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5,100 | Suppose that you have an abstract for a scientific paper: we show that in theories where neutrino masses arise from type i seesaw formula with three right handed neutrinos and where large atmospheric mixing angle owes its origin to an approximate leptonic @xmath0 interchange symmetry , the primordial lepton asymmetry of the universe , @xmath1 can be expressed in a simple form in terms of low energy neutrino oscillation parameters as @xmath2 , where @xmath3 and @xmath4 are parameters characterizing high scale physics and are each of order @xmath5 ev@xmath6 .
we also find that for the case of two right handed neutrinos , @xmath7 as a result of which , the observed value of baryon to photon ratio implies a lower limit on @xmath8 . for specific choices of the cp phase @xmath9 we find @xmath8
is predicted to be between @xmath10 . .
And you have already written the first three sentences of the full article: there may be a deep connection between the origin of matter in the universe and the observed neutrino oscillations .
this speculation is inspired by the idea that the heavy right handed majorana neutrinos that are added to the standard model for understanding small neutrino masses via the seesaw mechanism@xcite can also explain the origin of matter via their decay .
the mechanism goes as follows@xcite : cp violation in the same yukawa interaction of the right handed neutrinos , which go into giving nonzero neutrino masses after electroweak symmetry breaking , lead to a primordial lepton asymmetry via the out of equilibrium decay @xmath11 ( where @xmath12 are the known leptons and @xmath13 is the standard model higgs field ) ..
Please generate the next two sentences of the article | this asymmetry subsequently gets converted to baryon - anti - baryon asymmetry observed today via the the electroweak sphaleron interactions@xcite , above @xmath14 ( @xmath15 being the weak scale ) .
since this mechanism involves no new interactions beyond those needed in the discussion of neutrino masses , one would expect that better understanding of neutrino mass physics would clarify one of the deepest mysteries of cosmology both qualitatively as well as quantitatively . |
5,101 | Suppose that you have an abstract for a scientific paper: in this paper we construct a new type of cavity array , in each cavity of which multiple two - level atoms interact with two independent photon modes .
this system can be totally governed by a two - mode dicke - lattice model , which includes all of the counter - rotating terms and therefore works well in the ultrastrong coupling regime achieved in recent experiments . attributed to its special atom - photon coupling scheme , this model supports a global conserved excitation and a continuous @xmath0 symmetry , rather than the discrete @xmath1 symmetry in the standard dicke - lattice model .
this distinct change of symmetry via adding an extra photon mode strongly impacts the nature of photon localization / delocalization behavior .
specifically , the atom - photon interaction features stable mott - lobe structures of photons and a second - order superfluid - mott - insulator phase transition , which share similarities with the jaynes - cummings - lattice and bose - hubbard models .
more interestingly , the mott - lobe structures predicted here depend crucially on the atom number of each site .
we also show that our model can be mapped into a continuous @xmath2 spin model .
finally , we propose a scheme to implement the introduced cavity array in circuit quantum electrodynamics .
this work broadens our understanding of strongly - correlated photons . .
And you have already written the first three sentences of the full article: photons are excellent information carriers in nature , and generally pass through each other without consequence .
the realization of coherent manipulation and controlling of photons allows us to achieve photon quantum information processing @xcite as well as to explore exotic many - body phenomena of photons @xcite .
cavity array mjhf08,aah12,ss13,img14,cn17 , in which each single - mode cavity interacts with a two - level atom , is a promising platform to accomplish the required target and has now been considered extensively adg06,mfa06,mjh07,dga07,mim08,ss09,jk09,kt13,gk13,kkm13,sf14,bb14,mb15,zy15,ks15,ms16,hmj16,am16,alch16 . on one hand , this platform has a novel interplay between strong local nonlinearities and photon hopping of the nearest - neighbor cavities , which has a phenomenological analogy to those of the bose - hubbard model mpa89 realized , for example , by ultracold atoms in optical lattices ib08 ..
Please generate the next two sentences of the article | more importantly , compared with the condensed - matter or atomic physics , cavity array has a unique property that the fundamental many - body phenomena depend crucially on the intrinsic atom - photon coupling strength @xcite . for the weak and moderately - strong coupling regimes ,
the counter - rotating terms of the single - site hamiltonian are usually neglected by employing the rotating - wave approximation . as a result |
5,102 | Suppose that you have an abstract for a scientific paper: we present perturbative analytical results of the landau level quasienergy spectrum , autocorrelation function and out of plane pseudospin polarization for a single graphene sheet subject to intense circularly polarized terahertz radiation . for the quasienergy spectrum
, we find a striking non trivial level - dependent dynamically induced gap structure .
this photoinduced modulation of the energy band structure gives rise to shifts of the revival times in the autocorrelation function and it also leads to modulation of the oscillations in the dynamical evolution of the out of plane pseudospin polarization , which measures the angular momentum transfer between light and graphene electrons . for a coherent state , chosen as an initial pseudospin configuration ,
the dynamics induces additional quantum revivals of the wave function that manifest as shifts of the maxima and minima of the autocorrelation function , with additional partial revivals and beating patterns .
these additional maxima and beating patterns stem from the effective dynamical coupling of the static eigenstates .
we discuss the possible experimental detection schemes of our theoretical results and their relevance in new practical implementation of radiation fields in graphene physics . .
And you have already written the first three sentences of the full article: the dynamical control of the transport properties of dirac fermions in the condensed matter realm is currently an intense research topic .
these dirac fermions have been shown to emerge as the low energy excitations of two - dimensional systems with a honeycomb lattice structure as it occurs in graphene @xcite .
recent theoretical@xcite and experimental@xcite works have discussed the role of radiation fields in the manipulation of the transport properties of monolayer graphene samples . by focusing on the terahertz frequency regime particular attention.
Please generate the next two sentences of the article | is paid to the tunability of the induced band gaps .
in addition , the possibility of generating topological insulating behavior was theoretically put forward both in the static@xcite and dynamical regimes.@xcite in presence of a perpendicular quantizing magnetic field @xmath0 , the static spectrum of single layer graphene posseses a @xmath1 field dependence which strikingly contrasts the linear @xmath2 dependence for conventional non relativistic @xcite . |
5,103 | Suppose that you have an abstract for a scientific paper: we consider abstract operator equations @xmath0 , where @xmath1 is a compact linear operator between hilbert spaces @xmath2 and @xmath3 , which are function spaces on _ closed , finite dimensional riemannian manifolds _ , respectively .
this setting is of interest in numerous applications such as computer vision and non - destructive evaluation . in this work
, we study the approximation of the solution of the ill - posed operator equation with tikhonov type regularization methods .
we prove well - posedness , stability , convergence , and convergence rates of the regularization methods .
moreover , we study in detail the numerical analysis and the numerical implementation .
finally , we provide for three different inverse problems numerical experiments .
* key words : * inverse problems , variational regularization on riemannian manifolds , functions of bounded variation [ cols="^,^ " , ] in table [ tab : snr ] we summarized the results on the denoising and delurring problem for a fixed @xmath4 . in order to compare the performance of different choices for @xmath5 we use the signal - to - noise ratio ( snr ) measured in @xmath6 .
the snr is defined as @xmath7 the better performance of the total variation regularization stems from the fact that discontinuities along edges are preserved while the sobolev semi - norm introduces severe blurring of the edges . in a recent work louis et al @xcite discuss a problem of density estimation , which requires the inversion of the funk - radon transform on the @xmath8-sphere . in general , for arbitrary space dimension , the funk - radon transform maps a function defined on the @xmath8-sphere to its means over the great circles .
that is , @xmath9 helgason @xcite provids a closed form for the inverse of the funk - radon transform . in @xcite
an approximate inverse for the efficient numerical inversion of the radon - funk transform on the @xmath8-sphere has been proposed . here
we investigate quadratic tikhonov regularization with....
And you have already written the first three sentences of the full article: in this paper , we have studied the problem of variational regularization of inverse and ill posed problems for functions on closed riemannian manifolds .
the analysis ( stability , convergence , and rates ) follows from standard results on convex regularization and are reviewed . the main contribution of this paper concerns the numerical analysis of such regularization methods and the numerical implementation .
moreover , three inverse problems appearing in non - destructive evaluation and computer vision are discussed ..
Please generate the next two sentences of the article | the authors acknowledge the support by the austrian science fund ( fwf ) within the national research networks industrial geometry , project 9203-n12 and photoacoustic imaging , project p10505 .
all along this paper we use the notation : * @xmath51 denotes a closed @xmath52-dimensional manifold in @xmath53 . |
5,104 | Suppose that you have an abstract for a scientific paper: it was proposed by ryu and takayanagi that the entanglement entropy in conformal field theory ( cft ) is related through the ads / cft correspondence to the area of a minimal surface in the bulk .
we apply this holographic geometrical method of calculating the entanglement entropy to study the vacuum case of a cft which is holographically dual to empty anti - de sitter ( ads ) spacetime .
we present all possible minimal surfaces spanned on one or two spherical boundaries at ads infinity .
we give exact analytical expressions for the regularized areas of these surfaces and identify finite renormalized quantities . in the case of two disjoint boundaries
the existence of two different phases of the entanglement entropy is confirmed @xcite .
a trivial phase corresponds to two disconnected minimal surfaces , while the other one corresponds to a tube connecting the spherical boundaries .
a transition between these phases is reminiscent of the finite temperature deconfinement transition in the cft on the boundary .
the exact analytical results are thus consistent with previous numerical and approximate computations
. we also briefly discuss the character of a spacetime extension of the minimal surface spanned on two uniformly accelerated boundaries . .
And you have already written the first three sentences of the full article: the famous bekenstein hawking area law @xcite @xmath0 for the entropy of black holes connects thermodynamics , gravity and relativistic quantum field theory .
this relation remains valid not only in einstein s gravity in four dimensions but in higher dimensions too , as long as the gravitational constant @xmath1 is @xmath2-dimensional and the area @xmath3 is understood as the volume of the horizon surface . in quantum field theory ( qft )
an entanglement entropy can be attributed to any surface formally dividing the system in two parts ..
Please generate the next two sentences of the article | the leading uv contribution of quantum fields to the entanglement entropy is proportional to the area of the dividing surface @xcite .
this property is strikingly similar the bekenstein hawking area law . |
5,105 | Suppose that you have an abstract for a scientific paper: recently schlegel , finkbeiner & davis published an all - sky reddening map based on the cobe / dirbe and iras / issa infrared sky surveys . using the reddening map of baade s window and sample of 19 low - latitude ( @xmath0 ) galactic globular clusters
i find that the dirbe / iras reddening map overestimates @xmath1 at low galactic latitudes by a factor of @xmath2 .
i also demonstrate the usefulness of this high resolution map for selecting low - reddening windows near the galactic plane . .
And you have already written the first three sentences of the full article: we live in a dusty universe ( hoover 1998 , private communication ) , and correcting for the dust extinction and reddening affects almost all aspects of optical astronomy . for us , observing from within the milky way , it is of crucial importance to know how much galactic dust there is towards various objects .
burstein & hailes ( 1982 ; hereafter : bh ) constructed an all - sky reddening map , used extensively by the astronomical community .
recently , schlegel , finkbeiner & davis ( 1998 ; hereafter : sfd ) published a new all - sky reddening map , based on the cobe / dirbe and iras / issa maps ..
Please generate the next two sentences of the article | this map is intended to supersede the bh map in both the accuracy and the spatial resolution ( @xmath3 ) .
also , unlike the bh map , which presented the @xmath1 values only for the @xmath4 regions , the sfd map extends all the way to the galactic plane . |
5,106 | Suppose that you have an abstract for a scientific paper: the accuracy of the numerical solution of a fractional differential equation depends on the differentiability class of the solution .
the derivatives of the solutions of fractional differential equations often have a singularity at the initial point , which may result in a lower accuracy of the numerical solutions .
we propose a method for improving the accuracy of the numerical solutions of the fractional relaxation and subdiffusion equations based on the fractional taylor polynomials of the solution at the initial point . + * ams subject classification : * 33f05 , 34a08 , 57r10 + * key words : * fractional differential equation , caputo derivative , numerical solution , fractional taylor polynomial . .
And you have already written the first three sentences of the full article: differential equations with fractional derivatives are used for modeling non - markovian processes in various areas of science such as physics , biology and economics [ 1 - 5 ] .
the methods for analytical solution of ordinary and partial fractional differential equations can be applied to only special types of equations and initial conditions . in practical applications
the solutions of the fractional differential equations are determined by numerical methods ..
Please generate the next two sentences of the article | the development of efficient methods for numerical solution of fractional differential equations is an active research field .
an important approximation for the caputo fractional derivative is the @xmath0 approximation . |
5,107 | Suppose that you have an abstract for a scientific paper: we calculate the spectra of produced thermal photons in au+au collisions taking into account the nonequilibrium contribution to photon production due to finite shear viscosity .
the evolution of the fireball is modeled by second - order as well as by divergence - type 2 + 1 dissipative hydrodynamics , both with an ideal equation of state and with one based on lattice qcd that includes an analytical crossover . the spectrum calculated in the divergence - type theory
is considerably enhanced with respect to the one calculated in the second - order theory , the difference being entirely due to differences in the viscous corrections to photon production .
our results show that the differences in hydrodynamic formalisms are an important source of uncertainty in the extraction of the value of @xmath0 from measured photon spectra .
the uncertainty in the value of @xmath0 associated with different hydrodynamic models used to compute thermal photon spectra is larger than the one occurring in matching hadron elliptic flow to rhic data . .
And you have already written the first three sentences of the full article: experiments of ultrarelativistic heavy ion collisions performed at bnls relativistic heavy ion collider ( rhic ) create a hot and dense medium of quarks , antiquarks and gluons called the quark - gluon plasma ( qgp ) @xcite .
the understanding of the transport properties of the qgp , and the nature of confinement and the phase transition from this system to interacting hadrons is a central topic of modern high - energy physics .
one of the most important discoveries at rhic is the large elliptic flow in non - central au+au collisions , which is a clear indication of collective behavior ..
Please generate the next two sentences of the article | this implies that the qgp has a very low viscosity - to - entropy ratio @xmath0 not much larger than the ads / cft lower bound @xmath1 @xcite . by now
, it is generally agreed that the qgp thermalizes on times @xmath2 2.5 fm / c and that it behaves as a fluid with one of the lowest viscosity - to - entropy ratios ever observed in nature @xmath3/s @xmath2 0.5 @xcite . |
5,108 | Suppose that you have an abstract for a scientific paper: the coma cluster of galaxies hosts the brightest radio halo known and has therefore been the target of numerous searches for associated inverse compton ( ic ) emission , particularly at hard x - ray energies where the ic signal must eventually dominate over thermal emission .
the most recent search with the hard x - ray detector ( hxd ) failed to confirm previous ic detections with and , instead setting an upper limit 2.5 times below their nonthermal flux .
however , this discrepancy can be resolved if the ic emission is very extended , beyond the scale of the cluster radio halo . using reconstructed sky images from the 58month bat all sky survey ,
the feasibility of such a solution is investigated .
building on renaud et al . , we test and implement a method for extracting the fluxes of extended sources , assuming specified spatial distributions .
bat spectra are jointly fit with an epic - pn spectrum derived from mosaic observations .
we find no evidence for large - scale ic emission at the level expected from the previously detected nonthermal fluxes .
for all nonthermal spatial distributions considered , which span the gamut of physically reasonable ic models , we determine upper limits for which the largest ( most conservative ) limit is @xmath0 erg s@xmath1 @xmath2 ( 2080 kev ) , which corresponds to a lower limit on the magnetic field @xmath3 @xmath4 g .
a nominal flux upper limit of @xmath5 erg s@xmath1 @xmath2 , with corresponding @xmath6 @xmath7 g , is derived for the most probable ic distribution given the size of the radio halo and likely magnetic field radial profile . .
And you have already written the first three sentences of the full article: the x - ray emission from clusters of galaxies is primarily thermal in origin and is produced by a diffuse population of intergalactic electrons in the ionized intracluster medium ( icm ) .
these electrons coexist with a nonthermal , relativistic electron population in at least some clusters inferred from observations in the radio regime which should also radiate at x - ray energies .
while thermal emission clearly dominates in the kilo - electron volt ( kev ) energy range , it declines rapidly outside this range , allowing the detection of a nonthermal spectral signature as soft or hard excess emission ..
Please generate the next two sentences of the article | this possibility is especially promising at hard ( @xmath810 kev ) energies , where the exponential decline of the thermal bremsstrahlung continuum is distinctly steeper than the expected nonthermal spectrum .
measurements of nonthermal x - ray emission are critical to the determination of the total amount of relativistic energy in the icm , which is currently poorly constrained . while no more than @xmath910% of this energy is tied up in nonthermal components , |
5,109 | Suppose that you have an abstract for a scientific paper: using the concept of collision time ( time delay ) introduced by eisenbud and wigner and its connection to on - shell intermediate unstable states , we study mesonic resonances in @xmath0 and @xmath1 scattering .
the time - delay method proves its usefulness by revealing the spectrum of the well - known @xmath2 - and @xmath3- mesons and by supporting some speculations on @xmath2-mesons in the @xmath4 mev region .
we use this method further to shed some light on more speculative meson resonances , among others the enigmatic scalars .
we confirm the existence of chiralons below @xmath5 gev in the unflavoured and strange meson sector .
= cmbx10 scaled1 6.0 in 8.5 in -0.25truein 0.30truein 0.30truein * collision times in @xmath0 and @xmath1 scattering and spectroscopy of meson resonances + * @xmath6departamento de fisica , universidad de los andes , cra.1 no.18a-10 , santafe de bogota , colombia + @xmath7nuclear physics division , bhabha atomic research centre , mumbai 400085 .5 cm pacs numbers : 13.75.lb , 11.55.-m , 14.40.aq , 25.40.ny .
And you have already written the first three sentences of the full article: the study of hadronic resonances , be it baryons or mesons , has never ceased ( with seasonal fluctuations ) to interest the particle and nuclear physics community for several specific and one global reason @xcite .
the latter reason is to be found in the fact that hadrons and their interaction are the low energy manifestations of qcd .
the specific reasons include among others : ( i ) the wish to improve upon standard results ( e.g. resonance parameter extraction ) , ( ii ) the attempt to understand inconsistencies and puzzles , if any , ( iii ) possible new resonances ( of speculative status , enigmatic nature , predicted by models and/or resurrection of previously refuted results ) , ( iv ) exotic resonances like glueballs , hybrids ( named also hermaphrodites and meiktons ) , multiquark states such as @xmath8 , mesonic molecules and @xmath9-exotics , ( v ) the enigmatic scalar sector with the return of the @xmath10-meson into the data book of the particle data group ( pdg ) @xcite ..
Please generate the next two sentences of the article | we shall come back to ( i)-(v ) in the next section . here
it suffices to note that it is very often the existence of a resonance which is at stake . |
5,110 | Suppose that you have an abstract for a scientific paper: we calculate the very high energy ( sub - gev to tev ) inverse compton emission of grb afterglows .
we argue that this emission provides a powerful test of the currently accepted afterglow model .
we focus on two processes : synchrotron self - compton ( ssc ) emission within the afterglow blast wave , and external inverse compton ( eic ) emission which occurs when flare photons ( produced by an internal process ) pass through the blast wave .
we show that if our current interpretations of the swift xrt data are correct , there should be a canonical high energy afterglow emission light curve .
our predictions can be tested with high energy observatories such as glast , whipple , h.e.s.s . and magic .
under favorable conditions we expect afterglow detections in all these detectors .
gamma rays : bursts@xmath0ism : jets and outflows radiation mechanisms : nonthermal .
And you have already written the first three sentences of the full article: egret detected more than 30 gamma - ray bursts ( grbs ) with gev emission ( schneid et al .
1992 ; sommer et al . 1994 ; hurley et al . 1994 ; schaefer et al . 1998 ; gonzlez et al .
the highest energy photon detected was the 18 gev photon which arrived 4500 seconds after the trigger of grb 940217 ( hurley et al ..
Please generate the next two sentences of the article | these observations motivated many interesting ideas .
some focused on prompt high energy photon emission , e.g. , synchrotron - self - compton ( ssc ) emission or inverse compton scattering of photons emitted by one shell by electrons in another shell @xcite . |
5,111 | Suppose that you have an abstract for a scientific paper: we derive constraints on cosmological parameters using the power spectrum of galaxy clustering measured from the final two - degree field galaxy redshift survey ( 2dfgrs ) and a compilation of measurements of the temperature power spectrum and temperature - polarization cross - correlation of the cosmic microwave background radiation .
we analyse a range of parameter sets and priors , allowing for massive neutrinos , curvature , tensors and general dark energy models . in all cases ,
the combination of datasets tightens the constraints , with the most dramatic improvements found for the density of dark matter and the energy - density of dark energy .
if we assume a flat universe , we find a matter density parameter of @xmath0 , a baryon density parameter of @xmath1 , a hubble constant of @xmath2 , a linear theory matter fluctuation amplitude of @xmath3 and a scalar spectral index of @xmath4 ( all errors show the 68% interval ) .
our estimate of @xmath5 is only marginally consistent with the scale invariant value @xmath6 ; this spectrum is formally excluded at the @xmath7 confidence level .
however , the detection of a tilt in the spectrum is sensitive to the choice of parameter space . if we allow the equation of state of the dark energy to float , we find @xmath8 , consistent with a cosmological constant .
we also place new limits on the mass fraction of massive neutrinos : @xmath9 at the 95% level , corresponding to @xmath10 ev .
large scale structure of the universe - cosmic microwave background , cosmological parameters .
And you have already written the first three sentences of the full article: since the turn of the millennium , we have witnessed a dramatic improvement in the resolution and accuracy of measurements of fluctuations in the temperature of the cosmic microwave background radiation ( cmb ) .
the discovery of features in the power spectrum of the cmb temperature , the acoustic peaks , marked the start of a new , data - rich era in cosmology ( de bernardis et al .
2000 ; hanany et al ..
Please generate the next two sentences of the article | the relative positions and heights of the acoustic peaks encode information about the values of the fundamental cosmological parameters , such as the curvature of the universe or the physical density in cold dark matter and baryons .
perhaps the most striking example of the progress achieved is the first year data from the wmap satellite ( bennett et al . |
5,112 | Suppose that you have an abstract for a scientific paper: we present a detailed numerical study of the electronic transport properties of bilayer and trilayer graphene within a framework of single - electron tight - binding model .
various types of disorder are considered , such as resonant ( hydrogen ) impurities , vacancies , short- or long - range gaussian random potentials , and gaussian random nearest neighbor hopping .
the algorithms are based on the numerical solution of the time - dependent schrdinger equation and applied to calculate the density of states and conductivities ( via the kubo formula ) of large samples containing millions of atoms . in the cases under consideration , far enough from the neutrality point , depending on the strength of disorders and the stacking sequence , a linear or sublinear electron - density dependent conductivity is found .
the minimum conductivity @xmath0 ( per layer ) at the charge neutrality point is the same for bilayer and trilayer graphene , independent of the type of the impurities , but the plateau of minimum conductivity around the neutrality point is only observed in the presence of resonant impurities or vacancies , originating from the formation of the impurity band . .
And you have already written the first three sentences of the full article: graphene is a subject of numerous investigations motivated by its unique electronic and lattice properties , interesting both conceptually and for applications ( for reviews , see refs . ) .
single layer graphene ( slg ) is the two - dimensional crystalline form of carbon with a linear electronic spectrum and chiral ( a - b sublattice ) symmetry , whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics .
bilayer and trilayer graphenes , which are made out of two and three graphene planes , have also been produced by the mechanical friction and motivated a lot of researches on their transport properties natphys , falko2006,gcnt2006,ohta2006,mccann2006,koshino2006,santos2007 , katsnelson_bilayer , castro2007,castro2008,nilsson2007,morozov2008,nilsson2008 , nilsson2006,nilsson2006b , zhuw2009,dassarma2010,xiaos2010,lv2010,zhangf2010 , zhu2010,pereira2009,ribeiro2008,mallet2007,bostwick2007,gorbachev2007,linym2008,nakamura2008,feldman2009,trushin2010 ..
Please generate the next two sentences of the article | the charge - carrying quasiparticles in bilayer graphene ( blg ) obey parabolic dispersion with non - zero mass , but retain a chiral nature similar to that in slg ( with the berry phase @xmath1 instead of @xmath2 ) natphys , falko2006 .
furthermore , an electronic bandgap can be introduced in a dual gate blg mccann2006,castro2007,oostinga2008,zhangyb2009,castro2010,taychatanapat2010 , and it makes blg very appealing from the point of view of applications . |
5,113 | Suppose that you have an abstract for a scientific paper: we construct an effective lagrangian for new strong interactions at the lhc , including as a first step the two lightest triplets of spin-1 resonances .
our parametrization is general enough to allow for previously unstudied spectrum and couplings . among available frameworks to describe the spin-1 sector , we rely on an extra - dimensional description .
our approach limits the number of parameters , yet is versatile enough to describe the phenomenology of a wide range of new scenarios of strong electroweak symmetry breaking . .
And you have already written the first three sentences of the full article: the approach of lhc turn - on has renewed interest in dynamical electroweak symmetry breaking ( dewsb ) , whether in the traditional form of technicolor models @xcite , or that of its possible 5d dual description @xcite and related moose models @xcite . yet , only a handful of non - supersymmetric models of electroweak symmetry breaking have so far been implemented in monte - carlo generators @xcite . to pave the way for more simulations of dewsb
, we define a flexible framework with resonances and more generic interactions than have previously been considered . at the same time
, we strive to limit the number of parameters in this lagrangian , to make the parameter space manageable . dialing the parameters then allows to describe a sampling of strong interaction models , as msugra did for the mssm : our framework is intended to work in a similar way , applied to dewsb ..
Please generate the next two sentences of the article | we have already presented some phenomenological applications in @xcite ; the present paper details the inner workings of our framework . in practice
, our approach extends attempts to model strong interactions , based on the ideas of hidden local symmetry and mooses @xcite as well as 5d warped models @xcite ( themselves inspired by ads / cft @xcite ) . |
5,114 | Suppose that you have an abstract for a scientific paper: parton equilibration studies for a thermally equilibrated but chemically non - equilibrated quark - gluon plasma ( qgp ) , likely to be formed at the relativistic colliders at bnl and cern is presented .
parton equilibration is studied enforcing baryon number conservation .
process like quark - flavour interchanging is also taken into consideration .
the degree of equilibration is studied comparatively for the various reactions / constraints that are being considered . .
And you have already written the first three sentences of the full article: + + * * +
we observe that + + + + + + 2 . for a given initial ratio , except for the light quarks and anti - quarks
, the output does not depend much on the initial baryon number density ..
Please generate the next two sentences of the article | for the light quarks and antiquarks this variation is due to the presence of the exponentiated non - zero chemical potentials .
+ 3 . for a given initial baryon number density we can recast the equation for baryon number density in the form @xmath25 + @xmath26 ... (27 ) where c is a constant for a given temperature , light quark fugacity and given baryon number density . here |
5,115 | Suppose that you have an abstract for a scientific paper: we investigate the phase diagram of a two - species bose - hubbard model including a conversion term , by which two particles from the first species can be converted into one particle of the second species , and vice - versa .
the model can be related to ultracold atom experiments in which a feshbach resonance produces long - lived bound states viewed as diatomic molecules .
the model is solved exactly by means of quantum monte carlo simulations .
we show that an `` inversion of population '' occurs , depending on the parameters , where the second species becomes more numerous than the first species .
the model also exhibits an exotic incompressible `` super - mott '' phase where the particles from both species can flow with signs of superfluidity , but without global supercurrent .
we present two phase diagrams , one in the ( chemical potential , conversion)-plane , the other in the ( chemical potential , detuning)-plane . .
And you have already written the first three sentences of the full article: in the past years the bose - hubbard model @xcite has been extensively investigated and a lot of interest has been generated thanks to ultracold atom experiments on optical lattices @xcite , which provide an ideal realization of the model .
recently , much theoretical and experimental work has been performed on mixtures with several species of particles .
for instance , bose - fermi mixtures on lattices have been studied @xcite ..
Please generate the next two sentences of the article | another mixture that is likely of interest involves atoms and molecules , in which conversion between the two species is possible .
such conversion processes can describe , for instance , long - lived bound states of atoms ( diatomic molecules ) occuring in ultracold atom experiments where a feshbach resonance is used to tune the scattering length of the atoms @xcite . in those experiments , the hyperfine interaction between two spin polarized atoms can flip the spin of one of the atoms , reducing sensitively their scattering length . |
5,116 | Suppose that you have an abstract for a scientific paper: binarity and mass transfer appear to play a key role in the shaping and , possibly , formation of planetary nebulae ( pne ) , thereby explaining the large fraction of axisymmetric morphologies .
i present the binary hypothesis for pne and its current status .
recent discoveries have led to a quadrupling of the number of post - common envelope binary central stars of pne compared to the end of the last century , thereby allowing us to envisage statistical studies . moreover
, these binary systems let us study in detail the mass transfer episodes before and after the common envelope , and i present the evidences for mass transfer and accretion prior to the common envelope phase . .
And you have already written the first three sentences of the full article: planetary nebulae ( pne ) these magnificent cosmic bubbles that light up the universe in a colourful way @xcite are generally considered to be the swan song of low- and intermediate - mass ( i.e. 1 to 8 m@xmath0 ) stars , before becoming white dwarfs . as such
, the central stars of pne ( cspne ) are the precursors of white dwarfs and their study provides us with the initial conditions to study the latter .
they therefore fully deserve to be part of a workshop dedicated to white dwarfs . the classical scenario to form a pn is as follow : at the end of the asymptotic giant branch ( agb ) , the star has lost most of its envelope ( and thus its mass ) through a slow but fierce wind and the hot central star is being exposed ..
Please generate the next two sentences of the article | the latter is also undergoing mass loss through a fast , hot wind , which drags along the left - over material of the agb envelope in a narrow shell , which is then ionised by the hot star .
this scenario known as the interacting wind model @xcite should produce a spherical pn . and |
5,117 | Suppose that you have an abstract for a scientific paper: we present new self - consistent atmosphere models for transiting planets tres-1 and hd209458b .
the planets were recently observed with the _ spitzer space telescope _ in bands centered on 4.5 and 8.0 @xmath0 m , for tres-1 , and 24 @xmath0 m , for hd209458b .
we find that standard solar metallicity models fit the observations for hd209458b . for tres-1 , which has an @xmath1 k cooler
, we find that models with a metallicity 3 - 5 times enhanced over solar abundances can match the 1@xmath2 error bar at 4.5 @xmath0 m and 2@xmath2 at 8.0@xmath0 m . models with solar abundances that included energy deposition into the stratosphere give fluxes that fall within the 2@xmath2 error bars in both bands .
the best - fit models for both planets assume that reradiation of absorbed stellar flux occurs over the entire planet .
for all models of both planets we predict planet / star flux ratios in other _ spitzer _
bandpasses . .
And you have already written the first three sentences of the full article: the detection of photons emitted by an extrasolar planet is a landmark feat in the history of astronomy .
ten years after the initial discovery of the first extrasolar giant planet ( egp ) 51 peg b @xcite , @xcite report a dectection of infrared flux from tres-1 and @xcite report a similar detection for hd209458b .
both observations were made with the _.
Please generate the next two sentences of the article | spitzer space telescope _ as each planet passed behind its parent star . while a number of papers have aimed at predicting the optical and infrared spectra of hot egps @xcite , these results are the first infrared detections ( rather than upper limits ) that can be compared with models .
tres-1 , discovered by @xcite , is similar to the well - known planet hd209458b |
5,118 | Suppose that you have an abstract for a scientific paper: the bialas - bzdak model of elastic proton - proton scattering is generalized to the case when the real part of the parton - parton level forward scattering amplitude is non - vanishing .
such a generalization enables the model to describe well the dip region of the differential cross - section of elastic scattering at the isr energies , and improves significantly the ability of the model to describe also the recent totem data at @xmath0 tev lhc energy . within this framework , both the increase of the total cross - section , as well as the decrease of the location of the dip with increasing colliding energies ,
is related to the increase of the quark - diquark distance and to the increase of the fragility " of the protons with increasing energies .
in addition , we present and test the validity of two new phenomenological relations : one of them relates the total p+p cross - section to an effective , model - independent proton radius , while the other relates the position of the dip in the differential elastic cross - section to the measured value of the total cross - section . .
And you have already written the first three sentences of the full article: diffractive scattering of energetic electrons on various nuclei allowed hofstadter and collaborators to determine the radius and the surface thickness of electric charge distribution inside the nuclei , and also resulted in two simple phenomenological formulae : namely , that the charge radius scales with increasing mass number as ( 1.07 @xmath1 0.02)@xmath2 fm , while the surface thickness , within the errors of the observation , is a constant of ( 2.4 @xmath1 0.3 ) fm @xcite . by increasing the momentum of the elastically scattered particle one can probe deeper and deeper details of matter , due to the de broglie duality @xmath3 between particle properties like momentum @xmath4 and wave - like properties like wavelength @xmath5 . to resolve the internal charge distribution inside atomic nuclei , hofstadter and colleagues used electrons with bombarding energies of @xmath6 mev , corresponding to spatial resolutions of @xmath7 fm .
currently , elastic scattering of protons on protons has been experimentally investigated by the cern lhc experiment totem , at the colliding energies of @xmath0 tev , corresponding to a spatial resolution in the center of mass system of @xmath8 fm , which is sufficiently small to study the internal structure of protons . in the present paper
we exploit these experimental results and check how far can one progress with the qualitative as well as quantitative description of the differential cross section of elastic proton - proton scattering at isr as well as at cern lhc colliding energies , covering an impressive range from @xmath9 gev to 7 tev ..
Please generate the next two sentences of the article | our investigations were motivated not only by the first experimental results of totem on elastic proton - proton collisions @xcite , but also by an inspiring series of theoretical papers by a. bialas and a. bzdak @xcite , that considered pion - proton , proton - proton and nucleus - nucleus scattering using a geometrical picture . in the present investigation , following and improving the model of bialas and bzdak @xcite a quark - diquark based geometrical model is used to describe the isr and the recent lhc totem data
. we will refer to this bialas bzdak model as the bb model or bb , for convenience . |
5,119 | Suppose that you have an abstract for a scientific paper: when @xmath0 , where @xmath1 is the de broglie wavelength and @xmath2 , the distance of closest approach of thermal electrons , a classical analysis of the energy of a plasma can be made .
in all the classical analysis made until now , it was assumed that the frequency of the fluctuations @xmath3 ( @xmath4 ) . using the _ fluctuation - dissipation theorem _ , we evaluate the energy of a plasma , allowing the frequency of the fluctuations to be arbitrary .
we find that the energy density is appreciably larger than previously thought for many interesting plasmas , such as the plasma of the universe before the recombination era . .
And you have already written the first three sentences of the full article: there have been many classical calculations of the energy of a plasma @xcite .
they are based on perturbation theory of an ideal gas , in terms of the plasma parameter @xmath5 ( which usually is a small value ) .
the treatment , to the first order in @xmath5 , is the debye - hckel theory ..
Please generate the next two sentences of the article | however , in the calculations that have been made it is assumed that @xmath3 ( @xmath4 ) . this is a very strong assumption .
for example , in our previous analysis @xcite , we showed that only by not assuming @xmath3 , is the blackbody spectrum obtained . |
5,120 | Suppose that you have an abstract for a scientific paper: in this study , we present long term photometric variations of the close binary system .
modelling of the system shows that the primary is filling roche lobe and the secondary of the system is almost filling its roche lobe .
the physical parameters of the system are @xmath0 , @xmath1 , @xmath2 , @xmath3 , @xmath4 , @xmath5 , and @xmath6 .
our results show that is the most massive system near contact binary ( ncb ) .
analysis of times of the minima shows a sinusoidal variation with a period of @xmath7 years due to a third body whose mass is less than 2.3@xmath8 .
finally a period variation rate of @xmath9 d / yr has been determined using all available light curves .
stars : binaries : eclipsing stars : binaries : close stars : binaries : general stars : fundamental parameters stars : low - mass .
And you have already written the first three sentences of the full article: studies of the evolution of late - type close binary systems reveal that the evolution of detached , semi - detached and contact systems are closely related ( yakut & eggleton 2005 , eggleton 2010 and reference therein ) .
the more massive star in a detached binary system fills its roche lobe first because it has shorter evolutionary timescale before its companion .
the system is semi - detached binary ..
Please generate the next two sentences of the article | in addition to nuclear evolution and mass loss , mass transfer has a crucial role in driving a binary towards a contact phase of evolution .
the observations of detached , contact and semi - detached binaries are crucial to our further understanding of the evolution of close binary systems . |
5,121 | Suppose that you have an abstract for a scientific paper: the ( @xmath0 ) model in mean - field approximation where the meson fields are treated classically , describes much of observed nuclear structure and has been employed to describe the nuclear equation of state up to the quark - gluon phase transition .
the acceleration of the meson sources , for example , in relativistic heavy - ion collisions , should result in bremsstrahlung - like radiation of the meson fields .
the many mesons emitted serve to justify the use of classical meson fields .
the slowing of the nuclei during the collision is modeled here as a smooth transition from initial to final velocity . under ultra - relativistic conditions , vector radiation dominates .
the angular distribution of energy flux shows a characteristic shape .
it appears that if the vector meson field couples to the conserved baryon current , independent of the baryonic degrees of freedom , this mechanism will contribute to the radiation seen in relativistic heavy - ion collisions . the possible influence of the quark - gluon plasma is also considered .
relativistic heavy - ion collisions ; vector meson production ; bremsstrahlung ; quantum hadrodynamics ; relativistic mean - field theory 25.75.-q , 24.10.jv , 13.60.le .
And you have already written the first three sentences of the full article: the @xmath1 model of the nucleus @xcite is a relativistic quantum field theory which describes the nuclear interaction using three fields . they are neutral scalar meson , neutral vector meson and baryon fields .
the scalar meson field couples to the scalar density , @xmath2 , while the vector meson field couples to the conserved baryon current , @xmath3 . in the relativistic mean - field approximation ( rmft )
where the sources are large , the meson fields can be replaced by classical fields and the linearized dirac equation solved exactly . this model has had several successes , properly describing : bulk properties of nuclear matter , ground state properties of nuclei , the excitation spectrum of nuclei , low energy nucleon - nucleus scattering observables , as well as collective motion ..
Please generate the next two sentences of the article | all except the first of the preceding list incorporate spatial dependence for the meson fields and their sources .
the last item , collective motion , incorporates a slow time dependence in addition to the spatial dependence . |
5,122 | Suppose that you have an abstract for a scientific paper: the configurational and melting properties of large two - dimensional ( 2d ) clusters of charged classical particles interacting with each other via the coulomb potential are investigated through the monte carlo simulation technique .
the particles are confined by a harmonic potential . for a large number of particles in the cluster ( n150 )
the configuration is determined by two competing effects , namely in the center a hexagonal lattice is formed , which is the groundstate for an infinite 2d system , and the confinement which imposes its circular symmetry on the outer edge . as a result
a hexagonal wigner lattice is formed in the central area while at the border of the cluster the particles are arranged in rings . in the transition region defects
appear as dislocations and disclinations at the six corners of the hexagonal - shaped inner domain .
many different arrangements and type of defects are possible as metastable configurations with a slightly higher energy . the particles motion is found to be strongly related to the topological structure .
our results clearly show that the melting of the clusters starts near the geometry induced defects , and that three different melting temperatures can be defined corresponding to the melting of different regions in the cluster .
pacs numbers : 45.05.+x , 61.46.+w , 73.22.-f .
And you have already written the first three sentences of the full article: recently , there has been considerable theoretical and experimental progress in the study of mesoscopic systems consisting of a finite number of charged particles which are confined into an artificial circular symmetric potential . in 1934
, wigner suggested that a liquid to solid phase transition should occur in a three - dimensional ( 3d ) fermi system at low densities @xcite .
typical experimental model systems for the study of this system are electrons on the surface of liquid helium @xcite , electrons in quantum dots @xcite , colloidal suspensions@xcite and in confined plasma crystals@xcite . on the other hand , various similar systems , like the vortex clusters in an isotropic superfluid @xcite , vortices in superfluid he@xmath0@xcite , vortices in a bose - einstein condensate stirred with a laser beam @xcite and in mesoscopic superconducting disks.
Please generate the next two sentences of the article | @xcite have many common features with those of 2d charged particles .
colloidal particles dissolved in water @xcite are another example of an experimental system where classical particles exhibit wigner crystallization . recently , macroscopic |
5,123 | Suppose that you have an abstract for a scientific paper: we have systematically computed the generators of the symmetries arising in poincar gauge theory formulation of gravity , both in 2 + 1 and 3 + 1 dimensions .
this was done using a completely lagrangian approach .
the results are expected to be valid in any dimensions , as seen through lifting the results of the 2 + 1 dimensional example into the 3 + 1 dimensional one . .
And you have already written the first three sentences of the full article: symmetry plays an important role in our understanding of nature and is the primary ingredient that goes into shaping of physical laws .
symmetry dictates the dynamics in nature @xcite .
this simple _ and _ powerful insight has shaped our current knowledge of physics , right from the galilean invariance of newtonian mechanics , through the lorentz invariance of special relativity , to the reparametrization or diffeomorphism invariance of general relativity ..
Please generate the next two sentences of the article | so understanding the role and systematic construction of symmetries through their generators is an important aspect in the study of any physical theory . given an action ,
a symmetry is some transformation of the fields of the theory involving arbitrary functions of time that leaves the action off - shell invariant . |
5,124 | Suppose that you have an abstract for a scientific paper: we show that the weibel - mediated collisionless shocks are driven at non - relativistic propagation speed ( @xmath0 ) in unmagnetized electron - ion plasmas by performing two - dimensional particle - in - cell simulations .
it is shown that the profiles of the number density and the mean velocity in the vicinity of the shock transition region , which are normalized by the respective upstream values , are almost independent of the upstream bulk velocity , i.e. , the shock velocity .
in particular , the width of the shock transition region is @xmath1 ion inertial length independent of the shock velocity . for these shocks
the energy density of the magnetic field generated by the weibel - type instability within the shock transition region reaches typically 1 - 2% of the upstream bulk kinetic energy density .
this mechanism probably explains the robust formation of collisionless shocks , for example , driven by young supernova remnants , with no assumption of external magnetic field in the universe . .
And you have already written the first three sentences of the full article: collisionless shocks are important phenomena in the universe ; they heat and compress interstellar or intergalactic plasmas and often accelerate charged particles or cosmic rays .
the dissipation mechanism of the collisionless shocks is highly complex and generally involved with instabilities in the collisionless plasma .
the weibel instability is driven in anisotropic or counter - streaming collisionless plasmas @xcite and generates strong magnetic fields ..
Please generate the next two sentences of the article | collisionless shocks inevitably generate an anisotropy within their transition region , where the upstream and downstream plasmas are mixed up , therefore , the weibel instability can develop and generate strong magnetic fields there if the background magnetic field is weak .
@xcite considered such a process in non - relativistic collisionless shocks and @xcite discussed the magnetic field generation by the weibel instability in relativistic collisionless shocks of gamma - ray bursts . in this context , the weibel instability in relativistic counter - streaming plasmas has been investigated extensively by means of particle - in - cell simulations ( e.g. , * ? ? ? |
5,125 | Suppose that you have an abstract for a scientific paper: the electron - electron relaxation in impure two - dimensional superconductors is studied .
all channels of the electron - electron interaction classified in the nambu representation are taken into account .
it is shown that the recombination relaxation rate originates from quasipartical processes associated with fluctuations of the electron density and the phase of the order parameter . at low temperatures
the recombination relaxation rate has a double exponential temperature dependence .
the scattering relaxation rate at low temperatures has a power law temperature dependence due to contributions from gapless collective excitations , the phase modes .
two - layer superconductor - normal metal system is also considered .
it is shown that the recombination relaxation rate in the superconducting layer has a single exponential factor at low temperatures in comparison with a one layer superconducting system .
this increase in the recombination relaxation rate originates from the inter - layer coulomb interaction and may be used in constructing of superconducting radiation detectors . .
And you have already written the first three sentences of the full article: the electron - electron energy - relaxation time determines a number of parameters of nonequilibrium superconductors such as the relaxation times for the amplitude and the phase of the order parameter @xcite .
it is also important for nonequilibrium superconducting radiation detectors based on the resistive and inductive responses .
the electron - electron relaxation time is responsible for the quasiparticle multiplication coefficient which in turn determines the responsivity and detectivity of the detector and its noise characteristics @xcite ..
Please generate the next two sentences of the article | the energy relaxation time also serves as a pair - breaking parameter in the superconducting density of states which is measured in the tunneling experiment @xcite .
recently the energy relaxation time was measured in cuprate superconductors by studying an electronic instability at high vortex velocities in the mixed state @xcite . |
5,126 | Suppose that you have an abstract for a scientific paper: we study modules for the divided power algebra @xmath0 in a single variable over a commutative noetherian ring @xmath1 .
our first result states that @xmath0 is a coherent ring . in fact , we show that there is a theory of grbner bases for finitely generated ideals , and so computations with finitely presented @xmath0-modules are in principle algorithmic .
we go on to determine much about the structure of finitely presented @xmath0-modules , such as : existence of certain nice resolutions , computation of the grothendieck group , results about injective dimension , and how they interact with torsion modules .
our results apply not just to the classical divided power algebra , but to its @xmath2-variant as well , and even to a much broader class of algebras we introduce called `` generalized divided power algebras . '' on the other hand , we show that the divided power algebra in two variables over @xmath3 is not coherent . .
And you have already written the first three sentences of the full article: let @xmath0 be the divided power algebra in a variable @xmath4 over the commutative ring @xmath1 . recall that @xmath0 is free as a @xmath1-module with basis @xmath5 } , x^{[1 ] } , \ldots$ ] , and multiplication is defined by @xmath6 } x^{[m ] } = \binom{n+m}{n } x^{[n+m]}.\ ] ] if @xmath7 then @xmath0 is isomorphic to the polynomial ring @xmath8 $ ] via @xmath9 } \mapsto \frac{x^n}{n!}$ ] .
however , in general @xmath0 is quite different from the polynomial ring : for example , if @xmath10 then @xmath0 is not even noetherian .
this paper is an investigation of the theory of @xmath0-modules . even though @xmath0 is typically non - noetherian.
Please generate the next two sentences of the article | , we show that finitely presented @xmath0-modules are well - behaved , and prove a variety of results concerning them . in the remainder of the introduction , we summarize our results and explain our motivation for studying @xmath0-modules .
recall that a ring @xmath11 is * coherent * if every finitely generated ideal is finitely presented . |
5,127 | Suppose that you have an abstract for a scientific paper: an equation of state of neutron star matter with strange baryons has been obtained .
the effects of the strength of hyperon - hyperon interactions on the equations of state constructed for the chosen parameter sets have been analyzed .
numerous neutron star models show that the appearance of hyperons is connected with the increasing density in neutron star interiors .
the performed calculations have indicated that the change of the hyperon - hyperon coupling constants affects the chemical composition of a neutron star .
the obtained numerical hyperon star models exclude large population of strange baryons in the star interior . .
And you have already written the first three sentences of the full article: the analysis of the role of strangeness in nuclear structure in the aspect of multi - strange system is of great importance for relativistic heavy - ion collisions and for astrophysics for the description of hyperon star matter . at the core of a neutron star the matter density ranges from a few times the density of normal nuclear matter to about an order of a magnitude higher .
thus exotic forms of matter such as hyperons are expected to emerge in the interior of a neutron star .
the appearance of these additional degrees of freedom and their impact on a neutron star structure have been the subject of extensive studies @xcite , @xcite , @xcite , @xcite ..
Please generate the next two sentences of the article | properties of matter at such extreme densities are of particular importance in determining forms of equations of state relevant to neutron stars and successively in examining their global parameters .
+ the existence of bound strange hadronic matter which in addition to nucleons contains also hyperons has profound consequences for astrophysics . |
5,128 | Suppose that you have an abstract for a scientific paper: we have investigated an influence of the r - mode instability on hypercritically accreting ( @xmath0 ) neutron stars in close binary systems during their common envelope phases based on the scenario proposed by bethe et al . .
on the one hand neutron stars are heated by the accreted matter at the stellar surface , but on the other hand they are also cooled down by the neutrino radiation . at the same time , the accreted matter transports its angular momentum and mass to the star .
we have studied the evolution of the stellar mass , temperature and rotational frequency .
the gravitational - wave - driven instability of the r - mode oscillation strongly suppresses spinning - up of the star , whose final rotational frequency is well below the mass - shedding limit , typically as small as @xmath1 of that of the mass - shedding state . on a very short time
scale the rotational frequency tends to approach a certain constant value and saturates there as far as the amount of the accreted mass does not exceed a certain limit to collapse to a black hole .
this implies that the similar mechanism of gravitational radiation as the so - called wagoner star may work in this process .
the star is spun up by accretion until the angular momentum loss by gravitational radiation balances the accretion torque .
the time - integrated dimensionless strain of the radiated gravitational wave may be large enough to be detectable by the gravitational wave detectors such as ligo ii .
accretion binaries : close stars : neutron stars : rotation stars : oscillations .
And you have already written the first three sentences of the full article: in relation to the formation mechanism of compact binary systems such as double neutron star systems , double black hole systems or black hole neutron star systems , hypercritical accretion flows onto neutron stars in envelopes of massive stars of close binary systems have been investigated by several authors @xcite . the mass accretion rate ( @xmath2 ) of the hypercritical accretion flow amounts to @xmath3 times as high as the eddington s mass accretion limit .
chevalier found that for rather small values of the viscosity parameter , @xmath4 , the accretion flow which cools via neutrino radiation could be realized .
recently bethe et al ..
Please generate the next two sentences of the article | pointed out that the flow with much larger and conservative values of the viscosity parameter , @xmath5 , does not become so hot as to emit neutrinos during the accretion process but that the accretion will proceed to the advection dominated accretion flow ( adaf ) . in their model , the accreted matter onto the neutron star surface is processed there by nuclear reactions and cools via neutrino emission .
the hypercritical accretion increases the mass of the star rapidly and induces the collapse of the neutron star to a black hole . |
5,129 | Suppose that you have an abstract for a scientific paper: numerical magnetohydrodynamic ( mhd ) simulations of a turbulent solar nebula are used to study the growth of dust mantles swept up by chondrules .
a small neighborhood of the solar nebula is represented by an orbiting patch of gas at a radius of 3 au , and includes vertical stratification of the gas density .
the differential rotation of the nebular gas is replaced by a shear flow .
turbulence is driven by destabilization of the flow as a result of the magnetorotational instability ( mri ) , whereby magnetic field lines anchored to the gas are continuously stretched by the shearing motion .
a passive contaminant mimics small dust grains that are aerodynamically well coupled to the gas , and chondrules are modeled by lagrangian particles that interact with the gas through drag .
whenever a chondrule enters a region permeated by dust , its radius grows at a rate that depends on the local dust density and the relative velocity between itself and the dust .
the local dust abundance decreases accordingly .
compaction and fragmentation of dust aggregates are not included .
different chondrule volume densities @xmath0 lead to varying depletion and rimmed - chondrule size growth times .
most of the dust sweep up occurs within @xmath1 1 gas scale height of the nebula midplane .
chondrules can reach their asymptotic radius in 10 to 800 years , although short growth times due to very high @xmath0 may not be altogether realistic .
if the sticking effiency @xmath2 of dust to chondrules depends on their relative speed @xmath3 , such that @xmath4 whenever @xmath5 34 cm / s ( with @xmath6 a critical sticking velocity ) , then longer growth times result due to the prevalence of high mri turbulent relative velocities .
the vertical variation of nebula turbulent intensity results in a moderate dependence of mean rimmed - chondrule size with nebula height , and in a @xmath120% dispersion in radius values at every height bin .
the technique used here could be combined with monte carlo ( mc ) methods....
And you have already written the first three sentences of the full article: the origin of fine - grained dust rims surrounding chondrules in carbonaceous chondrites is still debated .
analyses of cm chondrite thin sections by optical and scanning electron microscopy ( metzler et al .
1992 ) , as well as detailed theoretical models ( morfill et al ..
Please generate the next two sentences of the article | 1998 , henceforth mdt ; cuzzi 2004 ; ormel et al .
2008 , henceforth oct ) suggest that these dust mantles could very well have formed in the gaseous environment of the primitive solar nebula , as a result of accretion processes . |
5,130 | Suppose that you have an abstract for a scientific paper: for zero - balanced gaussian hypergeometric functions @xmath0 @xmath1 we determine maximal regions of @xmath2 plane where well - known landen identities for the complete elliptic integral of the first kind turn on respective inequalities valid for each @xmath3 . thereby an exhausting answer is given to the open problem from @xcite .
keywords .
log - convexity ; hypergeometric functions ; inequalities . 2010 mathematics subject classification . .
And you have already written the first three sentences of the full article: among special functions , the hypergeometric function has perhaps the widest range of applications . for instance , several well - known classes of mathematical physics are particular or limiting cases of it . for real numbers @xmath4 and @xmath5 with @xmath6 , the gaussian hypergeometric function is defined by [ eq1.1 ] f(a , b;c;x ) : = _ 2 f_1(a , b;c;x)= _ n=0^ for @xmath7 , where @xmath8 for @xmath9 , and @xmath10 for @xmath11 . for many rational triples
@xmath12 the function can be expressed in terms of elementary functions and long lists of such particular cases are given in @xcite .
it is clear that small changes of the parameters @xmath13 will have small influence on the value of @xmath14 . in this paper.
Please generate the next two sentences of the article | we shall study to what extent some well - known properties of the complete elliptic integral of the first kind [ eq1.2 ] ( x ) f ( , ; 1;x^2 ) = _ 0^/2(1-x^2 ^ 2t)^-1/2dt , x ( 0,1 ) , can be extended to @xmath15 for @xmath16 close to @xmath17 . recall that @xmath18 is called _ zero - balanced _ if @xmath19 .
in the zero - balanced case , there is a logarithmic singularity at @xmath20 and gauss proved the asymptotic formula [ eq1.3 ] f(a , b;a+b;r)~- ( 1-r ) as @xmath21 tends to @xmath22 , where [ eq1.4 ] b(z , w ) , re z>0 , re w>0 is the classical beta function . |
5,131 | Suppose that you have an abstract for a scientific paper: we analyze the dynamical expansion of the h ii region , photodissociation region , and the swept - up shell , solving the uv- and fuv - radiative transfer , the thermal and chemical processes in the time - dependent hydrodynamics code .
following our previous paper , we investigate the time evolutions with various ambient number densities and central stars .
our calculations show that basic evolution is qualitatively similar among our models with different parameters .
the molecular gas is finally accumulated in the shell , and the gravitational fragmentation of the shell is generally expected .
the quantitative differences among models are well understood with analytic scaling relations .
the detailed physical and chemical structure of the shell is mainly determined by the incident fuv flux and the column density of the shell , which also follow the scaling relations .
the time of shell - fragmentation , and the mass of the gathered molecular gas are sensitive to the ambient number density . in the case of a low density ,
the shell - fragmentation occurs over a longer timescale , and the accumulated molecular gas is more massive than in the case of a high density .
the variations with different central stars are more moderate .
the time of the shell - fragmentation differs by a factor of several with the various stars of @xmath0 . according to our numerical results ,
we conclude that the expanding h ii region should be an efficient trigger for star formation in molecular clouds if the mass of the ambient molecular material is large enough . .
And you have already written the first three sentences of the full article: massive stars are ubiquitous in many star - forming regions , and their feedback processes have significant impacts on the surrounding interstellar medium ( ism ) .
uv / fuv radiation photoionizes / photodissociates molecular gas , and the h ii and photodissociation regions ( pdr ) expand around the massive star .
the stellar winds and supernovae explosions give rise to expanding bubbles in ism ..
Please generate the next two sentences of the article | the role of these feedback processes in relation to ism has been studied from two competing perspectives on their effects on star - formation activity .
the expanding h ii region and bubble erode the parental molecular clouds and suppress star formation ( _ negative feedback _ ) . on the other hand , |
5,132 | Suppose that you have an abstract for a scientific paper: the circular median problem in the double - cut - and - join ( dcj ) distance asks to find , for three given genomes , a fourth circular genome that minimizes the sum of the mutual distances with the three other ones .
this problem has been shown to be np - complete .
we show here that , if the number of vertices of degree @xmath0 in the breakpoint graph of the three input genomes is fixed , then the problem is tractable . .
And you have already written the first three sentences of the full article: comparative genomics has been an important source of combinatorial and algorithmic questions during the last 20 years , especially the computation of genomic distances and ancestral genomes , as illustrated by the recent book of fertin _ et al .
_ @xcite . among these problems ,
the _ median _.
Please generate the next two sentences of the article | problem is of particular interest : while the distance problem is tractable in many models , the median problem is its simplest natural extension ( a distance is a function of two genomes , while the median score is a function of three genomes ) and is computationally intractable in most models .
computing median is at the heart of inferring gene order phylogenies and ancestral gene orders @xcite . |
5,133 | Suppose that you have an abstract for a scientific paper: the busemann - petty problem asks whether origin - symmetric convex bodies in @xmath0 with smaller central hyperplane sections necessarily have smaller @xmath1-dimensional volume .
it is known that the answer to this problem is affirmative if @xmath2 and negative if @xmath3 .
we study this problem in hyperbolic and spherical spaces . .
And you have already written the first three sentences of the full article: the busemann - petty problem asks the following question . given two convex origin - symmetric bodies @xmath4 and @xmath5 in @xmath0 such that @xmath6 for every central hyperplane @xmath7 in @xmath0 , does it follow that @xmath8 the answer to this problem in @xmath0 is known to be affirmative if @xmath2 and negative if @xmath3 .
the solution appeared as the result of work of many mathematicians ( see @xcite or @xcite for historical details ) . in this paper
we consider the busemann - petty problem in hyperbolic and spherical spaces in place of the euclidean space ..
Please generate the next two sentences of the article | we prove let @xmath4 and @xmath5 be centrally symmetric convex bodies in the spherical space @xmath9 , @xmath10 ( more precisely in a hemisphere ) such that @xmath11 for every central totally - geodesic hyperplane @xmath7 in @xmath12 .
then @xmath13 on the other hand , if @xmath3 there are convex symmetric bodies @xmath4 , @xmath14 that satisfy ( [ eqn : condition ] ) but @xmath15 so , the answer to the busemann - petty in @xmath9 is exactly the same as in the euclidean space |
5,134 | Suppose that you have an abstract for a scientific paper: using instanton effects , we discuss the problem of fermion mass hierarchies in an mssm - like type iia orientifolded model with @xmath0 gauge symmetry obtained from intersecting d6-branes . in the corresponding four - stack quiver , the different scales of the generated superpotential couplings offer a partial solution to fermion mass hierarchies . using the known data with neutrino masses
@xmath1 @xmath2 @xmath3 @xmath4 , we give the magnitudes of the relevant scales .
* keywords * : type iia superstring , instanton effects and yukawa couplings . .
And you have already written the first three sentences of the full article: it has been recognized that important particle physics ingredients including gauge symmetry and chiral matter can be realized in type ii superstring models using the mechanism of intersecting d - branes @xcite .
more recently , this method has been extensively progressed and it is now possible to investigate some stringy effects which could give rise to deeper details seen in particle physics . in particular , d - brane instantons wrapping non trivial cycles in the internal manifold have been particularly explored in this regard @xcite .
they give non - perturbative superpotential corrections which could explain the large mass hierarchies including the smallness of neutrino masses in the standard model ( sm ) @xcite ..
Please generate the next two sentences of the article | many works have been done along these lines using configurations realizing mssm - like orientifolded models based on quiver approach . in this way , rather than considering full string theory models , working at the level of quivers allow for dealing with many important physical effects .
indeed , one could examine the possible presence or absence of couplings and other physical effects by considering quantum numbers associated with the quiver configuration data . |
5,135 | Suppose that you have an abstract for a scientific paper: we present the detailed theoretical study of a heterostructure comprising of two coupled ferromagnetic superconducting layers . our model may be also applicable to the layered superconductors with alternating interlayer coupling in a parallel magnetic field .
it is demonstrated that such systems exhibit a competition between the nonuniform larkin - ovchinnikov - fulde - ferrel ( fflo ) state and the @xmath0 superconducting state where the sign of the superconducting order parameter is opposite in adjacent layers .
we determine the complete temperature - field phase diagram . in the case of low interlayer coupling
we obtain a new @xmath0 phase inserted within the fflo phase and located close to the usual tricritical point , whereas for strong interlayer coupling the bilayer in the @xmath0 state reveals a very high paramagnetic limit and the phenomenon of field - induced superconductivity . .
And you have already written the first three sentences of the full article: the question of coexistence of singlet superconductivity and magnetism has been adressed for many years .
it was found that the superconducting order parameter is destroyed by a magnetic field both via the orbital effect @xcite and the paramagnetic effect.@xcite in the usual case of an isotropic three - dimensional ( 3d ) superconductor under an external magnetic field , the orbital effect prevails and leads to the well - known temperature - field phase diagram of conventional type i or ii superconductors.@xcite in contrast , superconductivity is essentially suppressed by the paramagnetic effect in presence of a ferromagnetic exchange interaction .
this is also true for quasi - two - dimensional ( 2d ) superconductors under in - plane magnetic field and for heavy fermions materials wherein the orbital effect is partially quenched . in the whole paper ,.
Please generate the next two sentences of the article | the magnetism is characterized by an internal exchange field @xmath1 ( given in energy units ) which may arise either from an externally applied magnetic field or from ferromagnetic ordering .
note that ferromagnetism must be weak in order to avoid complete suppression of superconductivity . |
5,136 | Suppose that you have an abstract for a scientific paper: in this paper we demonstrate that with vacuum @xmath0 gravity it is possible to describe the unification of late and early - time acceleration eras with the radiation and matter domination era .
the hubble rate of the unified evolution contains two mild singularities , so called type iv singularities , and the evolution itself has some appealing features , such as the existence of a deceleration - acceleration transition at late times .
we also address quantitatively a fundamental question related to modified gravity models description of cosmological evolution : is it possible for all modified gravity descriptions of our universe evolution , to produce a nearly scale invariant spectrum of primordial curvature perturbations ? as we demonstrate , the answer for the @xmath0 description is no , since the resulting power spectrum is not scale invariant , in contrast to the @xmath1 description studied in the literature .
therefore , although the cosmological evolution can be realized in the context of vacuum @xmath0 gravity , the evolution is not compatible with the observational data , in contrast to the @xmath1 gravity description of the same cosmological evolution . .
And you have already written the first three sentences of the full article: the observational data coming from type ia supernovae in the late 90 s @xcite indicated that in addition to the radiation and matter domination eras , there is also a late - time acceleration era , which occurred after the matter domination era and the universe is expanding in an accelerating way ever since .
this observation utterly changed our perception for the universe cosmological evolution , and it is a challenge for theoretical cosmologists to consistently describe the evolution of the universe . with regards to the radiation domination era , at the beginning of this era it is believed that the universe experienced a rapid acceleration era known nowadays as the inflationary era . during this era
the universe increased its size significantly and after the end of this era , the universe continued its expansion in a decelerating way , with the effective equation of state of the universe being described by a radiation perfect matter fluid ..
Please generate the next two sentences of the article | it is therefore compelling to find a model which can harbor all the evolution era of the universe , in the same theoretical framework .
modified gravity @xcite , in all its aspects and variant models , can describe consistently the evolution of the universe , so it is one of the most appealing candidates for the cosmological theory of everything , at least in the context of classical evolution . |
5,137 | Suppose that you have an abstract for a scientific paper: one approach to the understanding of fusion in cells and model membranes involves stalk formation and expansion of the hemifusion diaphragm .
we predict theoretically the initiation of hemifusion by stalk expansion and the dynamics of mesoscopic hemifusion diaphragm expansion in the light of recent experiments and theory that suggested that hemifusion is driven by intra - membrane tension far from the fusion zone .
our predictions include a square root scaling of the hemifusion zone size on time as well as an estimate of the minimal tension for initiation of hemifusion .
while a minimal amount of pressure is evidently needed for stalk formation , it is not necessarily required for stalk expansion .
the energy required for tension induced fusion is much smaller than that required for pressure driven fusion . .
And you have already written the first three sentences of the full article: membrane hemifusion is a possible pathway ( see @xcite for an alternative view ) to the complete fusion of membranes @xcite .
current theories associate the initiation of hemifusion with the formation of a contact zone between the membranes in which the two proximal monolayers are connected by a stalk - shaped neck .
the stalk then expands and a region is formed ( region c in fig ..
Please generate the next two sentences of the article | [ fig : setup ] ) , in which the two distal monolayers form a single bilayer . in general
, the energetic cost of the splay of the lipid chains in the stalk , prohibits its spontaneous expansion . |
5,138 | Suppose that you have an abstract for a scientific paper: quantitative morphological and structural parameters are estimated for galaxies detected in hst observations of wfpc2 survey fields .
a modeling approach based on maximum likelihood has been developed for two - dimensional decomposition of faint under - sampled galaxy images into components of disk and bulge morphology .
decomposition can be achieved for images down to f814w ( i ) @xmath0 , f606w ( v ) @xmath1 and f450w ( b ) @xmath2 magnitudes in wfpc2 exposures of one hour .
we discuss details of the fitting procedure , and present the observed distributions of magnitude , color , effective half - light radius , disk and bulge axis ratios , bulge/(disk+bulge ) flux ratio , bulge / disk half - light radius ratio and surface brightness .
we also discuss the various selection limits on the measured parameters .
the medium deep survey catalogs and images of random pure parallel fields and other similar archival primary wfpc2 fields have been made available via the internet with a searchable browser interface to the database .
3 @xmath3 .
And you have already written the first three sentences of the full article: wfpc2 pure parallel images from the hst medium deep survey key project ( @xcite hereafter mds ) cover a very wide range of signal - to - noise . for the few brightest galaxies observed , detailed structures such as spiral arms and bright regions of star - formation are well exposed and the morphology can be easily classified by eye and measured by traditional interactive one - dimensional profile fitting procedures . at these brighter magnitudes the two - dimensional light distributions of galaxies are not well fitted by simple parameterized models which are necessarily crude fits to the broad continuum using smooth image profiles . however , as the images get fainter and smaller ( undersampled ) , the morphology is less apparent and requires a model - based two - dimensional image analysis to derive quantitative estimates . for the extreme faint and small objects there is very little morphological information in the observations .
the mds procedure described in this paper has been optimized for the intermediate ( medium deep ) galaxies , in the rough magnitude range between v @xmath4 to 24 mag .
, as imaged in exposures of about one hour ..
Please generate the next two sentences of the article | this has yielded a significantly large catalog of quantitative morphological and structural parameter estimates .
this magnitude range is now accessible for spectroscopic determination of redshifts via the new generation of 8 - 10 meter class ground based telescopes . |
5,139 | Suppose that you have an abstract for a scientific paper: weakly interacting massive particles ( wimps ) are among the favored candidates for cold dark matter in the universe .
the phenomenology of supersymmetric wimps has been quite developed during recent years . however , there are other possibilities which have not been discussed as much .
one example is a right - handed massive neutrino , which has recently been proposed in the context of a version of the zee model for massive neutrinos .
this tev - scale , leptonic wimp ( or limp , for short ) may at first sight appear to be essentially undetectable .
however , we point out that the radiatively induced annihilation rate into leptons and photons is bound to be substantial , and provides a conspicuous gamma - ray signature for annihilations in the galactic halo .
this gives a window of opportunity for air erenkov telescopes with ability to observe the galactic center , such as the hess and cangaroo arrays , and also for the glast space telescope .
in addition , the contribution to the positron cosmic ray flux is in principle detectable , but this would require very strong local density enhancements in the dark matter halo distribution .
nsf - itp-02 - 165 + hep - ph/0211325 .
And you have already written the first three sentences of the full article: recently , krauss , nasri and trodden ( @xcite , knt in the following ) proposed an interesting model , where a right - handed neutrino of mass on the order of a few tev plays a crucial role in giving mass to the otherwise massless standard model neutrinos through a high - order loop mechanism .
this is a version of the zee model @xcite , which has been quite successful is reproducing the observed mass and mixing pattern of solar and atmospheric neutrinos ( see , e.g. , @xcite ) .
the particle content of the zee model is given by two higgs doublets @xmath0 and @xmath1 , and a charged field @xmath2 which transforms as a singlet under @xmath3 , with lagrangian @xmath4 knt consider a variant where neutrino masses appear only at the three loop level . to achieve this they supplement the sm fields with two charged singlet scalars @xmath5 and @xmath6 and one right handed neutrino @xmath7 ..
Please generate the next two sentences of the article | lepton number is broken explicitly by including a majorana mass term for the right - handed neutrino , and imposing a discrete @xmath8 symmetry under which the sm fields and @xmath5 are singlets but @xmath6 and @xmath7 transform as @xmath9 forbidding dirac masses for the neutrinos .
this gives the lagrangian @xmath10 in which the potential @xmath11 contains a @xmath12 coupling . |
5,140 | Suppose that you have an abstract for a scientific paper: we propose an alternative evaluation of the long - distance weak annihilation ( wa , also called one - photon exchange in this paper ) contribution to the rare semileptonic @xmath0 ( @xmath1 ) decays .
this hadronic description at low energies is matched at intermediate energies to its short - distance counterpart in terms of quark and gluon degrees of freedom .
although the wa contribution does not contribute to solve the possible breaking of lepton - universality observed by lhcb in the @xmath2 ratio , nor provides an important hadronic contamination to their decay rates , its contribution to the branching ratios ( and direct cp asymmetry ) of the @xmath3 transitions turns out to be significant . this hadronic pollution should be taken into account when looking for new physics effects in decays into pions , which suggests to restrict these searches to squared lepton - pair invariant mass in the @xmath4 gev@xmath5 range .
the interference of the one - photon exchange contribution with the dominant short - distance one - loop amplitude induces a sizable cp asymmetry in these rare decays , which calls for dedicated measurements . .
And you have already written the first three sentences of the full article: rare meson decays are expected to serve as harbinger for new physics ( np ) in experiments at the intensity frontier @xcite .
better measurements or upper limits on a plethora of rare ( semi)leptonic and radiative @xmath6 and @xmath7 meson decays in forthcoming experiments , compared to precise standard model ( sm ) predictions , eventually will provide indirect indications of heavier particles with new interactions . particularly sensitive for np searches are those decays dominated by short - distance ( sd ) dynamics where the hadronic uncertainties are well under control .
conversely , precise measurements of these rare decays , combined with non - observation of np effects , will furnish a better determination of flavor mixing parameters ..
Please generate the next two sentences of the article | very recently , the lhcb collaboration has reported a deficit in the ratio of muon to electron pairs produced in @xmath8 decays , in the @xmath9 gev@xmath5 region for the squared invariant - mass of the lepton pair @xcite .
this energy region is cleverly chosen as it excludes long - distance ( ld ) contributions associated to charmonium and light vector resonance production in @xmath10 decays followed by their conversion to lepton pairs ( for definiteness , hereafter we will focus on decays of negatively charged @xmath7 mesons , unless otherwise indicated ) . |
5,141 | Suppose that you have an abstract for a scientific paper: we consider conservative quantum evolutions possibly interrupted by macroscopic measurements . when started in a nonequilibrium state , the resulting path - space measure is not time - reversal invariant and the weight of time - reversal breaking equals the exponential of the entropy production .
the mean entropy production can then be expressed via a relative entropy on the level of histories .
this gives a partial extension of the result for classical systems , that the entropy production is given by the source term of time - reversal breaking in the path - space measure .
, , , , quantum systems , entropy production , time - reversal 05.30.ch , 05.70.ln .
And you have already written the first three sentences of the full article: in bridging the gap between classical mechanics and thermal phenomena , the founding fathers of statistical mechanics realized that a statistical characterization of macrostates in terms of microstates is essential for understanding the typical time evolution of thermodynamic systems .
but statistical reasoning requires proper counting , starting from a set of _ a priori _ equivalent microstates .
that is different in quantum statistics from what is done in classical statistics ..
Please generate the next two sentences of the article | nevertheless the same concepts can be put in place . in this paper , we show for the quantum case what has been proven useful in the classical case : that entropy production measures the breaking of time - reversal invariance . more exactly , we show that the logarithmic ratio of the probability of a trajectory and its time - reversal coincides with the physical entropy production . + we continue with an introduction about entropy , both classical and quantum , to specify what we mean by entropy production .
the main message is contained in sections 2 and 3 where the relation between entropy production and time - reversal is demonstrated . |
5,142 | Suppose that you have an abstract for a scientific paper: we report the parameter - free , density functional theory calculations of interatomic exchange interactions and curie temperatures of half - metallic ferrimagnetic full heusler alloys mn@xmath0vz ( z = al , ge ) . to calculate the interatomic exchange interactions we employ the frozen - magnon approach .
the curie temperatures are calculated within the mean field approximation to the classical heisenberg hamiltonian by solving a matrix equation for a multi - sublattice system .
our calculations show that , although a large magnetic moment is carried by mn atoms , competing ferromagnetic ( inter sublattice ) and antiferromagnetic ( intra sublattice ) mn - mn interactions in mn@xmath0val almost cancel each other in the mean - field experienced by the mn atoms . in mn@xmath0vge
the leading mn - mn exchange interaction is antiferromagnetic . in both compounds
the ferromagnetism of the mn subsystem is favored by strong antiferromagnetic mn - v interactions .
the obtained value of the curie temperature of mn@xmath0val is in good agrement with experiment .
for mn@xmath0vge there is no experimental information available and our calculation is a prediction . .
And you have already written the first three sentences of the full article: the increased interest in the field of spin electronics attracts strong attention to the magnetic systems suitable for the realization of spin injection into a semiconductor @xcite .
the heusler alloys are considered as a promising class of materials that can possess the necessary combination of properties . among the features useful for applications
are high curie temperature , high electron spin polarization at the fermi level and very small lattice mismatch with widely employed semiconductors @xcite . some of the heusler compounds were found to have half - metallic ground state @xcite characterized by a 100% spin - polarization of the charge carriers ..
Please generate the next two sentences of the article | an interesting combination of physical properties makes heusler alloys the subject of intensive experimental and theoretical investigations @xcite . in full heusler compounds characterized by
the formula x@xmath0yz the mn atoms usually enter as the y element . |
5,143 | Suppose that you have an abstract for a scientific paper: previously published data on inclusive neutral and charged current @xmath0 and @xmath1 deep inelastic scattering from hera have been combined .
the new , model - independent method of combining the measured cross sections takes full account of correlated systematics in a coherent way , leading to significantly reduced uncertainties in the combined measurement across the @xmath2 plane .
the combined cross section data have been used as the sole input for a new next - to - leading order qcd fit to extract the parton distribution functions ( pdfs ) of the proton .
the pdfs extracted have greatly reduced experimental uncertainties , compared to separate qcd analyses on data from h1 and zeus .
model uncertainties , including those arising from the parameterisation dependence , have also been carefully considered .
the resulting hera pdfs have impressive precision . .
And you have already written the first three sentences of the full article: the deep inelastic lepton - nucleon scattering ( dis ) process , in which a point - like lepton probes a single , initial state hadron , is an ideal environment in which to study quantum chromodynamics ( qcd ) , and constrain the parton distribution functions ( pdfs ) of the proton .
the hera collider ceased running in june 2007 , following 15 years of successful operation .
during hera i running ( 1992 - 2000 ) , the h1 and zeus experiments each collected approximately @xmath3 @xmath4 of @xmath0 and @xmath5 @xmath4 of @xmath1 data ..
Please generate the next two sentences of the article | this has allowed precision measurements of inclusive neutral ( nc ) and charged ( cc ) current dis cross sections , which have already proved fundamental to the rapid development in understanding of qcd and the structure of the proton . in these proceedings , a joint h1 and zeus analysis
is presented , in which previously published nc and cc inclusive dis cross section measurements from the two collider experiments are combined . the combination method @xcite uses an iterative @xmath6 minimisation , which carefully takes into account the correlations within the data that result from different sources of uncertainty . |
5,144 | Suppose that you have an abstract for a scientific paper: we show that in theories with a nontrivial kinetic term the contribution of the gravitational waves to the cmb fluctuations can be substantially larger than that is naively expected in simple inflationary models .
this increase of the tensor - to - scalar perturbation ratio leads to a larger b - component of the cmb polarization , thus making the prospects for future detection much more promising .
the other important consequence of the considered model is a higher energy scale of inflation and hence higher reheating temperature compared to a simple inflation .
lmu - asc 78/05 .
And you have already written the first three sentences of the full article: the main consequence of inflation is the generation of primordial cosmological perturbations @xcite and the production of long wavelength gravitational waves ( tensor perturbations ) @xcite .
the predicted slightly red - tilted spectrum of the scalar perturbations is at present in excellent agreement with the measurements of the cmb fluctuations @xcite .
the detection of a small deviation of the spectrum from flat together with the observation of primordial gravitational waves would make us completely confident in early - time cosmic acceleration ..
Please generate the next two sentences of the article | the detection of primordial gravitational waves is not easy , but they can be seen indirectly in the b - mode of the cmb polarization ( see , for example , @xcite ) . in standard slow - roll inflationary scenarios
@xcite the amplitude of the tensor perturbations can , in principle , be large enough to be discovered . |
5,145 | Suppose that you have an abstract for a scientific paper: monte carlo sampling techniques have been proposed as a strategy to reduce the computational cost of contractions in tensor network approaches to solving many - body systems .
here we put forward a variational monte carlo approach for the multi - scale entanglement renormalization ansatz ( mera ) , which is a unitary tensor network .
two major adjustments are required compared to previous proposals with non - unitary tensor networks .
first , instead of sampling over configurations of the original lattice , made of @xmath0 sites , we sample over configurations of an effective lattice , which is made of just @xmath1 sites .
second , the optimization of unitary tensors must account for their unitary character while being robust to statistical noise , which we accomplish with a modified steepest descent method within the set of unitary tensors .
we demonstrate the performance of the variational monte carlo mera approach in the relatively simple context of a finite quantum spin chain at criticality , and discuss future , more challenging applications , including two dimensional systems . .
And you have already written the first three sentences of the full article: understanding the collective behaviour of quantum many - body systems remains a central topic in modern physics , as well as one of the greatest computational challenges in science .
quantum monte carlo sampling techniques are capable of addressing a large class of ( unfrustrated ) bosonic and spin lattice models , but fail when applied to other models such as frustrated antiferromagnets and interacting fermions due to the so - called sign problem .
variational approaches , on the other hand , are sign - problem free but are typically strongly biased towards specific many - body wavefunctions ..
Please generate the next two sentences of the article | an important exception is given by the density matrix renormalization group,@xcite a variational approach based on the matrix product state ( mps),@xcite which is capable of providing an extremely accurate approximation to the ground state of most one - dimensional lattice models .
the success of dmrg is based on the fact that an mps can reproduce the structure of entanglement common to most ground states of one - dimensional lattice models . in order to extend the success of dmrg to other contexts , |
5,146 | Suppose that you have an abstract for a scientific paper: we describe how two vibrational degrees of freedom of a single trapped ion can be coupled through the action of suitably - chosen laser excitation .
we concentrate on a two - dimensional ion trap with dissimilar vibrational frequencies in the @xmath0- and @xmath1-directions of motion , and derive from first principles a variety of quantized two - mode couplings , concentrating on a linear coupling which takes excitations from one mode to another .
we demonstrate how this can result in a state rotation , in which it is possible to transfer the motional state of the ion from say the @xmath0-direction to the @xmath2-direction without prior knowledge of that motional state . 2 .
And you have already written the first three sentences of the full article: in recent years advances in the cooling and trapping of ions have led to a situation in which the centre - of - mass ( cm ) motion of trapped ions has to be treated quantum mechanically @xcite .
this motion can be coherently controlled by coupling the ion s external and internal degrees of freedom through laser irradiation @xcite .
systems of trapped ions have been employed to demonstrate experimentally the generation and measurement of non - classical states of the ion s cm motion @xcite ..
Please generate the next two sentences of the article | furthermore trapped ions have been used to implement quantum logic gates @xcite .
most of the previous investigations have focussed on the one - dimensional quantum motion of trapped ions . recently , |
5,147 | Suppose that you have an abstract for a scientific paper: using a plane wave pseudopotential approach to density functional theory we investigate the electron localization length in various oxides . for this purpose , we first set up a theory of the band - by - band decomposition of this quantity , more complex than the decomposition of the spontaneous polarization ( a related concept ) , because of the interband coupling .
we show its interpretation in terms of wannier functions and clarify the effect of the pseudopotential approximation .
we treat the case of different oxides : bao , @xmath0-pbo , batio@xmath1 and pbtio@xmath1 .
we also investigate the variation of the localization tensor during the ferroelectric phase transitions of batio@xmath1 as well as its relationship with the born effective charges . .
And you have already written the first three sentences of the full article: in the study of periodic crystalline solids , the electronic ground - state wave function is usually described in terms of bloch functions , delocalized on the whole system . as a consequence , for a long time , the understanding of electron localization in crystalline solids was mainly based on approximate pictures .
nevertheless , the basics of a quantitative characterization of electron localization had already been formulated by w. kohn @xcite in 1964 . recently
this problematic was renewed , thanks to the development of the theory of polarization based on berry phases @xcite , and the rigorous definition of the position operator in periodic systems @xcite ..
Please generate the next two sentences of the article | these ideas have been further developped using a cumulant generating function approach @xcite .
following these advances , sgiarovello and co - workers @xcite , have computed the localization lengths for different cubic semiconductors , in the framework of the kohn - sham density functional theory @xcite ( dft ) . |
5,148 | Suppose that you have an abstract for a scientific paper: we assemble a statistical set of global mass models for @xmath0 2,000 nearly spherical sloan digital sky survey ( sdss ) galaxies at a mean redshift of @xmath1 based on their aperture velocity dispersions and newly derived luminosity profiles in conjunction with published velocity dispersion profiles and empirical properties and relations of galaxy and halo parameters .
when two - component ( i.e. stellar plus dark ) mass models are fitted to the sdss aperture velocity dispersions , the predicted velocity dispersion profile ( vp ) slopes within the effective ( i.e. projected half - light ) radius @xmath2 match well the distribution in observed elliptical galaxies . from a number of input variations the models exhibit for the radial range
@xmath3 a tight correlation @xmath4 where @xmath5 is the mean slope absolute value of the total mass density and @xmath6 is the mean slope of the velocity dispersion profile , which leads to a super - isothermal @xmath7 for @xmath8 in observed elliptical galaxies .
furthermore , the successful two - component models appear to imply a typical slope curvature pattern in the total mass profile because for the observed steep luminosity ( stellar mass ) profile and the weak lensing inferred halo profile at large radii a total mass profile with monotonically varying slope would require too high dm density in the optical region giving rise to too large aperture velocity dispersion and too shallow vp .
galaxies : kinematics and dynamics galaxies : structure galaxies : haloes galaxies : formation .
And you have already written the first three sentences of the full article: observed galaxies exhibit substantial diversity in their morphological appearances and structure .
early - type , namely elliptical and lenticular , galaxies ( etgs ) are more massive on average among galaxy types and are thought to originate from mergers of late - type galaxies and smaller etgs under the paradigm of hierarchical galaxy formation and evolution ( e.g. , @xcite ) .
the empirical properties of etgs hold important clues to the physical processes shaping properties of the most massive galaxies ..
Please generate the next two sentences of the article | etgs also play a crucial role in modern cosmology including dark energy phenomenology .
owing to their large masses and high central densities etgs dominate observed population of strong lenses and are also important for weak lensing which provide both geometric ( through cosmological distances ) and dynamical ( through growth of structures ) probe of dark energy ( @xcite ) . |
5,149 | Suppose that you have an abstract for a scientific paper: the evolution of the total energy surface and the nuclear shape in the isotopic chain @xmath0pt are studied in the framework of the interacting boson model , including configuration mixing .
the results are compared with a self - consistent hartree - fock - bogoliubov calculation using the gogny - d1s interaction and a good agreement between both approaches shows up .
the evolution of the deformation parameters points towards the presence of two different coexisting configurations in the region 176 @xmath1 a @xmath1 186 . .
And you have already written the first three sentences of the full article: shape coexistence in atomic nuclei has become a very active field of research during the last decades and clear signals of its existence have been obtained at and near proton or neutron closed shells @xcite , more in particular in light nuclei with a closed neutron shell at n = 8 , 20 , 28 and 40 closed shells as well as in heavy nuclei such as the sn and the pb nuclei .
it seems that , without exception , shape coexistence is associated with the presence of low - lying excited @xmath2 states @xcite .
the pb region is a very well - documented example of shape coexistence , both experimental and theoretically ( see @xcite and references therein ).
Please generate the next two sentences of the article | . starting at the neutron closed shell ( at n=126 ) , decreasing in mass until reaching the very neutron - deficient nuclei , even going beyond the mid - shell point at n=104 , there is ample experimental evidence for shape coexisting bands in both the pb ( z=82 ) and hg ( z=80 ) nuclei .
a question that arises is whether or not this structure , in which two or more bands coexist , survives when moving away from the closed proton shell at z=82 . in particular , |
5,150 | Suppose that you have an abstract for a scientific paper: in recent years quantum monte carlo techniques provided to be a valuable tool to study strongly interacting fermi gases at zero temperature .
we have used qmc methods to investigate several properties of the two - components fermi gas at unitarity and in the bcs - bec crossover , both with equal and unequal masses corresponding to the @xmath0 fermi mixture . in this paper we present several recent qmc results , including the energy at zero and finite effective range , the contact parameter and the static structure factor , which , at low momentum , depends strongly on the phonons in the unitary fermi gas . .
And you have already written the first three sentences of the full article: during the last years important efforts have been devoted to study ultra - cold fermi gases , both experimentally and theoretically ( for a review see for example ref .
@xcite ) . by means of feshbach resonance
it is possible experimentally to adjust the interaction between atoms ..
Please generate the next two sentences of the article | the system can be tuned to a bcs state where fermions are weakly interacting , to the so called unitary regime where the two - body scattering length is infinite , or to form a bec condensate of bosons . theoretically , ultra - cold fermi gases have become an important testing ground for a host of many - body methods , as well as an avenue to studying new physics .
the study of ultra - cold fermi gases is very intriguing , and the unitary limit became a very interesting many - body problem to solve for several reasons . |
5,151 | Suppose that you have an abstract for a scientific paper: we discuss the sensitivity of the high - scale susy at @xmath0-@xmath1 tev in @xmath2 , @xmath3 , @xmath4 and @xmath5 meson systems together with the neutron edm and the mercury edm . in order to estimate the contribution of the squark flavor mixing to these fcncs ,
we calculate the squark mass spectrum , which is consistent with the recent higgs discovery .
the susy contribution in @xmath6 could be large , around @xmath7 in the region of the susy scale @xmath0-@xmath8 tev .
the neutron edm and the mercury edm are also sensitive to the susy contribution induced by the gluino - squark interaction .
the predicted edms are roughly proportional to @xmath9 . if the susy contribution is the level of @xmath10 for @xmath6 , the neutron edm is expected to be discovered in the region of @xmath11-@xmath12ecm .
the mercury edm also gives a strong constraint for the gluino - squark interaction .
the susy contribution of @xmath13 is also discussed .
kek - th-1830 * sensitivity of high - scale susy + in low energy hadronic fcnc * + + _ @xmath14department of physics , niigata university , + niigata 950 - 2181 , japan + @xmath14institute of particle and nuclear studies , + high energy accelerator research organization ( kek ) , + tsukuba 305 - 0801 , japan + _ .
And you have already written the first three sentences of the full article: the supersymmetry ( susy ) is one of the most attractive theories beyond the standard model ( sm ) .
therefore , the susy has been expected to be observed at the lhc experiments .
however , no signals of the susy have been discovered yet ..
Please generate the next two sentences of the article | the present searches for the susy particles give us important constraints for the susy .
since the lower bounds of the superparticle masses increase gradually , the squark and the gluino masses are supposed to be at the higher scale than @xmath15 tev @xcite . on the other hand , |
5,152 | Suppose that you have an abstract for a scientific paper: high - resolution , high signal - to - noise spectral data are presented for four young b - type stars lying towards the galactic centre .
determination of their atmospheric parameters from their absorption line profiles , and @xmath0 photometric measurement of the continua indicate that they are massive objects lying slightly out of the plane , and were probably born in the disk between 2.5@xmath15kpc from the centre .
we have carried out a detailed absolute and differential line - by - line abundance analyses of the four stars compared to two stars with very similar atmospheric parameters in the solar neighbourhood .
the stars appear to be rich in all the well sampled chemical elements ( c , n , si , mg , s , al ) , _ except for oxygen_. oxygen abundances derived in the atmospheres of these four stars are very similar to that in the solar neighbourhood . if the photospheric composition of these young stars is reflective of the gaseous ism in the inner galaxy , then the values derived for the enhanced metals are in excellent agreement with the extrapolation of the galactic abundance gradients previously derived by rolleston et al .
( 2000 ) and others .
however , the data for oxygen suggests that the inner galaxy may not be richer than normal in this element , and the physical reasons for such a scenario are unclear . .
And you have already written the first three sentences of the full article: the current metallicity of the galactic disk represents a fossil record of chemical enrichment since the birth of the milky way and during its subsequent evolution . as stars continually enrich the interstellar medium with their nucleosynthetic products , the metallicity of the disk increases over time . by investigating the relative abundance of chemical elements as a function of time and position within the galaxy , it is possible to constrain models of galaxy formation and evolution .
much work has been done on tracking the chemical evolution of the solar neighbourhood as a function of time using age - metallicity relations and element abundance ratios in cool f and g - type stars .
the seminal work by edvardsson et al ..
Please generate the next two sentences of the article | ( @xcite ) showed the potential of using samples of nearby stars with an age spread to trace the temporal evolution of the disk and the halo , and such work has been extended by , for example , fuhrmann ( @xcite ) and israelian et al .
( @xcite ) . |
5,153 | Suppose that you have an abstract for a scientific paper: we present multi - epoch near - infrared photo - spectroscopic observations of nova cephei 2014 and nova scorpii 2015 , discovered in outburst on 2014 march 8.79 ut and 2015 february 11.84 ut respectively .
nova cep 2014 shows the conventional nir characteristics of a fe ii class nova characterized by strong ci , hi and o i lines , whereas nova sco 2015 is shown to belong to the he / n class with strong he i , hi and oi emission lines .
the highlight of the results consists in demonstrating that nova sco 2015 is a symbiotic system containing a giant secondary .
leaving aside the t crb class of recurrent novae , all of which have giant donors , nova sco 2015 is shown to be only the third classical nova to be found with a giant secondary .
the evidence for the symbiotic nature is three - fold ; first is the presence of a strong decelerative shock accompanying the passage of the nova s ejecta through the giant s wind , second is the h@xmath0 excess seen from the system and third is the spectral energy distribution of the secondary in quiescence typical of a cool late type giant .
the evolution of the strength and shape of the emission line profiles shows that the ejecta velocity follows a power law decay with time ( @xmath1 ) .
a case b recombination analysis of the h i brackett lines shows that these lines are affected by optical depth effects for both the novae . using this analysis we make estimates for both the novae of the emission measure @xmath2 , the electron density @xmath3 and the mass of the ejecta .
[ firstpage ] infrared : spectra - line : identification - stars : novae , cataclysmic variables - stars : individual nova cephei 2014 , nova scorpii 2015 - techniques : spectroscopic , photometric . .
And you have already written the first three sentences of the full article: nova cephei 2014 was discovered as a transient by nishiyama and kabashima ( 2014 ) at a magnitude of 11.7 on unfiltered ccd frames ( limiting magnitude 13.7 ) taken around 2014 march 8.792 ut .
the object was confirmed to be a classical nova by munari et al .
( 2014 ) who obtained a low - resolution spectrogram ( range 395 - 852 nm , 0.21 nm / pixel ) on 2014 march 9.792 ut ..
Please generate the next two sentences of the article | the spectrum showed a red continuum with strong emission lines from the balmer series , o i 777.4 and 844.6 nm , ca ii 849.8 nm , and fe ii multiplets 42 , 48 , and 49 .
all emission lines showed strong p - cyg absorptions which were blue - shifted by 660 km s@xmath4 for the balmer lines , 780 km s@xmath4 for the fe ii lines , and 900 km s@xmath4 for the o i lines . |
5,154 | Suppose that you have an abstract for a scientific paper: we present an updated catalogue of m31 globular clusters ( gcs ) based on images from the wide field camera ( wfcam ) on the uk infrared telescope and from the sloan digital sky survey ( sdss ) .
our catalogue includes new , self - consistent _ ugriz _ and k - band photometry of these clusters .
we discuss the difficulty of obtaining accurate photometry of clusters projected against m31 due to small scale background structure in the galaxy .
we consider the effect of this on the accuracy of our photometry and provide realistic photometric error estimates . we investigate possible contamination in the current m31 gc catalogues using the excellent spatial resolution of these wfcam images combined with the sdss multicolour photometry .
we identify a large population of clusters with very blue colours .
most of these have recently been proposed by other work as young clusters .
we distinguish between these , and old clusters , in the final classifications .
our final catalogue includes 416 old clusters , 156 young clusters and 373 candidate clusters .
we also investigate the structure of m31 s old gcs using previously published king model fits to these wfcam images .
we demonstrate that the structure and colours of m31 s old gc system are similar to those of the milky way .
one gc ( b383 ) is found to be significantly brighter in previous observations than observed here .
we investigate all of the previous photometry of this gc and suggest that this variability appears to be genuine and short lived .
we propose that the large increase in its luminosity my have been due to a classical nova in the gc at the time of the previous observations in 1989 .
[ firstpage ] galaxies : individual : m31 - galaxies : star clusters - globular clusters : general .
And you have already written the first three sentences of the full article: globular clusters ( gcs ) are among the oldest known stellar systems .
they typically have ages similar to those of their host galaxies , making them ideal probes into galaxy formation and evolution .
the properties of gcs vary significantly ..
Please generate the next two sentences of the article | however , individual clusters contain populations of stars with similar ages and metallicities .
this makes them unique locations for studying stellar evolution . the milky way s gcs still represent the best studied gc system . while the study of these clusters has led to many advances , the milky way contains relatively few gcs ( @xmath0150 gcs : * ? ? ? |
5,155 | Suppose that you have an abstract for a scientific paper: observations by the wmap experiment have identified an excess of microwave emission from the center of the milky way . it has previously been shown that this `` wmap haze '' could be synchrotron emission from relativistic electrons and positrons produced in the annihilations of dark matter particles . in particular , the intensity , spectrum and angular distribution of the wmap haze is consistent with an electroweak scale dark matter particle ( such as a supersymmetric neutralino or kaluza - klein dark matter in models with universal extra dimensions ) annihilating with a cross section on the order of @xmath0 @xmath1/s and distributed with a cusped halo profile .
no further exotic astrophysical or annihilation boost factors are required .
if dark matter annihilations are in fact responsible for the observed haze , then other annihilation products will also be produced , including gamma rays . in this article
, we study the prospects for the glast satellite to detect gamma rays from dark matter annihilations in the galactic center region in this scenario .
we find that by studying _ only _ the inner 0.1@xmath2 around the galactic center , glast will be able to detect dark matter annihilating to heavy quarks or gauge bosons over astrophysical backgrounds with 5@xmath3 ( @xmath4 ) significance if they are lighter than approximately 320 - 500 gev ( 500 - 750 gev ) .
if the angular window is broadened to study the dark matter halo profile s angular extension ( while simultaneously reducing the astrophysical backgrounds ) , wimps as heavy as several tev can be identified by glast with high significance .
only if the dark matter particles annihilate mostly to electrons or muons will glast be unable to identify the gamma ray spectrum associated with the wmap haze . .
And you have already written the first three sentences of the full article: the wilkinson microwave anisotropy probe ( wmap ) has made the most precise measurements to date of the anisotropies of the cosmic microwave background ( cmb ) over a wide range of angular scales .
these measurements have been invaluable in constraining a wide range of cosmological parameters @xcite .
additionally , this data has been used to study standard interstellar medium emission mechanisms , including thermal dust , spinning dust , ionized gas , and synchrotron ..
Please generate the next two sentences of the article | after known foregrounds are subtracted from the wmap data , there remains an unexplained excess of microwave emission within the inner @xmath5 around the center of the milky way , distributed with approximate radial symmetry .
this microwave emission has been dubbed the `` wmap haze '' @xcite . |
5,156 | Suppose that you have an abstract for a scientific paper: we present internal velocity dispersion determinations from high - resolution spectroscopic observations of a sample of nine globular clusters in m31 .
comprehensive numerical simulations are used to show that the typical uncertainty of our velocity dispersion measurements is @xmath05% . using these new velocity dispersions together with structural parameters derived from hst observations , we estimate the @xmath1 ratios of these clusters and find that they are typical of those measured for galactic clusters .
we show relations between velocity dispersion , luminosity and physical scales for globular clusters belonging to the galaxy , the magellanic clouds , fornax , m31 , and centaurus a. the mean relations and the degree of scatter are similar in all galaxies .
this reveals remarkable similarities , in term of structure and @xmath1 ratio , between the globular clusters belonging to these different galaxies .
we briefly discuss the possible use of individual globular clusters as extragalactic distance indicators .
# 1#20=1=0=10by-1.2pt1.300 - 0.701 # 1#20=1=0=10by-1.2pt1.200 - 00.601 # 1#2 # 1 # 1#2=#1 # 1#2=#1 -1.5 cm .
And you have already written the first three sentences of the full article: valuable information about globular clusters and galaxy formation can be obtained by investigating the extent to which the properties of globular clusters belonging to different galaxies are similar .
for example , differences in initial mass function during cluster formation and/or in susbsequent cluster dynamical evolution , which may both depend on galactic environment , would translate into differences in present - day stellar content .
the globular cluster stellar content can be characterized by the mass - to - light ( @xmath2 ) ratio , which can now be determined for relatively remote globular clusters . collecting all the available data from the literature , pryor & meylan ( 1993 ) derive @xmath1 ratios for 56 galactic globular clusters using king - michie dynamical models ..
Please generate the next two sentences of the article | they obtain _ global _
@xmath1 ratios ranging from about 1 to 5 with a mean of 2.3 ( in solar units ) , and found no significant correlations ( apart from a possible weak one between @xmath1 and cluster mass ) between the _ global _ @xmath1 ratios and other parameters such as metallicity , concentration , half - mass relaxation time , or distance from either the galactic center or the galactic plane . |
5,157 | Suppose that you have an abstract for a scientific paper: for certain hierarchical structures , one can study the percolation problem using the renormalization - group method in a very precise way .
we show that the idea can be also applied to two - dimensional planar lattices by regarding them as hierarchical structures .
either a lower bound or an exact critical probability can be obtained with this method and the correlation - length critical exponent is approximately estimated as @xmath0 .
the percolation problem is a question about how a global connection can be made possible by randomly filling local components by a certain probability @xmath1 .
while it can be explained in purely geometric terms without any interaction , when a global connection actually appears , the macroscopic behavior of the system exhibits all the characteristic features of a continuous phase transition with a diverging correlation length , just as we observe in other interacting spin systems such as the two - dimensional ( 2d ) ising model @xcite .
this analogy is given a precise meaning by the fortuin - kasteleyn representation of the @xmath2-state potts model @xcite , where the percolation turns out to be equivalent to the limit of @xmath3 .
since the percolation transition at a critical probability @xmath4 has a diverging correlation length , every microscopic length scale becomes irrelevant with respect to the critical phenomena , and the system behaves as if it does not have any specific length scale .
this is a qualitative explanation of the reason why a percolating cluster connecting two opposite sides of a 2d plane has a fractal dimension at @xmath5 .
the lack of a specific length scale implies that the system remains statistically invariant even if we zoom the system up or down , and this scale invariance readily lends itself to a renormalization - group ( rg ) study of the percolation problem @xcite . in certain cases where the underlying structure itself is fractal , it is possible to carry out the rg calculation to a good approximation or exactly ,....
And you have already written the first three sentences of the full article: .
Please generate the next two sentences of the article | |
5,158 | Suppose that you have an abstract for a scientific paper: we consider the general landau - lifshitz - gilbert ( llg ) dynamical theory underlying the magnetization switching rates of a thin film uniaxial magnet subject to spin - torque effects and thermal fluctuations ( thermal noise ) . after discussing the various dynamical regimes governing the switching phenomena , we present analytical results for the mean switching time behavior .
our approach , based on explicitly solving the first passage time problem , allows for a straightforward analysis of the thermally assisted , low spin - torque , switching asymptotics of thin film magnets . to verify our theory ,
we have developed an efficient gpu - based micromagnetic code to simulate the stochastic llg dynamics out to millisecond timescales .
we explore the effects of geometrical tilts between the spin - current and uniaxial anisotropy axes on the thermally assisted dynamics .
we find that even in the absence of axial symmetry , the switching times can be functionally described in a form virtually identical to the collinear case .
we further verify that asymptotic behavior is reached fairly slowly , thus quantifying the role of thermal noise in the crossover regime linking deterministic to thermally assisted magnetization reversal . .
And you have already written the first three sentences of the full article: more than a decade has passed since spin - torque effects were demonstrated experimentally by the switching of the magnetization of a thin ferromagnetic film when current is passed between it and a pinned ferromagnetic layer @xcite .
a spin - polarized current passing through a small magnetic conductor will deposit spin - angular momentum into the magnetic system .
this in turn causes the magnetic moment to precess and in some cases even switch direction ..
Please generate the next two sentences of the article | this has led to sweeping advances in the field of spintronics through the development and study of spin - valves and magnetic tunnel junctions ( see , for example , @xcite ) .
the theoretical approach to such a problem has conventionally been to treat the thin ferromagnetic film as a single macrospin in the spirit of brown @xcite . |
5,159 | Suppose that you have an abstract for a scientific paper: we present a large sample of 501 radio - selected bl lac candidates from the combination of the sloan digital sky survey ( sdss ) data release 5 optical spectroscopy and from the faint images of the radio sky at twenty - centimeters ( first ) radio survey ; this is one of the largest bl lac samples yet assembled , and each object emerges with homogeneous data coverage .
each candidate is detected in the radio from first and confirmed in sdss optical spectroscopy to have : ( 1 ) no emission feature with measured rest equivalent width larger than 5 ; and ( 2 ) no measured h / k depression larger than 40% .
we subdivide our sample into 426 higher confidence candidates and 75 lower confidence candidates .
we argue that contamination from other classes of objects that formally pass our selection criteria is small , and we identify a few very rare radio agn with unusual spectra that are probably related to broad absorption line quasars .
about one - fifth of our sample were known bl lacs prior to the sdss .
a preliminary analysis of the sample generally supports the standard beaming paradigm .
while we recover sizable numbers of low - energy and intermediate - energy cutoff bl lacs ( lbls and ibls , respectively ) , there are indications of a potential bias toward recovering high - energy cutoff bl lacs ( hbls ) from sdss spectroscopy .
such a large sample may eventually provide new constraints on bl lac unification models and their potentially peculiar cosmic evolution ; in particular , our sample contains a significant number of higher redshift objects , a sub - population for which the standard paradigm has yet to be rigorously constrained . .
And you have already written the first three sentences of the full article: bl lacs are a rare subclass of active galactic nuclei ( agn ) characterized by nearly featureless optical spectra , multiwavelength emission , marked variability and strong polarization ( e.g. , see * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
their spectral energy distributions ( seds ) tend to be dominated by synchrotron radiation , with a component due to inverse compton scattering at higher frequencies . |
5,160 | Suppose that you have an abstract for a scientific paper: given a subset @xmath0 of the unit euclidean sphere , we estimate the minimal number @xmath1 of hyperplanes that generate a uniform tessellation of @xmath0 , in the sense that the fraction of the hyperplanes separating any pair @xmath2 is nearly proportional to the euclidean distance between @xmath3 and @xmath4 .
random hyperplanes prove to be almost ideal for this problem ; they achieve the almost optimal bound @xmath5 where @xmath6 is the gaussian mean width of @xmath0 . using the map that sends @xmath7 to the sign vector with respect to the hyperplanes , we conclude that every bounded subset @xmath0 of @xmath8 embeds into the hamming cube @xmath9 with a small distortion in the gromov - haussdorff metric . since for many sets @xmath0
one has @xmath10 , this yields a new discrete mechanism of dimension reduction for sets in euclidean spaces . _
keywords : _ embedding ; dimension reduction ; hyperplane tessellations ; mean width ; near isometry .
And you have already written the first three sentences of the full article: consider a bounded subset @xmath0 of @xmath8 .
we would like to find an arrangement of @xmath11 affine hyperplanes in @xmath8 that cut through @xmath0 as evenly as possible ; see figure [ fig : tessellation ] for an illustration .
the intuitive notion of an `` even cut '' can be expressed more formally in the following way : the fraction of the hyperplanes separating any pair @xmath2 should be proportional ( up to a small additive error ) to the euclidean distance between @xmath3 and @xmath4 . what is the smallest possible number @xmath12 of hyperplanes with this property ? besides having a natural theoretical appeal , this question is directly motivated by a certain problem of information theory which we will describe later . in the beginning.
Please generate the next two sentences of the article | it will be most convenient to work with subsets @xmath0 of the unit euclidean sphere @xmath13 , but we will lift this restriction later .
let @xmath14 denote the normalized geodesic distance on @xmath13 , so the distance between the opposite points on the sphere equals @xmath15 . |
5,161 | Suppose that you have an abstract for a scientific paper: jupiter - family comet 15p / finlay has been reportedly quiet in activity for over a century but has harbored two outbursts during its 2014/2015 perihelion passage . here
we present an analysis of these two outbursts using a set of cometary observations .
the outbursts took place between 2014 dec .
15.416.0 ut and 2015 jan .
15.516.0 ut as constrained by ground - based and spacecraft observations .
we find a characteristic ejection speed of @xmath0 to @xmath1 for the ejecta of the first outburst and @xmath2 to @xmath3 for that of the second outburst using a monte carlo dust model .
the mass of the ejecta is calculated to be @xmath4 to @xmath5 for the first outburst and @xmath6 to @xmath7 for the second outburst , corresponds to less than @xmath8 of the nucleus mass . the specific energy of the two outbursts is found to be @xmath9 to @xmath10 .
we also revisit the long - standing puzzle of the non - detection of the hypothetical finlayid meteor shower by performing a cued search using the 13-year data from the canadian meteor orbit radar , which does not reveal any positives .
the earth will pass the 2014/2015 outburst ejecta around 2021 oct .
6 at 22 h ut to oct . 7 at 1 h ut , with a chance for some significant meteor activity in the radio range , which may provide further clues to the finlayid puzzle .
a southerly radiant in the constellation of ara will favor the observers in the southern tip of africa . .
And you have already written the first three sentences of the full article: small bodies in the inner solar system are historically classified based on their appearance .
comet refers to an object with extended appearance and sometimes one or several tails ; while asteroid refers to an object that is much smaller than the major planets and appears star - like .
classification by orbital dynamics of these bodies shows that the dynamical characteristics of the two groups of objects differ as well : comets usually possess highly elliptical , parabolic or hyperbolic orbits , while asteroids usually possess more circular orbits ..
Please generate the next two sentences of the article | bodies which deviate from these trends ( i.e. comets in asteroidal orbits , or asteorids in cometary orbits ) are of significant interest , as their dynamical evolution and/or physical properties are apparently exceptional .
although the first such outlier was officially recognized no later than 1989 ( e.g. the case of 95p/(2060 ) chiron , c.f . |
5,162 | Suppose that you have an abstract for a scientific paper: we study a toy model for a superconductor on a bipartite lattice , where intrinsic pairing inhomogeneity is produced by two different coupling constants on the sublattices .
the simplicity of the model allows for analytic solutions and tests of the consequences of atomic - scale variations in pairing interactions which have been considered recently in the cuprates .
we present results for the transition temperature , density of states , and thermodynamics of the system over a phase diagram in the plane of two pairing coupling constants . for coupling constants of alternating sign ,
a gapless superconducting state is stable .
inhomogeneity is generally found to enhance the critical temperature , and at the same time the superfluid density is remarkably robust : at @xmath0 , it is suppressed only in the gapless phase . .
And you have already written the first three sentences of the full article: in recent years , the effect of underlying inhomogeneities in superconductors has attracted many researchers . in the context of high temperature superconductors ( htsc ) , checkerboard local density of states ( ldos ) oscillations and strong nanoscale gap inhomogeneity
have been observed in scanning tunnelling spectroscopy ( sts ) experiments @xcite , and signals in dynamical susceptibility measured by neutron scattering have been interpreted as stripelike nanoscale modulations of charge and spin degrees of freedom @xcite . while it is still not clear whether these modulations are intrinsic in nature or driven entirely by disorder , others have pointed out that the very existence of inhomogeneity may enhance @xmath1 , and implicitly suggested that the phenomenon of high critical temperatures may rely on it @xcite . in particular ,
martin et al ..
Please generate the next two sentences of the article | @xcite studied a simple model , in which they included a 1d inhomogeneous pair potential varying on an arbitrary length scale @xmath2 , where @xmath3 is the lattice spacing , and argued for an increase of the critical temperature with inhomogeneity , with a maximum enhancement obtained for @xmath4 , where @xmath5 is the coherence length of the analog homogeneous system .
similar results were obtained by loh and carlson , where they found however that an increase in the transition temperature occurred at the cost of reduced superfluid density @xcite . |
5,163 | Suppose that you have an abstract for a scientific paper: we study the thermal stability of the periodic ( p ) and quasi - periodic ( q ) precessional modes of the nanoparticle magnetic moment induced by a rotating magnetic field .
an analytical method for determining the lifetime of the p mode in the case of high anisotropy barrier and small amplitudes of the rotating field is developed within the fokker - planck formalism . in general case
, the thermal stability of both p and q modes is investigated by numerical simulation of the stochastic landau - lifshitz equation .
we show analytically and numerically that the lifetime is a nonmonotonic function of the rotating field frequency which , depending on the direction of field rotation , has either a pronounced maximum or a deep minimum near the larmor frequency . .
And you have already written the first three sentences of the full article: magnetic nanoparticles are of great interest because of their nanoscale physical properties and many current and potential applications .
these applications range from high - density storage media@xcite and spintronic devices@xcite to biomedical applications like drug delivery , cell separation , cancer treatment and many others ( for a review , see refs . ) .
since the physical properties of nanoparticles play a decisive role in all these applications , their study is of fundamental importance . in particular , for high - density storage media , e.g. , bit - patterned media@xcite where each nanoparticle is a carrier of information ,.
Please generate the next two sentences of the article | the thermal stability of a given direction ( or magnitude ) of the nanoparticle magnetic moment is one of the most important problems .
the reason is that under thermal fluctuations the magnetic moment can be randomly switched to a new state leading to the loss of information . in the case of ferromagnetic nanoparticles , |
5,164 | Suppose that you have an abstract for a scientific paper: we extended to the r and i bands the light curve coverage for 8 cepheids already studied in b and v by capaccioli [ aj , 103 , 1151 ( 1992 ) ] .
sixteen additional cepheid candidates have been identified and preliminary periods are proposed .
the new cepheids allow the period - luminosity relation to be extended one magnitude fainter .
apparent b , v , r , and i distance moduli have been calculated . combining the data at different wavelengths , and assuming a true distance modulus of 18.50 mag for the lmc
, we obtain for ngc 3109 a true distance modulus @xmath0 , corresponding to @xmath1 mpc . adopting @xmath2 for the lmc ,
the interstellar reddening for the cepheids in ngc 3109 is consistent with 0 .
a discussion on the possible implications of this result is presented .
a comparison of the period - color , period - amplitude , and period - luminosity relations suggests similar properties for the cepheids in the lmc , ngc 3109 , sextans a , sextans b , and ic 1613 , though the uncertainties in the main parameter determination are still unsatisfactorily high for a firm conclusion on the universality of the period - luminosity relation .
= 9.0 in .
And you have already written the first three sentences of the full article: this paper is part of a program aimed at increasing the number of galaxies with accurate distance determinations via ground - based multicolor ccd photometry of cepheid variables . in the first paper of the series , capaccioli , piotto and bresolin ( 1991 , cpb ) presented new @xmath3 photometry of the cepheids belonging to the sample of variables already identified by sandage and carlson ( 1988 , sc ) in ngc 3109 . in that work
, cpb derived a new zero point for the photometric scale .
the new data gave a distance modulus @xmath4 mag , @xmath5% shorter than previously measured by sc ..
Please generate the next two sentences of the article | the availability of only two photometric bands ( @xmath6 and @xmath7 ) did not allow cpb to apply the multicolor method discussed by freedman ( 1985 , f85 ) to directly estimate the internal absorption of the cepheids in ngc 3109 .
actually , bresolin , capaccioli , and piotto ( 1993 , bcp ) pointed out that the internal absorption in some of the fields studied by cpb could be greater than the adopted average value e(b - v)=0.04 . |
5,165 | Suppose that you have an abstract for a scientific paper: optical and x - ray studies have established the prevalence of significant substructure in clusters of galaxies , indicating that clusters are young systems , and that recent major mergers have occurred in many clusters .
numerical simulations show that sub - cluster merging will result in significant tidal forces on disk galaxies in accreting sub - groups , which is likely to lead to the transformation of spirals to s0s in clusters .
simulations predict simultaneous moderate starbursts in gas - rich disk galaxies in clusters which show on - going or recent merger activity , as well as enhanced galaxy galaxy interactions and mergers .
observational data from studies of spectral indicators , both of starburst activity in late - type galaxies in nearby clusters , and of poststarburst activity in early - type galaxies in nearby and intermediate redshift clusters , support this scenario . .
And you have already written the first three sentences of the full article: both optical studies of sky - projected cluster galaxy distributions ( e.g. baier 1979 ; geller & beers 1982 ) and studies of cluster x - ray morphologies ( e.g. mohr , fabricant & geller 1993 ; buote & tsai 1996 ) reveal the presence of significant substructure in clusters of galaxies .
subgroup velocity statistics ( e.g. dressler & shectman 1988 ; bird 1994 ; girardi et al . 1997 ; solanes , salvador - sol & gonzlez - casado 1999 ) confirm these results , and are in substantial agreement in showing that some 3040% of clusters have statistically significant substructure . numerical simulations also show that subclustering is a typical property of cluster formation in hierarchical theories of structure formation .
such subclustering is expected for a broad range of cosmologies , and its predicted extent is in agreement with that observed ( e.g. knebe & mller 2000 ) ..
Please generate the next two sentences of the article | its prevalance indicates that clusters are young objects , since such substructure is expected to be smoothed out over a few cluster crossing times .
moreover the existing substructure indicates that recent major mergers have occurred in many clusters . |
5,166 | Suppose that you have an abstract for a scientific paper: using a fourier approach we offer a general solution to calculations of slip velocity within the circuit description of the electro - hydrodynamics in a binary electrolyte confined by a plane surface with a modulated surface potential .
we consider the case with a spatially constant intrinsic surface capacitance where the net flow rate is in general zero while harmonic rolls as well as time - averaged vortex - like components may exist depending on the spatial symmetry and extension of the surface potential .
in general the system displays a resonance behavior at a frequency corresponding to the inverse rc time of the system .
different surface potentials share the common feature that the resonance frequency is inversely proportional to the characteristic length scale of the surface potential . for the asymptotic frequency dependence above resonance
we find a @xmath0 power law for surface potentials with either an even or an odd symmetry .
below resonance we also find a power law @xmath1 with @xmath2 being positive and dependent of the properties of the surface potential . comparing a @xmath3 potential and a @xmath4 potential we qualitatively find the same slip velocity , but for the below - resonance frequency response the two potentials display different power law asymptotics with @xmath5 and @xmath6 , respectively . .
And you have already written the first three sentences of the full article: the ability to manipulate liquids on microfluidic chips is essential to the functionality of micro total analysis systems @xcite and recently there has been quite some interest in utilizing ac electrical surface potentials for pumping , manipulating , and mixing electrolytes . for an overview of electro - hydrodynamics and ac electro - osmosis we refer to refs . and references therein .
in this paper we consider the rc model in ref . of an electrolyte confined by an insulating surface with an applied external potential of the general form @xmath7 here , @xmath8 is the driving frequency and @xmath9 is a dimensionless function representing the amplitude variations along the surface . for simplicity
we consider a binary electrolyte with permeability @xmath10 , viscosity @xmath11 , and conductivity @xmath12 . assuming a low pclet number we may neglect convection so that the electrodynamics can formally be solved independently of the hydrodynamics . on the other hand the hydrodynamics of course still depends on the electrodynamics through the body force which effectively may be taken into account through a finite slip velocity , see e.g. refs . and references therein ..
Please generate the next two sentences of the article | for the electrodynamics we follow ajdari @xcite with the surface and the debye layer each represented by a capacitive element while the bulk - liquid is represented by an ohmic element .
the model applies to the situation where spatial variations along the surface are slow on the length scale of the debye screening length @xmath13 , the driving frequency is small compared to the debye frequency @xmath14 , and the electrostatic energy is small compared to the thermal energy @xmath15 , i.e. the debye |
5,167 | Suppose that you have an abstract for a scientific paper: we have produced an atlas of spitzer infrared spectrograph ( irs ) spectra of mass - losing , evolved stars in the large magellanic cloud .
these stars were selected to have high mass - loss rates and so contribute significantly to the return of processed materials to the ism .
our high - quality spectra enable the determination of the chemistry of the circumstellar envelope from the mid - ir spectral features and continuum .
we have classified the spectral types of the stars and show that the spectral types separate clearly in infrared color - color diagrams constructed from 2mass data and synthetic irac / mips fluxes derived from our irs spectra .
we present diagnostics to identify and classify evolved stars in nearby galaxies with high confidence levels using spitzer and 2mass photometry .
comparison of the spectral classes determined using irs data with the ir types assigned based on nir colors also revealed a significant number of misclassifications and enabled us to refine the nir color criteria resulting in more accurate nir color classifications of dust - enshrouded objects . .
And you have already written the first three sentences of the full article: asymptotic giant branch ( agb ) stars dominate the return of processed materials to the interstellar medium ( ism ) and therefore are an important component of galaxy evolution .
high mass - loss rate objects are heavily obscured , so they can be missed in optical surveys and need to be observed in the infrared ( ir ) .
we have conducted a study using the _ spitzer space telescope _ infrared spectrograph ( irs ;.
Please generate the next two sentences of the article | @xcite ) of a sample of luminous 8 @xmath0 m sources in the large magellanic cloud ( lmc ) .
our sample was selected from a compilation of _ |
5,168 | Suppose that you have an abstract for a scientific paper: we investigate the dynamics of interacting electrons confined to two types of quantum dot system , when driven by an external ac field .
we first consider a system of two electrons confined to a pair of coupled quantum dots @xcite by using an effective two - site model of hubbard - type . numerically integrating
the schrdinger equation in time reveals that for certain values of the strength and frequency of the field the tunneling between the dots can be destroyed , thus allowing the correlated two - electron states to be manipulated .
we then show how floquet theory @xcite can be used to predict the field parameters at which this effect occurs .
we then consider the case of confining the electrons to a single two - dimensional quantum dot in the limit of low particle - density . in this system
the electrons form strongly correlated states termed wigner molecules , in which the coulomb interaction causes them to become highly localised in space . again using an effective model of hubbard - type
, we investigate how the ac field can drive the dynamics of the wigner states @xcite . as before , we find that the ac field can be used to control the tunneling between various charge configurations , and we relate this to the presence of avoided crossings in the floquet quasi - energy spectrum .
these results hold out the exciting possibility of using ac fields to control the time evolution of entangled states in mesoscopic devices , which has great relevance to the rapidly advancing field of quantum information processing . .
And you have already written the first three sentences of the full article: a quantum dot ( qd ) is a structure in which electrons can be confined to small length scales , comparable to their fermi wavelength . a set of electrons held in such a structure is conceptually similar to a set of atomic electrons bound to a nucleus , and for this reason quantum dots are sometimes termed `` artificial atoms '' @xcite .
unlike real atoms , the physical properties of quantum dots can be easily varied , which gives theorists and experimentalists the opportunity to study novel quantum effects in a well - controlled system . to extend the atomic analogy further , we can consider linking qds together to form `` artificial molecules '' . by allowing electrons to tunnel between the qds , the electronic states on the qds can hybridize , and form new states that extend over the whole system @xcite .
the degree of the tunneling determines the strength of this hybridization ..
Please generate the next two sentences of the article | if the tunneling is weak the electrons remain essentially localised on the qds in analogy with ionic bonding states .
conversely , if the tunneling is strong then the electrons form delocalised states with a covalent character . |
5,169 | Suppose that you have an abstract for a scientific paper: we investigate the survival of circularly polarized light in random scattering media .
the surprising persistence of this form of polarization has a known dependence on the size and refractive index of scattering particles , however a general description regarding polydisperse media is lacking . through analysis of mie theory , we present a means of calculating the magnitude of circular polarization memory in complex media , with total generality in the distribution of particle sizes and refractive indices .
quantification of this memory effect enables an alternate pathway towards recovering particle size distribution , based on measurements of diffusing circularly polarized light . .
And you have already written the first three sentences of the full article: an understanding of scattered radiation is deeply embedded within such scientific disciplines as astronomy , meteorology , climatology , and more recently biomedical imaging @xcite .
measurement of this radiation allows for the remote detection of object properties , through inspection of both the spectral , and spatial redistribution of energy .
notably , the inclusion of polarization in this analysis serves to enrich the source of available information ..
Please generate the next two sentences of the article | an area of immense interest concerning such behavior , is the study of optical radiation scattering within biological media @xcite .
it was first realized that through appropriate filtering , polarized light could enable the selective imaging of either surface , or subsurface tissue layers @xcite . since then |
5,170 | Suppose that you have an abstract for a scientific paper: experimental results on event shapes obtained within ( or related to ) the method of effective charges are discussed in view of measurements of the strong coupling , @xmath0 , the @xmath1-function and non - perturbative contributions to event shapes .
the data strongly advocate to use of the ech scheme instead of the conventional @xmath2 scheme . .
And you have already written the first three sentences of the full article: today the @xmath2-scheme is the _ de facto _ standard used for comparisons of qcd predictions as well as experimental results .
it was introduced for practical reason , as an offspring of dimensional regularisation , whereas the method of effective charges ( ech ) and the corresponding renormalisation scheme are motivated physically .
the ech method has been in some detail discussed in the talk of maxwell @xcite . for completeness here the basic formulae and results.
Please generate the next two sentences of the article | are assembled in view of the later interpretation of the data .
ech has been originally introduced in @xcite , a clear access , taking the observable itself as perturbative expansion parameter ( called renormalisation group improved perturbation theory , rgi ) is given in @xcite . |
5,171 | Suppose that you have an abstract for a scientific paper: the entanglement of pair cat states in the phase damping channel is studied by employing the relative entropy of entanglement .
it is shown that the pair cat states can always be distillable in the phase damping channel .
furthermore , we analyze the fidelity of teleportation for the pair cat states by using joint measurements of the photon - number sum and phase difference
. + pacs number : 03.67.-a , 03.65.ud , 42.50.dv .
And you have already written the first three sentences of the full article: quantum entanglement plays an important role in various fields of quantum information , such as quantum computation [ 1 ] , quantum cryptography [ 2 ] , quantum teleportation [ 3,4 ] , dense coding [ 5 ] and quantum communication [ 6 ] , etc .
it has been recognized [ 7,8 ] that quantum teleportation can be viewed as an achievable experimental technique to quantitatively investigate quantum entanglement .
there exists a class of states called maximally correlated states , which have an interesting property , i.e. , the ppt distillable entanglement is exactly the same as the relative entropy of entanglement [ 9 ] . both two - mode squeezed vacuum states and pair cat states [ 10 ] belong to this class . in continuous variable teleportation.
Please generate the next two sentences of the article | the entanglement resource is usually the two - mode squeezed state , or the einstein - podolsky - rosen ( epr ) states .
continuous variable quantum teleportation of arbitrary coherent states has been realized experimentally by employing a two - mode squeezed vacuum state as an entanglement resource [ 7 ] . |
5,172 | Suppose that you have an abstract for a scientific paper: optical images trace micron - sized grains , which are strongly affected by stellar radiation and need not coincide with their parent body population . here
we present alma 350 ghz observations of the fomalhaut debris ring .
these observations demonstrate that the parent body population is 13 - 19 au wide with a sharp inner and outer boundary .
we discuss three possible origins for the ring , and suggest that debris confined by shepherd planets is the most consistent with the ring s morphology . .
And you have already written the first three sentences of the full article: the fomalhaut debris system is a natural laboratory for testing planet formation theories .
the nearby ( 7.69 pc , * ? ? ?
* ) a3v star @xcite is surrounded by an eccentric debris ring with a peak brightness in scattered optical light at a semi - major axis @xmath0 au ( * ? ? ?.
Please generate the next two sentences of the article | * henceforth k05 ) . the inner edge is sharply truncated , which , along with the ring s eccentricity , suggests that a planet is shaping the ring s morphology @xcite .
a candidate for the reputed planet ( fom b ) has been discovered in the optical @xcite . |
5,173 | Suppose that you have an abstract for a scientific paper: we introduce the concept of back - reaction in relativistic cosmological modeling . roughly speaking ,
this can be thought of as the difference between the large - scale behaviour of an inhomogeneous cosmological solution of einstein s equations , and a homogeneous and isotropic solution that is a best - fit to either the average of observables or dynamics in the inhomogeneous solution .
this is sometimes paraphrased as ` the effect that structure has of the large - scale evolution of the universe ' .
various different approaches have been taken in the literature in order to try and understand back - reaction in cosmology .
we provide a brief and critical summary of some of them , highlighting recent progress that has been made in each case . .
And you have already written the first three sentences of the full article: the term ` back - reaction ' is often used in cosmology to mean ` the effect that structure has on the large - scale evolution of the universe , and observations made within it ' .
implicit within this statement are a number of fundamental problems that have yet to be fully understood .
these include : * what is meant by the large - scale expansion of space in an inhomogeneous universe , and how should it be calculated ? * how should we link the large - scale expansion of an inhomogeneous space - time with the observations made within it ? *.
Please generate the next two sentences of the article | how can we create relativistic cosmological models sophisticated enough to investigate these problems ?
let us now briefly consider each of these points , before moving on to discuss recent attempts to understand them . |
5,174 | Suppose that you have an abstract for a scientific paper: we study critical phenomena in the gravitational collapse of a radiation fluid .
we perform numerical simulations in both spherical symmetry and axisymmetry , and observe critical scaling in both supercritical evolutions , which lead to the formation of a black hole , and subcritical evolutions , in which case the fluid disperses to infinity and leaves behind flat space .
we identify the critical solution in spherically symmetric collapse , find evidence for its universality , and study the approach to this critical solution in the absence of spherical symmetry . for the cases that we consider , aspherical deviations from the spherically symmetric critical solution decay in damped oscillations in a manner that is consistent with the behavior found by gundlach in perturbative calculations .
our simulations are performed with an unconstrained evolution code , implemented in spherical polar coordinates , and adopting moving - puncture " coordinates . .
And you have already written the first three sentences of the full article: critical phenomena in gravitational collapse were first reported in the seminal work of chopuik @xcite . shortly after this original discovery , which was based on studies of massless scalar fields in spherical symmetry ,
similar behavior was found in other matter models , including vacuum ( i.e. pure gravitational waves ) @xcite , and radiation fluids @xcite ( see the excellent reviews @xcite for a much more comprehensive discussion . ) critical collapse can be observed in the evolution of generic initial data close to the threshold of black - hole formation .
we again refer to @xcite for thorough reviews , and briefly summarize only the most important characteristics here ..
Please generate the next two sentences of the article | consider initial data that are parametrized by some parameter @xmath0 , with the evolution of data with @xmath0 greater than some critical parameter @xmath1 leading to black - hole formation .
close to the critical parameter the following critical phenomena can then be observed in the resulting spacetimes . for @xmath2 , |
5,175 | Suppose that you have an abstract for a scientific paper: we show that the boost - invariant and cylindrically asymmetric hydrodynamic equations for baryon - free matter may be rewritten as only two coupled partial differential equations . in the case where the system exhibits the cross - over phase transition , the standard numerical methods may be applied to solve these equations .
an example of our results describing non - central gold on gold collisions at rhic energies is presented . .
And you have already written the first three sentences of the full article: the success of the relativistic hydrodynamics in describing the rhic data @xcite suggests that the hot and dense matter produced at rhic behaves like an almost perfect fluid @xcite . in this paper
we discuss how the boost - invariant and cylindrically asymmetric relativistic hydrodynamic equations for baryon - free perfect fluid may be very conveniently reduced to only two coupled partial differential equations .
our presentation is based on the recent investigations published in refs ..
Please generate the next two sentences of the article | we argue that the effects of the cross - over phase transition may be included by the use of the temperature dependent sound velocity @xmath0 . as long as the function @xmath0 satisfies the stability condition against the shock formation
, the resulting equations may be solved with the help of standard numerical methods and used to describe the expansion of matter produced in the central region of ultra - relativistic heavy - ion collisions , such as studied in the present rhic or future lhc experiments . |
5,176 | Suppose that you have an abstract for a scientific paper: we introduce a new class of sine - gordon models , for which the interaction term is present in a region different from the domain over which the quadratic part is defined .
we develop a _ nonperturbative _ approach for calculating partition functions of such models , which relies on mapping them to statistical properties of random surfaces . as a specific application of our method
, we consider the problem of calculating the amplitude of interference fringes in experiments with two independent low dimensional bose gases .
we calculate full distribution functions of interference amplitude for one - dimensional and two - dimensional gases with nonzero temperatures . .
And you have already written the first three sentences of the full article: sine - gordon ( sg ) models and their coulomb gas representations appear as a low energy effective theory for many types of physical systems .
the so - called `` bulk '' sg model describes the berezinskii - kosterlitz - thouless ( bkt ) transition in two - dimensional superfluids @xcite and the superfluid to insulator transition of cooper pairs in a chain of josephson junctions @xcite .
the so - called `` boundary '' sg model @xcite can be used to describe the chakravarty - schmid transition in a single josephson junction with dissipation @xcite and a quantum impurity problem @xcite in one dimension ( 1d ) ..
Please generate the next two sentences of the article | powerful theoretical techniques have been developed for studying such sg models including bethe ansatz solutions @xcite , renormalization group analysis ( see e.g. , ref .
@xcite ) , and functional renormalization group @xcite . |
5,177 | Suppose that you have an abstract for a scientific paper: we study a non - adiabatic excitation of an electron system in a 1d quantum ring radiated by a short thz pulse .
the response of two models , a continuous and discrete , is explored . by introducing a spatial asymmetry in the external perturbation
a net current can be generated in the ring at a zero magnetic field .
effect of impurities and ratchets are investigated in combination with symmetric and asymmetric external excitation . .
And you have already written the first three sentences of the full article: non - adiabatic generation of current in coherent quantum rings on the nanometer scale has attracted attention recently.@xcite a one - dimensional ( 1d ) quantum ring in its ground state exhibits a circulating current ( persistent current ) if the ring is placed in an external magnetic field perpendicular to the plane of the ring .
the magnetic field breaks the left / right symmetry and the occupation of states carrying equal but opposite current is distorted . by subjecting the ring to a strong perturbation
the persistent current can be changed non - adiabatically as the occupation of the single - electron states changes@xcite ..
Please generate the next two sentences of the article | here we consider two models of a one - dimensional ring , continuous and discrete , and investigate the response to a short - lived thz perturbation .
the electrons confined to the ring are spinless and coulomb interactions are neglected . |
5,178 | Suppose that you have an abstract for a scientific paper: we present adaptive optics assisted , spatially resolved spectroscopy of a sample of nine h@xmath0-selected galaxies at @xmath1=0.842.23 drawn from the hizels narrow - band survey .
these galaxies have star - formation rates of 127m@xmath2yr@xmath3 and are therefore representative of the typical high - redshift star - forming population .
our @xmath4kpc - scale resolution observations show that approximately half of the sample have dynamics suggesting that the ionised gas is in large , rotating disks .
we model their velocity fields to infer the inclination - corrected , asymptotic rotational velocities .
we use the absolute @xmath5-band magnitudes and stellar masses to investigate the evolution of the @xmath5-band and stellar mass tully - fisher relationships . by combining our sample with a number of similar measurements from the literature ,
we show that , at fixed circular velocity , the stellar mass of star - forming galaxies has increased by a factor 2.5 between @xmath1=2 and @xmath1=0 , whilst the rest - frame @xmath5-band luminosity has decreased by a factor @xmath46 over the same period . together , these demonstrate a change in mass - to - light ratio in the @xmath5-band of @xmath6(m / l@xmath7)/(m / l@xmath8)@xmath93.5 between @xmath1=1.5 and @xmath1=0 , with most of the evolution occuring below @xmath1=1 .
we also use the spatial variation of [ nii]/h@xmath0 to show that the metallicity of the ionised gas in these galaxies declines monotonically with galactocentric radius , with an average @xmath6log(o / h)/@[email protected]@xmath110.005dexkpc@xmath3 .
this gradient is consistent with predictions for high - redshift disk galaxies from cosmologically based hydrodynamic simulations .
galaxies : evolution galaxies : formation galaxies : high - redshift .
And you have already written the first three sentences of the full article: numerical simulations indicate that the majority of massive galaxies at @xmath1=13 , the epoch when galaxies were most rapidly growing their stellar mass , are continuously fed by gas which promotes and maintains star formation @xcite .
the accretion of gas from the halo , through minor mergers or by cold streams from the inter - galactic medium appears to dominate over that from major mergers and suggests that the star formation within the inter - stellar medium ( ism ) of high - redshift galaxies are driven by internal dynamical processes @xcite .
the observational challenge is now to quantitatively measure the internal properties ( e.g. gas surface density , disk scaling relations , chemical abundances , distribution and intensity of star - formation ) and so test whether the prescriptions developed to describe star - formation processes within disks at @xmath1=0 are applicable in the rapidly evolving ism of gas rich galaxies at high - redshift @xcite ..
Please generate the next two sentences of the article | high - spatial resolution observations of star - forming galaxies around @xmath1212 have shown that a large fraction of the population have their ionised gas in large , rotating disks ( e.g. * ? ? ?
* ; * ? ? ? |
5,179 | Suppose that you have an abstract for a scientific paper: new observations of 16 dwarf elliptical galaxies in the virgo cluster indicate that at least seven des have significant velocity gradients along their optical major axis , with typical rotation amplitudes of 20 - 30 km s@xmath0 . of the remaining nine galaxies in this sample , 6 have velocity gradients less than 20 km s@xmath0kpc@xmath0 while the other 3 observations had too low of a signal to noise ratio to determine an accurate velocity gradient .
typical velocity dispersions for these galaxies are @xmath144 @xmath2 5 km s@xmath0 , indicating that rotation can be a significant component of the stellar dynamics of virgo des . when corrected for the limited spatial extent of the spectral data , the rotation amplitudes of the rotating des are comparable to those of similar brightness dis .
evidence for a relationship between the rotation amplitude and galaxy luminosity is found , and , in fact , agrees well with the tully - fisher relation .
the similarity in the scaling relations of dis and des implies that it is unlikely that des evolve from significantly more luminous galaxies .
these observations reaffirm the possibility that some cluster dwarf elliptical galaxies may be formed when the neutral gaseous medium is stripped from dwarf irregular galaxies in the cluster environment .
we hypothesize that several different mechanisms are involved in the creation of the overall population of de galaxies , and that stripping of infalling dis may be the dominant process in the creation of des in clusters like virgo . .
And you have already written the first three sentences of the full article: dwarf elliptical galaxies ( de ) are the most ubiquitous type of galaxy in the local universe @xcite . despite their plenitude , we still do not understand fully the formation mechanism of these low mass , gas poor systems .
one clue to the evolution of dwarf elliptical galaxies is the morphology density relation : similar to giant elliptical galaxies , dwarf elliptical galaxies are found primarily in high density regions such as galaxy clusters , compact groups , and loose groups @xcite .
however , unlike their giant cousins , the stellar distribution in dwarf elliptical galaxies is exponential in nature @xcite , indicating that dwarf elliptical galaxies are not just lower mass versions of giant elliptical galaxies ..
Please generate the next two sentences of the article | thus , the evolutionary scenarios proposed for giant elliptical galaxies may not be relevant for the dwarf elliptical class . while some aspects of galaxy evolution undoubtedly arise from initial conditions , on - going evolution is likely accelerated and affected by different mechanisms in dense cluster environments .
as the nearest such location , the virgo cluster serves as the best laboratory for exploring the details of evolution under intracluster conditions , providing access to spatial scales and mass and luminosity ranges that are not achievable in more distant systems . as discussed in @xcite , the galaxy population in virgo |
5,180 | Suppose that you have an abstract for a scientific paper: the structure of the second @xmath0 state of @xmath1be is investigated using a microscopic @xmath2+@xmath2+@xmath3+@xmath3 model based on the molecular - orbit ( mo ) model .
the second @xmath0 state , which has dominantly the @xmath4 configuration , is shown to have a particularly enlarged @xmath2-@xmath2 structure .
the kinetic energy of the two valence neutrons occupying along the @xmath2-@xmath2 axis is reduced remarkably due to the strong @xmath2 clustering and , simultaneously , the spin - orbit interaction unexpectedly plays important role to make the energy of this state much lower .
the mixing of states with different spin structure is shown to be important in negative - parity states .
the experimentally observed small - level spacing between @xmath5 and @xmath6 ( @xmath7300 kev ) is found to be an evidence of this spin - mixing effect .
@xmath8be is also investigated using @xmath2+@xmath2+@xmath9 model , in which four valence neutrons are considered to occupy the @xmath10 configuration .
the energy surface of @xmath8be is shown to exhibit similar characteristics , that the remarkable @xmath2 clustering and the contribution of the spin - orbit interaction make the binding of the state with @xmath10 configuration properly stronger in comparison with the closed @xmath11-shell @xmath12 configuration .
* important role of the spin - orbit interaction in forming the @xmath13 orbital structure in be isotopes * + .25 in _ n. itagaki , s. okabe@xmath14 , and k. ikeda _ _ ri beam science laboratory , riken ( the institute of physical and chemical research ) , wako , saitama 351 - 0198 , japan _ @xmath14 _ center for information and multimedia studies , hokkaido university , + sapporo 060 - 0810 , japan _ pacs
number(s ) : 21.10.-k , 21.60.gx .
And you have already written the first three sentences of the full article: numerous experiments using unstable nuclear beams have succeeded to reveal exotic properties of @xmath15-unstable nuclei , including a neutron halo structure@xcite .
especially , the shift of the closed - shell structure is a characteristic behavior of systems with weakly bound neutrons .
recently , the contributions of the @xmath16 shell have been analyzed in @xmath17 nuclei based on the shell model ..
Please generate the next two sentences of the article | a calculation has shown that the slow @xmath15-decay of @xmath8be to @xmath8b can be explained by an admixture of the @xmath16 shell in @xmath8be ( @xmath17 ) in which the closed @xmath11-shell component must be less than 30@xmath18@xcite .
this shows that the concept of magic numbers is vague in @xmath8be . on the other hand , an @xmath2-@xmath2 structure |
5,181 | Suppose that you have an abstract for a scientific paper: mixing - demixing transition in one - dimensional mixtures of fermions and bosons is numerically investigated by changing various parameters such as number densities of each component , fermion - boson interactions , boson - boson interactions , and hopping energies . in most cases we found clear evidences of the mixing - demixing transitions and identified the roles of each microscopic parameter in the transitions .
several phase diagrams were obtained . .
And you have already written the first three sentences of the full article: recent studies of ultracold trapped atomic gases have led to the discovery of intriguing physical phenomena and have attracted more and more attentions to the atomic systems .
the trapped atomic gases have some advantages as a physical system in that any combinations of bosons and fermions can be put together on a lattice , microscopic parameters are tunable in most cases , and the systems can be constructed in various geometries , e.g. one - dimensional chain or two - dimensional plane .
one dimensional systems were constructed with bosons @xcite-@xcite and with bosons and fermions @xcite ..
Please generate the next two sentences of the article | these could be the first case that realized one - dimensional boson / boson - fermion systems , and triggered theoretical studies @xcite-@xcite . at a commensurate filling with the lattice periodicity ,
the mixtures of spinless fermions and bosons in one - dimensional optical lattice were predicted to undergo mott transition at sufficiently large fermion - boson and boson - boson interactions @xcite . in the boson - fermion mixtures at an incommensurate |
5,182 | Suppose that you have an abstract for a scientific paper: we report an anticorrelation between continuum luminosity and the equivalent width ( ew ) of the h@xmath0 emission line in x - ray binary systems . the effect is evident both in a universal monotonic increase in h@xmath0 ew with time following outbursts , as systems fade , and in a comparison between measured ews and contemporaneous x - ray measurements .
the effect is most clear for black hole binaries in the low / hard x - ray state , which is prevalent at x - ray luminosities below @xmath1% eddington .
we do not find strong evidence for significant changes in line profiles across accretion state changes , but this is hampered by a lack of good data at such times .
the observed anti - correlation , highly significant for black hole binaries , is only marginally so for neutron star systems , for which there are far less data .
comparison with previously established correlations between optical and x - ray luminosity suggest that the line luminosity is falling as the x - ray and optical luminosities drop , but not as fast ( approximately as @xmath2 ) .
we briefly discuss possible origins for such an effect , including the optical depth , form of the irradiating spectrum and geometry of the accetion flow .
further refinement of the relation in the future may allow measurements of h@xmath0 ew to be used to estimate the luminosity of , and hence the distance to , x - ray binary systems . beyond this , further progress will require a better sample of spectro - photometric data .
accretion , accretion discs x - rays : binaries .
And you have already written the first three sentences of the full article: the process of accretion is the power source driving the luminosities for a wide range of objects , including protostars , binary systems containing accreting white dwarfs , neutron stars or black holes , gamma ray bursts and supermassive black holes in active galactic nuclei .
a comprehensive review of this process is provided by frank , king & raine ( 2002 ) . in most of these systems ,
most of the time , the accretion process proceeds via an accretion disc which transports angular momentum outwards and matter inwards ..
Please generate the next two sentences of the article | the temperature of this disc increases towards the centre , and is a function of accretion rate and central accretor mass .
the disc may also produce ( or even be partially replaced by ) at various times a relatively cool disc wind , a very hot corona and a collimated relativistic outflow or ` jet ' . |
5,183 | Suppose that you have an abstract for a scientific paper: we identify nine young stellar objects ( ysos ) in the ngc 2264 star - forming region with optical _ corot _ light curves exhibiting short - duration , shallow , periodic flux dips .
all of these stars have infrared ( ir ) excesses that are consistent with their having inner disk walls near the keplerian co - rotation radius .
the repeating photometric dips have fwhm generally less than one day , depths almost always less than 15% , and periods ( 3 @xmath0 11 days ) consistent with dust near the keplerian co - rotation period .
the flux dips vary considerably in their depth from epoch to epoch , but usually persist for several weeks and , in two cases , were present in data collected on successive years . for several of these stars
, we also measure the photospheric rotation period and find that the rotation and dip periods are the same , as predicted by standard disk - locking " models .
we attribute these flux dips to clumps of material in or near the inner disk wall , passing through our line of sight to the stellar photosphere . in some cases , these dips are also present in simultaneous _ spitzer _
irac light curves at 3.6 and 4.5 microns .
we characterize the properties of these dips , and compare the stars with light curves exhibiting this behavior to other classes of yso in ngc 2264 .
a number of physical mechanisms could locally increase the dust scale height near the inner disk wall , and we discuss several of those mechanisms ; the most plausible mechanisms are either a disk warp due to interaction with the stellar magnetic field or dust entrained in funnel - flow accretion columns arising near the inner disk wall . .
And you have already written the first three sentences of the full article: understanding how young stellar objects ( ysos ) assemble themselves and how the accretion process works requires understanding the structure and evolution of the inner disk on size scales @xmath1 0.1 au .
even with the advent of infrared ( ir ) and radio interferometry , imaging of even the nearest ysos to detect structure on these size scales is impractical .
it therefore becomes necessary to infer the spatial structure and composition on these size scales indirectly from , for example , spectral energy distributions ( seds ) , high - resolution spectra , or variability studies ..
Please generate the next two sentences of the article | seds have provided some of the most important insights into the structure and evolution of the inner disks of ysos .
these seds have been used not only to argue for the presence of an inner disk wall , located roughly at the dust sublimation boundary , but also that the upper edge of the wall is in most cases curved ( mcclure et al . |
5,184 | Suppose that you have an abstract for a scientific paper: this is an analytical study of pinning and spontaneous vortex phase is a system consisting of a superconducting thin film pierced by a long ferromagnetic columnar defect of finite radius @xmath0 .
the magnetic fields , screening currents , energy and pinning forces for this system are calculated .
the interaction between the magnetic field of vortices and the magnetization outside the plane of the film and its close proximity enhances vortex pinning significantly .
spontaneous vortex phase appears when the magnetization of the columnar defect is increased above a critical value .
transitions between phases characterized by different number of flux quanta are also studied .
these results are generalized to the case when the superconductor is pierced by an array of columnar defects . .
And you have already written the first three sentences of the full article: optimizing pinning in superconductors ( sc ) is a problem that is interesting both experimentally and theoretically since pinning is the main viable mechanism for superconductivity in the presence of external magnetic field .
many tools and mechanisms for pinning has already been studied , in particular the use of crystal defects such as holes , non - magnetic impurities and both linear and screw dislocations .
pinning using structural defects suffers from many drawbacks , the most important is that the pins are randomly distributed which results in a low critical current . in recent years.
Please generate the next two sentences of the article | , it was claimed that pinning could be optimized if we employ ferromagnetic ( fm ) nano textures to pin superconducting vortices ( sv ) .
@xcite-@xcite the main obstacles of using ferromagnetic textures to pin superconducting vortices are the proximity effects which destroy superconductivity . |
5,185 | Suppose that you have an abstract for a scientific paper: in quasi - two dimensional ce(ir , rh)in@xmath0 system , it has been suggested that the phase diagram contains two distinct domes with different heavy fermion superconducting states .
we here report the systematic pressure dependence of the electron transport properties in the normal state of and , which locates in first and second superconducting dome , respectively .
we observed non - fermi liquid behavior at low temperatures in both compounds , including non - quadratic @xmath1dependence of the resistivity , large enhancement of the hall coefficient , and the violation of the kohler s rule in the magnetoresistance .
we show that the cotangent of hall angle @xmath2 varies as @xmath3 , and the magnetoresistance is quite well scaled by the hall angle as @xmath4 .
the observed transport anomalies are common features of ( @xmath5=co , rh , and ir ) and high-@xmath6 cuprates , suggesting that the anomalous transport properties observed in are mainly governed by the antiferromagnetic spin fluctuations , not by the ce - valence fluctuations which has been proposed to be the possible origin for the second superconducting dome . .
And you have already written the first three sentences of the full article: the resent discoveries of heavy fermion compounds ( @xmath5=rh , co , and ir ) give a unique opportunity to elucidate the interplay between the magnetism and the superconductivity .
the ground state of these compounds can be tuned by pressure and chemical doping . @xcite and @xcite are superconductors with the transition temperature @xmath7 2.3 k and 0.4 k at ambient pressure , respectively . on the other hand , is an antiferromagnet with @xmath8 3.8 k at ambient pressure and shows superconductivity under pressure.@xcite in and , the thermodynamic and transport properties in the normal state exhibit a striking deviation from conventional fermi liquid behavior,@xcite which is commonly observed in the systems in the vicinity of the antiferromagnetic ( af ) quantum critical point ( qcp ) .
then it is widely believed that the superconductivity in and is closely related to the af fluctuations ..
Please generate the next two sentences of the article | recently , it has been suggested that ceirin@xmath0 should be distinguished from cecoin@xmath0 and cerhin@xmath0 , although all three compounds share similar quasi - two dimensional ( 2d ) band structure.@xcite figure 1 depicts the schematic temperature
@xmath9 ( @xmath10-@xmath9 ) phase diagram of cerh@xmath11ir@xmath12in@xmath0 and temperature pressure ( @xmath10-@xmath13 ) phase diagram of ceirin@xmath0.@xcite in this system the rh substitution for ir increases the @xmath14 ratio , acting as a negative chemical pressure that increases af correlations . in cerh@xmath11ir@xmath12in@xmath0 , |
5,186 | Suppose that you have an abstract for a scientific paper: we find self - dual vortex solutions in a maxwell - chern - simons model with anomalous magnetic moment . from a recently developed @xmath0 supersymmetric extension ,
we obtain the proper bogomolnyi equations together with a higgs potential allowing both topological and non - topological phases in the theory . to be published in the _ int .
j. of mod .
phys .
a ( 1999 ) . _ .
And you have already written the first three sentences of the full article: a few years ago , it was proposed a maxwell - chern - simons ( mcs ) gauge theory with an additional magnetic moment interaction@xcite for which bogomolnyi - type self - dual equations can be derived and vortex - like configurations appear whenever suitable relationships among the parameters of the model are obeyed @xcite .
an important issue that comes about is the claim of a relation between the property of self - duality and the @xmath0 supersymmetric extension of the model , accomplished by means of a relationship between the central charge of the extended model and the existence of topological quantum numbers @xcite .
although a fundamental reason for this connection has not been given so far in the literature , in certain cases it appears to be unavoidable to construct the @xmath0 supersymmetric extension of a given bosonic model in order to obtain the proper higgs potential and self - dual conditions compatible with the euler - lagrange equations . in this regard ,.
Please generate the next two sentences of the article | we have succeeded in deriving an @xmath0 maxwell - chern - simons model with anomalous magnetic moment @xcite .
our strategy consisted in the formulation of an @xmath1 @xmath2 gauge model with a bf - term , free of constraints on the coupling constants dimensions . |
5,187 | Suppose that you have an abstract for a scientific paper: we investigate ice polyamorphism in the context of the two - dimensional mercedes - benz model of water . we find a first - order phase transition between a crystalline phase and a high - density amorphous phase .
furthermore we find a reversible transformation between two amorphous structures of high and low density ; however we find this to be a continuous and not an abrupt transition , as the low - density amorphous phase does not show structural stability .
we discuss the origin of this behavior and its implications with regard to the minimal generic modeling of polyamorphism . .
And you have already written the first three sentences of the full article: water is one of the most studied substances in all its phases , vapor , liquid and solid ice @xcite due to its ubiquity in nature and great relevance to mankind . despite the apparent simplicity of this molecule
, it shows complex behavior and some of its properties remain poorly understood .
water s hydrogen - bonding and proton - disorder effects lead to a complex phase diagram , which has been progressively extended over many years ..
Please generate the next two sentences of the article | an extensive range of crystalline solid phases or ice polymorphs are known , most of which are stable and/or metastable under extreme conditions . on the other hand , different amorphous solid phases of water , or polyamorphs , have been discovered , including some ices which are identified as the most common water phases in the universe , being those found in interstellar space .
ice polyamorphs are usually distinguished by their characteristic densities . |
5,188 | Suppose that you have an abstract for a scientific paper: we study the geometric and electronic structures of silicene monolayer using density functional theory based calculations .
the electronic structures of silicene show that it is a semi - metal and the charge carriers in silicene behave like massless dirac - fermions since it possesses linear dispersion around dirac point .
our results show that the band gap in silicene monolayer can be opened up at fermi level due to an external electric field by breaking the inversion symmetry .
the presence of buckling in geometric structure of silicene plays an important role in breaking the inversion symmetry .
we also show that the band gap varies linearly with the strength of external electric field .
further , the value of band gap can be tuned over a wide range . .
And you have already written the first three sentences of the full article: there has been a lot of interest in silicene since it shows properties similar to those of graphene@xcite . for example , the theoretical studies on silicene show that the charge carriers in this two - dimensional material behave like massless dirac - fermions due to presence of linear dispersion around fermi energy at a symmetry point k in the reciprocal lattice@xcite .
similar to its carbon counterpart - graphene , silicene is a potential candidate for applications in nanotechnology .
the silicon based nanostructures have an important advantage that they are compatible with the existing semiconductor technology ..
Please generate the next two sentences of the article | therefore , silicene and silicon nanoribbon have received much attention from both experimentalist and theoreticians@xcite .
recently , silicene has been epitaxially grown on a close - packed silver surface ag(111)@xcite . though graphene possesses many novel properties , its applications in nanoelectronic devices |
5,189 | Suppose that you have an abstract for a scientific paper: the standard model has been incredibly successful in predicting the outcome of almost all the experiments done up so far . in it
, neutrinos are mass - less . however , in recent years we have accumulated evidence pointing to tiny masses for the neutrinos ( as compared to the charged leptons ) .
these masses allow neutrinos to change their flavour and oscillate . in these lectures
i review the properties of neutrinos in and beyond the standard model . .
And you have already written the first three sentences of the full article: the last decade witnessed a revolution in neutrino physics . it has been observed that neutrinos have nonzero masses , and that leptons mix .
this fact was proven by the observation that neutrinos can change from one type , or `` flavour '' , to another .
almost all the knowledge we have gathered about neutrinos , is only fifteen years old ..
Please generate the next two sentences of the article | but before diving into the recent `` news '' about neutrinos , lets find out how neutrinos were born .
the 20s witnessed the assassination of many sacred cows , and physics was no exception , one of physic s most holly principles , the conservation of energy , appeared not to hold within the subatomic world . |
5,190 | Suppose that you have an abstract for a scientific paper: we sketch some recent ideas proposed as the behind the puzzling experimental results on baryon - antibaryon production in @xmath0 annihilation close to threshold . the essential new point in the proposed
is that it is a two - stage process , with a coherent state of pions serving as an intermediary between @xmath0 and the baryon - antibaryon system .
skyrmion - antiskyrmion annihilation is proposed as a concrete computational framework for a quantitative description of the baryon - antibaryon annihilation .
we also point out the possible connection to similarly puzzling data on baryon - antibaryon production in photon - photon collision . .
And you have already written the first three sentences of the full article: the fenice data @xcite , on the reaction close to threshold , together with earlier analogous measurements for the proton @xcite-@xcite indicate that at threshold . in other words ,
the timelike form factors of the neutron and the proton are approximately equal at @xmath1 .
this is a very surprizing and puzzling result and it is hard to understand in the conventional perturbative picture of baryon - antibaryon production in @xmath0 annihilation , as shown in fig ..
Please generate the next two sentences of the article | [ ee - fig ] .
.,width=321 ] in the naive perturbative description of the @xmath0 annihilation into baryons , the virtual timelike photon first makes a primary " @xmath2 pair , which then dresses up " with two additional quark - antiquark pairs which pop up from the vacuum . |
5,191 | Suppose that you have an abstract for a scientific paper: the one - dimensional ( 1d ) isotropic frustrated ferromagnetic spin-1/2 model is considered .
classical and quantum effects of adding a dzyaloshinskii - moriya ( dm ) interaction on the ground state of the system is studied using the analytical cluster method and numerical lanczos technique .
cluster method results , show that the classical ground state magnetic phase diagram consists of only one single phase : `` chiral '' .
the quantum corrections are determined by means of the lanczos method and a rich quantum phase diagram including the gapless luttinger liquid , the gapped chiral and dimer orders is obtained . moreover , next nearest neighbors will be entangled by increasing dm interaction and for open chains , end - spins are entangled which shows the long distance entanglement ( lde ) feature that can be controlled by dm interaction . .
And you have already written the first three sentences of the full article: an important goal in study of quantum spin systems is the search for novel phases emerging from competing interactions between particles .
low dimensional quantum spin systems typically exhibit strongly correlated effects which drive them toward new regimes with no classical analog .
many properties of the systems in these regimes or `` quantum phases '' can be understood if we explore their ground state and low - lying excitations ..
Please generate the next two sentences of the article | therefore a significant fraction of current research on such systems has focussed on understanding of frustrated systems , which exhibits a variety of exotic quantum states@xcite . in particular , the frustrated spin chains are described by competing interactions between the nearest - neighbor ( @xmath0 ) and next - nearest - neighbor ( @xmath1 ) interactions .
the hamiltonian of the model is given by @xmath2 , \label{j1-j2}\ ] ] where @xmath3 represents the @xmath4 operator at @xmath5-th site of the chain . |
5,192 | Suppose that you have an abstract for a scientific paper: decay rate and forward - backward asymmetries in @xmath0 , @xmath1 is the axial vector meson , are calculated in the universal extra dimension ( ued ) model .
the dependence of these physical quantities on the compactification radius @xmath2 , the only unknown paramter in ued model , is studied and it is shown that zero of forward - backward asymmetry is sensitive to the ued model , therefore they can be very useful tool to establish new physics predicted by the ued model .
this work is briefly extended to @xmath3 .
And you have already written the first three sentences of the full article: the flavor - changing - neutral - current ( fcnc ) transitions @xmath4 provide potentially stringent tests of standard model ( sm ) in flavor physics and are not allowed at tree level but are induced by the glashow - iliopoulos - miani ( gim ) amplitudes @xcite at the loop level in the sm . in addition , these are also suppressed in sm due to their dependence on the weak mixing angles of the quark - flavor rotation matrix @xmath5 the cabibbo - kobayashi - maskawa ( ckm ) matrix @xcite .
these two circumstances make the fcnc decays relatively rare and hence important for the study of physics beyond the sm commonly known as new physics .
the experimental observation of inclusive @xcite and exclusive @xcite decays , @xmath6 and @xmath7 , has prompted a lot of theoretical interest on rare @xmath8 meson decays . though the inclusive decays are theoretically better understood but are extremely difficult to be measured in a hadron mechine , such as the lhc , which is the only collider , except for a super-@xmath8 factory , that could provide enough luminosity for the precise study of the decay distribution of such rare processes ..
Please generate the next two sentences of the article | in contrast , the exclusive decays are easy to detect experimentally but are challanging to calculate theoretically and the difficulty lies in describing the hadronic structure , which provides the main uncertainty in the predictions of exclusive rare decays . in exclusive
@xmath9 decays the long - distance effects in the meson transition amplitude of the effective hamiltonian are encoded in the meson transition form factors which are the scalar functions of the square of momentum transfer and are model dependent quantites . |
5,193 | Suppose that you have an abstract for a scientific paper: we study the spin - dependent quark distributions at large transverse momentum .
we derive their transverse momentum behaviors in the collinear factorization approach in this region .
we further calculate the angular distribution of the drell - yan lepton pair production with polarized beams and present the results in terms of the collinear twist - three quark - gluon correlation functions . in the intermediate transverse momentum region , we find that the two approaches : the collinear factorization and the transverse momentum dependent factorization approaches are consistent in the description of the lepton pair angular distributions . .
And you have already written the first three sentences of the full article: spin dependent semi - inclusive hadronic processes have attracted much interest from both experiment and theory sides in recent years .
these processes provide us more opportunities to study the quantum chromodynamics ( qcd ) and internal structure of the hadrons , as compared to the inclusive hadronic processes or spin averaged processes .
measurements have been made in different reactions ..
Please generate the next two sentences of the article | in particular , the single transverse spin asymmetry ( ssa ) phenomena observed in various hadronic processes@xcite have stimulated remarkable theoretical developments . among the theoretical developments ,
two approaches in the qcd framework have been most explored : the higher twist collinear factorization approach @xcite and the transverse momentum dependent ( tmd ) approach . in these two approaches , |
5,194 | Suppose that you have an abstract for a scientific paper: we present the results of continuum and @xmath0co(32 ) and ch@xmath1oh(76 ) line observations of iras16547@xmath24247 made with the atacama large millimeter / submillimeter array ( alma ) at an angular resolution of @xmath305 .
the @xmath0co(32 ) emission shows two high - velocity outflows whose driving sources are located within the dust continuum peak .
the alignment of these outflows do not coincide with that of the wide - angle , large scale , bipolar outflow detected with apex in previous studies .
the ch@xmath1oh(76 ) line emission traces an @xmath4 structure associated with the cavity walls created by the outflow lobes .
taking into account our results together with the position of the h@xmath5o and class i ch@xmath1oh maser clusters , we discuss two possible scenarios that can explain the hourglass structure observed in iras16547@xmath24247 : ( 1 ) precession of a biconical jet , ( 2 ) multiple , or at least two , driving sources powering intersecting outflows . combining the available evidence , namely , the presence of two cross - aligned bipolar outflows and two different h@xmath5o maser groups , we suggest that iras16547@xmath24247 represents an early formation phase of a protocluster . .
And you have already written the first three sentences of the full article: most stars , particularly high - mass stars ( @xmath6@xmath78@xmath8 ) , form in clusters ( lada @xmath9 lada 2003 ) .
stellar clusters form in dense and massive molecular clumps ( size@xmath3@xmath71 pc , mass@xmath3@xmath71001000 @xmath10 , density @xmath310@xmath11 @xmath12 ) @xcite .
the gas in these clumps can be significantly affected by the feedback from newly formed stars , thus blurring our understanding of cluster formation . to explore the initial conditions and details of cluster formation , it is then necessary to study molecular clouds in the early stages of evolution at high - angular resolution ( e.g. , higuchi et al ..
Please generate the next two sentences of the article | high - mass stars are usually deeply embedded in their parent cloud , obscuring their early formative stages .
their formation timescales of @xmath3 10@xmath13 yr are short , and they form in distant clusters and associations ( e.g. , mckee @xmath9 ostriker 2007 ; zinnecker @xmath9 yorke 2007 ) . |
5,195 | Suppose that you have an abstract for a scientific paper: we establish a replacement lemma for a variational problem , which is not based on a local argument .
we then apply it to a phase transition problem and obtain pointwise estimates . .
And you have already written the first three sentences of the full article: we consider the elliptic system @xmath0 where @xmath1 a nonnegative @xmath2 potential possessing several minima and @xmath3 .
the system is variational with associated functional @xmath4 in what follows , we take @xmath5 to be a bounded , open , and connected set in @xmath6 , with lipschitz boundary .
we introduce the hypothesis * ( h ) * _ let @xmath7 , with @xmath8 , be a strictly increasing function on @xmath9 ..
Please generate the next two sentences of the article | the vector @xmath10 is a global minimum of @xmath11 and @xmath12 is positive and fixed .
_ note that ( h ) is a very weak nondegeneracy hypothesis that was introduced in @xcite . |
5,196 | Suppose that you have an abstract for a scientific paper: a new class of random partial differential equations of parabolic type is considered , where the stochastic term consists of an irregular noisy drift , not necessarily gaussian , for which a suitable interpretation is provided . after freezing a realization of the drift ( stochastic process ) ,
we study existence and uniqueness ( in some appropriate sense ) of the associated parabolic equation and a probabilistic interpretation is investigated . and . .
And you have already written the first three sentences of the full article: this paper focuses on a random partial differential equation consisting of a parabolic pde with irregular noise in the drift .
formulation , existence ( with uniqueness in a certain sense ) and double probabilistic representation are discussed .
the equation itself is motivated by _.
Please generate the next two sentences of the article | random irregular media models_. let @xmath0 , @xmath1 be a continuous function and @xmath2 a generalized random field playing the role of a noise .
let @xmath3 , |
5,197 | Suppose that you have an abstract for a scientific paper: classical geometry of de sitter spacetime is reviewed in arbitrary dimensions .
topics include coordinate systems , geodesic motions , and penrose diagrams with detailed calculations .
= 16.5 cm -1.85 cm -2 cm = .22 in hep - th/0212326 * classical geometry of de sitter spacetime : + an introductory review * + yoonbai [email protected] ] , chae young [email protected] ] , and namil [email protected] ] + _ @xmath2bk21 physics research division and institute of basic science , sungkyunkwan university , + suwon 440 - 746 , korea + @xmath3school of physics , korea institute for advanced study , + 207 - 43 , cheongryangri - dong , dongdaemun - gu , seoul 130 - 012 , korea _ .
And you have already written the first three sentences of the full article: cosmological constant @xmath4 was originally introduced in general relativity with the motivation to allow static homogeneous universe to einstein equations in the presence of matter .
once expansion of the universe was discovered , its role turned out to be unnecessary and it experienced a checkered history .
recent cosmological observations suggest some evidences for the existence of a positive cosmological constant @xcite : from a variety of observational sources , its magnitude is @xmath5 , and both matter @xmath6 and vacuum @xmath7 are of comparable magnitude , @xmath8 in spatially flat universe ..
Please generate the next two sentences of the article | both results are paraphrased as old and new cosmological constant problems @xcite .
inclusion of quantum field theory predicts naturally the energy density via quantum fluctuations even up to the planck scale , so the old problem is to understand why the observed present cosmological constant is so small . |
5,198 | Suppose that you have an abstract for a scientific paper: we present unrestricted hartree fock method coupled with configuration interaction ( ci ) method ( urhf - ci ) suitable for the calculation of ground and excited states of large number of electrons localized by complex gate potentials in quasi - two - dimensional quantum dot molecules .
the method employs real space finite difference method , incorporating strong magnetic field , for the calculating of single particle states .
the hartree - fock method is employed for the calculation of direct and exchange interaction contribution to the ground state energy .
the effects of correlations are included in energies and directly in the many - particle wavefunctions via configuration interaction ( ci ) method using a limited set of excitations above the fermi level .
the urhf - ci method and its performance are illustrated on the example of ten electrons confined in a two - dimensional quantum dot molecule . .
And you have already written the first three sentences of the full article: there is currently interest in localizing electrons in quantum dots and utilizing their spin for quantum information processing @xcite . alternatively
, we can view such devices as highly tunable quantum dot molecules , with large numbers of electrons or qubits , with gates and magnetic field used to perform quantum operations .
even with a relatively small number of bits , to understand working of such devices one needs a computational tool suitable for the calculation of wavefunctions of at least tens of electrons confined by complex gate potentials and in magnetic field ..
Please generate the next two sentences of the article | the wavefunctions must capture entanglement , or in condensed matter language , correlations .
the configuration interaction ( ci ) method is a suitable candidate modified here for the problem of quantum dot molecules . in the configuration interaction ( ci ) method the hamiltonian of an interacting system is calculated in the basis of a finite number of many - electron configurations and diagonalized exactly . |
5,199 | Suppose that you have an abstract for a scientific paper: in this work we re - examine the opacity of the cosmic background radiation to the propagation of extremely high energy cosmic rays .
we use the continuous energy loss approximation to provide spectral modification factors for several hypothesized cosmic ray sources .
earlier problems with this approximation are resolved including the effects of resonances other than the @xmath0 .
pacs numbers : 96.40,13.85.t,98.70.s,98.70.v _ accepted for publication in physical review d. _ .
And you have already written the first three sentences of the full article: with the discovery of the microwave background radiation ( mbr ) @xcite , it was realized that its effect on the propagation of ultrahigh energy cosmic rays ( uhecr s ) must be considered . the first treatments in 1966 by greisen , zatsepin and kuzmin @xcite indicated a sharp cutoff for cosmic rays with energies above due to the process @xmath1 .
physically , the thermal photons are seen highly blue - shifted by the cosmic rays in their rest frames so that this reaction becomes possible .
recently , several extensive air showers have been clearly observed which imply the arrival of cosmic rays of energies above @xmath2 ev . in particular , the akeno giant air shower array ( agasa ) experiment recorded an event with energy 1.7 - 2.6 @xmath3 ev @xcite , while the fly s eye experiment reported the highest energy cosmic ray ( cr ) event ever detected on earth , with an energy 2.3 - 4.1 @xmath3 ev @xcite ..
Please generate the next two sentences of the article | since the gzk cutoff provides an important constraint on the proximity of uhecr sources , the origin of such energetic particles has became one of the most pressing questions of cosmic ray astrophysics .
the study of the modification of the spectrum of cosmic rays due to their interactions with the mbr _ en route _ to us here on earth , is essential if one is to obtain a deeper understanding of the origin of the highest energy cosmic rays . |
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