is quite rich and in related analysis , we exhibit a regular cw complex which supports a minimal cellular resolution of a stable monomial ideal .
[ intheorem]lemma [ intheorem]proposition [ intheorem]corollary [ intheorem]definition [ intheorem]remark [ intheorem]notation [ equation]theorem [ equation]lemma [ equation]proposition [ equation]corollary [ equation]observation [ equation]conjecture [ equation]fact [ equation]example [ equation]definition [ equation]remark [ equation]remarks [ equation]notation .
And you have already written the first three sentences of the full article: let @xmath0}$ ] , where @xmath1 is a field and @xmath2 is considered with its standard @xmath3 grading ( multigrading ) .
a monomial ideal @xmath4 is called _ stable _ if for every monomial @xmath5 , the monomial @xmath6 for each @xmath7 , where @xmath8 .
the class of stable ideals , introduced by eliahou and kervaire in @xcite is arguably the most well - studied class of monomial ideals . in their work ,.
Please generate the next two sentences of the article
|
eliahou and kervaire construct the minimal free resolution of an arbitrary stable monomial ideal by identifying basis elements of the free modules present in the resolution which they call admissible symbols and by describing how the maps within the resolution act on these admissible symbols . among others ,
the class of stable ideals contains the so - called borel - fixed @xcite ideals as a subclass , which are fundamental to grbner basis theory .
|
12,598 |
Suppose that you have an abstract for a scientific paper: massive galaxies at higher redshifts ( @xmath0 @xmath1 2 ) show different characteristics from their local counterparts : they are compact and most likely have a disk . in this study , we trace the evolution of local massive galaxies by performing a detailed morphological analysis , namely , fitting single srsic profiles and performing bulge+disk decompositions .
we analyze @xmath2 250 massive galaxies selected from all candels fields ( cosmos , uds , egs , goods - south and goods - north ) .
we confirm that both star - forming and quiescent galaxies increase their sizes significantly from @xmath0 @xmath3 2.5 to the present day .
the global srsic index of quiescent galaxies increases over time ( from @xmath4 @xmath3 2.5 to @xmath4 @xmath1 4 ) , while that of star - forming galaxies remains roughly constant ( @xmath4 @xmath3 2.5 ) . by decomposing galaxy profiles into bulge+disk components
, we find that massive galaxies at high redshift have prominent stellar disks , which are also evident from visual inspection of the images .
by @xmath5 @xmath3 0.5 , the majority of the disks disappear and massive quiescent galaxies begin to resemble the local elliptical galaxies .
star - forming galaxies have lower bulge - to - total ratios ( @xmath6 ) than their quiescent counterparts at each redshift bin .
the bulges of star - forming and quiescent galaxies follow different evolutionary histories , while their disks evolve similarly .
based on our morphological analysis and previous cosmological simulations , we argue that major mergers , along with minor mergers , have played a crucial role in the significant size increase of high-_z _ galaxies and the destruction of their massive and large - scale disks . .
And you have already written the first three sentences of the full article: several studies have shown that at _ z _ @xmath3 2 a considerable fraction of the massive galaxies ( stellar mass @xmath7 @xmath3 10@xmath8 @xmath9 ) are compact compared to their local counterparts ( e.g. , @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ) .
the rarity of compact massive galaxies at the present time implies a considerable size increase in the last 10 billion years ( @xcite ; @xcite ; @xcite ; @xcite ; but see @xcite ; @xcite ; @xcite ; @xcite ) .
recent comprehensive simulations have found that the commonly used methods for measuring the sizes of these galaxies , such as fitting single - component srsic ( 1968 ) function , is reliable ( e.g. , @xcite ; @xcite ; davari et al ..
Please generate the next two sentences of the article
|
2016 ) , despite the fact that , in many instances , their sizes are comparable to the scale of the _ hubble space telescope ( hst ) _ point - spread function ( psf ) .
the compactness of high-_z _ massive galaxies strongly suggests that their formation process involved strong dissipation on rapid timescales ( e.g. , @xcite ) .
|
12,599 |
Suppose that you have an abstract for a scientific paper: in this work we consider the fucik problem for a family of weights depending on @xmath0 with dirichlet and neumann boundary conditions .
we study the homogenization of the spectrum .
we also deal with the special case of periodic homogenization and we obtain the rate of convergence of the first non - trivial curve of the spectrum . .
And you have already written the first three sentences of the full article: given a bounded domain @xmath1 in @xmath2 , @xmath3 we study the asymptotic behavior as @xmath4 of the spectrum of the following asymmetric elliptic problem @xmath5 either with homogeneous dirichlet or neumann boundary conditions . here , @xmath6 is the @xmath7laplacian with @xmath8 and @xmath9 . the parameters @xmath10 and @xmath11 are reals and depending on @xmath12 .
we assume that the family of weight functions @xmath13 and @xmath14 are positive and uniformly bounded away from zero . for a moment
let us focus problem for fixed @xmath12 with positive weights @xmath15 : @xmath16 with dirichlet or neumann boundary conditions ..
Please generate the next two sentences of the article
|
consider the fucik spectrum defined as the set @xmath17 let us observe that when @xmath18 and @xmath19 , equation becomes @xmath20 with dirichlet or neumann boundary conditions , which is the eigenvalue problem for the @xmath7laplacian . these has been widely studied .
see for instance @xcite for more information .
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.