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7,400 | Suppose that you have an abstract for a scientific paper: cd(se , te ) quantum dots ( qd ) in znse barrier typically exhibit a very high spectral density , which precludes investigation of single dot photoluminescence .
we design , grow and study individual cd(se , te)/znse qds of low spectral density of emission lines achieved by implementation of a mn - assisted epitaxial growth .
we find an unusually large variation of exciton - biexciton energy difference ( 3 mev @xmath0 @xmath1 @xmath0 26 mev ) and of exciton radiative recombination rate in the statistics of qds .
we observe a strong correlation between the exciton - biexciton energy difference , exciton recombination rate , splitting between dark and bright exciton , and additionally the exciton fine structure splitting @xmath2 and land factor . above results
indicate that values of the @xmath2 and of the land factor in the studied qds are dictated primarily by the electron and hole respective spatial shift and wavefunctions overlap , which vary from dot to dot due to a different degree of localization of electrons and holes in , respectively , cdse and cdte rich qd regions . .
And you have already written the first three sentences of the full article: three dimensional quantum confinement of electrons ( _ e _ ) and holes ( _ h _ ) , such as in a semiconductor quantum dot ( qd ) potential , results in a variety of effects resulting from a discrete energy levels structure and an increased overlap between the _ e _ and _ h_. typically , a qd and a surrounding barrier are made of materials sharing a common cation , to recall example of inas / gaas , cdte / znte or cdse / znse qds .
the qds for which the qd and the barrier materials have no common atom are by far less investigated , despite of several advantages they offer . in the case of such qds with type - i confinement
one should mention here larger band offsets providing higher confining potentials for both , _ e _ and _ h_. such mixed structures may lead also to type - ii confinement , with a decreased wavefunction overlap of the confined _ e _ and _ h_. such increased _ e - h _ spatial separation and resulting enhancement of confined carriers lifetimes is highly attractive for studies of magnetic polaron in semimagnetic qds@xcite or aharonov - bohm effect,@xcite as well as for implementation of qds in photovoltaic devices@xcite ..
Please generate the next two sentences of the article | the intermediate case between type - i and type - ii confinement , as in the present study , offers a chance of investigation of the impact of _ e _ and _ h _ wavefunctions overlap on properties of excitonic qds emission . in the present work , we design , produce and study individual cd(se , te ) qds embedded in znse barrier .
any composition gradient within the cd(se , te ) qd volume results in a decreased spatial overlap of wavefunctions of the _ e _ and _ h _ , due to localization of the _ e _ and _ h _ in regions , which are richer , respectively , in cdte and cdse ( see figure [ fig : bands ] providing a scheme of respective band alignments ) . |
7,401 | Suppose that you have an abstract for a scientific paper: constrained clustering has been well - studied for algorithms such as @xmath0-means and hierarchical clustering .
however , how to satisfy many constraints in these algorithmic settings has been shown to be intractable .
one alternative to encode many constraints is to use spectral clustering , which remains a developing area . in this paper
, we propose a flexible framework for constrained spectral clustering .
in contrast to some previous efforts that implicitly encode must - link and cannot - link constraints by modifying the graph laplacian or constraining the underlying eigenspace , we present a more natural and principled formulation , which explicitly encodes the constraints as part of a constrained optimization problem .
our method offers several practical advantages : it can encode the degree of belief in must - link and cannot - link constraints ; it guarantees to lower - bound how well the given constraints are satisfied using a user - specified threshold ; it can be solved deterministically in polynomial time through generalized eigendecomposition .
furthermore , by inheriting the objective function from spectral clustering and encoding the constraints explicitly , much of the existing analysis of unconstrained spectral clustering techniques remains valid for our formulation .
we validate the effectiveness of our approach by empirical results on both artificial and real datasets .
we also demonstrate an innovative use of encoding large number of constraints : transfer learning via constraints . .
And you have already written the first three sentences of the full article: spectral clustering is an important clustering technique that has been extensively studied in the image processing , data mining , and machine learning communities ( @xcite ) .
it is considered superior to traditional clustering algorithms like @xmath0-means in terms of having deterministic polynomial - time solution , the ability to model arbitrary shaped clusters , and its equivalence to certain graph cut problems .
for example , spectral clustering is able to capture the underlying moon - shaped clusters as shown in fig ..
Please generate the next two sentences of the article | [ fig : two_moon](b ) , whereas @xmath0-means would fail ( fig .
[ fig : two_moon](a ) ) . |
7,402 | Suppose that you have an abstract for a scientific paper: the semiclassical trace formula provides the basic construction from which one derives the semiclassical approximation for the spectrum of quantum systems which are chaotic in the classical limit .
when the dimensionality of the system increases , the mean level spacing decreases as @xmath0 , while the semiclassical approximation is commonly believed to provide an accuracy of order @xmath1 , _ independently _ of @xmath2 .
if this were true , the semiclassical trace formula would be limited to systems in @xmath3 only . in the present work we set about to define proper measures of the semiclassical spectral accuracy , and to propose theoretical and numerical evidence to the effect that the semiclassical accuracy , measured in units of the mean level spacing , depends only weakly ( if at all ) on the dimensionality .
detailed and thorough numerical tests were performed for the sinai billiard in @xmath4 and @xmath5 dimensions , substantiating the theoretical arguments . .
And you have already written the first three sentences of the full article: the semiclassical analysis has proven to be a very useful tool in the field of `` quantum chaos '' as well as in many other fields .
nevertheless , one should bear in mind , that it only _ approximates _ the true quantal solution .
thus , it is imperative to know what are the _ errors _ which are inherent to the semiclassical approximation , and whether they could be considered as sufficiently small for the problem at hand ..
Please generate the next two sentences of the article | we shall focus our attention on one particular application of the semiclassical approximation : the calculation of the energy spectra of classically chaotic systems .
the analytical tool that is used for this purpose is the semiclassical gutzwiller trace formula @xcite which expresses the _ quantum _ spectral density in terms of _ classical _ quantities , and in particular the actions and stabilities of classical periodic orbits . |
7,403 | Suppose that you have an abstract for a scientific paper: massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems .
the latter aspect is important for populations of massive stars as more than @xmath0 of all o - stars are expected to interact with a binary companion during their lifetime .
we show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters which can be used to infer their ages and to identify products of binary evolution .
we model the observed present day mass functions of the young galactic arches and quintuplet star clusters using our rapid binary evolution code .
we find that shaping of the mass function by stellar wind mass loss allows us to determine the cluster ages to @xmath1 and @xmath2 , respectively .
exploiting the effects of binary mass exchange on the cluster mass function , we find that the most massive stars in both clusters are rejuvenated products of binary mass transfer , i.e. the massive counterpart of classical blue straggler stars .
this resolves the problem of an apparent age spread among the most luminous stars exceeding the expected duration of star formation in these clusters .
we perform monte carlo simulations to probe stochastic sampling , which support the idea of the most massive stars being rejuvenated binary products .
we find that the most massive star is expected to be a binary product after @xmath3 in arches and after @xmath4 in quintuplet .
today , the most massive @xmath5 stars in arches and @xmath6 in quintuplet are expected to be such objects .
our findings have strong implications for the stellar upper mass limit and solve the discrepancy between the claimed @xmath7 limit and observations of fours stars with initial masses of @xmath8@xmath9 in r136 and of sn 2007bi , which is thought to be a pair - instability supernova from an initial @xmath10 star . using the stellar population of r136 ,
we revise the upper mass limit to values in the range @xmath11@xmath12 . .
And you have already written the first three sentences of the full article: massive stars play a key role in our universe .
they drive the chemical evolution of galaxies by synthesising most of the heavy elements . their strong stellar winds , radiation feedback , powerful supernova explosions and long gamma ray bursts shape the interstellar medium .
they are thought to have played an essential role in reionising the universe after the dark ages and are visible up to large distances ..
Please generate the next two sentences of the article | unfortunately , our understanding of the formation and evolution of the most massive stars in the local universe is incomplete .
recently it was established that most of the massive stars in the milky way are actually part of a binary star system and that more than @xmath0 of them will exchange mass with a companion during their life @xcite . |
7,404 | Suppose that you have an abstract for a scientific paper: we report the experimental observation of the collective excitations induced in a magnetically trapped @xmath0rb bose - einstein condensate .
low - lying mode excitations were studied by tracking the condensate s center - of - mass displacement , and its aspect ratio as a function of the hold time in the trap .
we were able to partially control the modes onset by modulating the amplitude of the additional field gradient used to excite the bec .
the measured excitation frequencies were found to be in good agreement with the literature .
we have also found that the modulation amplitude was able to change the phase of the center - of - mass oscillation . finally , an interesting , non - linear dependence was observed on the condensate aspect ratio as a function of the perturbing amplitude which induces the quadrupolar mode . .
And you have already written the first three sentences of the full article: dilute bose - einstein condensates ( becs ) are produced and probed using atomic physics tools @xcite , and their connection to condensed - matter physics is most clear when studying collective excitations @xcite , as well as the sound propagation @xcite .
much of our understanding of the nature of sound in quantum fluids comes from studies carried out in liquid helium @xcite .
recently , with gaseous condensates , the researchers have turned to these decades - old theories from condensed matter physics to test their validity thoroughly and very successfully @xcite ..
Please generate the next two sentences of the article | nowadays , these versatile experimental system are even being used as fast complex hamiltonian solvers , which may provide `` on demand '' solutions to particular interesting problems in condensed matter physics .
the nature of collective excitations in a homogeneous bose gas depends on the hierarchy of three length scales : the excitation reduced wavelength , @xmath1 ; the healing length , @xmath2 ; and the mean free path for collisions , @xmath3 . in a inhomogeneous bose trapped gas , |
7,405 | Suppose that you have an abstract for a scientific paper: helium line observations towards 11 galactic positions using westerbork synthesis radio telescope(wsrt ) have been reported .
these observations were made towards nearby positions where already hydrogen lines were detected at sufficiently high intensity(@xmath050mk ) at 1.4 ghz .
this approach gave a fair chance for the detection of helium line as well , keeping in mind the relative abundance(10 % ) of helium with respect to hydrogen .
care was also taken to avoid the presence of hii regions along the line of sight so that the line emission originates from the extended diffuse low density ionized component , eldwim of the galaxy .
the observations have resulted in the detection of helium line towards 5 positions out of 11 with signal to noise ratio(snr ) @xmath1 4@xmath2 .
an attempt has been made to associate detection / non - detection of helium line to the presence of surrounding hii regions .
a weighting scheme that accounts for nearby(@xmath3 500pc ) hii regions , their distances and other factors produces favourable results .
it is seen from this weighting scheme that a higher weight favours the detection of helium line while lower weight is associated with non - detection .
the idea is to correlate ionization of eldwim with the surrounding hii regions .
[ firstpage ] .
And you have already written the first three sentences of the full article: the presence of a diffuse extended low density warm ionized medium(eldwim ) within the inner galaxy has been established by low frequency(@xmath32ghz ) radio recombination line(rrl or rl for short ) observations(lockman 1976 ; mezger 1978 ; ananatharamaiah 1985 ) .
this component is understood to have a typical electron density @xmath4 of @xmath5 at temperatures of @xmath6 k. the eldwim was first considered by mezger(1978 ) who called it as the `` extended low density fully ionized gas '' which extends from the galactic center to 13kpc and 100pc above and below the galactic plane
. however continuum radiation from this particular medium was first discovered by westerhout(1958 ) in his dwingeloo survey , who also calculated the corresponding upper limits on density and total mass of ionized hydrogen in the galaxy ..
Please generate the next two sentences of the article | later investigators have chosen to call this component as extended low density warm ionized medium(petuchowski & bennett 1993 , heiles 1994 ) .
the recent estimated densities of eldwim are @xmath5(murray & rahaman 2010 ) with temperatures of the order of 3000 - 8000k . |
7,406 | Suppose that you have an abstract for a scientific paper: in this paper , we study the price responsiveness of electricity consumption from empirical commercial and industrial load data obtained from texas . employing a dynamical system perspective
, we show that price responsive demand can be modeled as a hybrid of a hammerstein model with delay following a price surge , and a linear arx model under moderate price changes .
it is observed that electricity consumption therefore has unique characteristics including ( 1 ) qualitatively distinct response between moderate and extremely high prices ; and ( 2 ) a time delay associated with the response to high prices .
it is shown that these observed features may render traditional approaches to demand response and retail pricing based on classical economic theories ineffective .
in particular , ultimate real - time retail pricing may be limitedly beneficial than as considered in classical economic theories .
demand response , electricity market , dynamic system modeling . .
And you have already written the first three sentences of the full article: , response to the emerging carbon emissions constrained world , the usage of renewable energy sources is increasing . the overall increase in penetration of renewable energy resources in the u.s .
is depicted in fig .
[ fig : renewablepercentage ] ..
Please generate the next two sentences of the article | such growth of renewable energy resource is not limited to the u.s .
globally , installed global renewable electricity capacity has continued to increase and represented 28.5% of total electricity capacity in 2014 @xcite @xcite . |
7,407 | Suppose that you have an abstract for a scientific paper: the scale factor @xmath0 , which characterizes double parton collisions in high energy hadron interactions , is a direct manifestation of the distribution of the interacting partons in transverse space , in such a way that different distributions give rise to different values of @xmath0 in different double parton collision processes .
we work out the value of the scale factor in a few reactions of interest , in a correlated model of the multi - parton density of the proton recently proposed .
e - mail [email protected] + e - mail [email protected] + .
And you have already written the first three sentences of the full article: double parton collisions are a new feature of high energy hadron interactions which becomes increasingly important at high energies .
the number of partons that can undergo a hard collision is in fact a fast growing function of @xmath1 and , as a consequence , when the c.m .
energy is large enough , the probability of having more than one hard partonic interaction in the same inelastic event becomes sizable ..
Please generate the next two sentences of the article | double parton collisions , foreseen long ago by several authors@xcite , have been in fact observed recently by cdf@xcite .
the non - perturbative input to the double parton collisions are the double parton distributions , which are independent on the parton distributions usually considered in large@xmath2 physics , since they are related directly to the two - body parton correlation of the hadron structure . in the simplified hypothesis of neglecting all correlations in fractional momenta , the inclusive double parton scattering cross section for the two parton processes @xmath3 and @xmath4 reduces nevertheless to a simplest factorized expression : @xmath5 where @xmath6 when @xmath3 and @xmath4 are indistinguishable processes and @xmath7 when they are distinguishable . @xmath8 and @xmath9 are the inclusive single scattering cross sections for producing the processes @xmath3 and @xmath4 respectively and all the new information on the structure of the hadron in transverse space is summarized in the value of the scale factor @xmath0 . |
7,408 | Suppose that you have an abstract for a scientific paper: a solution to the coincidence and big rip problems on the bases of an anisotropic space - time is proposed .
to do so , we study the interaction between viscous dark energy and dark matter in the scope of the bianchi type - i universe .
we parameterize the viscosity and the interaction between the two fluids by constants @xmath0 and @xmath1 respectively .
a detailed investigation on the cosmological implications of this parametrization has been made .
we have also performed a geometrical diagnostic by using the statefinder pairs @xmath2 and @xmath3 in order to differentiate between different dark energy models .
moreover , we fit the coupling parameter @xmath1 as well as the hubble s parameter @xmath4 of our model by minimizing the @xmath5 through the age differential method , involving a direct measurement of @xmath6 .
+ + + pacs numbers : 98.80.es , 98.80-k , 95.36.+x + key words : bianchi type - i model , dark energy , statefinder .
And you have already written the first three sentences of the full article: the fact that we live in an accelerating expanding universe is a well established reality today .
the direct evidence of such an accelerating expansion of the universe first published by the high - z supernova search teams ( riess et al .
1998 ; perlmutter et al . 1999 ) in 1998 and early 1999 ..
Please generate the next two sentences of the article | later on , some other observations such as measurements of cosmic microwave background ( miller et al . 1999 ; bernardis et al . 2000 ; halverson et al .
2002 ; benoit et al . 2003 ; mason et al . 2003 ) and the galaxy power spectrum ( spergal et al . 2003 ; tegmark et al . 2004 ; page et al . 2003 ) indicate that the expansion of our universe is speeding up currently . |
7,409 | Suppose that you have an abstract for a scientific paper: recent observations show that the oh 1720 mhz maser is a powerful probe of the shocked region where a supernova remnant strikes a molecular cloud .
we perform a thorough study of the pumping of this maser and find tight constraints on the physical conditions needed for its production .
the presence of the maser implies moderate temperatures ( 50 125 k ) and densities ( 5 ) , and oh column densities of order @xmath0 .
we show that these conditions can exist only if the shocks are of c - type .
j - shocks fail by such a wide margin that the presence of this maser could become the most powerful indicator of c - shocks .
these conditions also mean that the 1720 mhz maser will be inherently weak compared to the other ground state oh masers .
all the model predictions are in good agreement with the observations .
# 1 .
And you have already written the first three sentences of the full article: the ground state maser lines of the oh molecule have long been important sources of information about the regions in which they are formed .
the main lines at 1665 and 1667 mhz and the satellite line at 1612 mhz have been widely observed in star forming regions and the envelopes of late - type stars .
the satellite line at 1720 mhz has been the least commonly observed and has received the least attention until recently ..
Please generate the next two sentences of the article | however , the 1720 mhz maser is now known to be an important indicator of interactions between supernova remnants and molecular clouds .
this connection was first suggested by goss & robinson ( 1968 ) , who noted a new class of 1720 mhz masers in the supernova remnants ( snr ) w28 and w44 . |
7,410 | Suppose that you have an abstract for a scientific paper: in this publication a microscopic theory for the coupling of intrinsic josephson oscillations in layered superconductors with longitudinal c - axis - phonons is developed .
it is shown that the influence of lattice vibrations on the @xmath0-axis transport can be fully described by introducing an effective longitudinal dielectric function @xmath1 .
resonances in the @xmath2-@xmath3-characteristic appear at van hove singularities of both acoustical and optical longitudinal phonon branches .
this provides a natural explanation of the recently discovered subgap structures in the @xmath2-@xmath3-characteristic of highly anisotropic cuprate superconductors .
the effect of the phonon dispersion on the damping of these resonances and the coupling of josephson oscillations in different resistive junctions due to phonons are discussed in detail . .
And you have already written the first three sentences of the full article: the @xmath0-axis transport in the highly anisotropic cuprate superconductors tl@xmath4ba@xmath4ca@xmath4cu@xmath5o@xmath6 ( tbcco ) and bi@xmath4sr@xmath4cacu@xmath4o@xmath7 ( bscco ) can well be described by a stack of josephson junctions between the superconducting cuo@xmath4-multi - layers .
this intrinsic josephson effect can be seen in the multi - branch structure of the @xmath2-@xmath3 characteristic , each branch corresponding to a well - defined number of junctions in the resistive state.@xcite the intrinsic josephson effect is observed also in the behaviour of the material in external magnetic fields and under microwave irradiation.@xcite recently subgap structures in the @xmath2-@xmath3-characteristic have been discovered as intrinsic properties of the material,@xcite which could be explained by the coupling between the intrinsic josephson oscillations and phonons.@xcite this interaction is mediated by the oscillating electric field in the josephson junction , which excites vibrations of charged ions in the material . in our previous investigations @xcite
we used a simple model of a system of damped harmonic oscillators in order to describe the dynamics of oscillating ions in the barrier ..
Please generate the next two sentences of the article | we were able to derive an analytic expression for the dc - current density @xmath8 as function of the dc - voltage @xmath3 for one resistive junction @xmath9 where the voltage @xmath3 is related to the josephson oscillation frequency @xmath10 by @xmath11 and @xmath12 is the dielectric function of the oscillating ions . from this result
it can be seen that the @xmath2-@xmath3-curve has a maximum at the frequency ( voltage ) where the real part @xmath13 of the phonon - dielectric function vanishes , which corresponds to a longitudinal eigenfrequency of the phonon system . with appropriate values for the josephson plasma freqency @xmath14 , the quasiparticle conductivity @xmath15 , the critical current denstiy @xmath16 , and the frequencies , dampings and oscillator strengths of phonons in the dielectric function we were able to fit the experimental results for the sub - gap structures in the @xmath2-@xmath3-curves perfectly . |
7,411 | Suppose that you have an abstract for a scientific paper: ic10 is the nearest starburst galaxy , as revealed both by its h@xmath0 surface brightness and the large number of wolf - rayet stars ( wrs ) per unit area .
the relative number of known wc- to wn - type wrs has been thought to be unusually high ( @xmath1 ) , unexpected for ic10 s metallicity . in this _
letter _ we report the first results of a new and deeper survey for wrs in ic10 .
we sucessfully detected all of the spectroscopically known wrs , and based upon comparisons with a neighboring control field , estimate that the total number of wrs in ic10 is about 100 .
we present spectroscopic confirmation of two of our wr candidates , both of which are of wn type .
our photometric survey predicts that the actual wc / wn ratio is @xmath2 .
this makes the wc / wn ratio of ic 10 consistent with that expected for its metallicity , but greatly increases the already unusually high number of wrs , resulting in a surface density that is about 20 times higher than in the lmc .
if the majority of these candidates are spectroscopically confirmed , ic10 must have an exceptional population of high mass stars . .
And you have already written the first three sentences of the full article: mayall ( 1935 ) first recognized ic10 as an extragalactic object , and , in _ the realm of the nebula , _ hubble ( 1936 ) proposed that it was likely a member of the local group .
its location just 3 degrees out of the galactic plane has hampered investigations , but hubble s description of it as one of the most curious objects in the sky " has proven prophetic .
today ic10 is understood to be an irregular galaxy undergoing an intense burst of star formation likely triggered by infalling gas from an extended cloud which is counter - rotating with respect to the galaxy proper , as discussed by wilcots & miller ( 1998 ) , who conclude that ic10 is a galaxy that is still forming ..
Please generate the next two sentences of the article | the starburst nature of ic10 was revealed primarily from the high number of wolf - rayet stars ( wrs ) found by massey , conti & armandroff ( 1992 ) and massey & armandroff ( 1995 ) .
hodge & lee ( 1990 ) had motivated these studies by their discovery of 144 h ii regions , the brightest of which were known to be comparable to the brightest seen in the smc ( hunter & gallagher 1985 ; kennicutt 1988 ) , a galaxy known to contain a substantial massive star population . |
7,412 | Suppose that you have an abstract for a scientific paper: along cuspidal edge singularities on a given surface in euclidean 3-space @xmath0 , which can be parametrized by a regular space curve @xmath1 , a unit normal vector field @xmath2 is well - defined as a smooth vector field of the surface .
a cuspidal edge singular point is called _ generic _ if the osculating plane of @xmath1 is not orthogonal to @xmath2 .
this genericity is equivalent to the condition that its limiting normal curvature @xmath3 takes a non - zero value . in this paper , we show that a given generic ( real analytic ) cuspidal edge @xmath4 can be isometrically deformed preserving @xmath3 into a cuspidal edge whose singular set lies in a plane . such a limiting cuspidal edge is uniquely determined from the initial germ of the cuspidal edge . .
And you have already written the first three sentences of the full article: let @xmath5 be a 2-manifold .
a singular point @xmath6 of a @xmath7-map germ @xmath8 is a _
cuspidal edge _.
Please generate the next two sentences of the article | if @xmath4 at @xmath9 is right - left equivalent to @xmath10 at the origin .
recently , the differential geometry of co - rank one singularities ( including cuspidal edges ) on surfaces was discussed by several geometers ( @xcite ) . in particular , in @xcite , isometric deformations of a special class of cross caps were discussed . relating to this , |
7,413 | Suppose that you have an abstract for a scientific paper: we introduce , for the first time , a new class of birnbaum saunders nonlinear regression models potentially useful in lifetime data analysis .
the class generalizes the regression model described by rieck and nedelman [ 1991 , a log - linear model for the birnbaum saunders distribution , _ technometrics _ , * 33 * , 5160 ] .
we discuss maximum likelihood estimation for the parameters of the model , and derive closed - form expressions for the second - order biases of these estimates .
our formulae are easily computed as ordinary linear regressions and are then used to define bias corrected maximum likelihood estimates .
some simulation results show that the bias correction scheme yields nearly unbiased estimates without increasing the mean squared errors .
we also give an application to a real fatigue data set .
bias correction , birnbaum saunders distribution , maximum likelihood estimation , nonlinear regression . .
And you have already written the first three sentences of the full article: different regression models have been proposed for lifetime data such as those based on the gamma , lognormal and weibull distributions .
these models typically provide a satisfactory fit in the middle portion of the data , but very often fail to deliver a good fit at the tails , where only a few observations are generally available .
the family of distributions proposed by birnbaum and saunders ( 1969 ) can also be used to model lifetime data and it is widely applicable to model failure times of fatiguing materials ..
Please generate the next two sentences of the article | this family has the appealing feature of providing satisfactory tail fitting .
this family of distributions was originally obtained from a model for which failure follows from the development and growth of a dominant crack . |
7,414 | Suppose that you have an abstract for a scientific paper: pressure and temperature dependent susceptibility and raman scattering experiments on single crystalline have shown an unusually strong increase of the spin - peierls phase transition temperature upon applying hydrostatic pressure .
the large positive pressure coefficient ( 7.5 k / gpa ) - almost twice as large as for the pure compound ( 4.5 k / gpa ) - is interpreted as arising due to an increasing magnetic frustration which decreases the spin - spin correlation length , and thereby weakens the influence of the non - magnetic zn - substitution . version 2(june 23 1997 ) printed on .
And you have already written the first three sentences of the full article: the spin - peierls ( sp ) transition@xcite in low dimensional magnetic compounds is the magnetic analog of the well known peierls transition@xcite in low dimensional metals .
the interest in this magneto - elastic phenomenon , which has been studied widely in organic compounds in the 1980s@xcite , has been strongly renewed with the discovery of inorganic materials ( @xcite , @xmath0-nav@xmath1o@xmath2 @xcite ) exhibiting this unusual phase transition .
in particular has attracted strong experimental and theoretical attention over the past few years@xcite ..
Please generate the next two sentences of the article | there are at least three reasons for this : in the first place allows for the growth of large single crystals which permits for experiments which were difficult to perform in the past .
secondly , allows for well controlled substitutions ( e.g. , ) which provides a useful method to study its structural , and in particular its magnetic properties . |
7,415 | Suppose that you have an abstract for a scientific paper: a @xmath0-sunflower in a hypergraph is a family of edges with @xmath0 vertices in common .
we show that if we colour the edges of a complete hypergraph in such a way that any monochromatic @xmath0-sunflower has at most @xmath1 petals , then it contains a large rainbow complete subhypergraph .
this extends a theorem by lefmann , rdl and wysocka , but this version can be applied to problems in geometry and algebra .
we also give an infinite version of the theorem . .
And you have already written the first three sentences of the full article: let @xmath2 be the complete @xmath3-hypergraph on @xmath4 . in other words ,
let @xmath4 be a set and @xmath5 , where @xmath6 represents the family of subsets of size @xmath3 of @xmath4 .
a _ colouring _ of @xmath7 is simply a function @xmath8 ..
Please generate the next two sentences of the article | we think of each @xmath9 as a colour , so @xmath10 has colour @xmath11 if @xmath12 .
if @xmath13 $ ] , then we call it a _ @xmath14-colouring_. a subset @xmath15 of @xmath4 is _ monochromatic _ if @xmath16 for some @xmath17 $ ] , and it is _ rainbow _ |
7,416 | Suppose that you have an abstract for a scientific paper: the results of a 7-epoch interferometric imaging study , at wavelengths in the near - infrared k - band , of the carbon star irc+10216 are presented .
the use of non- and partially - redundant aperture masking techniques on the 10-m keck - i telescope has allowed us to produce images of the innermost regions of the circumstellar dust envelope with unprecedented detail . with roughly twice the resolving power of previous work ( @xcite ;
@xcite ; @xcite ) , the complex asymmetric structures reported within the central have been imaged at the size scale of the stellar disk itself ( @xmath050mas ) . a prominent dark lane at a position angle of approximately @xmath1
is suggested to be an optically thick disk or torus of dust which could help to explain irc+10216 s well - known bipolarity at a position angle of @xmath2 .
observations spanning more than a pulsational cycle ( @xmath0638days ) have revealed significant temporal evolution of the nebula , including the outward motion of bright knots and clumps .
registering these displacements against the compact bright core , which we tentatively identify as marking the location of the star , has allowed us to determine the apparent angular velocity at a number of points .
the magnitudes of the proper motions were found to be in agreement with current estimates of the stellar distance and radial velocity .
higher outflow speeds were found for features with greater separation from the core .
this is consistent with acceleration taking place over the region sampled by the measurements , however alternate interpretations are also presented .
although a number of changes of morphology were found , none were clearly interpreted as the condensation of new dust over the pulsation cycle .
unfortunately , ambiguities associated with the true three - dimensional nature of the nebula weaken a number of our quantitative and qualitative conclusions . .
And you have already written the first three sentences of the full article: the extreme carbon star irc+10216 is a classic example of a red giant caught in the act of evolving into a planetary nebula .
its relative proximity , high infrared luminosity , and abundance of molecules found in its dense outflow has resulted in a barrage of observations by astronomers , working across the spectrum , but particularly in the infrared and millimeter / sub - millimeter . despite all this attention , a good model of what is happening in the innermost regions where
the stellar outflow is born and accelerated is still sorely lacking ..
Please generate the next two sentences of the article | numerous studies of molecular lines in the outer envelope ( e.g. @xcite ) have revealed a spherically expanding outflow , a finding which was beautifully confirmed with deep @xmath3 and @xmath4 band images of the dust shell in ambient scattered galactic light ( @xcite ) .
however this spherical symmetry , a characteristic of most red giant winds , will likely be broken as the irc+10216 evolves into a planetary nebula , most of which are elongated or bipolar ( e.g. @xcite ) . |
7,417 | Suppose that you have an abstract for a scientific paper: an analysis of high - resolution anglo - australian telescope ( aat)/ university college london chelle spectrograph ( ucls ) optical spectra for the ultraviolet ( uv)-bright star roa5701 in the globular cluster @xmath0 cen ( ngc5139 ) is performed , using non - local thermodynamic equilibrium ( non - lte ) model atmospheres to estimate stellar atmospheric parameters and chemical composition .
abundances are derived for c , n , o , mg , si and s , and compared with those found previously by moehler et al . we find a general metal underabundance relative to young b - type stars , consistent with the average metallicity of the cluster .
our results indicate that roa5701 has not undergone a gas dust separation scenario as previously suggested .
however , its abundance pattern does imply that roa5701 has evolved off the agb prior to the onset of the third dredge - up .
[ firstpage ] stars : abundances stars : agb and post - agb stars : early - type stars : individual : cl@xmath1ngc5139wor1957 globular clusters : individual : ngc5139 .
And you have already written the first three sentences of the full article: stars with initial masses between 0.8 and 8 m@xmath2 pass through the asymptotic giant branch ( agb ) phase of evolution , and undergo significant mass loss @xcite . evolving from the tip of the agb to the planetary nebula stage , stars move through the post - agb phase ( typically 10@xmath3
10@xmath4 years ) , during which the circumstellar dust shell moves away from the star and decreases in temperature , from @xmath5 400 to 100 k @xcite .
the properties of post - agb stars have been reviewed by , for example , @xcite and @xcite ..
Please generate the next two sentences of the article | this evolutionary phase is important as it provides an insight into nucleosynthesis and mixing processes during the later stages of stellar evolution .
most post - agb stars have been identified from their infrared excess ( e.g. , from _ iras _ observations ) , originating from the circumstellar dust shell . |
7,418 | Suppose that you have an abstract for a scientific paper: absorbers induce reddening on background quasars .
we measure this effect and infer the cosmic density of dust residing in these systems to be @xmath0 , in units of the critical density of the universe , which is comparable to the amount of dust found in galactic disks or about half the amount inferred to exist outside galaxies .
we also estimate the neutral hydrogen abundance in clouds to be @xmath1 , which is approximately 5% of hydrogen in stars in galaxies . this implies a dust - to - gas mass ratio for clouds of about @xmath2 , which is similar to the value for normal galaxies .
this would support the hypothesis of the outflow origin of clouds , which are intrinsically devoid of stars and hence have no sources of dust .
considerations of the dust abundance imply that the presence of absorbers around galaxies lasts effectively for a few gyr .
high redshift absorbers allow us to measure the rest - frame extinction curve to @xmath3 , at which the absorption by the lyman edge dominates over scattering by dust in the extinction opacity . .
And you have already written the first three sentences of the full article: a significant amount of gas processed by stars may be ejected into interstellar space via stellar winds and supernova explosions .
about 30% of the metals in enriched gas would condense to form dust grains @xcite .
the total amount of dust in the universe that is produced in stellar evolution in the entire cosmic time was estimated from integrated star formation rate by @xcite to be @xmath4 , in units of the present - day critical mass density ..
Please generate the next two sentences of the article | this value is a few times higher than the amount of dust observed in galactic disks @xcite , which motivated us to explore the fate of the remaining amount .
evidence for the existence of dust beyond galactic disks has observationally been suggested by a few authors . from the study of a low - redshift foreground / background galaxy superposition |
7,419 | Suppose that you have an abstract for a scientific paper: we demonstrate the accuracy of the hypernetted chain closure and of the mean - field approximation for the calculation of the fluid - state properties of systems interacting by means of bounded and positive - definite pair potentials with oscillating fourier transforms .
subsequently , we prove the validity of a bilinear , random - phase density functional for arbitrary inhomogeneous phases of the same systems . on the basis of this functional , we calculate analytically the freezing parameters of the latter .
we demonstrate explicitly that the stable crystals feature a lattice constant that is independent of density and whose value is dictated by the position of the negative minimum of the fourier transform of the pair potential .
this property is equivalent with the existence of clusters , whose population scales proportionally to the density .
we establish that regardless of the form of the interaction potential and of the location on the freezing line , all cluster crystals have a universal lindemann ratio @xmath0 at freezing .
we further make an explicit link between the aforementioned density functional and the harmonic theory of crystals .
this allows us to establish an equivalence between the emergence of clusters and the existence of negative fourier components of the interaction potential .
finally , we make a connection between the class of models at hand and the system of infinite - dimensional hard spheres , when the limits of interaction steepness and space dimension are both taken to infinity in a particularly described fashion . .
And you have already written the first three sentences of the full article: cluster formation in complex fluids is a topic that has attracted considerable attention recently.@xcite the general belief is that a short - range attraction in the pair interaction potential is necessary to initiate aggregation and a long - range repulsive tail in order to limit cluster growth and prevent phase separation .
an alternative scenario for cluster formation pertains to systems whose constituent particles interact by means of purely repulsive potentials .
cluster formation in this case is counterintuitive at first sight : why should particles form clusters if there is no attraction acting between them ?.
Please generate the next two sentences of the article | the answer lies in an additional property of the effective repulsion , namely that of being _ bounded _ , thus allowing full particle overlaps .
though surprising and seemingly unphysical at first , bounded interactions are fully legitimate and natural as effective potentials@xcite between polymeric macromolecular aggregates of low internal monomer concentration , such as polymers,@xcite dendrimers,@xcite microgels,@xcite or coarse - grained block copolymers.@xcite the growing interest in this type of effective interactions is also underlined by the recent mathematical proof of the existence of crystalline ground states for such systems.@xcite cluster formation in the fluid _ and _ in the crystal phases was explicitly seen in the system of penetrable spheres , following early simulation results@xcite and subsequent cell - model calculations.@xcite cluster formation was attributed there to the tendency of particles to create free space by forming full overlaps . |
7,420 | Suppose that you have an abstract for a scientific paper: we present a randomized distributed approximation algorithm for the metric uncapacitated facility location problem .
the algorithm is executed on a bipartite graph in the @xmath0 model yielding a @xmath1 approximation factor , where @xmath2 is an arbitrary small positive constant .
it needs @xmath3 communication rounds with high probability ( @xmath4 denoting the number of facilities and clients ) . to the best of our knowledge
, our algorithm currently has the best approximation factor for the facility location problem in a distributed setting .
it is based on a greedy sequential approximation algorithm by jain et al(j .
acm 50(6 ) , pages : 795 - 824 , 2003 ) .
the main difficulty in executing this sequential algorithm lies in dealing with situations , where multiple facilities are eligible for opening , but ( in order to preserve the approximation factor of the sequential algorithm ) only a subset of them can actually be opened .
note that while the presented runtime bound of our algorithm is `` with high probability '' , the approximation factor is not `` in expectation '' but always guaranteed to be @xmath1 .
thus , our main contribution is a sublinear time selection mechanism that , while increasing the approximation factor by an arbitrary small additive term , allows us to decide which of the eligible facilities to open . .
And you have already written the first three sentences of the full article: facility location is one of the most studied optimization problems in operations research and captures a large variety of applications .
a classical motivation is placing facilities ( e.g , warehouses ) in such a way that the combined costs of customer satisfaction and warehouse construction are minimized . however , there are also plenty of applications in distributed scenarios . for instance , in wireless networks a set of nodes has to be chosen to provide some services ( e.g , a distributed database ) . making such services
available incurs costs at those _ facility _ nodes , while all remaining nodes act as _.
Please generate the next two sentences of the article | clients_. they use the services of the nearest facility node , and are charged a cost proportional to the corresponding distance .
the objective is to determine a set of facility nodes such that the costs caused by the facilities and the clients is as low as possible . |
7,421 | Suppose that you have an abstract for a scientific paper: we report on theoretical and numerical study of propagation of atomic beams crossing a detuned standing - wave laser beam in the geometric optics limit .
the interplay between external and internal atomic degrees of freedom is used to manipulate the atomic motion along the optical axis by light . by adjusting the atom - laser detuning
, we demonstrate how to focus , split and scatter atomic beams in a real experiment . the novel effect of chaotic scattering of atoms at a regular near - resonant standing wave is found numerically and explained qualitatively .
some applications of the effects found are discussed .
[ sh ] * * [ cols="^ " , ] * s.v .
prants , v.o .
vitkovsky , l.e .
konkov * _ laboratory of nonlinear dynamical systems , + pacific oceanological institute of the russian academy of sciences , + 690041 vladivostok , russia , url : dynalab.poi.dvo.ru_ @xmath0corresponding author e - mail : [email protected] + * keywords : * atomic scattering , standing wave , optical nanolithography .
And you have already written the first three sentences of the full article: manipulation of atoms by light becomes possible due to the dipole forces which are well described by the semiclassical model with quantum description of internal atomic transitions induced by a near resonant laser field and classical description of their center - of - mass motion @xcite .
for the first time , the ideas to trap and channel cold atoms with the help of standing laser waves ( slw ) have been proposed by v. letokhov and his co - workers @xcite .
the ability of a slw to deflect , channel and split atomic beams @xcite has been used for a variety of applications including atom microscopy , interferometry , isotope separation and optical lithography @xcite ..
Please generate the next two sentences of the article | lasers can be used to manipulate atomic trajectories to create atomic analogues of such familiar optical phenomena as focusing of light , beam splitting and light scattering .
it is remarkable that now we are able to reverse the roles of light and matter from their familiar roles . |
7,422 | Suppose that you have an abstract for a scientific paper: we review the very stringent lower bounds on the string scale that arise from flavor considerations in models with intersecting branes . despite the absence of a realistic flavor structure at tree level ,
flavor changing interactions induce a non - trivial pattern of fermion masses and mixing angles when quantum corrections are taken into account .
the resulting realistic theory of flavor allows us to constrain , in an unambiguous way , the string scale up to levels difficult to reconcile non - supersymmetric models . .
And you have already written the first three sentences of the full article: after the so - called second string revolution , string phenomenology has widen its subject beyond heterotic models .
one very exciting possibility came across a few years ago through the realization that d - branes intersecting at non - trivial angles @xcite allow for a neat way of breaking supersymmetry @xcite , generating four - dimensional chirality , and constructing in a bottom - up approach string models with a fully realistic matter and symmetry content @xcite .
a lot of effort has been put since in the study of the model building and phenomenology of such theories ..
Please generate the next two sentences of the article | ( see @xcite for the initial works and @xcite for a more detailed introduction and references . )
this intense dedication has resulted almost futile regarding the search of supersymmetric models . |
7,423 | Suppose that you have an abstract for a scientific paper: in a series of papers we have found statistically significant correlations between arrival directions of ultra - high energy cosmic rays and bl lacertae objects .
recently , our calculations were partly repeated by evans , ferrer and sarkar @xcite with different conclusions .
we demonstrate that the criticism of ref .
@xcite is incorrect .
we also present the details of our method . .
And you have already written the first three sentences of the full article: identification of sources of the ultra - high energy cosmic rays ( uhecr ) is a key to understanding their nature .
the observed small - scale clustering of uhecr @xcite suggests that already existing data @xcite may contain information sufficient to make first steps in this direction . in a series of papers @xcite
we have shown that there exist significant correlations between the arrival directions of uhecr and bl lacertae objects ( bl lacs ) , and therefore bl lacs are likely to be sources of uhecr ..
Please generate the next two sentences of the article | although present small dataset does not allow to determine with certainty the details of uhecr production and propagation , interesting hints may be obtained @xcite .
the first evidence of connection between uhecr and bl lacs was found in ref . |
7,424 | Suppose that you have an abstract for a scientific paper: known populations of qsos appear to fall short of producing the ionizing flux required for re - ionizing the universe .
the alternative , galaxies as sources of ionizing photons , suffers from the problem that known types of galaxies are almost completely opaque to ionizing photons . for reionization to happen ,
either large numbers of ( largely undiscovered ) sources are required , or the known populations of galaxies need to have had a much larger escape fraction for ionizing radiation in the past .
we discuss recent discoveries of faint @xmath0 lyman @xmath1 emitters with asymmetric , extended ly@xmath1 emission regions , which apparently are related to interacting galaxies .
the unusually shaped ly@xmath1 line profiles and the underlying stellar populations of these objects suggest the presence of damaged gaseous halos , infall of gas , tidal or stripped stellar features and young populations of hot stars that would all be conducive to the release of ionizing radiation into intergalactic space . as galaxy interactions and mergers
increase with redshift , these effects can only become more important at earlier times , and so these interacting @xmath2 objects may be late , lower redshift analogues of the sources of reionization .
address = carnegie observatories , 813 santa barbara street , pasadena ca 91101 , usa .
And you have already written the first three sentences of the full article: the known population of qsos , thought to be the main source of ionizing photons throughout most of the history of the universe , falls short of maintaining the ionization of the intergalactic medium at redshifts beyond @xmath3 ( e.g. , @xcite ) , whereas the universe is known to be fully ionized back to at least @xmath4 ( e.g. , @xcite ) .
ionizing flux escaping from galaxies is often invoked to make up for the missing photons .
the highest redshift galaxy surveys are finding increasing numbers of @xmath5 galaxies ..
Please generate the next two sentences of the article | however , to reach the number density of photons necessary for re - ionization may require either the existence of large numbers of ( still ) invisible sources ( e.g. , trenti , this conference ) , or rather large escape fractions for those types of galaxies currently observable ( e.g. , finkelstein , this conference ) .
the challenge posed by these conditions is exacerbated by a paucity of credible observations of any galaxies emitting a significant amount of ionizing radiation ( see , e.g. , @xcite for a recent discussion ) . |
7,425 | Suppose that you have an abstract for a scientific paper: one of the objectives of the physics programme of the wasa - at - cosy facility is to study the isospin violating @xmath0 hadronic decays into @xmath1 systems driven by the term of qcd lagrangian which depends on the d and u quark mass difference .
these studies can be made in terms of the dalitz plot parameters describing the density population which is proportional to the square of the amplitude @xmath2 .
this contribution describes the current status of the analysis of the @xmath3 decay in the @xmath4 and as well in the @xmath5 reaction with wasa - at - cosy . .
And you have already written the first three sentences of the full article: the isospin violating strong decay @xmath3 allows access to light quark mass ratios . at lowest order of chiral perturbation theory ( chpt )
the amplitude is proportional to the light quark mass difference @xmath6 and may be written as @xmath7 where @xmath8 is the pion decay constant , @xmath9 and @xmath10 . at higher order of chpt
it has been found that final state pion interaction contribute to the decay width@xcite@xmath11@xcite ..
Please generate the next two sentences of the article | the decay width scales as @xmath12 , where @xmath13 , @xmath14 , and the decay width @xmath15 and @xmath16 are calculated in the dashen limit@xcite .
this scaling works under the pre - requisite that @xmath15 is understood reliably . to test this , theoretical predictions and experimental measurements of pion kinematical distributions |
7,426 | Suppose that you have an abstract for a scientific paper: we present here two epochs of space vlbi observations at 18 cm of the bl - lac type object mkn 501 .
thanks to the high resolution of these new data we have found that the inner jet is centrally brightened at its beginning but becomes extended and limb brightened at @xmath0 8 mas from the core . moreover a comparison between the two epochs shows the presence of a possible proper motion with apparent velocity = 6.7c .
vlbi data at 6 and 18 cm of the bl - lac type object mkn 421 are also presented .
observational data have been used to constrain the jet velocity and orientation .
# 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: mkn 501 and mkn 421 are two nearby bl - lac type objects at z = 0.034 and 0.030 , respectively .
they are well studied sources in radio , optical and x - ray bands being among the brightest bl - lac objects at all wavelengths .
mkn 421 was the first source to be detected at tev energies , followed by mkn 501 . in the radio band ,.
Please generate the next two sentences of the article | both sources show a kpc scale morphology and a total radio power consistent with the expectation of unified scheme models that bl - lac type sources are fr i galaxies oriented at small angles to the line of sight .
we present here new space vlbi observations of mkn 501 and vlbi data of mkn 421 . |
7,427 | Suppose that you have an abstract for a scientific paper: the first stars ended the cosmic dark ages and created the first heavy elements necessary for the formation of planets and life .
the properties of these stars remain uncertain , and it may be decades before individual pop iii stars are directly observed .
their masses , however , can be inferred from their supernova explosions , which may soon be found in both deep - field surveys by the _ james webb space telescope _ ( _ jwst _ ) and in all - sky surveys by the _ wide field infrared survey telescope _ ( _ wfirst _ ) .
we have performed radiation hydrodynamical simulations of the near infrared signals of pop iii pair - instability supernovae in realistic circumstellar environments with lyman absorption by the neutral intergalactic medium .
we find that _ jwst _ and _ wfirst _ will detect these explosions out to @xmath0 and 20 , respectively , unveiling the first generation of stars in the universe . .
And you have already written the first three sentences of the full article: the cosmic dark ages ended with the formation of the first stars in 10@xmath110@xmath2 @xmath3 cosmological halos at @xmath4 2030 .
besides ionizing the universe with intense uv flux and forming the first heavy elements , pop iii stars also determined the luminosities and spectra of primeval galaxies and may have been the origin of the supermassive black holes ( smbhs ) at the centers of most massive galaxies today . unfortunately , because they lie at the edge of the observable universe , individual pop iii stars will likely remain beyond the reach of direct observation for decades to come despite their enormous luminosities @xcite and new near infrared ( nir ) observatories such as _ jwst _ @xcite and the _ thirty meter telescope _ ( tmt ) .
past numerical simulations have suggested that pop iii stars form in isolation in halos , with masses of 30300 @xmath3 @xcite , but more recent calculations point to the possibility of binaries @xcite , and perhaps small swarms of less massive 2040 @xmath3 stars @xcite ..
Please generate the next two sentences of the article | however , in spite of their increasing sophistication numerical simulations can not yet constrain the properties of the first stars , as they do not realistically bridge the gap between the formation and fragmentation of protostellar disks and their destruction by nascent stars up to a myr later .
it may soon be possible to deduce the properties of pop iii stars from their supernova ( sn ) explosions . |
7,428 | Suppose that you have an abstract for a scientific paper: we present magnetodielectric measurements in single crystals of the cubic spin-1/2 compound cu@xmath0oseo@xmath1 . a magnetic field - induced electric polarization
( @xmath2 ) and a finite magnetocapacitance ( mc ) is observed at the onset of the magnetically ordered state ( @xmath3 k ) .
both @xmath2 and mc are explored in considerable detail as a function of temperature ( t ) , applied field @xmath4 , and relative field orientations with respect to the crystallographic axes .
the magnetodielectric data show a number of anomalies which signal magnetic phase transitions , and allow to map out the phase diagram of the system in the @xmath5-t plane . below the 3up-1down collinear ferrimagnetic phase , we find two additional magnetic phases .
we demonstrate that these are related to the field - driven evolution of a long - period helical phase , which is stabilized by the chiral dzyalozinskii - moriya term @xmath6 that is present in this non - centrosymmetric compound .
we also present a phenomenological landau - ginzburg theory for the me@xmath7 effect , which is in excellent agreement with experimental data , and shows three novel features : ( i ) the polarization @xmath2 has a uniform as well as a long - wavelength spatial component that is given by the pitch of the magnetic helices , ( ii ) the uniform component of @xmath2 points along the vector @xmath8 , and ( iii ) its strength is proportional to @xmath9 , where @xmath10 is the longitudinal and @xmath11 is the transverse ( and spiraling ) component of the magnetic ordering .
hence , the field dependence of p provides a clear signature of the evolution of a conical helix under a magnetic field .
a similar phenomenological theory is discussed for the mc . .
And you have already written the first three sentences of the full article: in recent years there has been an extensive experimental and theoretical activity in the field of magnetoelectrics . the magnetoelectric effect ( me )
was originally predicted by curie in 1894,@xcite and describes the induction of electric polarization @xmath2 by a magnetic field and , vice - versa , the induction of magnetization @xmath12 by an electric field @xmath13 .
a phenomenological theory was developed by landau,@xcite who considered the invariants in the expansion of the free energy up to linear terms in the magnetic field . in this approach.
Please generate the next two sentences of the article | , symmetry considerations alone can fix the form of the coupling between @xmath2 and @xmath12.@xcite based on such symmetry arguments , dzyaloshinskii proposed the antiferromagnetic ( afm ) compound cr@xmath0o@xmath1 as a first candidate for the observation of the me effect.@xcite indeed , the electrically induced magnetization ( me@xmath14 ) in cr@xmath0o@xmath1 was observed experimentally for the first time by astrov,@xcite and soon after , rado and folen@xcite measured the the converse effect , i.e the magnetic - field induced electric polarization ( me@xmath7 ) . despite the scarcity of compounds with cross - coupled magnetic and electric properties , which is related to the antagonistic requirements for the existence of
both orders,@xcite the research in the field has grown enormously . |
7,429 | Suppose that you have an abstract for a scientific paper: a consequent approach is proposed to construct symplectic force - gradient algorithms of arbitrarily high orders in the time step for precise integration of motion in classical and quantum mechanics simulations . within this approach the basic algorithms
are first derived up to the eighth order by direct decompositions of exponential propagators and further collected using an advanced composition scheme to obtain the algorithms of higher orders .
contrary to the scheme by chin and kidwell [ phys .
rev .
e * 62 * , 8746 ( 2000 ) ] , where high - order algorithms are introduced by standard iterations of a force - gradient integrator of order four , the present method allows to reduce the total number of expensive force and its gradient evaluations to a minimum . at the same time
, the precision of the integration increases significantly , especially with increasing the order of the generated schemes .
the algorithms are tested in molecular dynamics and celestial mechanics simulations .
it is shown , in particular , that the efficiency of the new fourth - order - based algorithms is better approximately in factors 5 to 1000 for orders 4 to 12 , respectively .
the results corresponding to sixth- and eighth - order - based composition schemes are also presented up to the sixteenth order . for
orders 14 and 16 , such highly precise schemes , at considerably smaller computational costs , allow to reduce unphysical deviations in the total energy up in @xmath0 times with respect to those of the standard fourth - order - based iteration approach .
pacs numbers : 02.60.cb ; 05.10.-a ; 95.10.ce ; 95.75.pq 2 .
And you have already written the first three sentences of the full article: understanding the dynamic phenomena in classical and quantum many - body systems is of importance for the most of areas of physics and chemistry .
the development of efficient algorithms for solving the equations of motion in such systems should therefore impact a lot of fields of fundamental research . during the last decade
a considerable activity @xcite has been directed on the construction of symplectic time - reversible algorithms that employ decompositions of the evolution operators into analytically solvable parts ..
Please generate the next two sentences of the article | the decomposition algorithms exactly preserve all poincar invariants and , thus , are ideal for long - time integration in molecular dynamics @xcite and astrophysical @xcite simulations .
the reason is that for these algorithms the errors in energy conservation appear to be bounded even for relatively large values of the size of the time step . |
7,430 | Suppose that you have an abstract for a scientific paper: we report results on the decay @xmath0 and its charge conjugate using a data sample of 85.4 million @xmath1 pairs recorded at the @xmath2 resonance with the belle detector at the kekb asymmetric @xmath3 storage ring
. ratios of branching fractions of cabibbo - suppressed to cabibbo - favored processes are determined to be @xmath4 , @xmath5 and @xmath6 where the indices 1 and 2 represent the cp=+1 and cp=@xmath71 eigenstates of the @xmath8 system , respectively .
we find the partial - rate charge asymmetries for @xmath0 to be @xmath9 and @xmath10 .
the extraction of @xmath11 @xcite , an angle of the kobayashi - maskawa triangle @xcite , is a challenging measurement even with modern high luminosity @xmath12 factories .
recent theoretical work on @xmath12 meson dynamics has demonstrated the direct accessibility of @xmath11 using the process @xmath13
@xcite . if the @xmath14 is reconstructed as a cp eigenstate , the @xmath15 and @xmath16 processes interfere .
this interference leads to direct cp violation as well as a characteristic pattern of branching fractions .
however , the branching fractions for @xmath17 meson decay modes to cp eigenstates are only of order 1 % . since cp violation through interference
is expected to be small , a large number of @xmath12 decays is needed to extract @xmath18 . assuming the absence of @xmath19 mixing , the observables sensitive to cp violation that are used to extract the angle @xmath18 @xcite are , @xmath20 where the ratios @xmath21 and @xmath22 are defined as @xmath23@xmath24@xmath25 and @xmath26 are cp - even and cp - odd eigenstates of the neutral @xmath17 meson , @xmath27 is the ratio of the amplitudes of the two tree diagrams shown in fig . 1 and @xmath28 is their strong - phase difference
. the ratio @xmath29 corresponds to the magnitude of cp asymmetry and is suppressed to the level of @xmath30 due to the ckm factor @xmath31 and a color suppression factor @xmath32 .
note that the asymmetries @xmath33 and @xmath34 have opposite signs . ....
And you have already written the first three sentences of the full article: we wish to thank the kekb accelerator group for the excellent operation of the kekb accelerator .
we acknowledge support from the ministry of education , culture , sports , science , and technology of japan and the japan society for the promotion of science ; the australian research council and the australian department of industry , science and resources ; the national science foundation of china under contract no .
10175071 ; the department of science and technology of india ; the bk21 program of the ministry of education of korea and the chep src program of the korea science and engineering foundation ; the polish state committee for scientific research under contract no ..
Please generate the next two sentences of the article | 2p03b 17017 ; the ministry of science and technology of the russian federation ; the ministry of education , science and sport of the republic of slovenia ; the national science council and the ministry of education of taiwan ; and the u.s .
department of energy . |
7,431 | Suppose that you have an abstract for a scientific paper: we present a relativistic point - form approach for the calculation of electroweak form factors of few - body bound states . as an example , the transition form factors for the semileptonic weak decay @xmath0 are discussed and it is sketched how they can be extracted unambiguously from the invariant transition amplitude that describes the process .
it is shown how these form factors go over into one universal function , the isgur - wise function in the heavy - quark limit , @xmath1 , and comparison with the available experimental data is made . .
And you have already written the first three sentences of the full article: the point form is one of the three prominent forms proposed by dirac in his seminal paper of 1949 @xcite to formulate relativistic hamiltonian dynamics .
it has the nice feature that the whole lorentz group ( rotations and boosts ) is kinematical , i.e. is not affected by interactions .
this allows to boost and rotate bound - state wave functions in a simple way . as a price ,.
Please generate the next two sentences of the article | all components of the 4-momentum operator become interaction dependent .
the formalism presented here is based on the point form of relativistic quantum mechanics and makes use of the bakamjian - thomas construction @xcite for introducing interactions in a fully poincar invariant manner . as a consequence |
7,432 | Suppose that you have an abstract for a scientific paper: it has been conjectured that the bosonic open string theory around the non - perturbative tachyon vacuum has no open string dynamics at all .
we explore , in the cubic open string field theory with level truncation approximation , the possibility that this conjecture is realized by the absence of kinetic terms of the string field fluctuations .
we study the kinetic terms with two and four derivatives for the lower level scalar modes as well as their brst transformation properties .
the behavior of the coefficients of the kinetic terms in the neighborhood of the non - perturbative vacuum supports our expectation that the brst invariant scalar component lacks its kinetic term .
= 18.6pt plus 0.2pt minus 0.1pt addtoresetequationsection .
And you have already written the first three sentences of the full article: the bosonic d - brane has an unstable tachyonic mode on the perturbative vacuum .
it has been conjectured @xcite that there is a local minimum of the tachyon potential ( non - perturbative vacuum ) , where the tension of the d - brane and the negative contribution from the tachyon potential exactly cancel each other . on this vacuum , there should be no d - branes and hence no open string excitations at all , leaving only the closed string sector .
it has been also conjectured that the solutions on this non - perturbative vacuum represent various lower dimensional d - branes ( descent relations ) . for studying these conjectures , string field theories.
Please generate the next two sentences of the article | have proved to be very useful , and there have appeared many interesting works in this direction @xcite@xcite . in particular , witten s cubic open string field theory ( csft ) @xcite combined with the level truncation approximation @xcite has been successful in verifying the conjecture on the potential height to a very high degree of accuracy @xcite . though most of these conjectures , the potential height problem and the descent relation , have later been proved @xcite in another formulation of open string field theory called boundary string field theory ( bsft ) @xcite , there still remains an important problem to be understood : how the open string excitations disappear around the non - perturbative vacuum .
note that for analyzing this problem we have to treat all the modes in open string theory other than the tachyon mode . |
7,433 | Suppose that you have an abstract for a scientific paper: monte carlo simulations are employed to investigate the surface growth generated by deposition of particles of different sizes on a substrate , in one and two dimensions .
the particles have a linear form , and occupy an integer number of cells of the lattice .
the results of our simulations have shown that the roughness evolves in time following three different behaviors .
the roughness in the initial times behaves as in the random deposition model , with an exponent @xmath0 . at intermediate times , the surface roughness depends on the system dimensionality and , finally , at long times , it enters into the saturation regime , which is described by the roughness exponent @xmath1 .
the scaling exponents of the model are the same as those predicted by the villain - lai - das sarma equation for deposition in one dimension . for the deposition in two dimensions ,
we show that the interface width in the second regime presents an unusual behavior , described by a growing exponent @xmath2 , which depends on the size of the particles added to the substrate .
if the linear size of the particle is two , we found that @xmath3 , otherwise it is @xmath4 , for all particles sizes larger than three . while in one dimension the scaling exponents are the same as those predicted by the villain - lai - das sarma equation , in two dimensions , the growth exponents are nonuniversal .
_ keywords : growth models , surface roughness , film deposition , random deposition , computer simulations . _ .
And you have already written the first three sentences of the full article: the field of non - equilibrium statistical physics is related to those problems for which a hamiltonian formulation is not possible or the detailed - balance condition is not satisfied .
one of these problems is the study of surface growth and interfaces , where the understanding of the basic mechanisms is the key to developing thin - film devices with important technological applications @xcite . in this work
we are interested in the description of the morphology of a surface formed by adding particles to an initially flat substrate ..
Please generate the next two sentences of the article | particles , having one unit height and linear size @xmath5 , land horizontally onto the surface , or over a straigth line in the case of a one - dimensional substrate , and are not allowed to diffuse . in this way
, we calculate the interface width , @xmath6 , a function that determines the roughness of the interface , where @xmath7 is the linear size of the substrate and @xmath8 is the time variable . |
7,434 | Suppose that you have an abstract for a scientific paper: we propose a new numerical scheme of evolution for the einstein equations using the discrete variational derivative method ( dvdm ) .
we derive the discrete evolution equation of the constraint using this scheme and show the constraint preserves in the discrete level .
in addition , to confirm the numerical stability using this scheme , we perform some numerical simulations by discretized equations with the crank - nicolson scheme and with the new scheme , and we find that the new discretized equations have better stability than that of the crank - nicolson scheme . .
And you have already written the first three sentences of the full article: recently , the gravitational waves which are the solutions of the einstein equations and are the part of the most interesting astrophysical events were observed by ligo @xcite .
the einstein equations are sets of the nonlinear partial differential equations with constraints , numerical calculations are the realistic tools to study these equations for the actual physical events in the universe such as the gravitational waves . analyzing the einstein equations
numerically is called `` numerical relativity '' , these studies made a substantial contribution to observe the gravitational wave events ..
Please generate the next two sentences of the article | these discoveries must open new physical fields to survey of lots of astrophysical events .
therefore , it is important to improve numerical techniques to make high accuracy numerical results . |
7,435 | Suppose that you have an abstract for a scientific paper: we present an experimental study on the rotational inelastic scattering of oh ( @xmath0 ) radicals with he and d@xmath1 at collision energies between 100 and 500 @xmath2 in a crossed beam experiment .
the oh radicals are state selected and velocity tuned using a stark decelerator .
relative parity - resolved state - to - state inelastic scattering cross sections are accurately determined .
these experiments complement recent low - energy collision studies between trapped oh radicals and beams of he and d@xmath1 that are sensitive to the total ( elastic and inelastic ) cross sections ( sawyer _ et al .
_ , _ phys .
rev .
lett . _ * 2008 * , _ 101 _ , 203203 ) , but for which the measured cross sections could not be reproduced by theoretical calculations ( pavlovic _ et al .
_ , _ j. phys .
chem .
a _ * 2009 * , _ 113 _ , 14670 ) .
for the oh - he system , our experiments validate the inelastic cross sections determined from rigorous quantum calculations . .
And you have already written the first three sentences of the full article: the study of collisions between neutral atoms and molecules at low collision energies is a fast developing field in molecular physics @xcite .
this growing interest originates from the exotic scattering properties of molecules at low temperatures . at temperatures below @xmath3 10
k only a few partial waves contribute to the scattering , leading to dramatic changes in the dynamics ..
Please generate the next two sentences of the article | scattering resonances can occur when the collision energy is degenerate with a bound state of the collision complex @xcite .
low collision energies also allow for external control over the collision dynamics by electromagnetic fields . at collision energies below a few kelvin , |
7,436 | Suppose that you have an abstract for a scientific paper: electrons with spin - orbit coupling moving in mesoscopic structures can often exhibit local spin polarization . in this paper , we study the influence of the rashba coupling on the scattering of two - dimensional electrons from a circular disk .
it is observed that spin - polarized regions exist , even if the incident electrons are unpolarized .
in addition to the distributions of charge and spin current in the near - field region , we also analyze the symmetry and the differential cross - section of the scattering . .
And you have already written the first three sentences of the full article: spin - orbit interaction influences the electronic and transport properties of semiconductors . for example
, it lifts the degeneracy of the valence bands , modifies the electron g - factor,@xcite and causes skew scattering in the presence of ( spinless ) impurities .
such a skew scattering is a possible mechanism for the extrinsic spin hall effect.@xcite in addition , spin - orbit interaction plays an important role in the recently proposed intrinsic spin hall effect.@xcite it is also crucial in the mechanisms of spin relaxation and optical orientation in semiconductors.@xcite it is highly desirable to generate flows of polarized spins in semiconductors with the help of the spin - orbit interaction . in these endeavors ,.
Please generate the next two sentences of the article | the rashba spin - orbit coupling@xcite in two - dimensional electron gas ( 2deg ) plays a special role since it allows manipulation of spin flows by varying the gate bias .
this has motivated several creative proposals for its application.@xcite to explore the possibilities , the effect of rashba coupling in many types of mesoscopic structure have been investigated , such as a quantum wire,@xcite a quantum ring,@xcite and a quantum dot.@xcite in several studies , it was found that a device with a simple geometry , in combination with the rashba coupling , could serve as a spin filter . |
7,437 | Suppose that you have an abstract for a scientific paper: we perform successive umbrella sampling grand canonical monte carlo computer simulations of the original st2 model of water in the vicinity of the proposed liquid - liquid critical point , at temperatures above and below the critical temperature .
our results support the previous work of y. liu , a.z .
panagiotopoulos and p.g .
debenedetti [ j. chem
. phys . * 131 * , 104508 ( 2009 ) ] , who provided evidence for the existence and location of the critical point for st2 using the ewald method to evaluate the long - range forces .
our results therefore demonstrate the robustness of the evidence for critical behavior with respect to the treatment of the electrostatic interactions .
in addition , we verify that the liquid is equilibrated at all densities on the monte carlo time scale of our simulations , and also that there is no indication of crystal formation during our runs .
these findings demonstrate that the processes of liquid - state relaxation and crystal nucleation are well separated in time .
therefore , the bimodal shape of the density of states , and hence the critical point itself , is a purely liquid - state phenomenon that is distinct from the crystal - liquid transition . .
And you have already written the first three sentences of the full article: in 1992 , a numerical investigation of the equation of state ( eos ) of the st2 model @xcite in the supercooled region suggested the possibility of a liquid - liquid ( ll ) critical point in water @xcite . this initial study has subsequently generated a large amount of numerical and experimental work @xcite .
in addition to the conceptual novelty of a one - component system with more than one liquid phase , the existence of the associated ll critical point can also rationalize many of the thermodynamic anomalies which characterize liquid water ( e.g. the density maximum and compressibility minimum ) , and which become more pronounced in the supercooled regime .
furthermore , the existence of two distinct liquid phases of supercooled water can explain the polyamorphism which characterizes the glassy phase @xcite ..
Please generate the next two sentences of the article | indeed , simulations suggest that the low density amorphous solid form of water is similar to the structure of the low density liquid ( ldl ) phase , while the relaxed very - high density amorphous solid is related to the high density liquid ( hdl)@xcite .
evidence in support of a liquid - liquid critical point in water , and in other liquids with tetrahedral structure , has increased over time . |
7,438 | Suppose that you have an abstract for a scientific paper: the article describes a model of chess based on information theory . a mathematical model of the partial depth scheme
is outlined and a formula for the partial depth added for each ply is calculated from the principles of the model . an implementation of alpha - beta with partial depth is given .
the method is tested using an experimental strategy having as objective to show the effect of allocation of a higher amount of search resources on areas of the search tree with higher information .
the search proceeds in the direction of lines with higher information gain . the effects on search performance of allocating higher search resources on lines with higher information gain
are tested experimentaly and conclusive results are obtained . in order to isolate the effects of the partial depth scheme
no other heuristic is used .
= 1 .
And you have already written the first three sentences of the full article: there is gap in the scientific analysis of the fraction ply methods one of the best methods of search in computer chess and other strategy games . as hans berliner pointed out about the scheme of partial depths ,
... the success of these micros ( micro - processor based programs ) attests to the efficacy of the procedure .
unfortunately , little has been published on this ..
Please generate the next two sentences of the article | this research has the objective of developing a theoretical model of the partial depth scheme based on information theory , implementing it and providing experimental evidence for the method and for the model .
an introduction to games theory and information theory is given in the background section . |
7,439 | Suppose that you have an abstract for a scientific paper: g0.253 + 0.016 is a molecular clump that appears to be on the verge of forming a high mass , arches - like cluster .
here we present new alma observations of its small - scale ( @xmath00.07pc ) 3 mm dust continuum and molecular line emission .
the data reveal a complex network of emission features , the morphology of which ranges from small , compact regions to extended , filamentary structures that are seen in both emission and absorption .
the dust column density is well traced by molecules with higher excitation energies and critical densities , consistent with a clump that has a denser interior .
a statistical analysis supports the idea that turbulence shapes the observed gas structure within g0.253 + 0.016 .
we find a clear break in the turbulent power spectrum derived from the optically thin dust continuum emission at a spatial scale of @xmath00.1pc , which may correspond to the spatial scale at which gravity has overcome the thermal pressure .
we suggest that g0.253 + 0.016 is on the verge of forming a cluster from hierarchical , filamentary structures that arise from a highly turbulent medium . although the stellar distribution within arches - like clusters is compact , centrally condensed and smooth , the observed gas distribution within g0.253 + 0.016 is extended , with no high - mass central concentration , and has a complex , hierarchical structure .
if this clump gives rise to a high - mass cluster and its stars are formed from this initially hierarchical gas structure , then the resulting cluster must evolve into a centrally condensed structure via a dynamical process . .
And you have already written the first three sentences of the full article: young massive clusters ( ymcs , e.g. , arches , quintuplet , westerlund 1 , rscg , glimpse - co1 : @xcite ) are gravitationally bound stellar systems with masses @xmath110@xmath2m@xmath3and ages @xmath4 100myr @xcite . despite their small numbers and short lifetimes
, they appear to be the ` missing link ' between open clusters and globular clusters ( e.g. , @xcite ) . as such , understanding their formation may provide the link to understanding globular cluster formation .
if ymcs and even globular clusters form in a similar way to open clusters , then our knowledge of nearby stellar systems may potentially be used as a framework to understanding star formation across cosmic time , back to globular cluster formation @xmath0 10 gyr ago ..
Please generate the next two sentences of the article | an understanding of the formation of clusters requires observations of their natal dust and gas well before the onset of star formation . in recent surveys of dense cluster - forming molecular clumps ,
one object , g0.253 + 0.016 , stands out as extreme @xcite . |
7,440 | Suppose that you have an abstract for a scientific paper: observations of two of the formaldehyde ( h@xmath0co ) masers ( a and d ) in sgr b2 using the vlba+y27 ( resolution @xmath1 001 ) and the vla ( resolution @xmath2 ) are presented .
the vlba observations show compact sources ( @xmath3 milliarcseconds , @xmath4 au ) with brightness temperatures @xmath5 k. the maser sources are partially resolved in the vlba observations .
the flux densities in the vlba observations are about 1/2 those of the vla ; and , the linewidths are about 2/3 of the vla values . the applicability of a core - halo model for the emission distribution is demonstrated .
comparison with earlier h@xmath0co absorption observations and with ammonia ( nh@xmath6 )
observations suggests that h@xmath0co masers form in shocked gas .
comparison of the integrated flux densities in current vla observations with those in previous observations indicates that ( 1 ) most of the masers have varied in the past 20 years , and ( 2 ) intensity variations are typically less than a factor of two compared to the 20-year mean .
no significant linear or circular polarization is detected with either instrument . .
And you have already written the first three sentences of the full article: the nature of galactic formaldehyde ( h@xmath0co ) masers is a growing mystery . while hundreds of galactic oh , h@xmath0o , and ch@xmath6oh masers are known , only five galactic star - forming regions have associated h@xmath0co maser emission . to date , this emission is seen only in the @xmath7 transition at 6 cm wavelength . shortly after the discovery of the first h@xmath0co maser in ngc 7538 ( downes & wilson 1974 ; forster et al . 1980 ) , a radiative pumping model was proposed ( boland and de jong 1981 ) . the h@xmath0co masers discovered subsequently did not meet the conditions required for this mechanism ( gardner et al .
1986 ; mehringer , goss , & palmer 1994 , hereafter mgp94 ; hoffman et al .
2003 ; hereafter h03 ) ..
Please generate the next two sentences of the article | thus , twenty - five years after the discovery of the first h@xmath0co maser , these sources remain rare and the excitation mechanism remains unknown .
sgr b2 , the northernmost component of the extended sgr b radio source , is located within a few hundred pc of the galactic center ( reid et al . |
7,441 | Suppose that you have an abstract for a scientific paper: we analyze the existence , bifurcations , and shape transformations of one - dimensional gap solitons ( gss ) in the first finite bandgap induced by a periodic potential built into materials with local self - focusing and nonlocal self - defocusing nonlinearities .
originally stable on - site gs modes become unstable near the upper edge of the bandgap with the introduction of the nonlocal self - defocusing nonlinearity with a small nonlocality radius .
unstable off - site gss bifurcate into a new branch featuring single - humped , double - humped , and flat - top modes due to the competition between local and nonlocal nonlinearities .
the mechanism underlying the complex bifurcation pattern and cutoff effects ( termination of some bifurcation branches ) is illustrated in terms of the shape transformation under the action of the varying degree of the nonlocality .
the results of this work suggest a possibility of optical - signal processing by means of the competing nonlocal and local nonlinearities . .
And you have already written the first three sentences of the full article: the concept of photonic crystals ( phcs ) , i.e. , artificial media with a periodic modulation of local optical characteristics , provides ways to tailor the dispersion , diffraction , and routing of electromagnetic waves @xcite . as for natural crystals ,
fundamental characteristics of the phcs are the band - diagrams , which reveal gaps where bloch waves can not propagate
. in phcs made of nonlinear materials , self - trapped localized modes in the form of the gap solitons ( gss ) may exist , as a result of the interplay of the kerr - type nonlinearity and periodic structures npc - book , krug , ostrovskaya03 , konotop ..
Please generate the next two sentences of the article | unlike spatial bright solitons supported by the balance between the self - focusing nonlinearity and diffraction in uniform bulk media @xcite , the dispersion relation induced by the phc makes it possible to create gss in both focusing and defocusing media . combining assets of phcs and regular solitons , gss have a potential for applications to soliton - driven photonics .
new technologies enabling reconfigurable optical lattices , such as photorefractive crystals @xcite and nematic liquid crystals @xcite , also open new ways to control the dynamics of solitary waves by adjusting the lattice depth and period . while the modulational @xcite and oscillatory instabilities @xcite impose limits on the use of the gss , the stability and mobility of the gss may be enhanced in nonlinear media featuring a nonlocal response @xcite . |
7,442 | Suppose that you have an abstract for a scientific paper: osmosis is one of the most important physical phenomena in living and soft matter systems .
while the thermodynamics of osmosis is well understood , the underlying microscopic dynamical mechanisms remain the subject of discussion .
unraveling these mechanisms is a prerequisite for understanding osmosis in non - equilibrium systems . here , we investigate the microscopic basis of osmosis , in a system at equilibrium , using molecular dynamics simulations of a minimal model in which repulsive solute and solvent particles differ only in their interactions with an external potential . for this system , we can derive a simple virial - like relation for the osmotic pressure .
our simulations support an intuitive picture in which the solvent concentration gradient , at osmotic equilibrium , arises from the balance between an outward force , caused by the increased total density in the solution , and an inward diffusive flux caused by the decreased solvent density in the solution .
while more complex effects may occur in other osmotic systems , our results suggest that they are not required for a minimal picture of the dynamic mechanisms underlying osmosis . .
And you have already written the first three sentences of the full article: osmosis is the physical phenomenon in which a concentration difference of impermeant solute molecules across a semi - permeable membrane produces a difference in solvent density , and in pressure , across the membrane .
this has enormously important consequences - osmosis forms the basis of the transport of ions across cell membranes @xcite , the regulation of blood salt levels by the kidneys @xcite , uptake of water by plants @xcite , technologies for kidney dialysis @xcite and clean power production @xcite , and many other processes .
osmosis also lies at the heart of many important phenomena in chemical physics including the donnan effect @xcite , the depletion interaction @xcite and , recently , mechanisms for generating self - propelled colloidal particles @xcite ..
Please generate the next two sentences of the article | the cornerstone of our understanding of osmosis is the van t hoff relation , which states that a solute concentration difference , @xmath0 , leads to an equilibrium osmotic pressure difference @xmath1 @xcite .
remarkably , this relation predicts that the osmotic pressure difference is the same as the pressure of an ideal gas at concentration @xmath0 , regardless of the molecular nature of the solute and solvent molecules . |
7,443 | Suppose that you have an abstract for a scientific paper: effects of the bond dilution on the critical temperatures , phase diagrams and the magnetization behaviors of the isotropic and anisotropic quantum heisenberg model have been investigated in detail . for the isotropic case ,
bond percolation threshold values have been determined for several numbers of two ( 2d ) and three ( 3d ) dimensional lattices . in order to investigate the effect of the anisotropy in the exchange interaction on the results obtained for the isotropic model , a detailed investigation has been made on a honeycomb lattice .
some interesting results , such as second order reentrant phenomena in the phase diagrams have been found .
keywords : * quantum anisotropic heisenberg model ; bond dilution ; bond percolation threshold * .
And you have already written the first three sentences of the full article: quenched randomness effects are very important in modeling real materials , since consideration of these effects simulates a realistic model of real materials .
real materials have some uncontrollable defects and these defects can be modeled by introducing site dilution ( randomly distributed non magnetic atoms ) , bond dilution ( randomly broken bonds between the magnetic atoms ) or both of them into the related model .
it is a well known fact that , heisenberg model produces more realistic results than the ising model , in order to explain the magnetic properties of real materials ..
Please generate the next two sentences of the article | thus , it is important to work on the heisenberg model with these quenched randomness effects .
these quenched randomness effects produce different behaviors in the magnetic properties of the model , e.g. different phase transition characteristics from the pure model ( i.e. the model without any quenched randomness effects ) . |
7,444 | Suppose that you have an abstract for a scientific paper: we study the quantum summation ( * qs * ) algorithm of brassard , hyer , mosca and tapp , see @xcite , that approximates the arithmetic mean of a boolean function defined on @xmath0 elements .
we improve error bounds presented in @xcite in the worst - probabilistic setting , and present new error bounds in the average - probabilistic setting . in particular , in the worst - probabilistic setting , we prove that the error of the * qs * algorithm using @xmath1 quantum queries is @xmath2 with probability @xmath3 , which improves the error bound @xmath4 of @xcite .
we also present error bounds with probabilities @xmath5 $ ] , and show that they are sharp for large @xmath6 and @xmath7 . in the average - probabilistic setting , we prove that the * qs * algorithm has error of order @xmath8 iff @xmath6 is divisible by @xmath9 .
this bound is optimal , as recently shown in @xcite . for @xmath6
not divisible by @xmath9 , the * qs * algorithm is far from being optimal if @xmath10 since its error is proportional to @xmath11 . .
And you have already written the first three sentences of the full article: the quantum summation ( * qs * ) algorithm ( also known as the amplitude estimation algorithm ) of brassard , hyer , mosca and tapp , see @xcite , computes an approximation to the arithmetic mean of all values of a boolean function defined on a set of @xmath12 elements .
information regarding the boolean function is supplied by quantum queries .
the quantum queries play a role similar to the use of function values in the worst case and randomized settings ..
Please generate the next two sentences of the article | suppose that we use @xmath1 quantum queries .
obviously , the only case of interest is when @xmath6 is much smaller than @xmath0 . |
7,445 | Suppose that you have an abstract for a scientific paper: we develop a variational wave function for the ground state of a one - dimensional bosonic lattice gas .
the variational theory is initally developed for the quantum rotor model and later on extended to the bose - hubbard model .
this theory is compared with quasi - exact numerical results obtained by density matrix renormalization group ( dmrg ) studies and with results from other analytical approximations .
our approach accurately gives local properties for strong and weak interactions , and it also describes the crossover from the superfluid phase to the mott - insulator phase . .
And you have already written the first three sentences of the full article: during the last years a spectacular development in the storage and manipulation of cold atoms in optical lattices @xcite has taken place .
greiner et al .
@xcite , to name one important example , succeeded in experimentally driving a quantum phase transition between a superfluid and a mott - insulating phase in bosonic systems . this experimental progress has revived the interest in the bose - hubbard model [ eq ..
Please generate the next two sentences of the article | ( [ bh ] ) ] as a generic hamiltonian for strongly correlated bosons , by which the quantum phase transition can be described @xcite .
the bose - hubbard hamiltonian has been used previously in condensed matter physics to study the adsorption of noble gases in nanotubes @xcite , or cooper pairs in superconducting films with strong charging effects @xcite . in this context |
7,446 | Suppose that you have an abstract for a scientific paper: lately , it has been suggested that strange ( quark ) stars can be responsible for glitches and other observational features of pulsars . some discussions on whether quark stars , if really exist , are bare or crusted are also a source of controversy in the recent literature . in the present work we use the nambu - jona - lasinio model , known to incorporate chiral symmetry , necessarily present in the qcd formalism , in order to describe quark star properties .
we compare our results for the stars and the features of the model with the much simpler model normally used in the description of strange stars , namely the mit bag model .
we also investigate the differences in the stellar properties which arise due to the presence of the crust .
we show that the njl model produces results which are somewhat different as compared with the mit model .
pacs number(s ) : 26.60.+c,24.10.jv , 21.65.+f,95.30.tg .
And you have already written the first three sentences of the full article: neutron stars are the remnants of supernova explosions with masses 1@xmath0 , radii @xmath1 , and a temperature of the order of @xmath2 at birth , cooling within a few days to about @xmath3 by emitting neutrinos . in a conventional model for a neutron star ,
the star is composed of hadrons , predominantly degenerate neutrons with an admixture of protons , and degenerate electrons . in the stellar modeling ,
the structure of the star depends on the assumed equation of state ( eos ) , which contains a number of uncertainties associated with uncertainties in the strong force under conditions appropriate to a neutron star ..
Please generate the next two sentences of the article | an important uncertainty concerns the true ground star of matter . in conventional models ,
hadrons are assumed to be the true ground state of the strong interaction . |
7,447 | Suppose that you have an abstract for a scientific paper: we analyze the hamiltonian proposed by smilansky to describe irreversible dynamics in quantum graphs and studied further by solomyak and others .
we derive a weak - coupling asymptotics of the ground state and add new insights by finding the discrete spectrum numerically .
furthermore , we show that the model has a rich resonance structure . ` smilansky model , discrete spectrum , weak coupling , resonances 35j10 , 35p15 , 65n25 , 81q15 , 81q35 ` .
And you have already written the first three sentences of the full article: while the fundamental equations of motion , both in classical and quantum mechanics , are invariant with respect to time reversal , the world around us is full of irreversible processes . on a microscopic level , it is enough to recall spontaneous decays of particles , nuclei , inelastic scattering processes , etc . and , of course , an irreversible process _
par excellence _ is the wave packet reduction which is the core of copenhagen description of a measuring process performed on a quantum system . a description of such processes in quantum mechanics is typically associated with enlarging the state hilbert space , conventionally referred to as coupling the system to a heat bath @xcite .
as a rule , it is assumed that ( i ) the bath is a system with infinite number of degrees of freedom , ( ii ) the bath hamiltonian has a continuous spectrum , and ( iii ) the presence ( or absence ) of irreversible modes is determined by the energies involved rather than the coupling strength . while this all is true in many cases.
Please generate the next two sentences of the article | , situations may exist where the system has neither of the listed properties .
this was the motivation which led uzy smilansky to formulation a simple model @xcite of a quantum graph coupled to a heat bath consisting of a single harmonic oscillator which exhibits an irreversible behavior . the easiest way to describe |
7,448 | Suppose that you have an abstract for a scientific paper: we have used the correlation of grbs to measure the cosmological parameter . by adopting a maximum likelihood approach which allows us to correctly quantify the extrinsic ( i.e. non poissonian ) scatter of the correlation , we constrain ( for a flat universe ) to 0.040.40 ( 68% confidence level ) , with a best fit value of @xmath0 , and exclude = 1 at @xmath1 99.9% confidence level .
if we release the assumption of a flat universe , we still find evidence for a low value of ( 0.040.50 at 68% confidence level ) and a weak dependence of the dispersion of the correlation on ( with an upper limit of @xmath2 at 90% confidence level ) .
our approach makes no assumptions on the correlation and it does not use other calibrators to set the zero point of the relation , therefore our treatment of the data is not affected by circularity and the results are independent of those derived via type ia sne ( or other cosmological probes ) . unlike other multi - parameters correlations , our analysis grounds on only two parameters , then including a larger number ( a factor @xmath3 ) of grbs and being less affected by systematics .
simulations based on realistic extrapolations of ongoing ( and future ) grb experiments ( e.g. , , konus wind , glast ) show that : i ) the uncertainties on cosmological parameters can be significantly decreased ; ii ) future data will allow us to get clues on the `` dark energy '' evolution .
[ firstpage ] gamma rays : observations gamma rays : bursts cosmology : cosmological parameters . .
And you have already written the first three sentences of the full article: gamma ray bursts ( grbs ) are the brightest cosmological sources in the universe , with isotropic luminosities up to 10@xmath4 and a redshift distribution extending at least up to @xmath5 @xmath66.3 ( e.g. , tagliaferri et al . 2005 ) .
thus , these sources may be interesting for cosmological studies , if one can use them to provide measurements of the cosmological parameters independently of other methods , like the cmb ( e.g. , de bernardis et al . 2000 ; spergel et al .
2003 ; dunkley et al . 2008.
Please generate the next two sentences of the article | ; komatsu et al .
2008 ) , type ia sn ( e.g. , perlmutter et al . 1998 ; perlmutter et al . |
7,449 | Suppose that you have an abstract for a scientific paper: we describe the development of automated emission line detection software for the fiber multi - object spectrograph ( fmos ) , which is a near - infrared spectrograph fed by @xmath0 fibers from the @xmath1 deg@xmath2 prime focus field of view of the subaru telescope .
the software , field ( fmos software for image - based emission line detection ) , is developed and tested mainly for the fastsound survey , which is targeting h@xmath3 emitting galaxies at @xmath4 to measure the redshift space distortion as a test of general relativity beyond @xmath5 . the basic algorithm is to calculate the line signal - to - noise ratio ( @xmath6 ) along the wavelength direction , given by a 2-d convolution of the spectral image and a detection kernel representing a typical emission line profile .
a unique feature of fmos is its use of oh airglow suppression masks , requiring the use of flat - field images to suppress noise around the mask regions .
bad pixels on the detectors and pixels affected by cosmic - rays are efficiently removed by using the information obtained from the fmos analysis pipeline .
we limit the range of acceptable line - shape parameters for the detected candidates to further improve the reliability of line detection .
the final performance of line detection is tested using a subset of the fastsound data ; the false detection rate of spurious objects is examined by using inverted frames obtained by exchanging object and sky frames .
the false detection rate is @xmath7% at @xmath8 , allowing an efficient and objective emission line search for fmos data at the line flux level of @xmath9[erg / cm@xmath2/s ] . .
And you have already written the first three sentences of the full article: fmos ( the fiber multi - object spectrograph ) is a near - infrared ( nir ) fiber - fed spectrograph for the subaru telescope , which is capable of collecting nearly 400 spectra in a @xmath1 deg@xmath2 field - of - view ( @xcite ) available at the prime - focus of the telescope .
the 400 fibers are divided into two groups of 200 fibers and connected to the two spectrographs , irs1 ( infra - red spectrograph ) and irs2 , for spectroscopy .
a feature of fmos is the suppression of bright oh - airglow emission lines using oh mask mirrors , which reduce the oh - airglow emission lines by more than @xmath11 ( @xcite ) ..
Please generate the next two sentences of the article | since these airglow lines are the largest noise source in the nir region , the oh suppression allows fmos to perform nir spectroscopic observations with a substantially reduced background level .
nir spectroscopy is a useful probe for a variety of topics in astronomy . |
7,450 | Suppose that you have an abstract for a scientific paper: the polarization of the cosmic microwave background ( cmb)is a powerful observational tool at hand for modern cosmology .
it allows to break the degeneracy of fundamental cosmological parameters one can not obtain using only anisotropy data and provides new insight into conditions existing in the very early universe .
many experiments are now in progress whose aim is detecting anisotropy and polarization of the cmb .
measurements of the cmb polarization are however hampered by the presence of polarized foregrounds , above all the synchrotron emission of our galaxy , whose importance increases as frequency decreases and dominates the polarized diffuse radiation at frequencies below @xmath0 ghz . in the past the separation of cmb and synchrotron
was made combining observations of the same area of sky at different frequencies . in this paper
we show that the statistical properties of the polarized components of the synchrotron and dust foregrounds are different from the statistical properties of the polarized component of the cmb , therefore one can build a statistical estimator which allows to extract the polarized component of the cmb from single frequency data also when the polarized cmb signal is just a fraction of the total polarized signal .
our estimator improves the signal / noise ratio for the polarized component of the cmb and reduces from @xmath150 ghz to @xmath120 ghz the frequency above which the polarized component of the cmb can be extracted from single frequency maps of the diffuse radiation .
, , polarimetry , mathematical procedures , radio and microwave , observational cosmology : 95.75.hi , 95.75.pq , 95.85.bh , 90.80.es .
And you have already written the first three sentences of the full article: almost a decade elapsed since the first detection of the anisotropy of the cosmic microwave background at large angular scales ( @xmath2 ) @xcite , @xcite . today
the cmb anisotropy ( cmba ) has been detected also at intermediate ( @xmath3 ) and small angular scales ( @xmath4 ) , so the cmba angular spectrum is now reasonably known down to the region of the first and second doppler peaks @xcite , @xcite , @xcite .
its shape gives information e.g. on the spectrum of the primordial cosmological perturbations or can be used to test the inflation theory but rises new questions to which cmba can not answers ..
Please generate the next two sentences of the article | it is however possible to get answers looking at the cmb polarization ( cmbp ) .
for instance one can use cmbp to disentangle the effects of fundamental cosmological parameters like density of matter , density of dark energy etc . |
7,451 | Suppose that you have an abstract for a scientific paper: we present two schemes for driving raman transitions between the ground state hyperfine manifolds of a single atom trapped within a high - finesse optical cavity . in both schemes ,
the raman coupling is generated by standing - wave fields inside the cavity , thus circumventing the optical access limitations that free - space raman schemes must face in a cavity system .
these cavity - based raman schemes can be used to coherently manipulate both the internal and the motional degrees of freedom of the atom , and thus provide powerful tools for studying cavity quantum electrodynamics .
we give a detailed theoretical analysis of each scheme , both for a three - level atom and for a multi - level cesium atom .
in addition , we show how these raman schemes can be used to cool the axial motion of the atom to the quantum ground state , and we perform computer simulations of the cooling process . .
And you have already written the first three sentences of the full article: systems consisting of a single atom coupled to a high - finesse optical cavity are of fundamental importance to quantum optics and quantum information science .
such cavity qed systems have been experimentally implemented using neutral atoms @xcite and ions @xcite , and have been the subject of numerous theoretical studies @xcite . in particular , such systems play a key role in proposals for scalable quantum computation @xcite and distributed quantum networks @xcite .
an important requirement for many of these proposals is the ability to coherently control the internal and motional degrees of freedom of the trapped atom , and raman transitions provide the means for meeting this requirement ..
Please generate the next two sentences of the article | raman transitions are powerful tools that have diverse applications in atomic physics , including spectroscopy @xcite , precision measurement @xcite , and coherent state manipulation @xcite , and have been used to coherently control the motional degrees of freedom of trapped ions @xcite and of neutral atoms trapped in optical lattices @xcite . until recently
, however , raman transitions had not been incorporated into cavity qed . |
7,452 | Suppose that you have an abstract for a scientific paper: based on numerical simulations of gas - rich galaxy mergers , we discuss a model in which quasar activity is tied to the self - regulated growth of supermassive black holes in galaxies . the nuclear inflow of gas attending a galaxy collision triggers a starburst and feeds black hole growth , but for most of the duration of the starburst , the black hole is `` buried '' , being heavily obscured by surrounding gas and dust , limiting the visibility of the quasar , especially at optical and ultraviolet wavelengths . as the black hole grows , feedback energy from accretion heats the gas and eventually expels it in a powerful wind , leaving behind a `` dead quasar '' . in between the buried and dead phases
, there is a window in time during which the galaxy would be seen as a luminous quasar .
because the black hole mass , radiative output , and distribution of obscuring gas and dust all evolve strongly with time , the duration of this phase of observable quasar activity depends on both the waveband and imposed luminosity threshold .
we determine the observed and intrinsic lifetimes as a function of luminosity and frequency , and calculate observable lifetimes @xmath0myr for bright quasars in the optical b - band , in good agreement with empirical estimates and much smaller than our estimated black hole growth timescales @xmath1myr , naturally producing a substantial population of buried quasars .
however , the observed and intrinsic energy outputs converge in the ir and hard x - ray bands as attenuation becomes weaker and chances of observation greatly increase .
we also obtain the distribution of column densities along sightlines in which the quasar is seen above a given luminosity , and find that our result agrees remarkably well with observed estimates of the column density distribution from the sdss for the appropriate luminosity thresholds .
our model reproduces a wide range of quasar phenomena , including observed quasar lifetimes , intrinsic lifetimes , column density distributions , and....
And you have already written the first three sentences of the full article: more than 40 years have passed since the recognition that quasars are at cosmological distances ( schmidt 1963 ; greenstein & mathews 1963 ; mathews & sandage 1963 ) and hence must be powerful energy sources .
a combination of arguments based on time variability and energetics strongly supports the view that the activity is produced by the accretion of gas onto supermassive black holes in the centers of galaxies ( e.g. salpeter 1964 ; zeldovich & novikov 1964 ; lynden - bell 1969 ) .
however , the mechanism that provides the trigger to fuel quasars remains uncertain ..
Please generate the next two sentences of the article | recent discoveries of correlations between masses of black holes in nearby galaxies and either the mass ( magorrian et al . 1998 ) or velocity dispersion ( i.e. the @xmath4-@xmath5 relation : ferrarese & merritt 2000 ; gebhardt et al .
2000 ) of spheroids demonstrate a fundamental link between the growth of supermassive black holes and galaxy formation . |
7,453 | Suppose that you have an abstract for a scientific paper: squeezed states , a special kind of entangled states , are known as a useful resource for quantum metrology . in interferometric sensors they allow to overcome the `` classical '' projection noise limit stemming from the independent nature of the individual photons or atoms within the interferometer . motivated by the potential impact on metrology as wells as by fundamental questions in the context of entanglement , a lot of theoretical and experimental effort has been made to study squeezed states .
the first squeezed states useful for quantum enhanced metrology have been proposed and generated in quantum optics , where the squeezed variables are the coherences of the light field . in this tutorial
we focus on spin squeezing in atomic systems .
we give an introduction to its concepts and discuss its generation in bose - einstein condensates .
we discuss in detail the experimental requirements necessary for the generation and direct detection of coherent spin squeezing .
two exemplary experiments demonstrating adiabatically prepared spin squeezing based on motional degrees of freedom and diabatically realized spin squeezing based on internal hyperfine degrees of freedom are discussed . .
And you have already written the first three sentences of the full article: interferometers , which are among the most precise measurement devices known today , are based on the interference of two coherent atomic or photonic modes .
the quantity to be measured is mapped to the relative phase between the two modes , explicitly using the wave - like nature of the resources ( atoms or photons ) . however , in the actual detection process their particle - like character becomes important ; the population of the two modes can be at best be counted one by one .
traditional interferometers use uncorrelated resources in two coherent modes which results in a poissonian distribution of the population difference at the interferometer output ..
Please generate the next two sentences of the article | the standard deviation of this distribution @xmath0 is the so called projection noise or shot noise limit .
the best theoretically possible phase precision for uncorrelated resources and linear interferometers is given by the classical cramer - rao bound of parameter estimation @xcite . |
7,454 | Suppose that you have an abstract for a scientific paper: we consider the standard model extended by right - handed neutrinos to explain massive neutrinos through the seesaw mechanism .
the new fermion can be observed when it has a sufficiently small mass and large mixings to left - handed neutrinos .
if such a particle is the lightest right - handed neutrino , its contribution to the mass matrix of active neutrinos needs to be canceled by that of a heavier one .
yukawa couplings of the heavier one are then larger than those of the lightest one .
we show that the perturbativity condition gives a severe upper bound on the mixing of the lightest right - handed neutrino , depending on the masses of heavier ones .
models of high energy phenomena , such as leptogenesis , can be constrained by low energy experiments .
perturbativity in the seesaw mechanism * * 0.5 cm takehiko asaka@xmath0 , takanao tsuyuki@xmath1 + 0.4 cm _ @xmath0department of physics , niigata university , 950 - 2181 niigata , japan _
+ _ @xmath1graduate school of science and technology , niigata university , niigata 950 - 2181 , japan
_ 0.2 cm ( septemter 9 , 2015 ) .5 cm .
And you have already written the first three sentences of the full article: the masses of active neutrinos are the most prominent evidence for physics beyond the standard model .
the simplest and sufficient extension is to introduce right - handed neutrinos ( the seesaw mechanism @xcite ) .
they can also explain the baryon asymmetry of the universe @xcite ..
Please generate the next two sentences of the article | right - handed neutrinos have been searched for a long time at various experiments and observations ( for compilations , see refs .
their detectability is determined by two parameters : masses and mixings . in this letter |
7,455 | Suppose that you have an abstract for a scientific paper: converging research suggests that the resting brain operates at the cusp of dynamic instability signified by scale - free temporal correlations .
we asked if the scaling properties of these correlations differ between amplitude and phase fluctuations , which may reflect different aspects of cortical functioning .
using source - reconstructed magneto - encephalographic signals , we found power - law scaling for the collective amplitude and for phase synchronization , both capturing whole - brain activity .
the temporal changes of the amplitude comprise slow , persistent memory processes , whereas phase synchronization exhibits less temporally structured and more complex correlations , indicating a fast and flexible coding .
this distinct temporal scaling supports the idea of different roles of amplitude and phase in cortical functioning .
` power laws , criticality , dfa , amplitude , phase ` .
And you have already written the first three sentences of the full article: it has been proposed that the brain is in or near a critical state | its dynamics may be positioned at the border between spatiotemporal order and disorder , reminiscent of non - equilibrium phase transitions in thermodynamic systems .
the concept of brain criticality is attractive because critical systems display optimal performance on several characteristics such as information transfer , wide dynamic range , information capacity @xcite , and long - term stability .
criticality relates closely to self - organization , which is considered crucial to cortical functioning ..
Please generate the next two sentences of the article | a hallmark of critical behavior is the presence of power laws .
power laws symbolize scale - free behavior , adopting the same form on all time scales : they are self - similar . |
7,456 | Suppose that you have an abstract for a scientific paper: we present alma observations of the [ cii ] line and far - infrared ( fir ) continuum of a normally star - forming galaxy in the reionization epoch , the @xmath0 ly@xmath1 emitter ( lae ) iok-1 .
probing to sensitivities of @xmath2 240 @xmath3jy beam@xmath4 ( 40 km s@xmath4 channel ) and @xmath5 21 @xmath3jy beam@xmath4 , we found the galaxy undetected in both [ cii ] and continuum .
comparison of uv fir spectral energy distribution ( sed ) of iok-1 , including our alma limit , with those of several types of local galaxies ( including the effects of the cosmic microwave background , cmb , on the fir continuum ) suggests that iok-1 is similar to local dwarf / irregular galaxies in sed shape rather than highly dusty / obscured galaxies .
moreover , our @xmath6 fir continuum limit , corrected for cmb effects , implies intrinsic dust mass @xmath7 , fir luminosity @xmath8 ( 42.5122.5 @xmath3 m ) , total ir luminosity @xmath9 ( 81000 @xmath3 m ) and dust - obscured star formation rate ( sfr ) @xmath10
@xmath11 yr@xmath4 , if we assume that iok-1 has a dust temperature and emissivity index typical of local dwarf galaxies .
this sfr is 2.4 times lower than one estimated from the uv continuum , suggesting that @xmath12% of the star formation is obscured by dust .
meanwhile , our @xmath6 [ cii ] flux limit translates into [ cii ] luminosity , @xmath13 } < 3.4 \times 10 ^ 7 l_{\odot}$ ] .
locations of iok-1 and previously observed laes on the @xmath13}$ ] vs. sfr and @xmath13}/l_{\rm fir}$ ] vs. @xmath14 diagrams imply that laes in the reionization epoch have significantly lower gas and dust enrichment than agn - powered systems and starbursts at similar / lower redshifts , as well as local star - forming galaxies . .
And you have already written the first three sentences of the full article: probing visible and dust - obscured star formation and physical properties of galaxies from the local to the early universe , including the epoch of cosmic reionization at redshift @xmath15 , is key to understanding the formation and evolution of galaxies , roles of galaxies in reionization and their relation among diverse galaxy populations . to date , objects such as quasars , active galactic nuclei ( agns ) , their host galaxies , submm - detected starburst galaxies ( smgs ) , normal star - forming galaxies and ( ultra)luminous infrared galaxies ( ( u)lirgs ) have been detected at rest frame far - infrared ( fir ) wavelengths in the local to high redshift universe ( e.g. , * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* ; * ? ? ? |
7,457 | Suppose that you have an abstract for a scientific paper: a phase field model proposed by g.caginalp for the description of phase changes in materials is under consideration .
it is assumed that the medium is located in a container with heat conductive walls that are not subjected to phase changes .
therefore , the temperature variable is defined both in the medium and wall regions , whereas the phase variable is only considered in the medium part . the case of lipschitz domains in two and three dimensions
is studied .
we show that the temperature and phase variables are continuous in time functions with values in @xmath0 and @xmath1 , respectively , provided that the initial values of them are from @xmath0 and @xmath1 , respectively .
moreover , continuous dependence of solutions on the initial data and boundary conditions is proved . .
And you have already written the first three sentences of the full article: phase - field models have been introduced by g.caginalp in @xcite ( see also e.g. @xcite for generalizations ) as a relaxation of stefan problems where the development of the sharp interface between phases should be found exactly .
in contrast to that , phase field models operate with phase functions that assume values from -1 ( solid state ) to 1 ( liquid state ) at each spatial point and change sharply but smoothly over the solidification fronts so that the phase interfaces become smoothed . mathematically speaking , such models consist of two coupled parabolic equations describing the temperature and phase fields satisfying initial and boundary conditions .
phase field models are frequently used to describe processes of melting , solidification , evaporation , and condensation , which is directly related to applications such as metal casting , design of cooling systems , cryopreservation of living tissues etc ..
Please generate the next two sentences of the article | ( see e.g. @xcite ) .
phase field models are also appropriate for the description of phase changes when modeling co@xmath2 sequestration . |
7,458 | Suppose that you have an abstract for a scientific paper: we report the results of giant metrewave radio telescope ( gmrt ) observations of hi absorption towards the frii radio galaxy 3c321 ( j1531 + 2404 ) , which is associated with an active galaxy interacting with a companion .
the absorption profile towards the radio core is well resolved and consists three components , of which the two prominent ones are red - shifted by 186 and 235 km s@xmath0 relative to the optical systemic velocity . the neutral hydrogen column density towards the core is estimated to be @xmath1(hi)=9.23@xmath210@xmath3(@xmath4/100)(@xmath5/1.0 ) @xmath6 , where @xmath4 and @xmath7 are the spin temperature and covering factor of the background source respectively .
we also present radio continuum observations of the source with both the gmrt and the very large array ( vla ) in order to understand the properties of a plume of emission at an angle of @xmath830@xmath9 to the source axis .
this feature appears to have a steep high - frequency spectrum .
the current hotspots and jet are active and seen in x - ray emission .
the spectral ages of the lobes are @xmath1026 myr .
we discuss the possibility that the plume could be relic emission due to an earlier cycle of activity .
[ firstpage ] galaxies : active galaxies : nuclei galaxies : individual : 3c321 radio continuum : galaxies radio lines : galaxies .
And you have already written the first three sentences of the full article: studying the properties of the gaseous environments of radio galaxies and quasars on different scales are important for understanding the interactions of the radio jets with the external environment and the evolution of these sources .
such studies could also provide useful insights towards understanding the triggering of radio activity , and examining consistency of these properties with the unified schemes for active galactic nuclei ( agn ) ( pihlstrm , vermeulen & conway 2003 ; gupta & saikia 2006b ) .
a useful way of probing the cold neutral component of this gas is via 21-cm hi absorption towards radio sources , which range in size from the sub - galactic sized compact steep - spectrum ( css ) and gigahertz peaked - spectrum ( gps ) sources , to the large radio galaxies and quasars which are up to a few mpc in size ..
Please generate the next two sentences of the article | the css and gps objects ( o dea 1998 ) have been inferred to be young ( @xmath1110@xmath12 yr ) , while the larger sources could be older than @xmath810@xmath13 yr ( jamrozy et al .
2008 ; konar et al . |
7,459 | Suppose that you have an abstract for a scientific paper: the so - called negative mode problem in the path integral approach to the false vacuum decay with the effect of gravity has been an unsolved problem .
several years ago , we proposed a conjecture which is to be proved in order to give a consistent solution to the negative mode problem .
we called it the `` no - negative mode conjecture '' . in the present paper
, we give a proof of this conjecture for rather general models .
recently , we also proposed the `` no - supercritical supercurvature mode conjecture '' that claims the absence of supercritical supercurvature modes in the one - bubble open inflation model . in the same paper , we clarified the equivalence between the `` no - negative mode conjecture '' and the `` no - supercritical supercurvature mode conjecture '' .
hence , the latter is also proved at the same time when the former is proved . *
the no - negative mode theorem * * in false vacuum decay with gravity * takahiro tanaka _ department of earth and space science , graduate school of science _ _ osaka university , toyonaka 560 - 0043 , japan _ .
And you have already written the first three sentences of the full article: in recent years , the process of the false vacuum decay with the effect of gravity has been studied extensively in the context of the one - bubble open inflation scenario , in which an open universe is created in a nucleated bubble formed through false vacuum decay@xcite . in this context
, we are interested in the spectrum of quantum fluctuations after the bubble nucleation because it determines the spectrum of primordial fluctuations of the universe . by comparing the predicted spectrum with the observed one
, we can test whether a certain model is viable or not ..
Please generate the next two sentences of the article | the fluctuation can be decomposed by using the spatial harmonics in an open universe .
we denote the eigen value of the spatial harmonics by @xmath0 . |
7,460 | Suppose that you have an abstract for a scientific paper: let @xmath0 be a non - decreasing lvy process .
the first - hitting time process @xmath1 ( which is sometimes referred to as an inverse subordinator ) defined by @xmath2 is a process which has arisen in many applications .
of particular interest is the mean first - hitting time @xmath3 .
this function characterizes all finite - dimensional distributions of the process @xmath4 .
the function @xmath5 can be calculated by inverting the laplace transform of the function @xmath6 , where @xmath7 is the lvy exponent of the subordinator @xmath8 . in this paper , we give two methods for computing numerically the inverse of this laplace transform .
the first is based on the bromwich integral and the second is based on the post - widder inversion formula .
the software written to support this work is available from the authors and we illustrate its use at the end of the paper . .
And you have already written the first three sentences of the full article: let @xmath9 be a lvy subordinator , that is , a non - decreasing lvy process starting from @xmath10 , which is continuous from the right with left limits .
this process has stationary and independent increments and is characterized by its laplace transform @xmath11 the function @xmath7 above is known as the lvy exponent ( or laplace exponent ) and is given by the lvy - khintchine formula : @xmath12 where @xmath13 is the drift and the lvy measure @xmath14 is a measure on @xmath15 which satisfies @xmath16 ( see @xcite , @xcite or @xcite ) .
consider the _.
Please generate the next two sentences of the article | inverse subordinator _
@xmath17 , which is given by the first - passage time of @xmath8 : @xmath18 the process @xmath19 is non - decreasing , and its sample paths are a.s . |
7,461 | Suppose that you have an abstract for a scientific paper: we present measurements of the transmission of radio / microwave pulses through salt in the cote blanche salt mine operated by the north american salt company in st .
mary parish , louisiana .
these results are from data taken in the southwestern region of the 1500 ft .
( 457 m ) deep level of the mine on our third and most recent visit to the mine .
we transmitted and received a fast , high - power , broadband pulse from within three vertical boreholes that were drilled to depths of 100 ft .
( 30 m ) and 200 ft .
below the 1500 ft .
level using three different pairs of dipole antennas whose bandwidths span 125 to 900 mhz . by measuring the relative strength of the received pulses between boreholes with separations of 50 m and 169 m , we deduce the attenuation of the signal attributed to the salt medium .
we fit the frequency dependence of the attenuation to a power law and find the best fit field attenuation lengths to be @xmath0 m at 150 mhz , @xmath1 m at 300 mhz , and @xmath2 m at 800 mhz .
this is the most precise measurement of radio attenuation in a natural salt formation to date .
we assess the implications of this measurement for a future neutrino detector in salt . , , , , salt , radio , microwave , transmission , attenuation , neutrino 42.25.bs , 91.55.de , 93.85.fg , 95.85.ry .
And you have already written the first three sentences of the full article: the observation of cosmic rays with energy higher than the greisen - zatsepin - kuzmin ( gzk ) cutoff at @xmath3 ev @xcite implies a corresponding flux of ultra high - energy ( uhe ) neutrinos , with energy in the @xmath4 ev range @xcite .
these secondary neutrinos are created via photomeson production of cosmic rays on the 2.7 k cosmic microwave background .
detection of these neutrinos would provide unique information about the origin of primary cosmic rays and the nature of their sources ..
Please generate the next two sentences of the article | although predictions for the flux of uhe neutrinos differ by orders of magnitude , a reasonable set of parameters puts the rate of uhe neutrinos at the level of 10/km@xmath5/century @xcite .
a detector volume of hundreds of cubic kilometers water equivalent is required to detect a significant number of neutrinos in this energy regime . |
7,462 | Suppose that you have an abstract for a scientific paper: we set up a framework for the study of the power - suppressed three - parton contribution to the pion electromagnetic form factor in the @xmath0 factorization theorem .
it is first shown that the gauge dependence proportional to parton transverse momenta from the two - parton fock state and the gauge dependence associated with the three - parton fock state cancel each other .
after verifying the gauge invariance , we derive the three - parton - to - three - parton @xmath0-dependent hard kernel at leading order of the coupling constant , and find that it leads to about 5% correction to the pion electromagnetic form factor in the whole range of experimentally accessible momentum transfer squared .
this subleading contribution is much smaller than the leading - order twist-2 , next - to - leading - order twist-2 and leading - order two - parton twist-3 ones , which have been calculated in the literature . .
And you have already written the first three sentences of the full article: aspects of the @xmath0 factorization theorem @xcite in perturbative qcd have been investigated intensively .
one of the important issues is about the derivation of a @xmath0-dependent hard kernel at subleading level , which is defined as the difference between qcd diagrams and effective diagrams for transverse - momentum - dependent ( tmd ) hadron wave functions . we have explained that partons in both sets of diagrams should remain off mass shell by @xmath1 in the @xmath0 factorization theorem @xcite .
the same statement has been made in the application of the @xmath0 factorization theorem to inclusive processes such as prompt photon production @xcite ..
Please generate the next two sentences of the article | the off - shellness of partons may cause concern of the gauge invariance @xcite .
however , we have shown that the gauge dependence cancels between the above two sets of diagrams , and a @xmath0-dependent hard kernel is gauge invariant @xcite . following this prescription , the next - to - leading - order ( nlo ) correction to the pion transition ( electromagnetic ) form factor associated with the process @xmath2 has been calculated at leading twist , i.e. , twist 2 @xcite . here |
7,463 | Suppose that you have an abstract for a scientific paper: we reinvestigate the @xmath0 dissociation processes induced by the reactions with nucleons , @xmath1 , in the meson - exchange model .
main constraints used in this work are vector - meson dominance and charm vector - current conservation .
we show that the cross section for @xmath2 can be larger than that for @xmath3 when these constraints are imposed .
the dependence of the cross sections on the coupling constants is analyzed in detail , and the comparison with the recent quark - interchange model predictions is also made . .
And you have already written the first three sentences of the full article: since the suggestion of @xmath0 suppression as a signal for the formation of the quark - gluon plasma in relativistic heavy ion collisions @xcite , understanding the interactions of the @xmath0 with other hadrons has been an important issue as @xmath0 dissociation by hadrons could also cause the suppression of the produced @xmath0 @xcite . because the @xmath0-hadron interactions can not be directly accessed by present experiments ,
the @xmath0-hadron cross sections have been estimated through several assumptions and/or model calculations .
empirically , the @xmath0-nucleon cross sections have been estimated by using the data for @xmath0 photoproduction from the nucleon @xcite , @xmath0 photoproduction from nuclei , and @xmath0 production from the nucleon - nucleus collisions @xcite ..
Please generate the next two sentences of the article | since those data are scattered over a wide range of energy and the estimation is model - dependent , the estimated values for the @xmath0-nucleon cross sections range from @xmath4 mb to @xmath5 mb .
( see also ref . |
7,464 | Suppose that you have an abstract for a scientific paper: propagation of ultrashort optical pulses in a dense resonant medium is considered in the semiclassical limit . in our analysis , we place emphasis on several main points . first , we study transformations of spectra in the process of pulse propagation and interactions with another pulse .
the second point involves the transient processes ( including pulse compression ) connected with self - induced transparency soliton formation inside the medium .
finally , the third aspect is the study of collisions of co- and counter - propagating pulses in the medium . in the last case
, the investigation of symmetric and asymmetric collisions shows the possibility of effectively controlling the parameters of transmitted radiation . .
And you have already written the first three sentences of the full article: a two - level medium , i.e. a medium composed of a collection of two - level systems ( atoms , molecules , etc . ) , is the basic quantum - mechanical model in the theory of light - matter interaction .
it plays the same fundamental role as a harmonic oscillator in classical physics .
therefore , the comprehensive study of this model and its generalizations is one of the most important problems in theoretical optics ..
Please generate the next two sentences of the article | the two - level model has allowed the description of a number of well - known effects @xcite including the effect of self - induced transparency @xcite . among the further generalizations of the model we single out the one which takes into account the near dipole - dipole interactions between the elements of the dense medium due to introduction into the equations of the so - called local - field correction @xcite . in stationary regime ,
the presence of the local field results in the remarkable effect of intrinsic optical bistability @xcite . in the regime of optical pulses , the investigation of local - field effects is linked with solitonic dynamics @xcite , optical switching @xcite , etc . |
7,465 | Suppose that you have an abstract for a scientific paper: the fundamental solutions of diffusion equation for the local - equilibrium and nonlocal models are considered as the limiting cases of the solution of a problem related to consideration of the brownian particles random walks .
the differences between fundamental solutions were studied .
it was shown that on the period of observation time and distances exceeding the time and space associated with one step of random walk the fundamental solutions of diffusion and telegraph equations are very close to each other .
in particular , these fundamental solutions are very close to the values of the probability density distribution of diffusive particles that is obtained from the accurate solution of the random walk problem .
the difference between the probability density values for the models considered is decreased with time as @xmath0 , the relative difference as @xmath1 , and velocity of propagation of these fixed distribution densities is proportional to @xmath2 . the new modified non - local diffusion equation is suggested .
it contains only microparameters of the random walk problem . .
And you have already written the first three sentences of the full article: it is known that one of the properties of linear diffusion equation solution @xmath3 is the infinite velocity of perturbations propagation .
it is seen , for example , from the fundamental solution of this equation @xmath4 here @xmath5 is the fundamental solution presented in the gaussian form , @xmath6 is concentration , @xmath7 is the diffusion coefficient , @xmath8 defines the unit step heaviside function , @xmath9 is associated with current coordinate , @xmath10 is the current time .
this solution contradicts to intuitive speculations that diffusive particles and any information about their movement are propagated with finite velocities ..
Please generate the next two sentences of the article | we should mark that equation ( [ eq:1 ] ) is a consequence of supposition that principles associated with locality and local thermodynamic equilibrium are valid . in the frame of this supposition
one can use the diffusion fick s law in standard form @xmath11 connecting the current particle function and the concentration gradient . by analogy , for conductive heat transfer |
7,466 | Suppose that you have an abstract for a scientific paper: we discuss the finite - size effects on the chiral phase transition in qcd .
we employ the nambu - jona - lasinio model and calculate the thermodynamic potential in the mean - field approximation .
finite - size effects on the thermodynamic potential are taken into account by employing the multiple reflection expansion .
the critical temperature is lowered and the order of the phase transition is changed form first to second as the size of the system of interest is reduced . .
And you have already written the first three sentences of the full article: the phase structure of qcd at high temperature @xmath0 and/or quark chemical potential @xmath1 has attracted a great deal of interest in cosmology , compact stars and heavy - ion collisions . during the last decades , significant advances have been made in our understandings of the phase structure of hot and/or dense quark matter . at the present time
, it is widely accepted that the qcd vacuum undergoes a phase transition ( into a chirally symmetric phase or a color - superconducting phase ) at sufficiently high @xmath0 and @xmath1 .
the studies of the phase structure of qcd so far have been exclusively devoted to homogeneous quark matter in bulk ..
Please generate the next two sentences of the article | however , the qgp phase created in relativistic heavy - ion collisions has a finite size and it is not obvious that the size is large enough to allow to apply the thermodynamic limit .
if the size of the system of interest is not large enough , we need to take account of the deviations from thermodynamic calculations . |
7,467 | Suppose that you have an abstract for a scientific paper: proposed scaling relations of a characteristic timescale in the x - ray power spectral density of galactic and supermassive black holes have been used to argue that the accretion process is the same for small and large black holes . here , we report on the discovery of this timescale in the near - infrared radiation of sgr a * , the @xmath0 black hole at the center of our galaxy , which is the most extreme sub - eddington source accessible to observations .
previous simultaneous monitoring campaigns established a correspondence between the x - ray and near - infrared regime and thus the variability timescales are likely identical for the two wavelengths .
we combined keck and vlt data sets to achieve the necessary dense temporal coverage , and a time baseline of four years allows for a broad temporal frequency range .
comparison with monte carlo simulations is used to account for the irregular sampling .
we find a timescale at @xmath1min ( errors mark the 90% confidence limits ) which is inconsistent with a recently proposed scaling relation that uses bolometric luminosity and black hole mass as parameters .
however , our result fits the expected value if only linear scaling with black hole mass is assumed .
we suggest that the luminosity - mass - timescale relation applies only to black hole systems in the soft state . in the hard state , which is characterized by lower luminosities and accretion rates ,
there is just linear mass scaling , linking sgr a * to hard state stellar mass black holes . .
And you have already written the first three sentences of the full article: cosmic black holes ( bh ) show a very wide range of masses : from stellar masses to hundreds of millions of solar masses . an open question has long been whether the accretion and variability processes occurring in the immediate vicinity of the event horizon are the same over this broad mass range . to test this intriguing possibility , investigators identified and studied a characteristic timescale associated with the aperiodic x - ray variability of black hole x - ray binaries ( bhxrbs ) and active galactic nuclei ( agn ; see , e.g. , * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | this timescale corresponds to a break in the power spectral density ( psd ) at a certain temporal frequency where a power - law of slope @xmath2 ( with @xmath3 ) breaks to a steeper slope @xmath4 .
@xcite proposed a scaling relationship between the break frequency , the mass of the black hole and the bolometric luminosity of its accretion flow . |
7,468 | Suppose that you have an abstract for a scientific paper: we study the energy spectrum of the inclusive bottom - flavored mesons in top - quark decay into a charged - higgs - boson and a massless bottom quark at next - to - leading order ( nlo ) in the two - higgs - doublet model . to extract the result we work in the zero - mass variable - flavor - number scheme(zm - vfns ) using realistic nonperturbative fragmentation functions obtained through a global fit to @xmath0 data from cern lep1 and slac slc on the z - boson resonance .
we study both the contribution of the bottom - quark fragmentation and the gluon fragmentation to produce the bottom - flavored meson ( b - meson ) .
we find that the contribution of the gluon leads to an appreciable reduction in decay rate at low values of the b - meson energy .
it means the nlo corrections are significant . .
And you have already written the first three sentences of the full article: top quark is the heaviest elementary particle with a mass of @xmath1 gev @xcite .
top s large mass is a reason to rapid decay so that it has no time to hadronize and if it were not for the confinement of color , the top quark could be considered as a free particle .
this property allows the top quark to behave like a real particle and one can safely describe its decay in perturbative theory ..
Please generate the next two sentences of the article | the large hadron collider ( lhc ) is a superlative top factory with 90 million @xmath2-pairs per year which will allow us to perform accurate studies of the top - quark properties , such as its mass @xmath3 , total decay width @xmath4 , the effective weak mixing angle , and elements @xmath5 of the cabibbo - kobayashi - maskawa ( ckm ) @xcite quark mixing matrix .
the theoretical aspects of top - quark physics at the lhc are summarized in a recent paper @xcite . since @xmath6 , |
7,469 | Suppose that you have an abstract for a scientific paper: jerome h. friedman was born in yreka , california , usa , on december 29 , 1939 .
he received his high school education at yreka high school , then spent two years at chico state college before transferring to the university of california at berkeley in 1959 .
he completed an undergraduate degree in physics in 1962 and a ph.d . in high - energy particle physics in 1968 and was a post - doctoral research physicist at the lawrence berkeley laboratory during 19681972 .
in 1972 , he moved to stanford linear accelerator center ( slac ) as head of the computation research group , retaining this position until 2006 . in 1981 , he was appointed half time as professor in the department of statistics , stanford university , remaining half time with his slac appointment .
he has held visiting appointments at csiro in sydney , cern and the department of statistics at berkeley , and has had a very active career as a commercial consultant .
jerry became professor emeritus in the department of statistics in 2007 .
apart from some 30 publications in high - energy physics early in his career , jerry has published over 70 research articles and books in statistics and computer science , including co - authoring the pioneering books _ classification and regression trees _ and _ the elements of statistical learning_. many of his publications have hundreds if not thousands of citations ( e.g. , the cart book has over 21,000 ) .
much of his software is incorporated in commercial products , including at least one popular search engine .
many of his methods and algorithms are essential inclusions in modern statistical and data mining packages .
honors include the following : the rietz lecture ( 1999 ) and the wald lectures ( 2009 ) ; election to the american academy of arts and sciences ( 2005 ) and the us national academy of sciences ( 2010 ) ; a fellow of the american statistical association ; paper of the year ( _ jasa _ 1980 , 1985 ; _ technometrics _ 1998 , 1992 ) ; statistician of the year ( asa , chicago....
And you have already written the first three sentences of the full article: * nf : * welcome jerry . let s begin at the beginning , which was not in this part of california .
* jf : * that s correct .
i grew up in a tiny town near the oregon border called yreka : it s `` bakery '' spelled backwards without the `` b. '' yreka bakery is a palindrome and there _ was _ a yreka bakery in yreka ..
Please generate the next two sentences of the article | * nf : * what were your parents doing ?
* jf : * my mother was a housewife and my father , along with his brother , owned a laundry and dry - cleaning establishment there that they and my grandparents founded in the 1930s . |
7,470 | Suppose that you have an abstract for a scientific paper: we consider gas at densities appropriate to protoplanetary disks and calculate its ability to cool due to line radiation emitted by @xmath0 molecules within the gas .
our work follows that of neufeld & kaufman ( 1993 ; , 418 , 263 ) , expanding on their work in several key aspects , including use of a much expanded line database , an improved escape probability formulism , and the inclusion of dust grains , which can absorb line photons .
although the escape probabilities formally depend on a complicated combination of optical depth in the lines and in the dust grains , we show that the cooling rate including dust is well approximated by the dust - free cooling rate multiplied by a simple function of the dust optical depth .
we apply the resultant cooling rate of a dust - gas mixture to the case of a solar nebula shock pertinent to the formation of chondrules , millimeter - sized melt droplets found in meteorites .
our aim is to assess whether line cooling can be neglected in chondrule - forming shocks or if it must be included .
we find that for typical parameters , @xmath0 line cooling shuts off a few minutes past the shock front ; line photons that might otherwise escape the shocked region and cool the gas will be absorbed by dust grains . during the first minute or so
past the shock , however , line photons will cool the gas at rates @xmath1 , dropping the temperature of the gas ( and most likely the chondrules within the gas ) by several hundred k. inclusion of @xmath0 line cooling therefore must be included in models of chondrule formation by nebular shocks . .
And you have already written the first three sentences of the full article: in many astrophysical settings , emission of radiation via rotational and vibrational transitions of molecules plays an important role in cooling warm gas .
because the emission of such radiation is in sharp spectral lines , this mechanism is referred to as line cooling .
line radiation from the water molecule @xmath2 , with its permanent electric dipole and its high cosmochemical abundance , is significant in a variety of settings ranging from molecular clouds to protostellar envelopes ( e.g. , cernicharo & crovisier 2005 ) ..
Please generate the next two sentences of the article | more recently , line cooling from @xmath2 molecules has been recognized to play a pivotal role in the energetics following the passage of a shock wave through the dense gas in the solar nebula protoplanetary disk ( see desch et al .
2005 ) . |
7,471 | Suppose that you have an abstract for a scientific paper: fourier reconstruction algorithms significantly outperform conventional back - projection algorithms in terms of computation time . in photoacoustic imaging , these methods require interpolation in the fourier space domain , which creates artifacts in reconstructed images . we propose a novel reconstruction algorithm that applies the one - dimensional nonuniform fast fourier transform to photoacoustic imaging .
it is shown theoretically and numerically that our algorithm avoids artifacts while preserving the computational effectiveness of fourier reconstruction
. * key words . * image reconstruction , photoacoustic imaging , planar measurement geometry , fast algorithm , nonuniform fft . .
And you have already written the first three sentences of the full article: photoacoustic imaging ( pai ) is a novel promising tool for visualizing light absorbing structures in an optically scattering medium , which carry valuable information for medical diagnostics .
it is based on the generation of acoustic waves by illuminating an object with pulses of non - ionizing electromagnetic radiation , and combines the high contrast of pure optical and the high resolution of ultrasonic imaging .
the method has demonstrated great promise for a variety of biomedical applications , such as imaging of animals @xcite , early cancer diagnostics @xcite , and imaging of vasculature @xcite ..
Please generate the next two sentences of the article | when an object is illuminated with short pulses of non - ionizing electromagnetic radiation , it absorbs a fraction of energy and heats up .
this in turn induces acoustic ( pressure ) waves , that are recorded with acoustic detectors outside of the object . |
7,472 | Suppose that you have an abstract for a scientific paper: we have observed the millisecond x - ray pulsar sax j1808.43658 on three occasions during its 2000 outburst with the _ bepposax _ satellite .
the source was highly variable and erratic during this outburst , and by coincidence we obtained data only during times when the source had very low luminosities . during our observations
, we detected four faint sources .
the source closest to the position of sax j1808.43658 is still @xmath01.6@xmath1 away .
this source can only be identified with sax j1808.43658 if we assume that the _ bepposax _ positional reconstruction is not completely understood .
we also reanalyzed a _
bepposax _ observation taken in march 1999 when the source was in quiescence and during which the source was thought to have been detected ( stella et al .
2000 ) . based on the similarities ( position and luminosity ) of this source with the above mentioned source @xmath2 away from sax j1808.43658 ,
it is possible that they are the same source .
if this source is not the millisecond pulsar , then during all _ bepposax _ observations of sax j1808.43658 ( the 2000 outburst ones and the 1999 quiescent one ) , the millisecond pulsar was not detected .
a reanalysis of the _ asca _ quiescent data of sax j1808.43658 ( dotani , asai , & wijnands 2000 ) confirms that during this observation the source was securely detected in quiescence .
we discuss our results for sax j1808.43658 in the context of the quiescent properties of low - mass x - ray binary transients . .
And you have already written the first three sentences of the full article: in 1996 september , a new x - ray transient was discovered with the wide field cameras ( wfcs ) on board the _ bepposax _ satellite and the source was designated sax j1808.43658 ( in t zand et al .
type i x - ray bursts were detected demonstrating that the compact object in this system is a neutron star and that the source is a low - mass x - ray binary ( lmxb ) . from the bursts , an initial distance estimate of 4 kpc was determined but this was later revised to 2.5 kpc ( in t zand et al .
1998 , 2001 ) ..
Please generate the next two sentences of the article | the maximum luminosity of sax j1808.43658 was only approximately @xmath3 erg s@xmath4 indicating that the source was a faint neutron - star x - ray transient .
the outburst lasted about three weeks after which the source returned to quiescence . in april 1998 , |
7,473 | Suppose that you have an abstract for a scientific paper: the diluted ising antiferromagnet , fe@xmath0zn@xmath1f@xmath2 , has been investigated by dynamic susceptibility measurements in zero and and finite applied dc - fields . in zero field , there is a para- to antiferromagnetic phase transition at @xmath3 @xmath4 , followed by a dramatic slowing down of the dynamics at low temperatures .
the latter described by a pure arrhenius law .
the effect of a superposed dc - field on the antiferromagnetic phase transition and on the low - temperature dynamics is investigated , and a comprehensive static and dynamic phase diagram in the @xmath5 plane is derived . in agreement with earlier results on the same system , @xmath6follows a random - exchange ising model to random - field ising model crossover scaling for fields @xmath71.5 t. a random - field induced glassy dynamics appears for higher values of h , where the antiferromagnetic phase transition is destroyed .
the low - temperature dynamics shows striking similarities with the behavior observed in reentrant antiferromagnets .
0.2 cm pacs numbers : 75.40.gb 75.50.lk 0.2 cm 2 .
And you have already written the first three sentences of the full article: the diluted ising antiferromagnet fe@xmath8zn@xmath9f@xmath2 in an external magnetic field has proven to be a good model system for the random - exchange ising model ( reim ) ( @xmath10 0 ) and the random field ( rfim ) ising model ( @xmath11 0 ) @xcite . in the original derivation of the equivalence between the rfim and a diluted ising antiferromagnet in a uniform applied field
, weak dilution and small values of @xmath12 were assumed @xcite ( @xmath13 is the magnitude of the exchange interaction ) . in the fe@xmath8zn@xmath9f@xmath2 system ,
weak dilution implies fe concentrations well above the percolation threshold @xcite @xmath14=0.25 and the most convincing experimental results on the rfim critical behaviour have been obtained on samples with @xcite @xmath150.46 . on the other hand.
Please generate the next two sentences of the article | , interesting dynamic properties may become observable in the limit of strong dilution .
rfim systems have been argued to attain extremely long relaxation times at temperatures near @xmath16 @xcite and for large values of @xmath12 , where the ordered phase is destroyed , it has been argued that a glassy phase will appear , even without exchange frustration being present in the system @xcite . |
7,474 | Suppose that you have an abstract for a scientific paper: large - field inflation in supergravity requires the approximate global symmetry needed to protect flatness of the scalar potential . in helical - phase inflation ,
the u(1 ) symmetry of the khler potential is assumed , the phase part of the complex scalar of a chiral superfield plays the role of inflaton , and the radial part is strongly stabilized .
the original model of helical phase inflation , proposed by li , li and nanopoulos ( lln ) , employs an extra ( stabilizer ) superfield .
we propose a more economical new class of the helical phase inflationary models without a stabilizer superfield . as the specific examples , the quadratic , the natural , and the starobinsky - type inflationary models
are studied in our approach .
+ revised version ut-15 - 33 + october 2015 desy 15 - 163 + ipmu 15 - 0143 3 cm * single - superfield helical - phase inflation * .3 in sergei v. ketov @xmath0 and takahiro terada @xmath1 .1 in _ @xmath2 department of physics , tokyo metropolitan university + minami - ohsawa 1 - 1 , hachioji - shi , tokyo 192 - 0397 , japan + @xmath3 kavli institute for the physics and mathematics of the universe ( ipmu ) + the university of tokyo , chiba 277 - 8568 , japan + @xmath4 institute of physics and technology , tomsk polytechnic university + 30 lenin ave . ,
tomsk 634050 , russian federation + @xmath5 department of physics ,
the university of tokyo , tokyo 113 - 0033 , japan + @xmath6 deutsches elektronen - synchrotron ( desy ) , 22607 hamburg , germany _
.1 in [email protected] , [email protected] .4 in .
And you have already written the first three sentences of the full article: inflation well explains the origin of primordial density fluctuations , as well as flatness and homogeneity of our universe .
the general idea is so far quite successful , and inflationary models are confronted with precise observational data @xcite . since inflation is a high - energy phenomenon , it is important to study it in a more fundamental framework such as supergravity @xcite which is well motivated by particle physics and string theory . in particular , should tensor perturbations be detected in a near future , it would imply large ( trans - planckian ) excursions of the inflaton field @xcite . then the planck - suppressed corrections can not be neglected .
even if supersymmetry is broken at a higher scale than that of inflation , supergravity corrections have substantial impact on the scalar potential ..
Please generate the next two sentences of the article | as is well known , a generic scalar potential in supergravity tends to be very steep in the large - field region , because of the exponential factor of the khler potential .
accordingly , it is hard to achieve flatness of the scalar potential along the whole inflationary trajectory in the case of large - field models . |
7,475 | Suppose that you have an abstract for a scientific paper: we present a study of three - mode parametric instability in large - scale gravitational - wave detectors .
previous work used a linearised model to study the onset of instability .
this paper presents a non - linear study of this phenomenon , which shows that the initial stage of exponential rise of the amplitudes of a higher order optical mode and the mechanical internal mode of the mirror is followed by a saturation phase , in which all three participating modes reach a new equilibrium state with constant oscillation amplitudes .
results suggest that stable operation of interferometers may be possible in the presence of such instabilities , thereby simplifying the task of suppression . .
And you have already written the first three sentences of the full article: three mode parametric instability in large scale , high optical power gravitational wave detectors was predicted by braginsky _
et al . _ in 2001 @xcite .
all subsequent analyses @xcite relied on the model prediction where amplitudes of certain acoustic modes of the interferometer mirrors would grow exponentially once an instability threshold of input laser power is reached ..
Please generate the next two sentences of the article | it was generally considered that the exponential growth would eventually render the whole setup unstable and cause an interferometer to lose lock .
this prognosis , however , relied on a linearised approximation of the 3-mode optomechanical interaction which is valid only for small amplitudes of acoustic and stokes modes . for larger values , it is intuitively obvious that non - linearity should ultimately modify this growth . if the optical configuration can be maintained one would expect that the acoustic and higher - order optical oscillations should saturate . |
7,476 | Suppose that you have an abstract for a scientific paper: let @xmath0 be a transitive homeomorphism of the two - dimensional torus in the homotopy class of the identity .
we show that a lift of @xmath0 to the universal covering is transitive if and only if the rotation set of the lift contains the origin in its interior . .
And you have already written the first three sentences of the full article: given an homeomorphism @xmath0 of the torus @xmath1 which is in the homotopy class of the identity , and a lift @xmath2 of @xmath0 to the universal covering , one can associate to @xmath3 its rotation set @xmath4 , a convex and compact subset of the plane consisting of all the limit points of sequences of the form @xmath5 , with @xmath6 and @xmath7 .
this definition was introduced by misiurewicz and ziemian in @xcite as a generalization of the rotation number for circle homeomorphisms , and has proved to be a useful tool in the study of the dynamics of these homeomorphisms . in particular , when the rotation set has nonempty interior it has been shown that @xmath0 exhibits very rich dynamics , with an abundance of periodic points and positive topological entropy @xcite .
but this complex behavior is not restricted to rotation sets with nonempty interior : there are several examples of homeomorphisms with rich dynamical properties such that their rotation set is a singleton . in this work.
Please generate the next two sentences of the article | we are concerned with the interplay between transitivity of @xmath0 , transitivity on the universal covering space and rotation sets .
our motivation in studying transitivity on the universal covering space is to understand when it is possible for the dynamical system to exhibit this form of extreme transitivity , where there exist trajectories that are not only dense on the surface , but also explore all possible loops and directions . |
7,477 | Suppose that you have an abstract for a scientific paper: we have found a photoevaporated disk in the orion nebula that includes a wide binary .
hst / acs observations of the proplyd 124 - 132 show two point - like sources separated by @xmath0 , or about 60 au at the distance of orion .
the two sources have nearly identical @xmath1 and @xmath2 magnitudes .
we analyze the brightest component , source n , comparing the observed magnitudes with those predicted using a 1myr baraffe / nextgen isochrone with different accretion luminosities and extinctions .
we find that a low mass ( @xmath3 ) brown dwarf @xmath41 myr old with mass accretion rate @xmath5 , typical for objects of this mass , and about 2 magnitudes of visual extinction provides the best fit to the data .
this is the first observation of a circumbinary disk undergoing photoevaporation and , if confirmed by spectroscopic observations , the first direct detection of a wide substellar pair still accreting and enshrouded in its circumbinary disk . .
And you have already written the first three sentences of the full article: we report on the discovery of a circumbinary disk seen in silhouette against the bright nebular background of the orion nebula . using multicolor observations taken with the hubble space telescope as part of the hst treasury program on the orion nebula cluster ,
we show that source 124 - 132 , a photoevaporated disk @xmath6 north of the trapezium previously imaged in h@xmath7 @xcite , harbors a binary .
binaries represent a typical product of the gravitational collapse of cores with high angular momentum ..
Please generate the next two sentences of the article | in fact , the majority of stars in star - forming regions are in binary or multiple systems ( see duchene 1999 ; monin et al . 2007 ; and for a review mathieu 2000 and references therein ) .
also the onc contains a large number of binary stars @xcite , although the current counts indicate that the binary frequency , especially at the low - mass end , is lower by a factor 2 to 5 than in star - forming t associations like taurus - auriga @xcite . whether the relative paucity of binary systems in the onc is due to the initial conditions of the cloud or to a feedback " effect , like the ejection of binary companions in the cluster core caused by close dynamic encounters , is still a subject of debate . |
7,478 | Suppose that you have an abstract for a scientific paper: in the present article , we use an axially symmetric galactic gravitational model with a disk - halo and a spherical nucleus , in order to investigate the transition from regular to chaotic motion for stars moving in the meridian @xmath0 plane .
we study in detail the transition from regular to chaotic motion , in two different cases : the time independent model and the time evolving model . in both cases , we explored all the available range regarding the values of the main involved parameters of the dynamical system . in the time dependent model ,
we follow the evolution of orbits as the galaxy develops a dense and massive nucleus in its core , as mass is transported exponentially from the disk to the galactic center .
we apply the classical method of the poincar @xmath1 phase plane , in order to distinguish between ordered and chaotic motion .
the lyapunov characteristic exponent is used , to make an estimation of the degree of chaos in our galactic model and also to help us to study the time dependent model .
in addition , we construct some numerical diagrams in which we present the correlations between the main parameters of our galactic model .
our numerical calculations indicate , that stars with values of angular momentum @xmath2 less than or equal to a critical value @xmath3 , moving near to the galactic plane , are scattered to the halo upon encountering the nuclear region and subsequently display chaotic motion .
a linear relationship exists between the critical value of the angular momentum @xmath3 and the mass of the nucleus @xmath4 .
furthermore , the extent of the chaotic region increases as the value of the mass of the nucleus increases .
moreover , our simulations indicate that the degree of chaos increases linearly , as the mass of the nucleus increases .
a comparison is made between the critical value @xmath3 and the circular angular momentum @xmath5 at different distances from the galactic center . in the time dependent model
, there are orbits that change their....
And you have already written the first three sentences of the full article: central mass concentrations ( cmcs ) are frequently found in galaxies of all types , such as barred , spiral , disk or elliptical galaxies . a few examples of cmcs are : \1 .
large condensations of molecular gas with scales of 0.1 @xmath6 2kpc and masses of @xmath7 @xmath8 are found in the central regions ( e.g. , ohta , et al . , 1996 ;
sakamoto et al . , 1999 ; regan et al . ,.
Please generate the next two sentences of the article | they are particularly evident in barred galaxies , where they are believed to be created by bar - driven inflow ( e.g. , athanassoula , 1992 ; heller & shlosman , 1994 ) .
the contribution of gas in the galactic evolution is a very important parameter . |
7,479 | Suppose that you have an abstract for a scientific paper: we prove that refined analytic torsion on a manifold with boundary is an analytic section of the determinant line bundle over the representation variety . as a fundamental application
we establish a gluing formula for refined analytic torsion on connected components of the complex representation space which contain a unitary point .
finally we provide a new proof of brning - ma gluing formula for the ray - singer torsion associated to a non - hermitian connection .
our proof is quite different from the one given by brning and ma and uses a temporal gauge transformation . .
And you have already written the first three sentences of the full article: the ray - singer conjecture has been formulated in the seminal paper of ray and singer @xcite and proved independently by cheeger @xcite and mller @xcite for unitary representations .
its importance stems from the fact that as in the atiyah - singer index theorem , it equates analytic with combinatorial quantities , the analytic ray - singer and the combinatorial reidemeister torsions . by construction ,
both the analytic ray - singer and the combinatorial reidemeister torsions provide canonical norms on the determinant line of cohomology ..
Please generate the next two sentences of the article | there have been various approaches to obtain a canonical construction of analytic and reidemeister torsions as elements instead of norms of the determinant line of the cohomology .
these constructions seek to refine the notion of analytic and reidemeister torsion norms on that determinant line , which basically corresponds to fixing a complex phase in the family of complex vectors of length one . in case of the reidemeister torsion |
7,480 | Suppose that you have an abstract for a scientific paper: we analyze the transport of heat along a chain of particles interacting through anharmonic potentials consisting of quartic terms in addition to harmonic quadratic terms and subject to heat reservoirs at its ends .
each particle is also subject to an impulsive shot noise with exponentially distributed waiting times whose effect is to change the sign of its velocity , thus conserving the energy of the chain .
we show that the introduction of this energy conserving stochastic noise leads to fourier s law .
the behavior of thels heat conductivity for small intensities of the shot noise and large system sizes are found to obey a finite - size scaling relation .
we also show that the heat conductivity is not constant but is an increasing monotonic function of temperature .
pacs numbers : 05.10.gg , 05.70.ln , 05.60.-k .
And you have already written the first three sentences of the full article: the derivation of fourier s law , or any other macroscopic law , from the microscopic underlying motion of particles constitutes a major task in condensed matter physics .
this task comprises not only the derivation itself but also the problem of setting up the appropriate microscopic model . the simplest model one could conceive to derive fourier s law is a chain of particles interacting through harmonic potentials in contact with two heat reservoirs at each end .
however , it has been shown by rieder et al @xcite that this model does not lead to fourier s law . since then , several microscopic models have been introduced and studied @xcite some of them leading instead to the so called anomalous fourier s law ..
Please generate the next two sentences of the article | fourier s law states that the heat flux @xmath0 is proportional to the gradient of the temperature @xmath1 , that is , @xmath2 where @xmath3 is the heat conductivity . if we consider a small bar of length @xmath4 subject to a difference in temperature @xmath5 , then @xmath6 .
thus a microscopic model for fourier s law should predict a heat flux that decreases with @xmath4 , for a fixed value of @xmath5 , according to @xmath7 this amounts to saying that @xmath3 is finite . |
7,481 | Suppose that you have an abstract for a scientific paper: we present our theoretical and numerical results on thermodynamic properties and the microscopic mechanism of two successive transitions in vanadium spinel oxides @xmath0v@xmath1o@xmath2 ( @xmath0=zn , mg , or cd ) obtained by monte carlo calculations of an effective spin - orbital - lattice model in the strong correlation limit .
geometrical frustration in the pyrochlore lattice structure of v cations suppresses development of spin and orbital correlations , however , we find that the model exhibits two transitions at low temperatures .
first , a discontinuous transition occurs with an orbital ordering assisted by the tetragonal jahn - teller distortion .
the orbital order reduces the frustration in spin exchange interactions , and induces antiferromagnetic correlations in one - dimensional chains lying in the perpendicular planes to the tetragonal distortion . secondly , at a lower temperature , a three - dimensional antiferromagnetic order sets in continuously , which is stabilized by the third - neighbor interaction among the one - dimensional antiferromagnetic chains .
thermal fluctuations are crucial to stabilize the collinear magnetic state by the order - by - disorder mechanism .
the results well reproduce the experimental data such as transition temperatures , temperature dependence of the magnetic susceptibility , changes of the entropy at the transitions , and the magnetic ordering structure at low temperatures .
quantum fluctuation effect is also examined by the linear spin wave theory at zero temperature .
the staggered moment in the ground state is found to be considerably reduced from saturated value , and reasonably agrees with the experimental data . .
And you have already written the first three sentences of the full article: geometrical frustration in strongly - correlated systems is one of the long - standing problems in condensed matter physics .
frustration suppresses a formation of a simpleminded long - range order and results in nearly - degenerate ground - state manifolds of a large number of different states .
many well - known examples are found in frustrated antiferromagnetic ( af ) spin systems . there ,.
Please generate the next two sentences of the article | all the antiparallel spin conditions between interacting pairs can not be satisfied at the same time because closed loops contain an odd number of sites .
the degeneracy due to the frustration yields nontrivial phenomena such as complicated ordering structures , spin liquid states , and glassy states . |
7,482 | Suppose that you have an abstract for a scientific paper: we calculated for the nearest active galactic nucleus ( agn ) , centaurus a ( cen a ) , the flux of high energy cosmic rays and of accompanying secondary photons and neutrinos expected from hadronic interactions in the source .
we used as two basic models for the generation of ultrahigh energy cosmic rays ( uhecr ) shock acceleration in the radio jet and acceleration in the regular electromagnetic field close to the core of the agn , normalizing the uhecr flux to the observations of the auger experiment .
here we compare the previously obtained photon fluxes with the recent data reported by the fermi lat and h.e.s.s
. collaborations . in the case of the core model ,
we find good agreement both for the predicted spectral shape and the overall normalization between our earlier results and the h.e.s.s .
observations for a primary proton energy @xmath0 with @xmath1 or smaller .
a broken - power law with high - energy part @xmath2 leads to photon fluxes in excess of the fermi measurements .
the energy spectrum of the photon fluxes obtained by us for the jet scenario is in all cases at variance with the h.e.s.s
. and fermi observations . .
And you have already written the first three sentences of the full article: progress in cosmic ray ( cr ) physics@xcite has been hampered for long time by the deflection of charged cosmic rays in magnetic fields , preventing the identification of individual sources .
this problem could be solved by using the neutral messengers that should be produced as secondaries in hadronic cr interactions close to the source . however , the secondary photons generated are difficult to disentangle from photons produced by synchrotron radiation or inverse compton scattering of electrons .
moreover , high energy photons are strongly absorbed both in the source and propagating over extragalactic distances . by contrast , the extremely large mean free path of neutrinos together with the relatively poor angular resolution of neutrino telescopes and the small expected event numbers makes the identification of extragalactic sources challenging using only the neutrino signal ..
Please generate the next two sentences of the article | performing neutrino astronomy beyond the establishment of a diffuse neutrino background requires therefore most likely additional input , either timing or angular information from high energy photon or cr experiments . the recently announced evidence@xcite for a correlation of the arrival directions of uhecrs observed by the pierre auger observatory ( pao ) with active galactic nuclei ( agn ) may provide a first test case for successful `` multi - messenger astronomy . ''
in particular , ref |
7,483 | Suppose that you have an abstract for a scientific paper: we present the results of direct numerical simulations ( dns ) of turbulent flows seeded with millions of passive inertial particles .
the maximum reynolds number is @xmath0 .
we consider particles much heavier than the carrier flow in the limit when the stokes drag force dominates their dynamical evolution .
we discuss both the _ transient _ and the _ stationary _ regimes . in the transient regime , we study the growth of inhomogeneities in the particle spatial distribution driven by the preferential concentration out of intense vortex filaments . in the stationary regime , we study the acceleration fluctuations as a function of the stokes number in the range @xmath1 $ ] .
we also compare our results with those of pure fluid tracers ( @xmath2 ) and we find a critical behavior of inertia for small stokes values . starting from the pure monodisperse statistics we also characterize polydisperse suspensions with a given mean stokes , @xmath3 . .
And you have already written the first three sentences of the full article: suspensions of dust , impurities , droplets , bubbles , and other finite - size particles advected by incompressible turbulent flows are commonly encountered in many natural phenomena and industrial processes .
these finite - size particles , whose density may differ from that of the underlying fluid , can not be modeled as point - like tracers because of their inertia .
often , they are characterized by the presence of strong inhomogeneities in their spatial distribution ..
Please generate the next two sentences of the article | indeed , light ( heavy ) particles tend to concentrate into specific regions of the flow characterized by high ( low ) values of the vorticity .
such a phenomenon is dubbed ` preferential concentration ' @xcite . |
7,484 | Suppose that you have an abstract for a scientific paper: we have taken optical and infrared observations during the 2002 outburst of the soft x - ray transient , 4u 1543 - 47 .
a secondary maximum occurs in the lightcurves during the outburst decline .
this feature is much stronger at infrared wavelengths than optical .
we have applied single blackbody , multicolor blackbody and broken - power law models to the optical / infrared spectral energy distribution of the secondary maximum and find that the broken power - law provides the best fit .
we therefore conclude that the secondary maximum emission originates from a jet .
we also show the most recent lightcurves of the 2002/2003 outburst of gx 339 - 4 in which a secondary maximum appears .
this leads us to the conclusion that secondary maxima may be a common occurrence in soft x - ray transients during outburst decline which appear after the object transitions into the low - hard state .
infrared observations of such phenomena will give reliable triggers for multiwavelength observations , allowing us to greatly improve our knowledge of jet formation and behavior , and how this relates to the accretion geometry .
address = department of astronomy , yale university , new haven ct 06511 , u.s.a .
address = department of astronomy , yale university , new haven ct 06511 , u.s.a . .
And you have already written the first three sentences of the full article: the soft x - ray transient ( sxt ) 4u1543 - 47 was discovered on 17 august 1971 by the _ uhuru _ satellite @xcite . since then , additional x - ray outbursts have been observed in 1983 , 1992 and 2002 .
the optical counterpart was found during the 1983 outburst by @xcite .
dynamical studies of the companion star @xcite show that the compact object is most likely a black hole with a mass of 2.7 @xmath0 m@xmath1 7.5 m@xmath2 ..
Please generate the next two sentences of the article | the 2002 outburst began on mjd 52442 ( ut june 16.683 ) and was observed by rxte @xcite . during this
outburst the soft x - ray light curve exhibited a classical fast rise , exponential decay profile as observed in many other soft x - ray transients @xcite . |
7,485 | Suppose that you have an abstract for a scientific paper: the @xmath0 read - rezayi ( rr ) parafermion quantum hall state hosts non - abelian excitations which provide a platform for the universal topological quantum computation .
although the rr state may be realized at the filling factor @xmath1 in gaas - based two - dimensional electron systems , the corresponding quantum hall state is weak and at present nearly impossible to study experimentally . here
we argue that the rr state can alternatively be realized in a class of chiral materials with massless and massive dirac - like band structure .
this family of materials encompasses monolayer and bilayer graphene , as well as topological insulators .
we show that , compared to gaas , these systems provide several important advantages in realizing and studying the rr state .
most importantly , the effective interactions can be tuned _ in situ _ by varying the external magnetic field , and by designing the dielectric environment of the sample .
this tunability enables the realization of rr state with controllable energy gaps in different landau levels .
it also allows one to probe the quantum phase transitions to other compressible and incompressible phases . .
And you have already written the first three sentences of the full article: strongly correlated phases of electrons confined to move in the plane , subject to a perpendicular magnetic field , have attracted significant attention since the discovery of fractionally quantized hall conductivity @xcite .
the profound role of topology in this extreme quantum limit leads to the presence of quasiparticles that carry a fraction of electron charge @xcite , and fractional ( abelian , or possibly non - abelian ) statistics @xcite .
the prospect of excitations possessing non - abelian statistics has motivated different schemes for topological quantum computation @xcite based on these systems ..
Please generate the next two sentences of the article | these remarkable phenomena occur in the fractional quantum hall ( fqh ) regime , when the number of electrons , @xmath2 , is comparable to the number of magnetic flux quanta @xmath3 through the two - dimension electron system ( 2des ) .
correlated fqh liquid states appear at certain partial filling @xmath4 of the active landau level ( ll ) . in traditional semiconductor heterostructures , |
7,486 | Suppose that you have an abstract for a scientific paper: we present the results of a _
chandra _ observation of the central region of abell 3112 .
this cluster has a powerful radio source in the center and was believed to have a strong cooling flow .
the x - ray image shows that the intracluster medium ( icm ) is distributed smoothly on large scales , but has significant deviations from a simple concentric elliptical isophotal model near the center .
regions of excess emission appear to surround two lobe - like radio - emitting regions .
this structure probably indicates that hot x - ray gas and radio lobes are interacting . from an analysis of the x - ray spectra in annuli
, we found clear evidence for a temperature decrease and abundance increase toward the center .
the x - ray spectrum of the central region is consistent with a single - temperature thermal plasma model .
the contribution of x - ray emission from a multiphase cooling flow component with gas cooling to very low temperatures locally is limited to less than 10% of the total emission .
however , the whole cluster spectrum indicates that the icm is cooling significantly as a whole , but in only a limited temperature range ( @xmath0 kev ) .
inside the cooling radius , the conduction timescales based on the spitzer conductivity are shorter than the cooling timescales .
we detect an x - ray point source in the cluster center which is coincident with the optical nucleus of the central cd galaxy and the core of the associated radio source .
the x - ray spectrum of the central point source can be fit by a 1.3 kev thermal plasma and a power - law component whose photon index is 1.9 .
the thermal component is probably plasma associated with the cd galaxy .
we attribute the power - law component to the central agn . .
And you have already written the first three sentences of the full article: the central regions of clusters of galaxies are very interesting and enigmatic places .
the intracluster medium ( icm ) in the central region is often so dense that its radiative cooling time is significantly shorter than the hubble time .
therefore , the icm will cool down unless it is heated significantly ..
Please generate the next two sentences of the article | unbalanced radiative cooling would cause a `` cooling flow '' in the cluster center ( see fabian 1994 for a review ) .
x - ray imaging analyses by _ rosat _ and _ exosat _ indicated that mass deposition rates , @xmath1 , were more than @xmath2 for many clusters ( edge , stewart , & fabian 1992 ; allen & fabian 1997 ; peres et al . |
7,487 | Suppose that you have an abstract for a scientific paper: a two - component system of penetrable particles interacting via a gaussian core potential is considered , which may serve as a crude model for binary polymer solutions .
the pair structure and thermodynamic properties are calculated within the random phase approximation ( rpa ) and the hypernetted chain ( hnc ) integral equation .
the analytical rpa predictions are in semi - quantitative agreement with the numerical solutions of the hnc approximation , which itself is very accurate for gaussian core systems .
a fluid - fluid phase separation is predicted to occur for a broad range of potential parameters .
the pair structure exhibits a nontrivial clustering behaviour of the minority component .
similiar conclusions hold for the related model of parabolic core mixtures , which is frequently used in dissipative particle dynamics ( dpd ) simulations . .
And you have already written the first three sentences of the full article: demixing of binary or multicomponent mixtures is a very common phenomenon observed in a broad range of molecular fluids @xcite , polymer solutions and blends @xcite , or colloidal dispersions @xcite .
phase separation is generally associated with differences in the attractive interactions between particles of different chemical species . in polymer solutions these differences
are usually embodied in the flory @xmath0-parameter @xcite , which controls the competition between the entropy of mixing and the total interaction energy , at least within a mean - field picture . on the other hand , in multi - component colloidal systems like binary dispersions involving colloidal particles of very different sizes , or mixtures of colloidal particles and non - adsorbing.
Please generate the next two sentences of the article | polymer , phase separation can be driven by purely repulsive , excluded volume interactions . by mapping the initial multi - component system onto
an _ effective _ one - component system involving only the bigger colloidal particles , the largely entropy - driven demixing can be understood in terms of _ attractive _ depletion interactions induced between the large particles by the smaller species ( the `` depletant '' ) @xcite |
7,488 | Suppose that you have an abstract for a scientific paper: a problem of optimal debt management is modeled as a noncooperative game between a borrower and a pool of lenders , in infinite time horizon with exponential discount .
the yearly income of the borrower is governed by a stochastic process . when the debt - to - income ratio @xmath0 reaches a given size @xmath1 , bankruptcy instantly occurs .
the interest rate charged by the risk - neutral lenders is precisely determined in order to compensate for this possible loss of their investment . for a given bankruptcy threshold @xmath1 , existence and properties of optimal feedback strategies for the borrower
are studied , in a stochastic framework as well as in a limit deterministic setting .
the paper also analyzes how the expected total cost to the borrower changes , depending on different values of @xmath1 . .
And you have already written the first three sentences of the full article: we consider a problem of optimal debt management in infinite time horizon , modeled as a noncooperative game between a borrower and a pool of risk - neutral lenders .
since the debtor may go bankrupt , lenders charge a higher interest rate to offset the possible loss of part of their investment . in the models studied in @xcite ,
the borrower has a fixed income , but large values of the debt determine a bankruptcy risk ..
Please generate the next two sentences of the article | namely , if at a given time @xmath2 the debt - to - income ratio @xmath0 is too big , there is a positive probability that panic spreads among investors and bankruptcy occurs within a short interval @xmath3 $ ] .
this event is similar to a bank run . |
7,489 | Suppose that you have an abstract for a scientific paper: _ cis - trans _ isomerization in retinal , the first step in vision , is often computationally studied from a time dependent viewpoint .
motivation for such studies lies in coherent pulsed laser experiments that explore the isomerization dynamics .
however , such biological processes take place naturally in the presence of incoherent light , which excites a non - evolving mixture of stationary states . here
the isomerization problem is considered from the latter viewpoint and applied to a standard two - state , two - mode linear vibronic coupling model of retinal that explicitly includes a conical intersection between the ground and first excited electronic states .
the calculated quantum yield at 500 nm agrees well with both the previous time - dependent calculations of hahn and stock ( 0.63 ) and with experiment ( @xmath0 ) , as does its wavelength dependence .
significantly , the effects of environmental relaxation on the quantum yield in this well - established model are found to be negligible .
the results make clear the connection of the photoisomerization quantum yield to properties of stationary eigenstates , providing alternate insights into conditions for yield optimization . .
And you have already written the first three sentences of the full article: light - induced 11-_cis _ @xmath1 all-_trans _ isomerization in retinal is a paradigmatic example of an important ultrafast photochemical reaction in biology @xcite .
the photoreaction is the first step in dim - light vision , and its high quantum yield , and formation of all-_trans _ product within 200 fs , contribute to the high efficiency of the phototransduction cascade @xcite .
the importance of retinal photoisomerization has made its mechanism the subject of numerous experimental and computational studies . a related biological process , _ cis - trans _ isomerization in retinoic acid , has become of increasing interest in its role in zebrafish hindbrain development@xcite . to study retinal dynamics ,.
Please generate the next two sentences of the article | current pump - probe experiments use ultrashort femtosecond laser pulses to excite the retinal from the ground ( @xmath2 to the first excited ( @xmath3 ) electronic state .
the subsequent isomerization dynamics is then followed using a series of probe pulses , providing important insights into the sub-200 fs timescale of photoproduct formation @xcite , the coherent dynamics of all-_trans _ photoproduct @xcite , and most recently , the role of conical intersections in determining the reaction rate @xcite . |
7,490 | Suppose that you have an abstract for a scientific paper: we present the first d / h measurement in a damped ly@xmath0 ( hereafter dla ) system at @xmath1 towards qso 03473819 obtained from the uves - vlt spectra .
the dla absorber has a metallicity of [ zn / h ] @xmath2 and a relatively simple velocity structure , with two dominating components detected in several metal lines .
the hydrogen lyman series can be followed down to ly12 thanks to the high uv - blue efficiency of uves .
the best fit of the lyman series lines , and in particular of ly@xmath3 , ly8 , ly10 and ly12 , relatively free of local contamination , is obtained when the absorption is included in the two main components .
the measured deuterium column density yields @xmath4 close to other low d / h values from lyman limit systems .
the corresponding values for the baryon to photon ratio and the baryon density derived from d / h are @xmath5 and @xmath6 respectively . .
And you have already written the first three sentences of the full article: deuterium ( d or @xmath7h ) is the only element entirely produced by nuclear reactions in the first minutes after big bang ( wagoner et al .
the d yields are the most sensitive to the nuclear density at the nucleosynthesis epoch among the primordial light elements @xmath8he , @xmath9he and
@xmath10li , thus making the d abundance the most sensitive measurement of the baryon density in the universe ( wagoner 1973 , schramm & turner 1998 ) . deuterium is currently measured in the local interstellar medium ( ism ) , ( d / h)@xmath11 ( linsky et al . 1993 ) , but since whenever it is cycled through stars it is completely burned away , extrapolation to the primordial d / h value requires a modeling of the galactic chemical evolution ..
Please generate the next two sentences of the article | direct d measurements of primordial material are thus of high interest . adams ( 1976 ) suggested that almost primordial d could be measured in low metallicity absorption line systems in the spectra of distant quasars ( qsos ) .
this was recently achieved for a few systems , but with conflicting results differing by almost an order of magnitude . |
7,491 | Suppose that you have an abstract for a scientific paper: the adsorption of charged colloids ( macroions ) onto an oppositely charged planar substrate is investigated theoretically .
taking properly into account the finite size of the macroions , unusual behaviors are reported .
it is found that the role of the coions ( the little salt - ions carrying the same sign of charge as that of the substrate ) is crucial to understand the mechanisms involved in the process of macroion adsorption . in particular
, the coions can accumulate near the substrate s surface and lead to a counter - intuitive _ surface charge amplification_. .
And you have already written the first three sentences of the full article: whereas the bulk behavior of homogeneous ( charged @xcite and uncharged @xcite ) colloidal suspensions is rather well understood , the situation for its inhomogeneous counterpart , such as that emerging in an adsorption process , is less clear .
potential applications of adsorption of charged colloidal particles ( macroions ) can vary from technological processes such as surface coating @xcite to biological material problems .
@xcite from a fundamental point of view , the tremendous long - ranged coulomb interaction that sets in represents a formidable theoretical challenge ..
Please generate the next two sentences of the article | consequently , a deeper understanding of the phenomenon of macroion adsorption is justified and needed .
on one hand , experiments @xcite and the well known mean field gouy - chapman theory @xcite seem to nicely agree for the ion distribution of an aqueous monovalent electrolyte near planar charged interfaces , as long as non - specific forces as well as excluded volume effects are negligible . |
7,492 | Suppose that you have an abstract for a scientific paper: we propose a bragg spectroscopy experiment to measure the onset of superfluid pairing in ultracold trapped fermi gases . in particular , we study two component fermi gases in the weak coupling bcs and bec limits as well as in the strong coupling unitarity limit .
the low temperature bragg spectrum exhibits a gap directly related to the pair - breaking energy .
furthermore , the bragg spectrum has a large maximum just below the critical temperature when the gas is superfluid in the bcs limit . in the unitarity regime , we show how the pseudogap in the normal phase leads to a significant suppression of the low frequency bragg spectrum . .
And you have already written the first three sentences of the full article: bragg spectroscopy , using two laser beams , has proven to be a very successful tool for probing the structure factor of trapped atomic bec s @xcite . in this paper , we examine the analogous experiment on two - component fermi gases in both the normal and superfluid phases .
we calculate the bragg scattering rate for varying interaction strengths in both the weak coupling bcs and bec limits and in the strong coupling unitarity limit .
previously , we proposed measuring the inelastic ( stokes / anti - stokes ) scattering of an off - resonant laser beam on a two - component fermi gas @xcite . in the bcs limit ,.
Please generate the next two sentences of the article | the intensity of the scattering in this stokes experiment exhibits a large maximum just below the critical temperature , @xmath0 , at which the gas becomes superfluid .
this effect is the light scattering analog of the hebel - slichter effect in conventional superconductors , a hallmark experimental test of bcs theory @xcite . here , |
7,493 | Suppose that you have an abstract for a scientific paper: the physics program at the upgraded jefferson lab ( jlab ) and the physics program envisioned for the proposed electron - ion collider ( eic ) include large efforts to search for interactions beyond the standard model ( sm ) using parity violation in electroweak interactions .
these experiments require precision electron polarimetry with an uncertainty of @xmath0 0.5 % .
the spin dependent synchrotron radiation ( sr ) , called spin - light , can be used to monitor the electron beam polarization . in this article
we develop a conceptual design for a `` spin - light '' polarimeter that can be used at a high intensity , multi - gev electron accelerator .
we have also built a geant4 based simulation for a prototype device and report some of the results from these simulations .
shell : bare demo of ieeetran.cls for journals polarized electrons , synchrotron radiation , spin light , differential ionization chambers . .
And you have already written the first three sentences of the full article: the determination of the longitudinal polarization of the electron beam is one of the dominant systematic uncertainties in any parity violating electron scattering ( pves ) experiment . in order to achieve the desired high precision , the polarization of the electron beam
must be monitored continuously with an uncertainty of @xmath00.5% .
these ambitious goals can be achieved if multiple independent and high precision polarimeters are used simultaneously ..
Please generate the next two sentences of the article | in addition to being precise , the polarimeters must be non - invasive and must achieve the desired statistical precision in the shortest time possible .
compton and mller polarimeters are typically the polarimeters of choice for these experiments and are essential to achieve the desired precision . |
7,494 | Suppose that you have an abstract for a scientific paper: etching experiments were performed that reveal the vertical distribution of optically active nitrogen - vacancy ( nv ) centers in diamond created in close proximity to a surface through ion implantation and annealing .
the nv distribution depends strongly on the native nitrogen concentration , and spectral measurements of the neutral and negatively - charged nv peaks give evidence for electron depletion effects in lower - nitrogen material .
the results are important for potential quantum information and magnetometer devices where nv centers must be created in close proximity to a surface for coupling to optical structures . .
And you have already written the first three sentences of the full article: nitrogen - vacancy ( nv ) centers located deep within a diamond lattice appear promising as solid - state spin qubits since they combine optical initialization and readout capabilities @xcite , long electron spin coherence lifetimes ( approaching @xmath0 at room temperature @xcite ) , and the ability to control coupling to individual nuclear spins @xcite .
while these capabilities were initially demonstrated in high - purity natural diamond samples , similar results have recently been achieved in high - purity cvd - grown diamond @xcite .
there is now much interest in fabricating spin - based devices in diamond , with potential applications in quantum communication @xcite , quantum computation @xcite , and magnetometry @xcite . in all of these applications.
Please generate the next two sentences of the article | it is necessary or at least advantageous to couple nv centers to optical structures such as waveguides @xcite and microresonators @xcite , to enable communication between distant qubits or to allow efficient extraction of emitted photons .
therefore , a reliable method is needed to create nv centers with good spectral properties in close proximity ( @xmath1 ) to a diamond surface . |
7,495 | Suppose that you have an abstract for a scientific paper: possible outcomes of neutrino events at both super - kamiokande and sno for a type - ii supernova are analyzed considering the uncertainties in sn neutrino spectra ( temperature ) at emission , which may complicate the interpretation of the observed events . with the input of parameters deduced from the current solar and atmospheric experiments , consequences of direct - mass hierarchy @xmath0 and inverted - mass hierarchy @xmath1
are investigated .
even if the @xmath2 temperatures are not precisely known , we found that future experiments are likely to be able to separate the currently accepted solutions to the solar neutrino problem ( snp ) : large angle msw , small angle msw , and the vacuum oscillation , as well as to distinguish between the direct and inverted mass hierarchies of the neutrinos . .
And you have already written the first three sentences of the full article: during the past few decades , elaborate solar neutrino @xcite and atmospheric neutrino @xcite experiments have provided a wealth of convincing evidences for the existence of massive neutrinos and neutrino mixing , which could have an essential impact on particle physics , astrophysics and cosmology .
attentions have been focused on solving the puzzles of unexpected discrepancies between calculated and observed neutrino fluxes . instead of the more difficult and unlikely solution from an improved solar model @xcite , the solar @xmath3 deficit could be reconciled with the prediction if neutrino oscillations occur either in vacuum or in the presence of solar matter .
the flavor oscillation can be parameterized by the mass - squared differences of the neutrino mass eigenstates @xmath4 and @xmath5 , the mixing angles between weak eigenstates and mass eigenstates of the neutrinos ( @xmath6 is assumed ) . in terms of these parameters , the just - so vacuum oscillation @xcite requires @xmath7 ev@xmath8 and @xmath9 , while the msw resonant effect @xcite in the sun becomes important if @xmath10 ev@xmath8 @xmath11 ev@xmath8 , @xmath12 ( large angle solution ) , or.
Please generate the next two sentences of the article | @xmath13 ev@xmath8 @xmath14 ev@xmath8 , @xmath15 ( small angle solution ) @xcite .
recent atmospheric neutrino data from the super - kamiokande @xcite further provide a strong evidence in support of neutrino oscillation as the cause to deficit of muon neutrinos , provided @xmath16 ev@xmath8 and @xmath17 . |
7,496 | Suppose that you have an abstract for a scientific paper: an optical transmitter that uses entangled light generated by spontaneous parametric downconversion ( spdc ) , in conjunction with an optimal quantum - optical receiver ( whose implementation is not yet known ) is in principle capable of obtaining up to a 6 db gain in the error - probability exponent over the optimum - reception un - entangled coherent - state lidar to detect the presence of a far - away target subject to entanglement - breaking loss and noise in the free - space link @xcite .
we present an explicit design of a structured quantum - illumination receiver , which in conjunction with the spdc transmitter is shown to achieve up to a 3 db error - exponent advantage over the classical sensor .
apart from being fairly feasible for a proof - of - principle demonstration , this is to our knowledge the first structured design of a quantum - optical sensor for target detection that outperforms the comparable best classical lidar sensor appreciably in a low - brightness , lossy and noisy operating regime . .
And you have already written the first three sentences of the full article: an optical transmitter is employed to interrogate a distant region engulfed in bright thermal light , suspected of containing a weakly reflecting target .
the return light is processed by a receiver to decide whether or not the target is present .
recently @xcite , lloyd , building up on work by sacchi @xcite showed that in the above scenario , a quantum illumination " transmitter , i.e. , one that uses entangled light at the transmitter and an optimal quantum receiver , can perform substantially better than an un - entangled coherent laser transmitter , despite there being no entanglement left between the target - return and the idler beams due to high loss and noise ..
Please generate the next two sentences of the article | this is the first example of an entanglement - based performance gain in the bosonic - channel setting where the initial entanglement does not survive the loss and noise in the system .
more recently @xcite , tan et . |
7,497 | Suppose that you have an abstract for a scientific paper: polynomial chaos expansions ( pce ) allow us to propagate uncertainties in the coefficients of differential equations to the statistics of their solutions .
their main advantage is that they replace stochastic equations by systems of deterministic equations .
their main challenge is that the computational cost becomes prohibitive when the dimension of the parameters modeling the stochasticity is even moderately large .
we propose a generalization of the pce framework that allows us to keep this dimension as small as possible in favorable situations .
for instance , in the setting of stochastic differential equations ( sdes ) with markov random forcing , we expect the future evolution to depend on the present solution and the future stochastic variables .
we present a restart procedure that precisely allows pce to depend only on that information .
the computational difficulty then becomes the construction of orthogonal polynomials for dynamically evolving measures .
we present theoretical results of convergence for our dynamical generalized polynomial chaos ( dgpc ) method .
numerical simulations for linear and nonlinear sdes show that it adequately captures the long - time behavior of their solutions as well as their invariant measures when the latter exist .
keywords : polynomial chaos , stochastic differential equations , uncertainty quantification , markov processes .
And you have already written the first three sentences of the full article: _ polynomial chaos _ ( pc ) is a computational spectral method that is used to propagate and quantify uncertainties arising in the modeling of physical systems .
the method originated from the works of wiener @xcite and cameron and martin @xcite on the decomposition of functionals in a basis of hermite polynomials of gaussian random variables .
ghanem and spanos @xcite used such an expansion to solve stochastic equations with random data ..
Please generate the next two sentences of the article | xiu and karniadakis @xcite introduced _ generalized polynomial chaos _ ( gpc ) involving non - gaussian random parameters .
extensions to arbitrary probability measures followed in the works @xcite ; see also @xcite for recent theoretical developments and a convergence result for gpc expansions . _ polynomial chaos expansions _ ( pce ) |
7,498 | Suppose that you have an abstract for a scientific paper: _ hubble space telescope _ ( _ hst _ ) wfpc2 archival images obtained years prior to the explosion of the type ii - plateau supernova ( sn ) 2001du in ngc 1365 previously have been analyzed to isolate the progenitor star .
the sn site was located using precise astrometry applied to the _ hst _ images , with significant uncertainty , leaving three possible progenitor candidates .
images of the fading sn have recently become publicly available in the _ hst _ archive , allowing us to pinpoint the sn s exact location on the pre - explosion images .
we show that the sn occurred in very close proximity to one of the blue candidate stars , but we argue that this star is not the actual progenitor . instead
, the progenitor was not detected on the pre - sn images , and we constrain the progenitor s mass to be less than @xmath0 .
this is consistent with previous constraints on the progenitor masses of other type ii - plateau supernovae ( sne ) , suggesting that such sne arise from the iron core collapse of massive stars at the lower extreme of the possible mass range . .
And you have already written the first three sentences of the full article: supernova 2001du was visually discovered by r. evans ( 2001 ) on august 24.7 ( ut dates are used throughout this paper ) at the western end of the bar in the spiral galaxy ngc 1365 ( about 90 w and 10 s of the nucleus ) .
smartt , kilkenny , & meikle ( 2001 ) classified the sn as type ii ; wang et al . ( 2001 ) , from a spectrum obtained on august 30 ut , confirmed the sn as type ii - plateau ( ii - p ) before optical maximum .
ngc 1365 has also been host to sn 1957c ( of unknown type ) and the type ic sn 1983v . using.
Please generate the next two sentences of the article | _ hubble space telescope _
( _ hst _ ) observations of cepheids , silbermann et al . |
7,499 | Suppose that you have an abstract for a scientific paper: we exploit alma 870-@xmath0 m ( 345ghz ) observations of sub - millimetre sources in the extended _ chandra _ deep field south to investigate the far - infrared properties of high - redshift sub - millimetre galaxies ( smgs ) . using the precisely located 870@xmath0 m alma positions of 99 smgs , together with 24@xmath0 m and radio imaging of this field
, we deblend the _ herschel_/spire imaging of this region to extract their far - infrared fluxes and colours .
the median redshifts for alma less ( aless ) smgs which are detected in at least two spire bands increases as expected with wavelength of the peak in their seds , with @[email protected] , [email protected] and [email protected] for the 250 , 350 and 500-@xmath0 m peakers respectively .
we find that 34 aless smgs do not have a @xmath33@xmath4 counterpart at 250 , 350 or 500@xmath0 m .
these galaxies have a median photometric redshift derived from the rest - frame uv mid - infrared seds of @[email protected] , which is higher than the full aless smg sample ; @[email protected] . using the photometric redshifts together with the 250870@xmath0 m photometry
, we estimate the far - infrared luminosities and characteristic dust temperature of each smg .
the median infrared luminosity and characteristic dust temperature of the @xmath52mjy smgs is @xmath6=([email protected])@xmath710@xmath8@xmath9 ( star formation rate of sfr=300@xmath230@xmath10yr@xmath11 ) and @xmath12=32@xmath21k ( @xmath13=93@xmath24@xmath0 m ) . at a fixed luminosity ,
the characteristic dust temperature of these high - redshift smgs is @xmath14=35k lower than comparably luminous galaxies at @xmath1=0 , reflecting the more extended star formation occurring in these systems . by extrapolating the 870@xmath0 m number counts to @xmath15=1mjy
, we show that the contribution of @xmath161mjy smgs to the cosmic star formation budget is 20% of the total over the redshift range @xmath1714 .
we derive a median dust mass for these galaxies of....
And you have already written the first three sentences of the full article: ultra - luminous infrared galaxies ( ulirgs ; @xcite ) have total infrared luminosities @xmath2710@xmath28l@xmath20 and implied star formation rates ( sfr ) @xmath31001000m@xmath20yr@xmath11 .
their low space densities mean that ulirgs contribute @xmath291% of the volume average star formation density at @xmath1=0 . however , the first deep , single - dish bolometer surveys in the 870-@xmath0 m atmospheric window uncovered high number densities of high - redshift sub - mm galaxies ( smgs ) at mjy flux density levels @xcite .
subsequent spectroscopic studies of the radio-/mid - infrared detected subset of the population gave a median redshift of @xmath302.5 @xcite , confirming their ulirg - like luminosities @xcite and demonstrated that ulirgs undergo a 1000-fold increase in space density from @xmath1=0 to @xmath302.5 ..
Please generate the next two sentences of the article | thus , in contrast to the local universe , ulirgs are a non - negligible component of the star - forming population at @xmath3023 ( e.g. * ? ? ?
* ; * ? ? ? |
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