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8,600 | Suppose that you have an abstract for a scientific paper: we derive an analytical description for quantum state preparation using systems of on - off detectors .
our method will apply the true click statistics of such detector systems .
in particular , we consider heralded quantum state preparation using correlated light fields , photon addition , and photon subtraction processes . using a post - selection procedure to a particular number of clicks of the detector system , the output states reveal a variety of quantum features .
the rigorous description allows the identification and characterization of fundamentally unavoidable attenuations within given processes .
we also generalize a known scenario of noiseless amplification with click detectors for the purpose of the preparation of various types of nonclassical states of light .
our exact results are useful for a choice of experimental parameters to realize a target state . .
And you have already written the first three sentences of the full article: the measurement and generation of photons is one of most challenging tasks in nowadays quantum optics .
since the photon can be considered as the carrier of information , it plays a fundamental role in quantum information and quantum communications @xcite .
the generation of single photons is typically described by conditional measurements of quantum correlated light fields with single photon detectors @xcite ..
Please generate the next two sentences of the article | the sophisticated task is to find a proper device that can detect at least in a good approximation single photons . among other approaches ,
e.g. , @xcite , an avalanche photo diode in geiger mode is an experimentally accessible device , being close to a single photon counter @xcite . |
8,601 | Suppose that you have an abstract for a scientific paper: recently , fukushima [ phys . rev .
b * 78 * 115105 ( 2008 ) ] proposed a systematic derivation of the gutzwiller approximation for the t - j model . in the present paper , using this approach we construct an effective single - particle hamiltonian , which leads to a renormalized mean - field theory ( rmft ) .
we also use the method proposed by us recently and based on the maximum entropy principle ( maxent ) , which in turn , yields a consistent statistical description of the problem . on the examples of
non - magnetic superconducting d - wave resonating valence bond ( drvb ) and normal staggered - flux ( sf ) solutions , we compare two selections of the gutzwiller renormalization schemes , i.e. the one proposed by fukushima with that used earlier by sigrist et al .
[ phys .
rev .
b * 49 * , 12 058 ( 1994 ) ] .
we also confront the results coming from our variational solutions with the self - consistency conditions build in , with those of the non - variational approach based on the bogoliubov - de gennes self - consistent equations .
combination of the present variational approach with the new renormalization scheme ( taken from fukushima s work ) provides , for @xmath0 , an upper critical hole concentration @xmath1 for the disappearance of the d - wave superconductivity .
also , the hole concentration @xmath2 is obtained for the optimal doping .
these results are in rough accordance with experimental results for high-@xmath3 superconducting cuprates . a statistically consistent variational approach to the renormalized mean - field theory of the t - j model : critical hole concentrations for a paired state + jakub jdrak@xmath4 and jozef spaek@xmath5 + marian smoluchowski institute of physics , jagiellonian university , + reymonta 4 , 30 - 059 krakw , poland + * pacs : * 05.30.-d , 71.10.fd , 75.10.jm . .
And you have already written the first three sentences of the full article: the t - j model @xcite is commonly regarded as a minimal model capable of describing correctly the essential physics of the cuprate high - temperature superconductors . in its simplest form ,
used in the present paper , it is expressed by the following hamiltonian @xmath6 here @xmath7 is a gutzwiller projection operator , ensuring that no doubly occupied sites are present .
unfortunately , the rigorous treatment of the t - j model is limited to very special cases ..
Please generate the next two sentences of the article | this is both due to the interaction term ( @xmath8 ) , as well as to the presence of @xmath9 operators . even in the @xmath10 limit ,
hamiltonian ( [ t - j exact ] ) is not an independent - particle one . to proceed further , ( [ t - j exact ] ) |
8,602 | Suppose that you have an abstract for a scientific paper: we discuss and propose the minimal generalization of the witten - veneziano relation to finite temperatures , prompted by star and phenix experimental results on the multiplicity of @xmath0 mesons . after explaining why these results show that the zero - temperature witten - veneziano relation can not be straightforwardly extended to temperatures @xmath1 too close to the chiral restoration temperature @xmath2 and beyond , we find the quantity which should replace , at @xmath3 , the yang - mills topological susceptibility appearing in the @xmath4 witten - veneziano relation , in order to avoid the conflict with experiment at @xmath3 .
this is illustrated through concrete @xmath1-dependences of pseudoscalar meson masses in a chirally well - behaved , dyson - schwinger approach , but our results and conclusions are of a more general nature and , essentially , model - independent . .
And you have already written the first three sentences of the full article: the ultrarelativistic heavy - ion collider facilities like rhic at bnl and lhc at cern strive to produce a new form of hot qcd matter .
the experiments show @xcite that it has very intricate properties and presents a big challenge especially for theoretical understanding . while above the ( pseudo)critical temperature @xmath5 mev this matter is often called the quark - gluon plasma ( qgp ) , it can not be a perturbatively interacting quark - gluon gas ( as widely expected before rhic results @xcite ) until significantly higher temperatures @xmath6 . instead
, the interactions and correlations in the hot qcd matter are still strong ( e.g. , see refs ..
Please generate the next two sentences of the article | @xcite ) so that its more recent and more precise name is _ strongly coupled qgp _ ( sqgp ) @xcite .
one of its peculiarities seems to be that strong correlations in the form of quark - antiquark ( @xmath7 ) bound states and resonances still exist @xcite in the sqgp well above @xmath8 . in the old qgp paradigm , |
8,603 | Suppose that you have an abstract for a scientific paper: prospects of parametric x - rays ( pxr ) application for the development of a tuneable quasi - monochromatic x - ray source for medical imaging are discussed .
analysis of basic requirements for electron accelerator shows that it must be relatively low - energy and high - current linac . in comparison with known ultra - relativistic cases , at low energies pxr properties
will be modified to a great extent by multiple scattering of the electrons .
pxr intensity dependence on target thickness and beam energy are calculated taking multiple scattering into account . it is concluded that pxr source based on real medical accelerators is feasible and can provide x - ray flux needful for obtaining high quality medical images . *
_ keywords _ : * parametric x - rays ; pxr ; monochromatic tuneable x - ray source ; medical imaging * * _ pacs _ * * _ _ : _ _ 78.70.-g ; 11.80.la ; 87.56.by .
And you have already written the first three sentences of the full article: parametric x - rays ( pxr ) produced by a relativistic charged particle uniformly moving through a single crystal were declared as a very attractive radiation mechanism for x - ray source since its theoretical prediction in 1972 @xcite - @xcite and first experimental observation in 1985 @xcite . actually , it has a number of indisputable features , namely , high monochromaticity , energy tuneability , polarization , directivity , and possibility to be emitted to large angles relative to beam direction , i.e. provide monochromatic x - rays virtually free of background .
pxr properties were studied at a number of accelerator facilities worldwide but a pxr - based x - ray source developments are still in progress . evidently , this is connected with the fact that pxr research is performed at existing linear and annular accelerators and limited by their technical specifications .
so , we should recognize how to design a pxr - based source that will meet the consumer s requirements for its use in industry and medicine ..
Please generate the next two sentences of the article | industry and science , as consumers , essentially yield to medicine , which represents the huge market for devices and methods for x - ray diagnostics . statistically
, x - ray devices count for about 60% of medical diagnostics devices @xcite . despite the development of alternative diagnostics methods , e.g. ultrasound and magnetic resonance imaging |
8,604 | Suppose that you have an abstract for a scientific paper: we analyse the events with two same flavour , opposite sign leptons + @xmath0 + ( jets ) as expected in @xmath1 collisions at lhc within the framework of the minimal supergravity model .
the objective is the determination of the parameters @xmath2 and @xmath3 of this model ( for a given value of @xmath4 ) .
the signature @xmath5 + ( jets ) selects the leptonic decays of @xmath6 , @xmath7 , @xmath8 .
we exploit the fact that the invariant dilepton mass distribution has a pronounced structure with a sharp edge at the kinematical endpoint even in such an inclusive final state over a significant part of parameter space .
we determine the domain of parameter space where the edge is expected to be visible .
we show that a measurement of this edge already constrains the model parameters essentially to three lines in the ( @xmath9 ) parameter plane .
we work out a strategy to discriminate between the three body leptonic decays of @xmath6 and the decays into sleptons @xmath10 .
this procedure may make it possible to get information on susy particle masses already with low luminosity , @xmath11 pb@xmath12 .
# 1#23.6pt cms note 1997/094
hephy - pub 678/97 * determining the parameters of the minimal supergravity model from final states at lhc . * d. denegri@xmath13 , w.majerotto@xmath14 , and l. rurua@xmath15 @xmath13_centre detudes nucle@xmath16ire de saclay , gif - sur - yvette , france
_ @xmath14_institut f@xmath17r hochenergiephysik , @xmath18sterreichische akademie d.wissenschaften , vienna , austria _
@xmath19_institute of physics , tbilisi , georgia _ .
And you have already written the first three sentences of the full article: if low - energy supersymmetry ( susy ) is realised in nature it should show up at the large hadron collider ( lhc ) .
strongly interacting particles as gluinos and squarks will be most likely the first susy particles to be seen at lhc .
gluinos of mass less than @xmath20 tev and squarks of mass less than @xmath21 tev [ 1 - 3 ] can be detected , covering in such a way the whole theoretically motivated parameter space ..
Please generate the next two sentences of the article | lhc is also a good laboratory for the search of electro - weakly interacting particles , e.g. sleptons [ 4,5 ] . in a recent paper [ 6 ] it was shown within the minimal supergravity ( msugra ) [ 7 ] model that sleptons in the mass range of @xmath22 to 400 gev can be detected at lhc by investigating the signature @xmath23 .
however , this final state where direct production ( drell - yan ) of sleptons predominates requires high luminosity , @xmath24 . |
8,605 | Suppose that you have an abstract for a scientific paper: we propose a numerical variational method for three - dimensional ( 3d ) classical lattice models .
we construct the variational state as a product of local tensors , and improve it by use of the corner transfer matrix renormalization group ( ctmrg ) , which is a variant of the density matrix renormalization group ( dmrg ) applied to 2d classical systems .
numerical efficiency of this approximation is investigated through trial applications to the 3d ising model and the 3d 3-state potts model .
dmrg ; ctmrg ; variational formulation .
And you have already written the first three sentences of the full article: the density matrix renormalization group ( dmrg ) @xcite has been widely applied to one - dimensional ( 1d ) quantum systems and two - dimensional ( 2d ) classical systems @xcite .
a frontier in dmrg is to extend its numerical algorithm to higher dimensional systems , chiefly for 2d quantum and 3d classical systems .
as far as the finite system algorithm is concerned , decomposition of higher - dimensional clusters to 1d chains proposed by liang and pang works efficiently @xcite . on the other hand ,.
Please generate the next two sentences of the article | we have not obtained any satisfactory answer to extend dmrg toward infinite - size systems in higher dimension .
nishino and okunishi proposed a way of extending dmrg to 3d classical systems , which they call ` the corner tensor renormalization group ( cttrg ) ' @xcite , as a 3d generalization of both the transfer matrix dmrg @xcite and the corner transfer matrix renormalization group ( ctmrg ) @xcite for 2d classical systems . |
8,606 | Suppose that you have an abstract for a scientific paper: we study a system of two coupled nonlinear schrdinger equations , where one equation includes gain and the other one includes losses .
strengths of the gain and the loss are equal , i.e. , the resulting system is parity - time ( @xmath0 ) symmetric . the model includes both linear and nonlinear couplings , such that when all nonlinear coefficients are equal , the system represents the @xmath0-generalization of the manakov model . in the one - dimensional case , we prove the existence of a global solution to the cauchy problem in energy space @xmath1 , such that the @xmath1-norm of the global solution may grow in time . in the manakov case ,
we show analytically that the @xmath2-norm of the global solution is bounded for all times and numerically that the @xmath1-norm is also bounded . in the two - dimensional case
, we obtain a constraint on the @xmath2-norm of the initial data that ensures the existence of a global solution in the energy space @xmath1 . .
And you have already written the first three sentences of the full article: a system of two coupled nonlinear schrdinger ( nls ) equations represents the basic model of propagation of weakly dispersive waves having vectorial nature , i.e. , characterized by two components , below designated by @xmath3 and @xmath4 .
this model is relevant for almost all applications of the nonlinear physics .
when the system is supplied by balanced gain and losses , as well as by the linear coupling , characterized respectively by positive coefficients @xmath5 and @xmath6 , it reads @xmath7 where all the nonlinear coefficients , i.e. , @xmath8 , @xmath9 and @xmath10 are real ..
Please generate the next two sentences of the article | model ( [ manakov ] ) describes wave guiding in structures obeying parity - time ( @xmath0 ) symmetry @xcite . here
the parity symmetry is defined by the mapping @xmath11 . |
8,607 | Suppose that you have an abstract for a scientific paper: i will review the latest developments in understanding the high - energy emission of rotation - powered pulsars and magnetically - powered anomalous x - ray pulsars ( axps ) and soft gamma - ray repeaters ( sgrs ) .
these fields have been extremely active in the last few years , both observationally and theoretically , driven partly by new x - ray data from chandra , xmm - newton and rxte . at the same time , the parkes multibeam survey has discovered over 700 new radio pulsars , some of them young and coincident with egret sources , and others having magnetar - strength magnetic fields .
these new observations are raising important questions about neutron star birth and evolution , as well as the properties of their high - energy emission .
address = nasa goddard space flight center , greenbelt , md 20771 , usa .
And you have already written the first three sentences of the full article: the last several years have seen significant developments in detection and understanding of energetic emission from pulsating neutron stars .
new surveys and detectors have not only discovered more sources but have discovered new and unexpected characteristics and behavior of these sources .
three types of neutron stars that are the subject of this review , rotation - powered pulsars , anomalous x - ray pulsars ( axps ) and soft gamma - ray repeaters ( sgrs ) , were thought to be separate and unrelated objects as recently as seven years ago ..
Please generate the next two sentences of the article | today , we know that sgrs and axps are both neutron stars possessing magnetic fields with unprecedented strength of @xmath0 g , collectively called magnetars " , that show both steady x - ray pulsations as well as soft @xmath1-ray bursts .
their inferred steady x - ray luminosities are about one hundred times higher than their spin - down lumnosities , requiring a source of power beyond the magnetic dipole spin - down that powers radio pulsars . but |
8,608 | Suppose that you have an abstract for a scientific paper: in this work we present a detailed computation of the spectra of uhecr in the top - down scenario .
we compare the spectra of hadrons obtained by two different methods in qcd and supersymmetric ( susy ) qcd with large primary energies @xmath0 up to @xmath1 gev .
the two methods discussed are a monte carlo ( mc ) simulation and the evolution of the hadron fragmentation functions as described by the dokshitzer - gribov - lipatov - altarelli - parisi ( dglap ) equations .
the hadron spectra obtained by the two methods agree fairly well in the interesting energy range @xmath2 ( @xmath3 is the energy scale of the process @xmath4 gev ) .
we have also computed the spectra of photons , neutrinos and nucleons obtaining a good agreement with other published results .
the consistency of the spectra computed by different methods allows us to consider the spectral shape as a signature of the production model for uhecr , such as the decay of super heavy relic particles or topological defects . .
And you have already written the first three sentences of the full article: ultra high energy cosmic rays ( uhecrs ) are still an open problem in astro - particle physics .
the 11 akeno grand air shower array ( agasa ) events with energy larger than @xmath5 ev @xcite contradict the expected suppression of the uhecr spectrum due to the interaction with the cosmic microwave background ( cmb ) radiation , the graisen - zatsepin - kuzmin ( gzk ) cut - off @xcite . on the other hand the hires data seems to be consistent with the gzk cut - off picture @xcite .
if the uhecr primaries are protons and if they propagate rectilinearly , as the claimed correlation with bl - lacs at energy @xmath6 ev implies , than their sources must be seen in the direction of the highest energies events with energies up to @xmath7 ev detected by hires , fly s eye and agasa @xcite . at these energies.
Please generate the next two sentences of the article | the proton attenuation length is only about @xmath8 mpc and no counterparts in any frequency band was observed in the direction of these uhecr events .
this is a strong indication that cr particles with energies larger than @xmath5 ev may have a different origin from those with lower energies . another important point of this discussion |
8,609 | Suppose that you have an abstract for a scientific paper: we present studies of helium- and argon - filled ionization chambers exposed to intense neutron fluxes from pube neutron sources ( @xmath0 mev ) .
the sources emit about 10@xmath1 neutrons per second . the number of ion pairs in the chamber gas volume per incident neutron is derived . while limited in precision because of a large gamma ray background from the pube sources , our results are consistent with the expectation that the neutrons interact purely elastically in the chamber gas .
5 cm 1.0 cm -.25 cm ionization chambers , neutron scattering , elastic scattering , electrical phenomena in gases 25.40 , 29.40 , 51.50 .
And you have already written the first three sentences of the full article: the neutrinos at the main injector ( numi ) beamline at the fermi national accelerator laboratory @xcite will generate an intense @xmath2 beam from the decays of mesons produced in the collisions of 120 gev protons on a graphite target .
the mesons are focused into a 675 m long evacuated volume where they decay to neutrinos .
the meson decays @xmath3 produce an energetic muon for every neutrino , allowing monitoring and validation of the neutrino beam focusing to be accomplished by monitoring of the muon flux . as in several previous experiments ,.
Please generate the next two sentences of the article | the muon flux and remnant hadron flux at the end of the decay volume will be measured by arrays of ionization chambers @xcite .
in addition to charged particle fluxes , the ionization chambers are exposed to large fluences of neutrons , primarily produced in the aluminum / steel beam absorber upstream of the first muon monitor ( see figure [ fig : alcove_layout ] ) . |
8,610 | Suppose that you have an abstract for a scientific paper: we consider the interaction between electrons and molecular vibrations in the context of electronic transport in nanoscale devices .
we present a method based on non - equilibrium to calculate both equilibrium and non - equilibrium electronic properties of a single - molecule junction in the presence of electron - vibron interactions .
we apply our method to a model system consisting of a single electronic level coupled to a single vibration mode in the molecule , which is in contact with two electron reservoirs .
higher - order diagrams beyond the usual self - consistent born approximation ( scba ) are included in the calculations . in this paper
we consider the effects of the double - exchange diagram and the diagram in which the vibron propagator is renormalized by one electron - hole bubble .
we study in detail the effects of the first- and second - order diagrams on the spectral functions for a large set of parameters and for different transport regimes ( resonant and off - resonant cases ) , both at equilibrium and in the presence of a finite applied bias .
we also study the linear response ( linear conductance ) of the nanojunction for all the different regimes .
we find that it is indeed necessary to go beyond the scba in order to obtain correct results for a wide range of parameters . .
And you have already written the first three sentences of the full article: single - molecule electronics has shown significant progress in the recent years . a variety of interesting effects have been observed in the transport properties of single ( or a few ) conjugated organic molecules including rectification , negative differential resistance , and switching @xcite . in these quasi - one dimensional systems , which present well delocalised @xmath0-electrons
, the electronic current flowing through the quite flexible backbone of the molecule affects the ground state properties of both electronic and mechanical degrees of freedom of the molecule .
the importance of inelastic effects in the transport properties has been demonstrated in several ground - breaking experiments @xcite ; these effects are related to the interaction between electron and mechanical degrees of freedom of the molecule ..
Please generate the next two sentences of the article | the interaction between an injected charge carrier ( electron or hole ) and the mechanical degrees of freedom ( phonon , vibron ) in the molecular junctions is important in order to understand energy transfer , heating and dissipation in the nanojunction @xcite .
the electron - vibron interaction is also at the heart of inelastic electron tunneling spectroscopy ( iets ) . |
8,611 | Suppose that you have an abstract for a scientific paper: the interplay between flavour symmetries connecting @xmath0 decays with the recently measured @xmath1 decay and qcd factorisation opens new strategies to describe the decays @xmath2 and @xmath3 in the sm and in supersymmetry .
a new relation , emerging from the sum - rule for the @xmath4 decay mode , is presented offering a new way to determine the weak mixing angle @xmath5 of the @xmath6 system . .
And you have already written the first three sentences of the full article: the huge effort on the experimental side at present b facilities ( babar , belle and cdf ) to increase the precision on data measurements force us to revise the strategies on the theory side to produce more accurate predictions .
non leptonic b decays offer different strategies to determine the unitarity triangle , to search for new physics ( np)@xcite but also to rule out models @xcite .
while a lot of attention has been devoted to the @xmath7@xcite decay modes , here we will focus on @xmath8 decays that has been observed at cdf @xcite ( @xmath3 ) and at babar @xcite and belle @xcite ( @xmath1 ) ..
Please generate the next two sentences of the article | there are two main approaches in the literature to describe @xmath9 decays : flavour symmetries and @xmath10expansion methods ( qcd factorisation @xcite/ soft collinear effective theories @xcite or pqcd @xcite ) .
each of those methods has pros and cons , that we will discuss in turn . |
8,612 | Suppose that you have an abstract for a scientific paper: effects of electron doping on the bis@xmath0-based superconductors sr@xmath1la@xmath2fbis@xmath0 ( @xmath3 ) have been investigated using the systematically synthesized polycrystals by means of x - ray diffraction , x - ray absorption spectroscopy , transport and thermodynamic measurements .
the pristine compound is a band insulator with the bis@xmath0 layer , which accommodates electron carriers through the la substitution for sr , as evidenced by the change in x - ray absorption spectra reflecting the occupancy of bi 6@xmath4 orbitals . with increasing the carrier density ,
the resistivity progressively decreases and a bad metallic state appears for @xmath5 , where bulk superconductivity manifests itself below approximately 3 k. the value of @xmath6 gradually increases with decreasing @xmath7 from 0.6 to 0.45 and immediately decreases down to zero at the critical concentration of @xmath8 , resulting in an insulator - superconductor transition highly sensitive to the carrier density .
thermodynamic measurements furthermore have revealed the possible enhancement of the superconducting coupling strength as the insulating phase is approached .
the obtained superconducting phase diagram is markedly different from the broad dome - shaped superconducting phase previously reported for @xmath9o@xmath1f@xmath2bis@xmath0 ( @xmath9 : rare - earth ion ) , suggesting a strong influence of the blocking layer on the superconductivity .
instead all these features are similar to those observed in li - intercalated zrncl superconductor , except for the critical electron concentration of as low as 6% in the latter compound . for the present superconductor ,
notably , the existence of hole - type carriers has been indicated in the normal state from the hall effect measurements .
the sr@xmath1la@xmath2fbis@xmath0 system providing the phase diagram for the rigid - band doping in the bis@xmath0 layer would be another prototypical example of superconductivity derived from a doped layered band insulator , hosting both....
And you have already written the first three sentences of the full article: exotic superconductivity with high-@xmath6 has been often discovered in doped layered compounds , such as cuprates@xcite , @xmath10-@xmath11ncl ( @xmath11=zr , hf)@xcite , and iron pnictides@xcite .
recently , materials with bis@xmath0 layers have attracted much attention as a new family of layered superconductors .
superconductivity was first reported in bi@xmath12s@xmath12o@xmath13@xcite ( @xmath14 k ) , followed by @xmath9o@xmath1f@xmath2bis@xmath0 ( @xmath9=la , ce , pr , nd and yb)@xcite , where the maximum @xmath6 reaches @xmath1510 k around @xmath7=0.5 for @xmath9=la ..
Please generate the next two sentences of the article | a characteristic crystal structure common to these materials is the bis@xmath0 layers consisting of the bi and s ions positioned alternately on the square lattice , which are separated by insulating blocking layers .
the superconductivity has been believed to reside in the bis@xmath0 layer , when electron - type carriers are doped . for the @xmath9o@xmath1f@xmath2bis@xmath0 compounds , for instance , |
8,613 | Suppose that you have an abstract for a scientific paper: we propose a method for obtaining the schmidt decomposition of bipartite systems with continuous variables .
it approximates the modes to the prescribed accuracy by well known orthogonal functions .
we give some criteria for the control of errors .
we illustrate the method comparing its results with the already published analysis for entanglement of biphotons .
the agreement is excellent . .
And you have already written the first three sentences of the full article: bipartite and multipartite entanglement is one of the features that give rise to many of the developments of quantum computation and information , like quantum teleportation @xcite and quantum cryptography @xcite , among others @xcite .
the evaluation of the entanglement of a composite state is thus a main task to be done . for this purpose ,
the schmidt decomposition @xcite has proven to be a valuable tool , for systems with just two components ..
Please generate the next two sentences of the article | in this paper we consider the case of continuous variables entanglement . for us , these variables may be @xmath0 which commute as phase space variables do .
we also refer to continuous variable entanglement in systems described by momentum and/or energy observables . |
8,614 | Suppose that you have an abstract for a scientific paper: background : : the deuteron plays a pivotal role in nuclear and hadronic physics , as both the simplest bound multi - nucleon system and as an `` effective neutron target ''
. quasi - elastic electron scattering on the deuteron is a benchmark reaction to test our understanding of deuteron structure and the properties and interactions of the two nucleons bound in the deuteron .
purpose : : the experimental data presented here can be used to test state - of - the - art models of the deuteron and the two - nucleon interaction in the final state after two - body breakup of the deuteron . focusing on polarization degrees of freedom , we gain information on spin - momentum correlations in the deuteron ground state ( due to the d - state admixture ) and on the limits of the impulse approximation ( ia ) picture as it applies to measurements of spin - dependent observables like spin structure functions for bound nucleons .
information on this reaction can also be used to reduce systematic uncertainties on the determination of neutron form factors or deuteron polarization through quasi - elastic polarized electron scattering .
method : : we measured the beam - target double spin asymmetry ( @xmath0 ) for quasi - elastic electron scattering off the deuteron at several beam energies ( [email protected] gev , 2.5 gev , 4.2 gev and [email protected] gev ) , using the cebaf large acceptance spectrometer ( clas ) at the thomas jefferson national accelerator facility . the deuterons were polarized along ( or opposite to ) the beam direction . the double spin asymmetries were measured as a function of photon virtuality @xmath2 ( [email protected] ( gev@xmath3)@xmath4 ) , missing momentum ( @xmath5 gev@xmath3 ) , and the angle between the ( inferred ) `` spectator '' neutron and the momentum transfer direction ( @xmath6 ) . results : : the results are compared with a recent model that includes final state interactions ( fsi ) using a....
And you have already written the first three sentences of the full article: the deuteron , as the simplest nuclear system , serves the dual role of an `` effective free neutron target '' @xcite and as a testing ground for sophisticated models of nucleon - nucleon interactions and scattering mechanisms @xcite .
electron scattering off the deuteron has been used as a means to extract information on its nuclear structure , including the @xmath10-wave ( @xmath11 ) contribution to the ground state wave function @xcite . on the other hand , experiments that look for modifications of nucleon structure due to nuclear binding
have also used the deuteron as a testbed @xcite . in all of these cases ,.
Please generate the next two sentences of the article | a thorough and detailed understanding of the scattering mechanism is necessary . in particular , quasi - elastic scattering off the deuteron has been widely studied @xcite as an ideal reaction to disentangle various contributions to the reaction mechanism , such as relativistic effects , non - nucleonic components of the deuteron wave function , meson - exchange ( mec ) and isobar ( ic ) currents , and final state interactions ( fsi ) between the outgoing nucleons .
recent experiments @xcite have focused on higher momentum transfers , where one - nucleon currents are expected to dominate the cross section . because of the continuing ( and growing ) importance of the deuteron as an effective neutron target @xcite |
8,615 | Suppose that you have an abstract for a scientific paper: we study the qcd phase diagram using a non - local su(3 ) njl model with vector interactions among quarks .
we analyze several thermodynamic quantities such as entropy and specific heat , and study the influence of vector interactions on the thermodynamic properties of quark matter . upon imposing electric charge neutrality and baryon number conservation on the field equations ,
we compute models for the equation of state of the inner cores of proto - neutron stars and providing a non - local treatment of quark matter for astrophysics . .
And you have already written the first three sentences of the full article: it is known that quantum chromodynamics ( qcd ) , has two very important properties , namely asymptotic freedom and confinement .
the former implies that at high momentum transfers , the quarks behave as quasi free particles , i.e. , the interaction between two quarks due to gluon interchange can be treated using perturbation theory . for this momentum range
, the dispersion processes can be then be calculated with a very good precision . by contrast ,.
Please generate the next two sentences of the article | at low momentum exchange among the quarks ( @xmath0 gev ) qcd is highly nonlinear and leads to quark confinement .
several approximate methods have been developed to study the physical processes among quarks in the low momentum range of qcd . among them |
8,616 | Suppose that you have an abstract for a scientific paper: we introduce distribution functions for quarks and gluons in the glasma and discuss how they satisfy various relationships of statistical physics .
we use these distributions to compute photon production in the early stages of heavy ion collisions .
photon rates satisfy geometric scaling , that is , the emission rate per unit area scales as a function of the saturation momenta divided by the transverse momentum of the photon .
photon distributions from the glasma are steeper than those computed in the thermalized quark gluon plasma ( tqgp ) .
both the delayed equilibration of the glasma and a possible anisotropy in the pressure lead to slower expansion and mean times of photon emission of fixed energy are increased .
this delayed emission might allow for larger photon elliptic flow . .
And you have already written the first three sentences of the full article: there is a discrepancy between what is experimentally observed in heavy ion collisions @xcite , and theoretical computations of photon emission from a thermalized quark gluon plasma ( tqgp ) @xcite .
computations using realistic equations of state and state of the art computations of photon emission from the tqgp give results whose slope in @xmath0 is too shallow ( falls too slowly in @xmath0 ) and is about a factor of 4 smaller than the observed rate @xcite . even more significant
is the difference between theoretically computed and experimentally observed photon elliptic flow ..
Please generate the next two sentences of the article | photon emission is dominated by early times when temperatures are high and flow is not yet built up .
this early time emission in theoretical calculations leads to a significant under - estimation of elliptic flow compared to experimental data . |
8,617 | Suppose that you have an abstract for a scientific paper: i review the observational side of the present state of the debate about the dark matter in galaxies , with emphasis on the core / cusp problem in low surface brightness galaxies , and the question of maximum / sub - maximum disks in spiral galaxies .
some remarks are made about the dwarf spheroidals around the milky way , and about elliptical galaxies .
# 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: the wmap results ( spergel et al . 2003 ) have given rather strict limits on the matter and energy content of the universe , in agreement with the @xmath0cdm model .
typically , for @xmath1@xmath2 = 1 , @xmath1@xmath3 = 0.73 , and @xmath1@xmath4 = 0.27 , with @xmath1@xmath5 = 0.044 , and @xmath1@xmath6 = 0.23 .
some of these results depend on data from the 2df galaxy redshift survey ..
Please generate the next two sentences of the article | initial results from the sdss redshift survey are not much different ( tegmark et al .
the ratio of baryonic to non - baryonic matter is thus 1 to @xmath7 5 - 6 . |
8,618 | Suppose that you have an abstract for a scientific paper: a two - body quantum correlation is calculated for a particle reflecting from a moving mirror . correlated interference results when the incident and reflected particle substates and their associated mirror substates overlap .
using the copenhagen interpretation of measurement , an asynchronous joint probability density ( pdf ) , which is a function both of the different positions and different times at which the particle and mirror are measured , is derived assuming that no interaction occurs between each measurement .
measurement of the particle first , in the correlated interference region , results in a splitting of the mirror substate into ones which have and have not reflected the particle .
an analog of the interference from the doppler effect for only measurements of the particle ( a marginal pdf ) , in this two - body system , is shown to be a consequence of the asynchronous measurement .
the simplification obtained for a microscopic particle reflecting from a mesoscopic or macroscopic mirror is used to illustrate asynchronous correlation interferometry . in this case , the small displacement between these mirror states can yield negligible environmental decoherence times . in addition , interference of these mirror states does not vanish in the limit of large mirror mass due to the small momentum exchange in reflecting a microscopic particle . .
And you have already written the first three sentences of the full article: correlation and interference distinguish quantum from classical physics .
the former is manifest in the measurement of many - body coincidences predicted by a quantum joint probability density function ( pdf ) .
some observable correlations can not be realized classically @xcite ..
Please generate the next two sentences of the article | quantum interference is most familiar as a one - body pdf for an outcome that can be achieved in at least two indistinguishable ways .
however , it can also be generated by superposing many - body states in indistinguishable ways @xcite . |
8,619 | Suppose that you have an abstract for a scientific paper: we present a non - linear numerical model for a geometrically thin accretion disk with the addition of stochastic non - linear fluctuations in the viscous parameter .
these numerical realizations attempt to study the stochastic effects on the disk angular momentum transport .
we show that this simple model is capable of reproducing several observed phenomenologies of accretion driven systems .
the most notable of these is the observed linear rms - flux relationship in the disk luminosity .
this feature is not formally captured by the linearized disk equations used in previous work . a fourier analysis of the dissipation and mass accretion rates across disk radii show coherence for frequencies below the local viscous frequency .
this is consistent with the coherence behavior observed in astrophysical sources such as cygnus x-1 . .
And you have already written the first three sentences of the full article: strong and rapid variability is a key observational feature of systems driven by the accretion of material onto a central compact object .
the power spectral density ( psd ) of emission from such objects is characterized by broadband noise across several decades in frequency .
this broadband component is generally well described by a broken - powerlaw form , however the physics that governs such breaks is poorly understood ..
Please generate the next two sentences of the article | additionally , the psd can feature distinct and resolved peaks indicative of quasi - periodic oscillations ( qpos ) in the emission .
the broadband noise structure displays many interesting characteristics beyond the psd . |
8,620 | Suppose that you have an abstract for a scientific paper: we describe the pitfalls encountered in deducing from classical double radio source observables ( luminosity , spectral index , redshift and linear size ) the essential nature of how these objects evolve .
we discuss the key role played by hotspots in governing the energy distribution of the lobes they feed , and subsequent spectral evolution .
we present images obtained using the new 74mhz receivers on the vla and discuss constraints which these enforce on models of the backflow and ages in classical doubles . , , , & .
And you have already written the first three sentences of the full article: to identify the true nature of the ways in which radio galaxies grow and evolve is not a trivial problem to tackle : we can not observe any radio galaxy at well - separated intervals throughout its life .
we can only make observations of a particular radio galaxy if it intercepts our light - cone . whether or not any radio galaxy is intercepted by our light - cone , and at what point in its life ,
is entirely random ..
Please generate the next two sentences of the article | [ fig : rain1 ] schematically illustrates the randomness of the sampling of any radio galaxy by our light - cone .
unavoidably imposed on the random sampling by our light - cone is the effect of more selective sampling of the radio galaxy population determined by the _ finding - frequency _ of the survey . |
8,621 | Suppose that you have an abstract for a scientific paper: we describe and model high velocity ( @xmath0 ) ly@xmath1 and h@xmath1 emission from supernova remnant 1987a seen in september and october 1997 with the space telescope imaging spectrograph .
part of this emission comes from a reverse shock located at @xmath2 of the radius of the inner boundary of the inner circumstellar ring and confined within @xmath3 of the equatorial plane .
departure from axisymmetry in the ly@xmath1 and h@xmath1 emission correlates with that seen in nonthermal radio emission and reveals an asymmetry in the circumstellar gas distribution .
we also see diffuse high velocity ly@xmath1 emission from supernova debris inside the reverse shock that may be due to excitation by nonthermal particles accelerated by the shock . .
And you have already written the first three sentences of the full article: on may 24 , 1997 ( day 3743 after core collapse ) , sonneborn _ et al . _
( 1998 ) observed supernova remnant ( snr ) 1987a with the space telescope imaging spectrograph ( stis ) .
they discovered very broad ( @xmath4 ) ly@xmath1 emission in the ultraviolet spectrum ..
Please generate the next two sentences of the article | ( 1998 , hereafter m98 ) interpreted this emission as the result of excitation of neutral hydrogen atoms in the supernova debris crossing a reverse shock .
the observed ly@xmath1 flux was close to the value predicted by borkowski _ |
8,622 | Suppose that you have an abstract for a scientific paper: very deep near - infrared observations in the faint infrared extragalactic survey ( fires ) have recently uncovered a significant population of red galaxies at redshifts @xmath0 . these distant red galaxies ( drgs )
are efficiently selected by the criterion @xmath1 .
we use chandra data to examine the x - ray emission from drgs in the @xmath2 fires ms105403 field .
two of 40 drgs with @xmath3 are detected by chandra , and we infer that @xmath4% of drgs host active nuclei with @xmath5 . this fraction is smaller than that inferred from optical and near - ir spectroscopy , probably largely due to strong spectroscopic selection biases . by stacking all undetected drgs
we find that their average x - ray flux in the @xmath6kev band is @xmath7 .
the detection is only significant in the soft ( @xmath8kev ; @xmath9 ) and full ( @xmath6kev ; @xmath10 ) energy bands .
the mean detection may result from star formation , the presence of low luminosity agn , or a combination of both .
assuming the detection is due exclusively to star formation , we find an average instantaneous star formation rate of @xmath11 ( random ) @xmath12 ( systematic ) , in excellent agreement with previous results from spectral energy distribution fitting when constant star formation histories are assumed .
these results may imply that drgs contribute significantly to the cosmic star formation rate at @xmath13 .
however , the mean x - ray flux strictly provides only an upper limit to the star formation rate due to the uncertain contribution of low luminosity , possibly obscured agns .
observations at other wavelengths are needed to provide independent estimates of the star formation rate of drgs .
50min@xmath14 727[oii]3727 007[oiii]5007 1054ms105403 ang4000 .
And you have already written the first three sentences of the full article: recent studies have demonstrated that galaxies at @xmath0 can be efficiently selected by the simple observed near - infrared ( nir ) color criterion @xmath1 ( franx et al .
2003 ; van dokkum et al .
2003 ) . these distant red galaxies ( drgs ).
Please generate the next two sentences of the article | are typically very faint in the rest - frame ultra - violet ( uv ) , and are complementary to the uv - selected lyman break galaxies ( lbgs ) .
studies of their broad - band spectral energy distributions ( seds ) ( frster schreiber et al . |
8,623 | Suppose that you have an abstract for a scientific paper: a linear irreversible thermodynamic framework of heat conduction in rigid conductors is introduced . the deviation from local equilibrium
is characterized by a single internal variable and a current multiplier .
a general constitutive evolution equation of the current density of the internal energy is derived by introducing linear relationship between the thermodynamic forces and fluxes .
the well - known fourier , maxwell - cattaneo - vernotte , guyer - krumhansl , jeffreys type and green - naghdi type equations of heat conduction are obtained as special cases . the universal character of the approach is demonstrated by two examples . solutions illustrating the properties of the equation with jump boundary conditions are given . .
And you have already written the first three sentences of the full article: the increasing importance of micro- and nanotechnology initiated an intensive research in heat conduction @xcite .
experiments show deviations from the classical fourier theory @xcite and there are several theoretical developments to understand the nature of the deviations @xcite .
the starting point of all these approaches is the balance of internal energy @xmath0 where @xmath1 is the density , @xmath2 is the specific internal energy , and @xmath3 is the conductive part of the current density of internal energy , i.e. , the heat flow ..
Please generate the next two sentences of the article | we are dealing with rigid heat conductors , the dot denotes the partial time derivative , @xmath4 is the space derivative of the corresponding physical quantity , and index notation with the einstein summation convention is applied . in the phenomenological generalizations of fourier s law of classical heat conduction , the constitutive equation ( [ four ] )
is modified by additional terms . |
8,624 | Suppose that you have an abstract for a scientific paper: hydrodynamic interactions with confining boundaries often lead to drastic changes in the diffusive behaviour of microparticles in suspensions . for axially symmetric particles ,
earlier numerical studies have suggested a simple form of the near - wall diffusion matrix which depends on the distance and orientation of the particle with respect to the wall , which is usually calculated numerically . in this work ,
we derive explicit analytical formulae for the dominant correction to the bulk diffusion tensor of an axially symmetric colloidal particle due to the presence of a nearby no - slip wall .
the relative correction scales as powers of inverse wall - particle distance and its angular structure is represented by simple polynomials in sines and cosines of the particle s inclination angle to the wall .
we analyse the correction for translational and rotational motion , as well as the translation - rotation coupling .
our findings provide a simple approximation to the anisotropic diffusion tensor near a wall , which completes and corrects relations known from earlier numerical and theoretical findings .
* published in : * j. chem .
phys * 145 * , 034904 ( 2016 ) . .
And you have already written the first three sentences of the full article: boundaries and interfaces are omnipresent in the colloidal world @xcite .
geometric confinement introduces anisotropy in the diffusive motion of sub - micron particles , and the presence of neighbouring walls leads to a general slow - down of brownian motion due to hydrodynamic interactions of the diffusing particle with boundaries @xcite .
the central quantity in this context is the near - wall hydrodynamic mobility tensor @xmath0 which is related to the diffusion tensor @xmath1 by the fluctuation - dissipation theorem @xmath2 recent years have brought significant advancement in experimental techniques which allow to explore near - wall dynamics in more detail , including optical microscopy @xcite and scattering techniques , such as evanescent wave dynamic light scattering @xcite ..
Please generate the next two sentences of the article | the latter is now a well - established tool which has profitably been used to investigate translational @xcite and rotational diffusion @xcite of spherical colloids in dilute suspensions .
due to the complex nature of the experiments , available experimental data for non - spherical particles such as dumbbells @xcite or rods are still lacking proper interpretation . |
8,625 | Suppose that you have an abstract for a scientific paper: we present an approach that includes temperature - dependent shell effects and fluctuations of the pairing field in the thermal shape fluctuation model ( tsfm ) .
we apply this approach to study the width of giant dipole resonance ( gdr ) in @xmath0tc , @xmath1sn and @xmath2pb .
our results demonstrate that the tsfm that includes pairing fluctuations can explain the recently observed quenching in the gdr width .
we also show that to validate pairing prescriptions and the parameters involved , we require more and precise data . .
And you have already written the first three sentences of the full article: the study of nuclear properties at high temperature , spin and isospin has gained much of interest in recent times .
thanks to the recent developments in experimental facilities , these highly - excited nuclei are becoming more accessible and provide theorists with a challenging task . apart from these extremes
, there are still some unexplored regimes of hot nuclei ..
Please generate the next two sentences of the article | the properties of nuclei at very low temperatures and the phase transitions associated with that belong to such area where conclusive experimental results are scarce . at such low temperatures , the shell ( quantal ) and pairing effects are quite active though being modified by thermal effects . among the famous and open questions in this regime
are the existence of pairing phase transition , the order of it if it exists , the role of fluctuations , etc . in hot nuclei , |
8,626 | Suppose that you have an abstract for a scientific paper: we analyse the fundamental plane ( fp ) of 26 strong gravitational lens galaxies with redshifts up to @xmath0 , using tabulated data from kochanek et al .
( 2000 ) and rusin et al .
( 2003 ) .
the lens galaxies effectively form a mass - selected sample of early - type galaxies in environments of relatively low density .
we analyse the fp and its evolution in the restframe johnson @xmath1 and gunn @xmath2 bands . assuming that early - type galaxies are a homologous family , the fp then provides a direct measurement of the @xmath3 ratio evolution .
if we assume that the @xmath3 ratios of field early - type galaxies evolve as power - laws , we find for the lens galaxies an evolution rate @xmath4 of @xmath5 in restframe @xmath1 and @xmath6 in restframe gunn @xmath2 for a flat cosmology with @xmath7 and @xmath8 . for a salpeter ( 1955 )
initial mass function and solar metallicity these results correspond to mean stellar formation redshifts of @xmath9 and @xmath10 respectively . after correction for maximum progenitor bias ,
van dokkum & franx ( 2001 ) find a mean stellar formation redshift for cluster galaxies of @xmath11 , which is not significantly different from that found for the lens galaxies .
however , if we impose the constraint that lens and cluster galaxies that are of the same age have equal @xmath3 ratios and we do not correct for progenitor bias , the difference is significant and we find that the stellar populations of the lens galaxies are 1015@xmath12 younger than those of the cluster galaxies .
we find that both the @xmath3 ratios as well as the restframe colors of the lens galaxies show significant scatter .
about half of the lens galaxies are consistent with an old cluster - like stellar populations , but the other galaxies are bluer and best fit by single burst models with younger stellar formation redshifts as low as @xmath13 . moreover ,
the scatter in color is correlated with the scatter in @xmath3 ratio .
we interpret this as evidence of a significant age....
And you have already written the first three sentences of the full article: one of the central problems in astronomy is that of galaxy formation and evolution : when were the visible parts of galaxies assembled and when were the stars formed ?
the merging of galaxies leads to changes in their masses , and stellar evolution changes their luminosities .
the evolution of the mass - to - light ( @xmath3 ) ratio relates the mass and luminosity evolution ..
Please generate the next two sentences of the article | galaxy mass measurements are notoriously difficult .
fortunately , empirical relations such as the tully - fisher relation for spiral galaxies ( tully & fisher 1977 ) and the fundamental plane ( fp ) for early - type galaxies ( dressler et al . 1987 ; djorgovski & davis 1987 ) can provide us with information on the masses and mass evolution of galaxies . |
8,627 | Suppose that you have an abstract for a scientific paper: we find that _ singlet _ superconducting pairing can lead to majorana fermions in three dimensional dirac superconductors ( 3dds ) if the pairing order parameter is a pseudo - scalar , i.e. it changes sign under mirror reflection .
the pseudo - scalar superconducting order parameter , @xmath0 can close and reopen the spectral gap caused by the scalar dirac mass @xmath1 in a three - dimensional dirac material ( 3ddm ) , giving rise to a two - dimensional majorana sea ( 2dms ) at the plane of the gap kink . by bringing the hamiltonian into a canonical form which then gives the winding number , we show that this system belongs to the diii class of topological superconductors .
we calculate the transport signature of 2dms , namely a perfect andreev - klein transmission that manifests in a robust peak in the differential conductance .
further , we find the @xmath2 periodicity in the @xmath3 josephson junctions .
gauge transformed version of the present scenario implies that the interface of a conventional s - wave superconductor with a peculiar 3ddm whose mass is a pseudo - scalar , @xmath4 also hosts a 2dms . _
introduction_. band topology in insulators and superconductors is connected with the change in the sign of the gap parameter which in turn gives rise to zero energy states at the location of gap kink .
this mechanism in the case of insulators gives rise to gapless surface modes protected by a topological invariant @xcite .
when the spectral gap is of the superconducting ( pairing ) nature , these topologically protected modes will be majorana zero modes , which are their own anti - particles @xcite . to realize majorana fermions ( mfs ) various scenarios
have been proposed which involve closing and re - opening the superconducting gap in one way or another .
gaping chiral modes of topological insulators ( tis ) by zeeman field and superconducting pairing gives rise to mfs in the interface region where these two gapping mechanisms are of comparable strength @xcite . in one -....
And you have already written the first three sentences of the full article: the wave functions satisfying the dirac equation @xmath128 is a four component spinor as , @xmath129 where @xmath38 and @xmath130 correspond to the conduction and valence band , respectively .
also , @xmath78 correspons to the spin directions of carrier with respect to @xmath79-axis .
the hole part of dbdg equation is obtained by operating with the charge conjugation on the hamiltonina and its spinor of eq.([e.01 ] ) ..
Please generate the next two sentences of the article | it consists in the complex conjugation operator @xmath41 and multiplication by some @xmath9 matrxi the form of which depends on the representation of @xmath131 matrices and in our case is @xcite , @xmath132 such that , @xmath133 which can be recast into the form , @xmath134 where the charge conjugated state @xmath135 is explicitely given by @xcite , @xmath136 from @xmath137 and @xmath135 we can construct a nambu spinor @xmath138 that satisfies dbdg equation in the direct product space of eqs .
( [ e.04 ] ) and ( [ e.06 ] ) , @xmath139 the explicit representation of the dbdg hamiltonian matrix in the pseudo - scalar pairing channel becomes , @xmath140 to clarify the total spin of the pairing symmetry let extract the pairing part of @xmath141 which in terms of @xmath142 becomes , @xmath143 and simplifies to , @xmath144 which clearly shows the singlet nature of pairing as is expected from singlet character of a pseudo - scalar pairing . |
8,628 | Suppose that you have an abstract for a scientific paper: we present the discovery of a bright ( j = [email protected] ) t dwarf , 2mass 1503 + 2525 , identified in a new , wide - field search for t dwarfs using the recently completed two micron all sky survey ( 2mass ) .
the 12.5 @xmath1 spectrum of this object exhibits the strong h@xmath2o and ch@xmath3 bands characteristic of mid- and late - type t dwarfs , and we derive a spectral type of t5.5 using both the burgasser et al . and the geballe et al .
classification schemes . based on its spectral type and the absolute magnitudes of known t dwarfs
, we estimate the distance of this object as 8@xmath03 pc if it is single , likely within 10 pc of the sun .
our new 2mass search , which covers 74% of the sky and greatly expands on earlier color constraints , should identify 1525 new t dwarfs with j @xmath4 16 . combined with the 20 known members of this class that already fall within our search criteria , our new sample will provide improved statistics for such key quantities as the binary fraction and the field substellar mass function .
furthermore , multiple detections from overlapping 2mass scans provide multiple epoch astrometry and photometry , and we present proper motions for five t dwarfs in our sample . .
And you have already written the first three sentences of the full article: t dwarfs are low - temperature ( t@xmath5 @xmath6 13001500 k ) brown dwarfs exhibiting distinct absorption bands of ch@xmath3 in the near - infrared h- and k - bands @xcite .
they are distinguished from warmer l - type @xcite and m - type dwarfs in the near - infrared by the presence of these molecular features , in addition to significant h@xmath2o and collision - induced ( cia ) h@xmath2 absorption @xcite . since the discovery of the prototype of this class , gliese 229b @xcite , over 30 t dwarfs have been identified , most in the wide - field two micron all - sky survey ( * ? ? ?
* hereafter 2mass ) and sloan digital sky survey ( * ? ? ?.
Please generate the next two sentences of the article | * hereafter sdss ) .
classification schemes for these objects based on near - infrared spectral morphology have been defined by @xcite and @xcite . |
8,629 | Suppose that you have an abstract for a scientific paper: we analyse phase averaging in one - dimensional interacting mesoscopic systems with several barriers and show that for incommensurate positions an independent average over several phases can be induced by finite temperature . for three strong barriers with conductances @xmath0 and mutual distances larger than the thermal length , we obtain @xmath1 for the total conductance @xmath2 . for an interacting wire ,
this implies power laws in @xmath3 with novel exponents , which we propose as an experimental fingerprint to distinguish temperature induced phase averaging from dephasing . .
And you have already written the first three sentences of the full article: mesoscopic systems are characterized by spatial dimensions smaller than the phase breaking length @xmath4 so that the phase of an electron is not destroyed by inelastic processes . along their optical paths , electrons pick up phases from propagation and scattering . even for negligible dephasing , certain circumstances can lead to an _ averaging _ of these phases , a phenomenon which has been analyzed in connection with localization , see e.g. refs . .
it remains however a fundamental task to compare in detail the effects of phase averaging and dephasing . for a noninteracting model system
it was recently shown that a single one - channel dephasing probe gives the same full counting statistics as a single phase - averaging probe.@xcite however , it was noted that this result does no longer hold for several probes , i.e. phase averaging over many independent phases seems to be fundamentally different from dephasing . in the present paper we address this issue in detail ..
Please generate the next two sentences of the article | we discuss a generic one - dimensional interacting system coupled to two reservoirs with few barriers at arbitrary but fixed positions .
we show that for incommensurate barrier positions an independent average over several phases can be induced by finite temperature . for more than two barriers |
8,630 | Suppose that you have an abstract for a scientific paper: [ sec : abstract ] the infrared array camera ( irac ) is one of three focal plane instruments in the spitzer space telescope .
irac is a four - channel camera that obtains simultaneous broad - band images at 3.6 , 4.5 , 5.8 , and 8.0 @xmath0 m .
two nearly adjacent [email protected] arcmin fields of view in the focal plane are viewed by the four channels in pairs ( 3.6 and 5.8 @xmath0 m ; 4.5 and 8 @xmath0 m ) .
all four detector arrays in the camera are 256@xmath1256 pixels in size , with the two shorter wavelength channels using insb and the two longer wavelength channels using si : as ibc detectors .
irac is a powerful survey instrument because of its high sensitivity , large field of view , and four - color imaging .
this paper summarizes the in - flight scientific , technical , and operational performance of irac . .
And you have already written the first three sentences of the full article: the three spitzer space telescope focal plane instruments were designed to investigate four major scientific topics : ( 1 ) early universe , ( 2 ) brown dwarfs and superplanets , ( 3 ) active galactic nuclei , and ( 4 ) protoplanetary and planetary debris disks . of these topics ,
the most important in defining the infrared array camera ( irac ) design was the study of the early universe , and in particular , the study of the evolution of normal galaxies to z @xmath2 3 by means of deep , large - area surveys .
the 3 to 10 @xmath0 m wavelength range was selected because stars have a peak emission at a wavelength of 1.6 @xmath0 m , at the minimum of the h@xmath3 opacity @xcite ..
Please generate the next two sentences of the article | the emission peak is an ubiquitous feature of stellar atmospheres and can be used to determine a photometric redshift for 1 @xmath4 z @xmath5 5 @xcite .
the irac sensitivity requirement was set such that irac could achieve a 10@xmath6 detection of an @xmath7 galaxy at z = 3 . |
8,631 | Suppose that you have an abstract for a scientific paper: most viable models of type ia supernovae ( sn ia ) require the thermonuclear explosion of a carbon / oxygen white dwarf that has evolved in a binary system .
rotation could be an important aspect of any model for sn ia , whether single or double degenerate , with the white dwarf mass at , below , or above the chandrasekhar limit .
_ differential rotation _ is specifically invoked in attempts to account for the apparent excess mass in the super chandrasekhar events .
some earlier work has suggested that only uniform rotation is consistent with the expected mechanisms of angular momentum transport in white dwarfs , while others have found pronounced differential rotation .
we show that if the baroclinic instability is active in degenerate matter and the effects of magnetic fields are neglected , both nearly - uniform and strongly - differential rotation are possible .
we classify rotation regimes in terms of the richardson number , ri . at small values of ri @xmath0 0.1 , we find both the low - viscosity zahn regime with a non - monotonic angular velocity profile and a new differential rotation regime for which the viscosity is high and scales linearly with the shear , @xmath1 .
employment of kelvin - helmholtz viscosity alone yields differential rotation .
large values of ri @xmath2 1 produce a regime of nearly - uniform rotation for which the baroclinic viscosity is of intermediate value and scales as @xmath3 .
we discuss the gap in understanding of the behavior at intermediate values of ri and how observations may constrain the rotation regimes attained by nature . .
And you have already written the first three sentences of the full article: although the basic explosion mechanism of supernovae of type ia ( henceforth sn ia ) has been established to be the thermonuclear combustion of degenerate c / o white dwarfs ( henceforth wd ) , many aspects of the progenitor systems of remain to be understood .
nearly all viable progenitor models involve mass transfer in binary systems ( howell 2011 ; wang & han 2102 ; maoz , mannucci & nelemans 2014 ; but see chiosi et al .
one idea is the initiation of carbon ignition as the mass approaches the classical chandrasekhar limit of stability , @xmath4 , for non rotating wds by means of accretion in a binary system ..
Please generate the next two sentences of the article | this classic model is most closely associated with mass transfer from a non degenerate companion , the single degenerate ( sd ) scenario .
variations on this theme allow for explosions with less than @xmath5when accretion of helium from a companion leads to the accumulation of an explosive degenerate layer of helium on top of the c / o core that generates compression waves that can trigger a central carbon detonation ( fink et al . |
8,632 | Suppose that you have an abstract for a scientific paper: high - redshift submillimetre - bright galaxies identified by blank field surveys at millimetre and submillimetre wavelengths appear in the region of the irac colour colour diagrams previously identified as the domain of luminous active galactic nuclei ( agns ) .
our analysis using a set of empirical and theoretical dusty starburst spectral energy distribution ( sed ) models shows that power - law continuum sources associated with hot dust heated by young ( @xmath0 myr old ) , extreme starbursts at @xmath1 also occupy the same general area as agns in the irac colour colour plots .
a detailed comparison of the irac colours and seds demonstrates that the two populations are distinct from each other , with submillimetre - bright galaxies having a systematically flatter irac spectrum ( @xmath2 mag bluer in the observed [ 4.5][8.0 ] colour ) .
only about 20% of the objects overlap in the colour colour plots , and this low fraction suggests that submillimetre galaxies powered by a dust - obscured agn are not common .
the red ir colours of the submillimetre galaxies are distinct from those of the ubiquitous foreground irac sources , and we propose a set of ir colour selection criteria for identifying smg counterparts that can be used even in the absence of radio or _ _
s__pitzer mips 24 data .
[ firstpage ] cosmology : observations galaxies : evolution galaxies : high redshift galaxies : starburst galaxies : active infrared : galaxies . .
And you have already written the first three sentences of the full article: one of the most exciting developments of the past decade has been the resolution of the cosmic far - infrared background into discrete sources , providing a first glimpse of the rapid build - up of massive galaxies in the early universe long predicted by theory .
deep , wide blank field surveys at millimetre ( mm ) and submillimetre ( submm ) wavelengths @xcite have shown that ultraluminous infrared galaxies ( ulirgs ) at @xmath3 contribute significantly to the observed far - ir background .
wavelength follow up studies of these so - called submillimetre galaxies ( smgs ) suggest that they are massive , young galaxies seen during the period of rapid stellar mass build - up , with very high specific star formation rates at @xmath4 ( see review by * ? ? ?.
Please generate the next two sentences of the article | a major obstacle in understanding the nature of this luminous dusty galaxy population is the limited angular resolution ( @xmath5 ) of current instrumentation , which prevents unambiguous identification of their counterparts at other wavelengths .
deep interferometric radio imaging and _ _ |
8,633 | Suppose that you have an abstract for a scientific paper: we investigate the effect of the coulomb interaction on the applicability of quantum gates on a system of two coulomb - coupled quantum dots .
we calculate the fidelity for a single- and a two - qubit gate and the creation of bell states in the system . the influence of radiative damping is also studied .
we find that the application of quantum gates based on the coulomb interaction leads to significant input state - dependent errors which strongly depend on the coulomb coupling strength . by optimizing the coulomb matrix elements via the material and the external field parameters , error rates in the range of @xmath0
can be reached .
radiative dephasing is a more serious problem and typically leads to larger errors on the order of @xmath1 for the considered gates . in the specific case of the generation of a maximally entangled bell state , error rates in the range of @xmath0 can be achieved even in the presence of radiative dephasing . .
And you have already written the first three sentences of the full article: quantum dots ( qds ) have long been discussed as a source for semiconductor - based quantum information processing @xcite . for a physical realization of a quantum computer , a quantum mechanical two - level system that can serve as a qubit is required .
this system must allow for preparation , manipulation , and readout of its quantum state @xcite .
furthermore , a coupling mechanism between the qubits is needed to allow for conditional operations on multiple qubits ..
Please generate the next two sentences of the article | other interactions , especially damping mechanisms that affect the two - level system , have to be minimized . as representations of qubits , excitonic states in single or double qds as well as spin states have been proposed @xcite .
quantum information schemes in qd systems are often based on the coherent optical control of the electronic states , taking advantage of the femtosecond time scales common in current ultrafast laser optics @xcite . |
8,634 | Suppose that you have an abstract for a scientific paper: the distinctive cometary x - ray morphology of the recently discovered massive galaxy cluster `` el gordo '' ( act - ct j0102 - 4915 ; @xmath0 = 0.87 ) indicates that an unusually high - speed collision is ongoing between two massive galaxy clusters . a bright x
- ray `` bullet '' leads a `` twin - tailed '' wake , with the sz centroid at the end of the northern tail .
we show how the physical properties of this system can be determined using our flash - based , n - body / hydrodynamic model , constrained by detailed x - ray , sunyaev
zeldovich ( sz ) , and hubble lensing and dynamical data .
the x - ray morphology and the location of the two dark matter components and the sz peak are accurately described by a simple binary collision viewed about 480 million years after the first core passage .
we derive an impact parameter of @xmath1300 kpc , and a relative initial infall velocity of @xmath12250 @xmath2 when separated by the sum of the two virial radii assuming an initial total mass of @xmath3 @xmath4 and a mass ratio of 1.9 .
our model demonstrates that tidally stretched gas accounts for the northern x - ray tail along the collision axis between the mass peaks , and that the southern tail lies off axis , comprising compressed and shock heated gas generated as the less massive component plunges through the main cluster .
the challenge for @xmath5cdm will be to find out if this physically extreme event can be plausibly accommodated when combined with the similarly massive , high infall velocity case of the bullet cluster and other such cases being uncovered in new sz based surveys . .
And you have already written the first three sentences of the full article: collisions between galaxy clusters are the most energetic events in the cosmos , with unique implications for structure - formation and the nature of dark matter .
the concordance @xmath5cdm model , predicts that the infall velocities of massive merging systems are typically less than 1000 @xmath2 @xcite .
however , a few massive merging clusters discovered recently suggest a significant tail in the velocity distribution at high infall velocities ( @xmath6@xmath73000 @xmath2 ) . the bullet cluster ( 1e0657 - 56 ).
Please generate the next two sentences of the article | is readily identified as an extreme example by its clearcut mach cone found in its x - ray image @xcite .
velocities derived from x - ray observations using the shock jump conditions and n - body / hydrodynamical simulations support this interpretation @xcite , but with inferred velocities in the range 27004500 @xmath2 . |
8,635 | Suppose that you have an abstract for a scientific paper: we investigate the behaviour of a cluster of young massive star clusters ( hereafter super - cluster ) in the tidal field of a host galaxy with a high - resolution particle - mesh code , _
superbox_. specifically we want to establish if and how such super star - clusters merge and carry out a detailed study of the resulting merger - object .
this merger - object shows either the properties of a compact spherical object or the elongated ( ` fluffy ' ) shape of dsph - galaxies depending on the initial concentration of the super - cluster . .
And you have already written the first three sentences of the full article: interacting galaxies like the antennae ( ngc 4038/4039 ; whitmore & schweizer 1995 ) or stephan s quintet ( hcg 92 ; hunsberger 1997 ) show much star - burst activity in their tidal features .
high resolution images from the hst resolve these regions into many compact groups of young massive star clusters ( i.e. super - clusters ) and/or tidal - tail dwarf galaxies , with typical radii of 100500 pc . here
we aim to study the future fate of these super - clusters ..
Please generate the next two sentences of the article | + we begin with an overview of the numerical method and explain the setup of our simulations .
we then show results obtained so far and conclude with an outlook on future work we intend to pursue . |
8,636 | Suppose that you have an abstract for a scientific paper: the rashba interaction induced when inversion symmetry is broken in solids is a key interaction connecting spin and charge for realizing novel magnetoelectric cross - correlation effects . here
, we theoretically explore the optical properties of a bulk rashba conductor by calculating the transport coefficients at finite frequencies .
it is demonstrated that the combination of direct and inverse edelstein effects leads to a softening of the plasma frequency for the electric field perpendicular to the rashba field , resulting in a hyperbolic electromagnetic metamaterial . in the presence of magnetization , a significant enhancement of anisotropic propagation ( directional dichroism )
is predicted because of interband transition edge singularity . based on an effective hamiltonian analysis , the dichroism is demonstrated to be driven by toroidal and quadratic moments of the magnetic rashba system .
the effective theory of the cross - correlation effects has the same mathematical structure as that of insulating multiferroics .
# 1 # 1 _ 0 # 1 # 1 _ i # 1 | # 1|#1 # 1#2 .
|#2 # 1 # 1#2 # 1 # 1 # 1 # 1 # 1#2 # 1#2 # 1#2 # 1 # 1#2 ( c # 1 + # 2 ) # 1#2#3 ( c # 1 + # 2 + # 3 ) # 1#2#3#4 ( cc # 1 & # 2 + # 3 & # 4 ) # 1eq .
( [ # 1 ] ) # 1#2eqs .
( [ # 1])([#2 ] ) # 1([#1]) # 1#2?[#1])([#2 ] ) # 1@xmath0 l # 1#2g_#1^#2 # 1#2j_s#1^#2 # 1#2_s#1^#2 # 1_s#1 # 1#2a_s,#1^#2 # 1e_s,#1 # 1b_s,#1 # 1 * # 1 .
And you have already written the first three sentences of the full article: the spin@xmath1orbit interaction is a relativistic interaction connecting the spin and orbital motion of charged elementary particles .
this interaction plays essential roles in conversion between electric signals and magnetic ones @xcite .
of particular interest is the rashba spin@xmath1orbit interaction@xmath1the one that arises when the inversion symmetry of the system is broken @xcite ..
Please generate the next two sentences of the article | it is represented by the quantum mechanical hamiltonian @xmath2 where @xmath3 is the electron mass , @xmath4 is the planck constant divided by @xmath5 , @xmath6 is a vector representing the direction and strength of the rashba field and @xmath7 and @xmath8 are the momentum operators for the electron and vector of pauli matrices , respectively .
the interaction leads to various cross - correlation effects in electromagnetism , i.e. a mixing of electric and magnetic fields . |
8,637 | Suppose that you have an abstract for a scientific paper: electromagnetic and strong hadron processes at low energies are considered in the renormalizable model with the spontaneously broken @xmath0 gauge symmetry
. calculated radiative widths of vector mesons and effective couplings @xmath1 agree with the experimental data .
residual higgs degrees of freedom are associated with scalar states @xmath2 and @xmath3 with the degeneration in masses .
two - gamma decays of @xmath4 and @xmath5 mesons are analyzed in detail . to provide an `` infrared confinement ''
a cutoff procedure has been also used in calculations . .
And you have already written the first three sentences of the full article: low - energy phenomena in the hadron physics are strongly determined by the nonperturbative ( np ) interactions . at the fundamental ( qcd ) level hadron characteristics
are analyzed in the qcd sum rules with a np vacuum condensates .
hadron structure and interactions can be also considered in the effective lagrangian approach ..
Please generate the next two sentences of the article | starting from the qcd , chiral low - energy expansion of green functions leads to effective lagrangian with phenomenological coupling constants @xcite .
effective chiral hadron model having the nambu - jona - lasinio structure with the quark - meson interactions and incorporating vector mesons as a gauge fields , has been also applied to the hadron reactions studying @xcite . |
8,638 | Suppose that you have an abstract for a scientific paper: contribution to electron - impact ionization cross sections from excitations to high-@xmath0 shells and a consequent autoionization is investigated .
we perform relativistic subconfiguration - average and detailed level - to - level calculations for this process .
ionization cross sections for the w@xmath1 ion are presented to illustrate large influence of the high shells ( @xmath2 ) and orbitals ( @xmath3 ) in the excitation - autoionization process .
the obtained results show that the excitations to the high shells ( @xmath2 ) increase cross sections of indirect ionization process by a factor of two compared to the excitations to the lower shells ( @xmath4 ) .
the excitations to the shells with the orbital quantum number @xmath5 give the largest contribution compared with the other orbital quantum numbers @xmath6 .
radiative damping reduces the cross sections of the indirect process approximately two times in the case of the level - to - level calculations .
determined data show that the excitation - autoionization process contributes approximately @xmath7 to the total ionization cross sections . .
And you have already written the first three sentences of the full article: energy losses from heavy elements , such as tungsten , due to radiative emission are one of the crucial problems to be overcome for the successful performance of themonuclear reactors .
nevertheless , tungsten is used as the plasma - facing component in the modern fusion facilities because of its essential properties , like high - energy threshold for sputtering , low sputtering yield , and excellent thermal features .
even small concentration of tungsten ions ( @xmath8 ) relative to the electron density prevents ignition of a deuterium - tritium plasma @xcite ..
Please generate the next two sentences of the article | theoretical modeling provides information about processes in such harsh conditions .
however , fusion plasma modeling requires a significant amount of atomic data . |
8,639 | Suppose that you have an abstract for a scientific paper: we have extended , from order 12 through order 25 , the high - temperature series expansions ( in zero magnetic field ) for the spin - spin correlations of the spin-@xmath0 ising models on the square , simple - cubic and body - centered - cubic lattices . on the basis of this large set of data ,
we confirm accurately the validity of the scaling and universality hypotheses by resuming several tests which involve the correlation function , its moments and the exponential or the second - moment correlation - lengths . .
And you have already written the first three sentences of the full article: moderate - length high - temperature ( ht ) expansions ( through order 12 ) and low - temperature ( lt ) expansions for the spin - spin correlation function ( sscf ) @xmath1 of the nearest - neighbor ising models with general spin s were first computed@xcite three decades ago on various lattices in 2d and in 3d .
motivations for the study of these models came not only from their direct phenomenological interest , but mainly from the conjecture@xcite that , in a given space dimension , the exponents characterizing the critical behavior are independent both of the lattice structure and of the spin magnitude @xmath0 .
this conjecture was the first step towards the modern notion of universality class ..
Please generate the next two sentences of the article | in the same years also the hypothesis of critical scaling@xcite was put forward .
many studies@xcite of the mentioned ht and lt series were devoted to test the validity and the main consequences of these basic hypotheses@xcite . |
8,640 | Suppose that you have an abstract for a scientific paper: as a first step toward circumventing the difficulty to obtain an attractive isospin - independent @xmath0 spin - orbit force from skyrme - type models involving only pions , we investigate an improved skyrme lagrangian that incorporates the scalar - isoscalar meson @xmath1 which can be viewed as the cause behind the enhancement of the @xmath2-wave .
we find that at large distances , the main contribution to the spin - orbit potential comes from the scalar lagrangian and it is found to be attractive .
we briefly discuss how to pursue this work to finally obtain a medium - range attractive interaction .
0.5 cm pacs numbers(s ) : 11.10 lm , 12.39 dc , 13.75 cs .
report - no : mc / th 96/17 hep - ph/9606270 .
And you have already written the first three sentences of the full article: ten years before the advent of qcd , skyrme proposed a model @xcite describing hadronic physics which involves only pion fields and where baryons emerge as topological solitons .
this model is recognized as the simplest chiral realization of qcd at low energies and large @xmath3 @xcite .
the corresponding lagrangian contains , in addition to the well known nonlinear @xmath4 model , an antisymmetric term of fourth order in powers of the derivatives of the pion field ( the so - called skyrme term ).
Please generate the next two sentences of the article | . the latter has been added by skyrme in order to avoid soliton collapse . despite its relative success in describing some properties of baryons ( _ cf . _
@xcite for a review ) , the skyrme model presents several shortcomings such as its prediction of a very small value for the axial coupling constant @xcite and an almost zero nucleon mass when the casimir effects are taken into account @xcite . |
8,641 | Suppose that you have an abstract for a scientific paper: the saturation of the two weinberg sum rules is studied at finite temperature , using recent independent qcd sum rule results for the thermal behaviour of hadronic parameters in the vector and axial - vector channels .
both sum rules are very well satisfied from @xmath0 up to @xmath1 . at higher temperatures close to @xmath2 a hadronic , pion - loop contribution in the space - like region proportional to @xmath3 , present at leading order in the vector but not in the axial - vector channel
, induces an asymmetry leading to a small deviation . in this region , though , qcd sum rules for the hadronic parameters begin to have no solutions , as the hadronic widths of the @xmath4 and the @xmath5 mesons diverge signaling deconfinement .
close to , and at @xmath6 there are no pions left in the medium and chiral symmetry is restored , so that the sum rules are trivially satisfied . .
And you have already written the first three sentences of the full article: the two weinberg sum rules ( wsr ) ( at t=0 ) @xcite were first derived in the framework of chiral @xmath7 symmetry and current algebra , and read @xmath8 = 2 \ , f_\pi^2\;,\ ] ] @xmath9 = 0 \;,\ ] ] where @xmath10 @xcite , and @xmath11 & = & ( -g_{\mu\nu}\ , q^2 + q_\mu q_\nu ) \ , \pi_v(q^2 ) \ ; , \end{aligned}\ ] ] @xmath12 & = & -g_{\mu\nu}\ ; \pi_1(q^2 ) -
q_\mu q_\nu\ ; \pi_a(q^2)\,,\end{aligned}\ ] ] with @xmath13 the conserved vector current in the chiral limit , @xmath14 the axial - vector current , and @xmath15 the four - momentum carried by the currents .
the functions @xmath16 are free of kinematical singularities , thus satisfying dispersion relations , and in perturbative qcd ( pqcd ) they are normalized as @xmath17\,.\ ] ] in the framework of qcd eqs ..
Please generate the next two sentences of the article | ( 1)-(2 ) become effectively finite energy sum rules ( in the chiral limit : @xmath18 ) @xmath19 = 2 \ , f_\pi^2\ , \delta_{n 0}\;,\ ] ] where @xmath20 is the squared energy beyond which qcd is valid , and both sum rules have been combined .
this result also follows from cauchy s theorem in the complex squared energy plane , together with the assumption of quark - hadron duality , to wit . |
8,642 | Suppose that you have an abstract for a scientific paper: within the framework of restricted four - body problem , we study the motion of an infinitesimal mass by assuming that the primaries of the system are radiating - oblate spheroids surrounded by a circular cluster of material points . in our model , we assume that the two masses of the primaries @xmath0 and @xmath1 are equal to @xmath2 and the mass @xmath3 is @xmath4 . by using numerical approach , we have obtained the equilibrium points and examined their linear stability . the effect of potential created by the circular cluster and oblateness coefficients for the more massive primary and the less massive primary , on the existence and linear stability of the libration point have been critically examine via numerical computation . the stability of these points examined shows that the collinear and the non - collinear equilibrium points are unstable .
the result presented in this paper have practical application in astrophysics .
= 0.20 in * * -1.2cm0.5 cm effect of oblateness , radiation and a circular cluster of material points on the stability of equilibrium points in the restricted four - body problem _ applied theoretical physics division , department of physics , federal university lafia , p. m. b. 146 , lafia , nigeria .
_ few body sys .
( 2014 ) doi : 10.1007/s00601 - 014 - 0922 - 3 * keywords * : restricted four - body problem ; potential from a circular cluster of material points ; stability ; oblateness .
And you have already written the first three sentences of the full article: in recent years , there has been a growing interest in studying three - body problem with the aim of approximating the behavior of real celestial systems ( @xcite and refs .
therein ) . the results from the study have been found useful in the theory of dynamical systems and in astronomy .
the simplest form of the three - body problem is restricted three - body problem ( r3bp ) ..
Please generate the next two sentences of the article | it describe the motion of an infinitesimal mass moving under the gravitational influence of two massive bodies called the primaries which moves in circular orbits around their center of mass on account of their mutual attraction and the infinitesimal mass not influencing the motion of the primaries .
the classical restricted three - body problem possesses five equilibrium points . |
8,643 | Suppose that you have an abstract for a scientific paper: for the 3d ferromagnets iron , cobalt and nickel we compute the spin - dependent inelastic electronic lifetimes due to carrier - carrier coulomb interaction including spin - orbit coupling . we find that the spin - dependent density - of - states at the fermi energy does not , in general , determine the spin dependence of the lifetimes because of the effective spin - flip transitions allowed by the spin mixing .
the majority and minority electron lifetimes computed including spin - orbit coupling for these three 3-d ferromagnets do not differ by more than a factor of 2 , and agree with experimental results . .
And you have already written the first three sentences of the full article: the theoretical and experimental characterization of spin dynamics in ferromagnetic materials due to the interaction with short optical pulses has become an important part of research in magnetism .
@xcite in this connection , spin - dependent hot - electron transport processes in metallic heterostructures have received enormous interest in the past few years .
@xcite in particular , superdiffusive - transport theory has played an increasingly important role in the quantitative interpretation of experimental results . @xcite superdiffusive transport - theory , which was introduced and comprehensively described in refs . , uses spin- and energy - dependent electron lifetimes as input , @xcite and its quantitative results for hot - electron transport on ultrashort timescales in ferromagnetic materials rely heavily , to the best of our knowledge , on the relation between majority and minority electrons for these materials ..
Please generate the next two sentences of the article | the spin - dependent lifetimes that are used for hot - electron transport , both in ferromagnets and normal metals , are the so - called `` inelastic lifetimes . ''
these state ( or energy ) dependent lifetimes result from out - scattering processes due to the coulomb interaction between an excited electron and the inhomogeneous electron gas in the system . |
8,644 | Suppose that you have an abstract for a scientific paper: we study continuous - time quantum walks mimicking the quantum search based on grover s procedure .
this allows us to consider structures , that is , databases , with arbitrary topological arrangements of their entries .
we show that the topological structure of the database plays a crucial role by analyzing , both analytically and numerically , the transition from the ground to the first excited state of the hamiltonian associated with different ( fractal ) structures .
additionally , we use the probability of successfully finding a specific target as another indicator of the importance of the topological structure . .
And you have already written the first three sentences of the full article: in the past two decades quantum computation has attracted growing interest , encouraged by the development of tools for the manipulation of single quantum objects as well as by several remarkable theoretical findings @xcite .
different systems have been proposed as candidates for quantum computing ; they are based , for instance , on cavity - laser atoms , bose - einstein condensates , or nmr techniques ( see e.g. @xcite ) . at the same time , a number of quantum algorithms have been designed and some have been shown to be even exponentially faster than their best classical counterparts @xcite . in particular , quantum search algorithms , although able to achieve `` only '' a polynomial speedup , have been proved to be very promising and of widespread use in quantum computation @xcite .
one of the best known quantum search algorithms is attributed to grover @xcite ..
Please generate the next two sentences of the article | the algorithm can find a target within an unsorted database made up of @xmath0 items using @xmath1 queries . due to its broad range of applications and its ability
to be effectively used as a subroutine @xcite , grover s algorithm has been thoroughly investigated and a number of different implementations have been proposed ( see e.g. @xcite ) . |
8,645 | Suppose that you have an abstract for a scientific paper: adopting neutrino oscillation parameters obtained by super - kamiokande , a numerical computer experiment for neutrino events occurring outside the detector , is carried out in the same sk live days , 1645.9 live days , constructing the virtual super - kamiokande detector in the computer .
the numerical results by the computer experiment could be directly compared with the real sk experimental data .
the comparison shows that it is difficult to obtain convincing conclusion on the existence of the neutrino oscillation with specified neutrino oscillation parameters claimed by sk through analysis for neutrino events occurring outside the detector .
_ keywords _ : neutrino oscillation , exact monte carlo methods , cosmic rays + .
And you have already written the first three sentences of the full article: the present situation around @xmath0 oscillation initiated by super - kamiokande hereafter , sk , simply is to be described as follows if we follow majority opinion : + ( 1 ) sk found anomaly in the atmospheric neutrinos ( muon deficit ) @xcite , + ( 2 ) sk found anomaly in the zenith angle distribution @xcite , + ( 3 ) sk discovered atmospheric neutrino oscillation @xcite , + ( 4 ) soudan 2 and macro confirmed sk results @xcite , + ( 5 ) k2k confirmed atmospheric neutrino results based on the baseline experiment @xcite , + ( 6 ) sk found oscillations themselves directly @xcite , + ( 7 ) minos begins precise experiment and confirmed sk results @xcite . +
as one fully understand from the history on @xmath0 oscillation on atmospheric neutrinos , it is said that the experimental results by sk play decisively important role in @xmath1 oscillation .
therefore , to reach the final conclusions on @xmath0 oscillation by sk , it is more desirable that careful examination on the sk conclusion is performed by the minority opinion ..
Please generate the next two sentences of the article | we have been performing computer numerical experiments to re - examine the atmospheric neutrino experiment results , constructing the virtual super - kamiokande apparatus in the computer and analyzing the virtual neutrino events produced both inside and outside the detector . in principle
, we could obtain any physical events which sk obtain and , therefore , could compare our results with sk results directly , which may lead less ambiguous discussion around the atmospheric neutrino oscillation problems . in the discussion on the atmospheric neutrino oscillation , there are two fundamental issues to be clarified from the experimental point of view , namely , the discrimination of the neutrino events ( electron events or muon events ) and the differences between the directions of the incident neutrinos and those of the produced leptons . |
8,646 | Suppose that you have an abstract for a scientific paper: we report unsuccessful searches for pulsations from the neutron star identified with the egret source . a 24-hr observation with the nrao green bank telescope at 820 mhz placed an upper limit on flux density of 17 @xmath0jy for @xmath1 ms , and gradually increasing limits for @xmath2 ms .
the equivalent luminosity is lower than that of any known pulsar with the possible exception of the radio - quiet @xmath3-ray pulsar geminga .
a set of observations with the _ chandra x - ray observatory _ hrc totaling 118 ks revealed no pulsar with 1 ms @xmath4 s. the upper limit on its pulsed fraction is 35% assuming a sinusoidal pulse shape .
the position of in observations separated by 3 years is unchanged within errors , leading to an upper limit on its proper motion of @xmath5 yr@xmath6 , or @xmath7 km s@xmath6 at @xmath8 pc , a maximum distance estimated from its thermal x - ray spectrum . with these null results ,
the properties of and its x - ray counterpart are consistent with a more distant or older version of geminga , or perhaps a recycled pulsar . having nearly exhausted the capabilities of current instrumentation at all wavelengths , it will likely fall to the _ gamma - ray large area space telescope _ to discover pulsations from . .
And you have already written the first three sentences of the full article: the brightest of the `` unidentified '' high - galactic - latitude egret sources @xcite , at @xmath9 has long been associated with the x - ray emitting neutron - star , which remains its most plausible counterpart even though pulsations have not been detected at any wavelength . unlike blazars , which are highly variable and have steeper @xmath3-ray spectra , shows no evidence for long - term variability , and its spectrum
can be fitted by a relatively flat power law of photon index @xmath10 from 70 mev to 4 gev , with a turn - down above 4 gev @xcite , similar to known @xmath3-ray pulsars .
is the only optically undetected x - ray source in the @xmath3-ray error box , all the others being classified as unlikely @xmath3-ray emitters @xcite ..
Please generate the next two sentences of the article | the detection of as a weak , ultrasoft source in the all - sky survey @xcite suggested that it is a thermally emitting neutron star that is either older or more distant than the @xmath3-ray pulsar geminga @xcite .
observations using the advanced ccd imaging camera ( acis ) and the ( _ hst _ ) further supported this interpretation @xcite . |
8,647 | Suppose that you have an abstract for a scientific paper: we assess the performance of generic text summarization algorithms applied to films and documentaries , using extracts from news articles produced by reference models of extractive summarization .
we use three datasets : ( i ) news articles , ( ii ) film scripts and subtitles , and ( iii ) documentary subtitles .
standard rouge metrics are used for comparing generated summaries against news abstracts , plot summaries , and synopses .
we show that the best performing algorithms are lsa , for news articles and documentaries , and lexrank and support sets , for films . despite the different nature of films and documentaries ,
their relative behavior is in accordance with that obtained for news articles .
automatic text summarization , generic summarization , summarization of films , summarization of documentaries .
And you have already written the first three sentences of the full article: input media for automatic summarization has varied from text @xcite to speech @xcite and video @xcite , but the application domain has been , in general , restricted to informative sources : news @xcite , meetings @xcite , or lectures @xcite .
nevertheless , application areas within the entertainment industry are gaining attention : e.g. summarization of literary short stories @xcite , music summarization @xcite , summarization of books @xcite , or inclusion of character analyses in movie summaries @xcite .
we follow this direction , creating extractive , text - driven video summaries for films and documentaries ..
Please generate the next two sentences of the article | documentaries started as cinematic portrayals of reality @xcite .
today , they continue to portray historical events , argumentation , and research . they are commonly understood as capturing reality and therefore , seen as inherently non - fictional . |
8,648 | Suppose that you have an abstract for a scientific paper: the vulpecula ob association , vul@xmath0ob1 , is a region of active star formation located in the galactic plane at 2.3@xmath1kpc from the sun .
previous studies suggest that sequential star formation is propagating along this 100@xmath1pc long molecular complex . in this paper
, we use _ spitzer _ mipsgal and glimpse data to reconstruct the star formation history of vul@xmath0ob1 , and search for signatures of past triggering events .
we make a census of young stellar objects ( yso ) in vul@xmath0ob1 based on ir color and magnitude criteria , and we rely on the properties and nature of these ysos to trace recent episodes of massive star formation .
we find 856 yso candidates , and show that the evolutionary stage of the yso population in vul@xmath0ob1 is rather homogeneous - ruling out the scenario of propagating star formation .
we estimate the current star formation efficiency to be @xmath2% .
we also report the discovery of a dozen pillar - like structures , which are confirmed to be sites of small scale triggered star formation . .
And you have already written the first three sentences of the full article: the physical mechanisms describing stellar birth are fairly well understood for low- and intermediate - mass stars but still under debate for their high - mass analogues @xcite . on larger scales , observations show that star forming mechanisms are of relatively poor efficiency , as only a fraction of the gas reservoir in the universe is turning into stars . typical star formation efficiencies ( sfe ) are of the order 3 - 6% in the galaxy @xcite , and 5% or less in other galaxies @xcite . still , in extreme environments like in the starburst galaxy arp 220
, the sfe can reach 50% @xcite suggesting that the star forming mechanism at work in such objects could be of a different nature .
for instance the feedback into the interstellar medium ( ism ) from short - lived massive stars seems to influence the yield of star formation in their local environment ..
Please generate the next two sentences of the article | as they evolve off the main sequence , high - mass stars produce a copious amount of energy while still embedded in their native cocoon ; such disruption of a molecular cloud leads to gravitational instabilities and possibly to the onset of a new episode of star formation .
@xcite showed that under certain conditions runaway triggering can take place around massive ob stars . |
8,649 | Suppose that you have an abstract for a scientific paper: the @xmath0 seems to be a loosely - bound hadronic molecule whose constituents are two charm mesons .
a novel feature of this molecule is that the mass difference of the constituents is close to the mass of a lighter meson that can be exchanged between them , namely the pion .
we analyze this feature in a simple model with spin-0 mesons only .
various observables are calculated to next - to - leading order in the interaction strength of the exchanged meson .
renormalization requires summing a geometric series of next - to - leading order corrections .
the dependence of observables on the ultraviolet cutoff can be removed by renormalizations of the mass of the heaviest meson , the coupling constant for the contact interaction between the heavy mesons , and short - distance coefficients in the operator product expansion .
the next - to - leading order correction has an unphysical infrared divergence at the threshold of the two heavier mesons that can be eliminated by a further resummation that takes into account the nonzero width of the heaviest meson . .
And you have already written the first three sentences of the full article: the @xmath0 is a new hadronic resonance discovered in 2003 by the belle collaboration @xcite and subsequently confirmed by the cdf , babar , and d0 collaborations @xcite .
all the properties of the @xmath0 that have been measured thus far are compatible with its identification as a weakly - bound molecule whose constituents are a superposition of the charm meson pairs @xmath1 and @xmath2 @xcite . because it is so weakly bound
, the @xmath0 has many features in common with the deuteron , which is a weakly - bound baryonic molecule consisting of a proton and a neutron ..
Please generate the next two sentences of the article | their binding energies are both small compared to the natural energy scale associated with pion exchange : @xmath3 , where @xmath4 is the reduced mass of the two constituents .
the binding energy 2.2 mev of the deuteron is small compared to the natural scale of about 20 mev . after taking into account a recent precision measurement of the @xmath5 mass by the cleo collaboration @xcite , the difference between the measured mass of the @xmath0 and the @xmath1 threshold is @xmath6 this is small compared to the natural energy scale of about 10 mev . |
8,650 | Suppose that you have an abstract for a scientific paper: this paper concerns iterative reconstruction for low - dose and few - view ct by minimizing a data - fidelity term regularized with the total variation ( tv ) penalty .
we propose a very fast iterative algorithm to solve this problem .
the algorithm derivation is outlined as follows .
first , the original minimization problem is reformulated into the saddle point ( primal - dual ) problem by using the lagrangian duality , to which we apply the first - order primal - dual iterative methods .
second , we precondition the iteration formula using the ramp filter of filtered backprojection ( fbp ) reconstruction algorithm in such a way that the problem solution is not altered .
the resulting algorithm resembles the structure of so - called iterative fbp algorithm , and it converges to the exact minimizer of cost function very fast . .
And you have already written the first three sentences of the full article: within the famous total variation ( tv ) regularization framework , image reconstruction in low - dose ct is formulated as minimizing the cost function expressed as @xmath0 subject to @xmath1 , and that in few - view ct is formulated as @xmath2 , where @xmath3 is the tv norm which aims at regularizing the ill - conditioned reconstruction problem .
a variety of iterative algorithms have been proposed for solving the above problems in ct reconstruction fields based on modifying classical iterative algorithms such as the gradient method , art ( algebraic reconstruction technique ) , sirt ( simultaneous iterative reconstruction technique ) , and sart ( simultaneous algebraic reconstruction technique ) , often combined with the ordered - subsets ( os ) technique [ 1]-[10 ] ( and many others ) .
however , it is fair to say that there exist very few iterative algorithms in engineering literatures , which not only converge fast but also can exactly solve the above tv - regularized problems ..
Please generate the next two sentences of the article | it is known that , from mathematical point of view , this difficulty partly comes from the non - differentiability of tv penalty . however , in applied mathematics fields , the research progress on this topic is very fast so that many nice algorithms to handle the tv regularization have been developed since 2010 .
therefore , we believe that it would be time for ct engineers like us to develop and use more rigorous iterative algorithms for the tv - regularized image reconstructions . in this paper , we propose a very fast iterative algorithm which can be applied to the above two typical tv - regularized image reconstructions in a unified way . |
8,651 | Suppose that you have an abstract for a scientific paper: a localized perturbation of a magnetic flux tube produces a pair of wave trains that propagate in opposite directions along the tube .
these wave packets disperse as they propagate , where the extent of dispersion depends on the physical properties of the magnetic structure , on the length of the initial excitation , and on its nature ( e.g. , transverse or axisymmetric ) . in @xcite
we considered a transverse initial perturbation , whereas the temporal evolution of an axisymmetric one is examined here . in both papers
we use a method based on fourier integrals to solve the initial value problem .
previous studies on wave propagation in magnetic wave guides have emphasized that the wave train dispersion is influenced by the particular dependence of the group velocity on the longitudinal wavenumber .
here we also find that long initial perturbations result in low amplitude wave packets and that large values of the magnetic tube to environment density ratio yield longer wave trains . to test the detectability of propagating transverse or axisymmetric wave packets in magnetic tubes of the solar atmosphere ( e.g. , coronal loops , spicules , or prominence threads ) a forward modelling of the perturbations must be carried out .
this is left for a future work . .
And you have already written the first three sentences of the full article: the solar corona supports a rich variety of wave phenomena whose main features are determined by the magnetic field and plasma structuring . for our purposes
it is important to distinguish between different wave manifestations such as driven and impulsively excited perturbations .
driven waves are often caused by a continuous , periodic exciter at the photospheric or chromospheric level and propagate away from the place where they are generated ..
Please generate the next two sentences of the article | this is the case , for example , of waves propagating upwards along spicules @xcite or along the coronal magnetic field @xcite .
the disturbances propagating in filament threads observed by @xcite are probably representative of driven waves too , although the exciting agent is not clear in this case . rapidly propagating quasi - periodic coronal disturbances |
8,652 | Suppose that you have an abstract for a scientific paper: the relation between parity - check matrices of quasi - cyclic ( qc ) low - density parity - check ( ldpc ) codes and biadjacency matrices of bipartite graphs supports searching for powerful ldpc block codes . using the principle of tailbiting , compact representations of bipartite graphs based on convolutional codes can be found .
bounds on the girth and the minimum distance of ldpc block codes constructed in such a way are discussed .
algorithms for searching iteratively for ldpc block codes with large girth and for determining their minimum distance are presented .
constructions based on all - ones matrices , steiner triple systems , and qc block codes are introduced .
finally , new qc regular ldpc block codes with girth up to @xmath0 are given .
ldpc code , convolutional code , tanner graph , biadjacency matrix , tailbiting , girth , minimum distance .
And you have already written the first three sentences of the full article: low - density parity - check ( ldpc ) codes , invented by gallager @xcite in the @xmath1s , constitute a hot research topic since they are a main competitor to turbo codes @xcite .
recently , a connection between ldpc codes and codes based on graphs was shown ( see , for example , @xcite ) , which opens new perspectives in searching for powerful ldpc codes .
moreover , coding theory methods can be applied in describing and searching for graphs better than previously known ..
Please generate the next two sentences of the article | for example , in @xcite compact representations based on convolutional ldpc codes for famous bipartite graphs such as heawood s , tutte s , and balaban s graphs@xcite are presented .
typically , ldpc codes have a minimum distance which is less than that of the best known linear codes , but due to their structure they are suitable for low - complexity iterative decoding , like for example the believe - propagation algorithm . |
8,653 | Suppose that you have an abstract for a scientific paper: we investigate , by means of numerical simulations , the kinematics of elliptical - spiral merger remnants .
counterrotation can appear both in coplanar and in non - coplanar retrograde mergers , and it is mostly associated to the presence of a disk component , which preserves part of its initial spin . in turn ,
the external regions of the two interacting galaxies acquire part of the orbital angular momentum , due to the action of tidal forces . .
And you have already written the first three sentences of the full article: the simulations analyzed are a small subset of the simulations realized in the framework of the galmer project @xcite .
the 2d velocity maps and the rotation curves of the remnants of retrograde elliptical - spiral mergers are analyzed at least 400 myr after the coalescence of the two systems ( see figs.[maps ] and [ curves ] ) .
the rotation curves clearly show that the counter - rotating region is completely associated to stars initially belonging to the spiral galaxy and that counter - rotating cores are more extended in the case of e0-sa merger remnants rather than for e0-sb ones @xcite ..
Please generate the next two sentences of the article | + initially , the redistribution of the orbital angular momentum affects mostly the outer parts of the galaxies .
as the interaction proceeds toward the final merging phase , tidal torques begin to affect inner regions too . |
8,654 | Suppose that you have an abstract for a scientific paper: @xmath0 surfaces with non - symplectic involution are classified by open sets of seventy - five arithmetic quotients of type iv .
we prove that those moduli spaces are rational except two classical cases . and grant - in - aid for scientific research ( s ) , no 22224001 . ] .
And you have already written the first three sentences of the full article: @xmath0 surfaces with non - symplectic involution are basic objects in the study of @xmath0 surfaces .
they connect @xmath0 surfaces with rational surfaces , enriques surfaces , and low genus curves . in this article
we address the rationality problem for the moduli spaces of @xmath0 surfaces with non - symplectic involution . to be more precise , let @xmath1 be a complex @xmath0 surface with an involution @xmath2 ..
Please generate the next two sentences of the article | when @xmath2 acts nontrivially on @xmath3 , @xmath2 is called _ non - symplectic _ , and the pair @xmath4 is called a _ 2-elementary @xmath0 surface_. by nikulin @xcite , the deformation type of @xmath4 is determined by its _ main invariant _
@xmath5 , a triplet of integers associated to the lattice of @xmath2-invariant cycles . |
8,655 | Suppose that you have an abstract for a scientific paper: we present the results of an exhaustive numerical study of fully relativistic non - axisymmetric bondi - hoyle accretion onto a moving schwarzschild black hole .
we have solved the equations of general relativistic hydrodynamics with a high - resolution shock - capturing numerical scheme based on a linearized riemann solver .
the numerical code was previously used to study axisymmetric flow configurations past a schwarzschild hole .
we have analyzed and discussed the flow morphology for a sample of asymptotically high mach number models .
the results of this work reveal that initially asymptotic uniform flows always accrete onto the hole in a stationary way which closely resembles the previous axisymmetric patterns .
this is in contrast with some newtonian numerical studies where violent flip - flop instabilities were found .
as discussed in the text , the reason can be found in the initial conditions used in the relativistic regime , as they can not exactly duplicate the previous newtonian setups where the instability appeared .
the dependence of the final solution with the inner boundary condition as well as with the grid resolution has also been studied . finally , we have computed the accretion rates of mass and linear and angular momentum .
-.5 in 0.0 in 0.0 in 6.4 in 8.75 in 0.5 in = 24pt * non - axisymmetric relativistic bondi - hoyle accretion onto a schwarzschild black hole * jos a. font@xmath0 and j.m@xmath1 ibez@xmath2 @xmath0 max - planck - institut fr gravitationsphysik , albert - einstein - institut + schlaatzweg 1 , 14473 potsdam , germany + e - mail : [email protected] @xmath2 departamento de astronoma y astrofsica + universidad de valencia , 46100 burjassot ( valencia ) , spain + e - mail : [email protected] * key words * accretion hydrodynamics methods : numerical relativity shock waves .
And you have already written the first three sentences of the full article: in a previous paper ( font and ibez 1997 , hereafter paper i ) we studied the morphology and dynamics of relativistic bondi - hoyle accretion in axisymmetric flows past a schwarzschild black hole .
the main conclusion of that work was to extend the validity of the bondi - hoyle accretion picture ( hoyle and lyttleton , 1939 ; bondi and hoyle , 1944 ) to the relativistic regime , finding that the matter is always accreted onto the hole in a stationary way .
furthermore , if the flow was , initially , supersonic , the main feature of the accretion pattern was the presence of a shock cone in the solution ..
Please generate the next two sentences of the article | at the same time , we checked the validity of our numerical code revisiting an existing previous calculation ( petrich et al . , 1989 ) using more accurate numerical techniques specifically designed to capture discontinuities . in the present investigation
we have extended those studies to account for non - axisymmetric configurations . |
8,656 | Suppose that you have an abstract for a scientific paper: we extract parameters relevant for distinguishing among single - field inflation models from the wilkinson microwave anisotropy probe ( wmap ) data set , and from a combination of the wmap data and seven other cosmic microwave background ( cmb ) experiments .
we use only cmb data and perform a likelihood analysis over a grid of models including the full error covariance matrix . we find that a model with a scale - invariant scalar power spectrum ( @xmath0 ) , no tensor contribution , and no running of the spectral index , is within the 1-@xmath1 contours of both data sets .
we then apply the monte carlo reconstruction technique to both data sets to generate an ensemble of inflationary potentials consistent with observations .
none of the three basic classes of inflation models ( small - field , large - field , and hybrid ) are completely ruled out , although hybrid models are favored by the best - fit region .
the reconstruction process indicates that a wide variety of smooth potentials for the inflaton are consistent with the data , implying that the first - year wmap result is still too crude to constrain significantly either the height or the shape of the inflaton potential . in particular
, the lack of evidence for tensor fluctuations makes it impossible to constrain the energy scale of inflation . nonetheless , the data rule out a large portion of the available parameter space for inflation .
for instance , we find that potentials of the form @xmath2 are ruled out to @xmath3 by the combined data set , but not by the wmap data taken alone . .
And you have already written the first three sentences of the full article: one of the fundamental ideas of modern cosmology is that there was an epoch early in the history of the universe when potential , or vacuum , energy dominated other forms of energy densities such as matter or radiation . during such a vacuum - dominated era
the scale factor grew exponentially ( or nearly exponentially ) in some small time . during this phase , dubbed inflation @xcite , a small , smooth spatial region of size of order the hubble radius grew so large that it easily could encompass the comoving volume of the entire presently observable universe .
if the universe underwent such a period of rapid expansion , one can understand why the observed universe is homogeneous and isotropic to such high accuracy ..
Please generate the next two sentences of the article | one of the predictions of the simplest models of inflation is a spatially flat universe , _
@xmath4 , with great precision . |
8,657 | Suppose that you have an abstract for a scientific paper: ultraluminous infrared galaxies ( ulirgs ) with multiple ( @xmath0 ) nuclei are frequently observed .
it has been suggested that these nuclei are produced by multiple major mergers of galaxies
. the expected rate of such mergers is , however , too low to reproduce the observed number of ulirgs with multiple nuclei .
we have performed high - resolution simulations of the merging of two gas - rich disk galaxies .
we found that extremely massive and compact star clusters form from the strongly disturbed gas disks after the first or second encounter between the galaxies .
the mass of such clusters reaches @xmath1 , and their half - mass radii are @xmath2 .
since these clusters consist of young stars , they appear to be several bright cores in the galactic central region ( @xmath3 ) .
the peak luminosity of these clusters reaches @xmath4 of the total luminosity of the merging galaxy .
these massive and compact clusters are consistent with the characteristics of the observed multiple nuclei in ulirgs .
multiple mergers are not necessary to explain multiple nuclei in ulirgs . .
And you have already written the first three sentences of the full article: ultraluminous and luminous infrared galaxies ( ulirgs / lirgs ) have strong infrared ( ir ) luminosities of @xmath5 and @xmath6 , respectively @xcite .
their intense ir luminosities are mainly due to starburst activities , and the contribution of active galactic nuclei ( agn ) to ir luminosity seems to be rather limited , i.e. , @xmath7 @xcite . the starburst activities in ( u)lirgs are likely to be triggered by mergings of galaxies , in particular gas - rich galaxies , since observations suggest that ( u)lirgs have complex and disturbed morphologies @xcite . in the @xmath8-band ( f814w filter )
images of 100 sampled ( u)lirgs at @xmath9 taken with _ hubble space telescope _.
Please generate the next two sentences of the article | ( _ hst _ ) , about @xmath10 of ulirgs have multiple ( @xmath0 ) nuclei @xcite .
the fraction increases to more than @xmath11 , if all probable galaxies are included @xcite . |
8,658 | Suppose that you have an abstract for a scientific paper: we consider the statistical mechanics of a general relativistic one - dimensional self - gravitating system .
the system consists of @xmath0-particles coupled to lineal gravity and can be considered as a model of @xmath0 relativistically interacting sheets of uniform mass . the partition function and one - particle distitrubion functions
are computed to leading order in @xmath1 where @xmath2 is the speed of light ; as @xmath3 results for the non - relativistic one - dimensional self - gravitating system are recovered .
we find that relativistic effects generally cause both position and momentum distribution functions to become more sharply peaked , and that the temperature of a relativistic gas is smaller than its non - relativistic counterpart at the same fixed energy .
we consider the large-@xmath0 limit of our results and compare this to the non - relativistic case .
watphys - th01/01 * statistical mechanics of relativistic one - dimensional self - gravitating systems * + r.b . mann and p. chak + dept . of physics ,
university of waterloo waterloo , ont n2l 3g1 , canada + pacs numbers : 5.20.-y , 04.40.-b 5.90.+m + + .
And you have already written the first three sentences of the full article: one - dimensional systems of @xmath0 particles mutually interacting through gravitational forces have been of interest in astrophysics for more than three decades . while used primarily as prototypes for the behaviour of gravity in higher dimensions , one - dimensional self - gravitating systems ( ogs s ) also approximate the behaviour of some physical systems in 3 spatial dimensions .
these include the dynamics of stars in a direction orthogonal to the plane of a highly flattened galaxy and the collisions of flat parallel domain walls moving in directions perpendicular to their surfaces .
furthermore , very long - lived core - halo structures in the ogs phase space are known to exist , reminiscent of structures observed in globular clusters , in which a dense massive core in near equilibrium is surrounded by a halo of stars with high kinetic energy that interact only weakly with the core yawn ..
Please generate the next two sentences of the article | the statistical properties of the ogs are particularly intriguing . despite extensive study
, many unanswered questions remain . |
8,659 | Suppose that you have an abstract for a scientific paper: constructing the operators connecting the state of energy associated with super partner hamiltonians and super partner potentials for a linear harmonic oscillator has been discussed and it is shown that any super symmetric eigen state of one of the super partner potentials in @xmath0- space is paired in energy with a symmetric eigen state of the other partner potential .
department of physics + kumaun university + s. s. j. campus + almora - 263601 ( india ) email : - [email protected] [email protected] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ key words : - supersymmetry , superluminal transformation pacs no : 14.80ly _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .
And you have already written the first three sentences of the full article: during the past few years , there has been continuing interest @xcite in higher dimensional kinematical models for proper and unified theory of subluminal ( bradyon ) and superluminal ( tachyon ) objects @xcite .
the problem of representation and localization of extended particles and superluminal objects may be solved only by the use of higher dimensional space .
several attempts of extending special theory of relativity to superluminal realm in the usual four - space @xcite led to controversies @xcite and satisfactory theory for tachyons could not be made acceptable so far ..
Please generate the next two sentences of the article | several experimental investigations @xcite have been shown towards the evidences for the existence of tachyons : particle moving faster than light @xmath1 ( superluminal particles ) .
still there are doubts ( due to lack of experimental verification)@xcite for the existence of tachyons and it still needs the necessity of constructing a self - consistent quantum field theory , which might yield their quantum properties relevant for their production and detection . |
8,660 | Suppose that you have an abstract for a scientific paper: we study the effect of chargeable monomers on the conformation of dendrimers of low generation by computer simulations , employing bare coulomb interactions .
the presence of the latter leads to an increase in size of the dendrimer due to a combined effect of electrostatic repulsion and the presence of counterions within the dendrimer , and also enhances a shell - like structure for the monomers of different generations . in the resulting structures the bond - length between monomers , especially near the center ,
will increase to facilitate a more effective usage of space in the outer - regions of the dendrimer .
+ + * keywords : * dendrimers , molecular dynamics simulations , polyelectrolytes , scattering .
And you have already written the first three sentences of the full article: dendrimers have been the subject of intensive investigations ever since their synthesis@xcite in the late 1970s .
they are characterized by a high degree of monodispersity and a well - defined , highly branched internal structure ; efficient dendrimer assembly has been boosted by recent progress in synthetic techniques.@xcite a great deal of research activity has focused on the issue of whether they possess an open , _ dense - shell _ or a collapsed , _ dense - core _ configuration , the motivation arising by the potential to employ them as hollow , carrier - type molecules in the former case . for neutral dendrimers , a large number of simulation studies,@xcite careful self - consistent field calculations@xcite and not least scattering experiments@xcite have revealed that the dense - shell conformation is _ not _ the real one . due to back - folding of the end - groups , caused by entropic considerations , a dense - core calculation results instead , leading even to compact , hard - sphere - like conformations at high generation numbers.@xcite from the point of view of applications , this may sound like a disappointing result , as one would like to have dense - shell molecules .
however , seen from the angle of fundamental research , the growing compactness of dendrimers with increasing generation number is very welcome , since it allows to use them as model colloidal / nano particles with tunable stiffness,@xcite bridging the gap between flexible polymers and rigid spheres ..
Please generate the next two sentences of the article | the issue of dendrimer conformations is less clear when _ charged _ or _ polyelectrolyte _ dendrimers are considered .
charge on the building blocks of , e.g. , poly(amidoamine ) ( pamam ) dendrimers can be manipulated by changing the ph of the solution@xcite and their conformations can be further influenced by added salt . |
8,661 | Suppose that you have an abstract for a scientific paper: the _ geometric motivic poincar series _ of a germ @xmath0 of complex algebraic variety takes into account the classes in the grothendieck ring of the jets of arcs through @xmath0 .
denef and loeser proved that this series has a rational form .
we give an explicit description of this invariant when @xmath0 is an irreducible germ of _ quasi - ordinary hypersurface singularity _ in terms of the newton polyhedra of the _ logarithmic jacobian ideals_. these ideals are determined by the _
characteristic monomials _ of a quasi - ordinary branch parametrizing @xmath0 . .
And you have already written the first three sentences of the full article: a germ @xmath0 of complex analytic variety equidimensional of dimension @xmath1 is _ quasi - ordinary _ ( q.o . ) if there exists a finite map @xmath2 which is unramified outside a normal crossing divisor in @xmath3 .
quasi - ordinary singularities admit fractional power series parametrizations , which generalize newton - puiseux expansions of plane curves ( see @xcite ) .
quasi - ordinary surface singularities appear classically in the jung s method to parametrize and resolve surface singularities ( see @xcite ) and are related to the classification of singularities by zariski s dimensionality type ( see @xcite ) ..
Please generate the next two sentences of the article | classical examples are plane curve singularities , hirzebruch - jung surfaces and simplicial toric varieties .
in addition to the applications in equisingularity problems , the class of q.o . |
8,662 | Suppose that you have an abstract for a scientific paper: we show that the strong dependence of the amplitude for @xmath0 hard scattering on the collision energy can be used to magnify the effects of short range nucleon correlations in quasielastic @xmath1 scattering . under specific kinematical conditions
the effect of initial and final state interactions can be accounted for by rescaling the cross section calculated within the plane wave impulse approximation .
the feasibility to investigate the role of relativistic effects in the deuteron wave function is demonstrated by comparing the predictions of different formalisms .
binding effects due to short range correlations in deuteron are discussed as well . * probing short range nucleon correlations in high energy hard quasielastic @xmath1 reactions + * l. frankfurt@xmath2 , e. piasetsky@xmath3 , m. sargsyan@xmath4 , m. strikman@xmath5 _ @xmath6 raymond and beverly sackler faculty of exact science , + school of physics and astronomy , tel aviv university , + tel aviv , 69978 , israel + @xmath7 on leave of absence from st .
petersburg nuclear physics institute , + st .
petersburg , russia + @xmath8 also at the yerevan physics institute , yerevan , 375036 , armenia + @xmath9 pennsylvania state university , university park , pa , 16802 , usa + @xmath10 also at the st .
petersburg nuclear physics institute , st .
petersburg , russia _ .
And you have already written the first three sentences of the full article: the deuteron is the simplest and best understood nuclear system bound by strong interactions . as such
it has received an extraordinary amount of attention .
the binding energy of the deuteron is rather small compared to the nuclear potential and to the binding energy of heavier nuclei and the average distance between the nucleons in the deuteron is larger than the typical distance in nuclei . at first glance these facts would seem to discourage one from using the deuteron for studying short range correlations ( src ) between nucleons . however , a conventional theory of the deuteron based on a phenomenological potential of the nucleon - nucleon interaction with a repulsive core at small distances predicts a fairly substantial contribution of high - momentum nucleon components in the wave function ( wf ) @xcite ..
Please generate the next two sentences of the article | note that the fourier transform of the deuteron wf implies that high momentum nucleon components originate predominantly from src .
the recent measurements of elastic magnetic , electric and quadrupole form factors at @xmath11 @xcite as well as previous data for elastic @xcite and nearthreshold @xmath12 @xcite scattering at @xmath13 up to @xmath14 , elastic @xmath1 scattering @xcite and the backward production of secondary @xmath15 , @xmath16 on the deuteron @xcite are all consistent with a conventional nonrelativistic theory of the deuteron which has a core in the nn force ( see e.g. @xcite ) . |
8,663 | Suppose that you have an abstract for a scientific paper: x - ray and neutron scattering studies of the lead - based family of perovskite relaxors pzn-@xmath0pt and pmn-@xmath0pt have documented a highly unusual situation in which the near - surface region of a single crystal can exhibit a structure that is different from that of the bulk when cooled to low temperatures .
the near - surface region , or `` skin '' can also display critical behavior that is absent in the crystal interior , as well as a significantly different lattice spacing . by varying the incident photon energy , and thus the effective penetration depth ,
x - ray measurements indicate a skin thickness of order 10 @xmath1 m to 50 @xmath1 m for pzn-@xmath0pt samples with @xmath2% .
neutron residual stress measurements on a large pmn single crystal reveal a uniform lattice spacing within the bulk , but an increased strain near the surface .
the presence of this skin effect has led to incorrect phase diagrams for both the pzn-@xmath0pt and pmn-@xmath0pt systems and erroneous characterizations of the nature of the relaxor state . .
And you have already written the first three sentences of the full article: the exceptional piezoelectric properties of the lead - oxide class of relaxor ferroelectrics has fueled an intense amount of scientific research on these materials over the past several years .
@xcite numerous studies have been performed in an attempt to understand the fundamental mechanism(s ) responsible for the ultrahigh piezoelectric response of these compounds .
@xcite during the course of these studies , additional anomalous behavior has been documented including the truly remarkable situation in which the structure of the bulk of a single crystal relaxor specimen can differ from that of the near - surface region , or `` skin , '' which spans tens of microns ..
Please generate the next two sentences of the article | the x - ray scattering studies of xu _ et al . _
have revealed a striking discrepancy between the low - temperature crystal structure reported by earlier x - ray scattering studies on the parent compound pb(zn@xmath3nb@xmath4)o@xmath5 ( pzn ) and that observed using high - energy x - rays . |
8,664 | Suppose that you have an abstract for a scientific paper: we investigate the condensation phase transitions of conserved - mass aggregation ( ca ) model on weighted scale - free networks ( wsfns ) . in wsfns
, the weight @xmath0 is assigned to the link between the nodes @xmath1 and @xmath2 .
we consider the symmetric weight given as @xmath3 .
in ca model , the mass @xmath4 on the randomly chosen node @xmath1 diffuses to a linked neighbor of @xmath1,@xmath2 , with the rate @xmath5 or an unit mass chips off from the node @xmath1 to @xmath2 with the rate @xmath6 . the hopping probability @xmath5 is given as @xmath7 , where the sum runs over the linked neighbors of the node @xmath1 .
on the wsfns , we numerically show that a certain critical @xmath8 exists below which ca model undergoes the same type of the condensation transitions as those of ca model on regular lattices .
however for @xmath9 , the condensation always occurs for any density @xmath10 and @xmath11 .
we analytically find @xmath12 on the wsfn with the degree exponent @xmath13 .
to obtain @xmath8 , we analytically derive the scaling behavior of the stationary distribution @xmath14 of finding a walker at nodes with degree @xmath15 , and the probability @xmath16 of finding two walkers simultaneously at the same node with degree @xmath15 .
we find @xmath17 and @xmath18 respectively . with @xmath14
, we also show analytically and numerically that the average mass @xmath19 on a node with degree @xmath15 scales as @xmath20 without any jumps at the maximal degree of the network for any @xmath10 as in the sfns with @xmath21 . .
And you have already written the first three sentences of the full article: a wide variety of mass transport systems ranging from traffic flow to polymer gels @xcite exhibit nonequilibrium condensation phenomena .
these include basic microscopic dynamics ubiquitous in nature such as aggregation , fragmentation and diffusion .
the nonequilibrium steady states of these systems are classified into two types of phases , so - called fluid phase and condensed phase ..
Please generate the next two sentences of the article | a finite fraction of total particles condenses on a single site in the condensed phase . in the fluid phase
, the particle number on each site fluctuates around the density of total particles ( @xmath10 ) without the condensation . |
8,665 | Suppose that you have an abstract for a scientific paper: we discuss the phase structure of quantum chromodynamics ( qcd ) with two colors and two flavors of light quarks .
this is motivated by the increasing interest in the qcd phase diagram as follows : ( 1 ) the qcd critical point search has been under intensive dispute and its location and existence suffer from uncertainty of effective @xmath0 symmetry restoration .
( 2 ) a new phase called quarkyonic matter is drawing theoretical and experimental attention but it is not clear whether it can coexist with diquark condensation . we point out that two - color qcd is nontrivial enough to contain essential ingredients for ( 1 ) and ( 2 ) both , and most importantly , is a system without the sign problem in numerical simulations on the lattice .
we adopt the two - flavor nambu jona - lasinio model extended with the two - color polyakov loop and make quantitative predictions which can be tested by lattice simulations . .
And you have already written the first three sentences of the full article: understanding the phase structure of quantum chromodynamics ( qcd ) is one of the key issues in current high - energy physics .
thorough phenomenological knowledge of properties of the hadron spectrum as well as nuclear matter is now being complemented by increasingly precise first - principle numerical studies of qcd at nonzero temperature .
however , the application of lattice techniques to matter at high baryon chemical potential @xmath1 remains a major challenge due to the infamous sign problem @xcite ..
Please generate the next two sentences of the article | the difficulties encountered in simulations of qcd triggered interest in similar theories which are free of the sign problem .
these include simulations at imaginary chemical potential @xcite , qcd at nonzero isospin density @xcite , a qcd - like theory with adjoint quarks @xcite , and two - color qcd @xcite . |
8,666 | Suppose that you have an abstract for a scientific paper: the elementary vortex pinning potential is studied in unconventional superconductors within the framework of the quasiclassical theory of superconductivity .
numerical results are presented for @xmath0- , anisotropic @xmath1- , and isotropic @xmath1-wave superconductors to show explicitly that in unconventional superconductors the vortex pinning potential is determined mainly by the loss of the condensation energy in bulk due to the presence of the pinning center , i.e. , by the breakdown of the anderson s theorem .
it is found that the vortex pinning energy in the @xmath0-wave pairing case is 4 13 times larger than those in the @xmath1-wave pairing cases .
this means that an enhancement of pinning effect in unconventional superconductors occurs due to the breakdown of the anderson s theorem .
the case of a chiral @xmath2-wave superconductor is also investigated in terms of the vortex core states subject to the andreev reflection , where important is whether the vorticity and chirality are parallel or antiparallel . and vortex pinning , unconventional superconductor , @xmath0-wave pairing , chiral @xmath2-wave pairing 74.60.ge .
And you have already written the first three sentences of the full article: much attention has been focused on the vortex pinning in type - ii superconductors .
the vortex pinning in the superconductors under magnetic fields plays an important role on various vortex - related quantities and phenomena such as the critical current , hysteresis of the magnetization , and quantum vortex tunneling .
the problem of the vortex pinning is categorized in two aspects ..
Please generate the next two sentences of the article | one is the elementary vortex pinning force , which is the interaction between a vortex and a single defect .
the other is the summation problem , which is how the elementary vortex pinning forces add up to a holding force on the elastic vortex lattice under a distribution of defects @xcite . |
8,667 | Suppose that you have an abstract for a scientific paper: we set forth a new type of phase transition that might take place in gravitational theories whenever higher - curvature corrections are considered .
it can be regarded as a sophisticated version of the hawking - page transition , mediated by the nucleation of a bubble in anti - de sitter ( ads ) space .
the bubble hosts a black hole in its interior , and separates two spacetime regions with different effective cosmological constants .
we compute the free energy of this configuration and compare it with that of thermal ads .
the result suggests that a phase transition actually occurs above certain critical temperature , ultimately changing the value of the cosmological constant .
we discuss the consistency of the thermodynamic picture and its possible relevance in the context of ads / cft . .
And you have already written the first three sentences of the full article: higher - curvature corrections to the einstein - hilbert ( eh ) action appear in any sensible theory of quantum gravity as next - to - leading orders in the effective action .
quadratic terms , for instance , such as the lanczos - gauss - bonnet ( lgb ) action @xcite , appear in _ bona fide _ realizations of string theory @xcite and m - theory @xcite .
interesting implications of these terms within the context of the ads / cft correspondence has been recently the focus of thorough investigation ( see , _.
Please generate the next two sentences of the article | e.g. _ , @xcite ) .
they allow for the holographic description of a broad family of quantum field theories ( like 4d superconformal field theories with unequal central charges @xcite ) , as well as for the study of the fluid / gravity correspondence beyond the eh gravitational sector . |
8,668 | Suppose that you have an abstract for a scientific paper: i discuss and connect a number of topics in small-@xmath0 physics at hera and at lhc , pointing out recent progress and open questions in theory and phenomenology . .
And you have already written the first three sentences of the full article: an anticipated highlight of diffraction at lhc is the study of new particles in central exclusive production , @xmath1 .
detailed investigations have been made for the case where @xmath2 is a higgs boson in the standard model or its supersymmetric extension ( see e.g.@xcite ) , but other systems with a strong coupling to two gluons , like a gluino pair @xmath3 @xcite , can be equally interesting . provided that rates are sufficiently high
, central exclusive production enables us to study the system @xmath2 in a clean environment , with a signal - to - background ratio often much larger than in conventional , inclusive production channels ..
Please generate the next two sentences of the article | measurement of the outgoing proton momenta in forward detectors gives the possibility of a precise determination of the mass and possibly the width of @xmath2 , and the exclusive production mechanism strongly favours systems @xmath2 with quantum numbers @xmath4 .
if the effective two - gluon luminosity for @xmath5 can be determined from standard - model channels such as @xmath6 or @xmath7 , the cross section measurement for a new particle @xmath2 decaying into a final state @xmath8 yields the combination @xmath9 of widths . |
8,669 | Suppose that you have an abstract for a scientific paper: we propose a predictive radiative seesaw model at one - loop level with a flavor dependent gauge symmetry @xmath0 and majorana fermion dark matter .
for the neutrino mass matrix , we obtain an @xmath1 type texture ( with two zeros ) that provides us several predictions such as the normal ordering for the neutrino masses .
we analyze the constraints from lepton flavor violations , relic density of dark matter , and collider physics for the new @xmath0 gauge boson . within the allowed region ,
the lhcb anomalies in @xmath2 and @xmath3 with @xmath4 or @xmath5 can be resolved , and such @xmath6 could be also observed at the lhc
. kias - p17007 .
And you have already written the first three sentences of the full article: non - zero neutrino masses and their flavor mixings require physics beyond the standard model ( sm ) . one of the attractive mechanisms for generating neutrino masses and mixings is the so - called radiative seesaw in which the smallness of neutrino mass is explained by the suppression from the loop factor . in this class of radiative neutrino mass models ,
dark matter ( dm ) candidate often appears naturally if we assign dark @xmath7 parity to stabilize the dm candidates @xcite .
the predictive neutrino mass model can be achieved by applying some symmetry which distinguishes fermion flavor ..
Please generate the next two sentences of the article | flavor dependent @xmath8 gauge symmetry is one of the interesting candidates which is discussed in the case of tree level neutrino mass generation @xcite .
furthermore , flavor dependent @xmath8 gauge symmetries including the quark sector have been motivated in order to explain various anomalies gauge theories with additional higgs doublets carrying nonzero @xmath9 charges were discussed in refs . |
8,670 | Suppose that you have an abstract for a scientific paper: cloaking using complementary media was suggested by lai et al . in @xcite .
the study of this problem faces two difficulties .
firstly , this problem is unstable since the equations describing the phenomenon have sign changing coefficients , hence the ellipticity is lost .
secondly , the localized resonance , i.e. , the field explodes in some regions and remains bounded in some others as the loss goes to 0 , might appear . in this paper
, we give a proof of cloaking using complementary media for a class of schemes inspired from @xcite in the quasistatic regime .
to handle the localized resonance , we introduce the technique of removing localized singularity and apply a three spheres inequality .
the proof also uses the reflecting technique in @xcite . to our knowledge
, this work presents the first proof on cloaking using complementary media .
* msc . * 35b34 , 35b35 , 35b40 , 35j05 , 78a25 , 78m35 .
* key words . * negative index materials , cloaking , sign changing coefficients , localized resonance , complementary media . .
And you have already written the first three sentences of the full article: negative index materials ( nims ) were first investigated theoretically by veselago in @xcite and were innovated by nicorovici et al . in @xcite and pendry in @xcite .
the existence of such materials was confirmed by shelby , smith , and schultz in @xcite .
the study of nims has attracted a lot the attention of the scientific community thanks to their many possible applications ..
Please generate the next two sentences of the article | one of the appealing ones is cloaking .
there are at least three ways to do cloaking using nims . the first one is based on the concept of anomalous localized resonance discovered by milton and nicorovici in @xcite . |
8,671 | Suppose that you have an abstract for a scientific paper: the phonon propagation dynamics in a phononic crystal waveguide , realized via a suspended one - dimensional membrane array with periodic air holes , is investigated as function of its geometry .
the bandstructure of the phononic crystal can be engineered by modifying the characteristics of the phonon standing waves in the waveguide by varying the waveguide width and the pitch of the air holes .
this enables the phonon transmission bands , the bandgaps , the velocity and the nonlinear dispersion in the phononic crystal to be controlled .
indeed the engineered bandstructure can also be tuned to sustain multiple phonon modes in a given branch which whilst being spectrally degenerate can be temporally resolved via their differing group velocities .
this systematic study reveals the key geometric parameters that enable the phonon transport in phononic crystal waveguides to be fully controlled . .
And you have already written the first three sentences of the full article: phononic crystals ( pncs ) have emerged as novel platform in which the phonon propagation dynamics can be controlled @xcite .
pncs are usually composed from a periodically modulated elastic media with the period determined by the wavelength of the corresponding phonon waves . the long range periodic modulation in these structures results in phonon standing waves to be established that give rise to phonon bandgaps .
this concept was first put into practice in the macroscopic regime within a two - dimensional ( 2d ) periodic arrangement of stainless steel cylinders which could block sound waves at frequencies corresponding to the bandgap @xcite ..
Please generate the next two sentences of the article | the ultimate evolution of this concept has led to the development of 2d pncs which consist of a 2d periodic arrangement of air holes typically in a silicon crystal @xcite .
the 2d pnc can not only completely block phonons at the bandgap frequencies but the introduction of point and line defects , by modulating the air holes , even enables phonons to be guided and trapped within these structures . indeed |
8,672 | Suppose that you have an abstract for a scientific paper: energy spectra of galactic cosmic rays calculated within the framework of the nord ( nonlocal relativistic diffusion ) model are presented .
the model accounts for the turbulent character of the interstellar medium and the relativistic speed limit requirement .
calculations account for spiral distribution of sources , boundedness of halo , spallation of nuclei , energy dependence of the diffusion coefficient , tempered power law injection spectrum .
we show that the knee in the background spectra from the ensemble of supernovae can arise due to relativistic speed limit requirement .
we compare our calculations with the results obtained in frames of the local models ( lod and lord ) and nonlocal nonrelativistic model ( nod ) . .
And you have already written the first three sentences of the full article: the first explanation ( or rather prediction ) of the power law of primary cosmic ray spectrum made by e. fermi was purely phenomenological : it was based on the exponential growth of energy with time and exponential distribution of ages of observed particles .
both of them ignored the real space - time distribution of sources , highly inhomogeneous structure of the interstellar medium and boundedness of the galaxy .
a few years later , the cr propagation was interpreted as some kind of brownian motion and began to be calculated in terms of the ordinary ( normal ) diffusion theory @xcite ..
Please generate the next two sentences of the article | it is easy to understand the origin of this model : fermi wrote about random walk of cr particles among magnetic clouds chaotically distributed in interstellar space , and brownian motion was the most expressive image of such a process .
however , its mathematical representation in the form of the _ local diffusion _ ( lod ) equation ( or its other local modifications ) did not involve the particle velocity in an explicit form and for this reason failed in description of front propagation and some other pecularities of the cr transport . |
8,673 | Suppose that you have an abstract for a scientific paper: the new mesons @xmath0 and @xmath1 have been found by belle collaboration in the processes @xmath2 . considering @xmath0 and @xmath1 as @xmath3 and @xmath4 states , the two - body open charm ozi - allowed strong decay of @xmath3 and @xmath4
are studied by the improved bethe - salpeter method combine with the @xmath5 model .
the strong decay width of @xmath3 is @xmath6 mev , which is close to the result of @xmath0 measured by belle , therefore , @xmath3 is a good candidate of @xmath0 .
the strong decay width of @xmath4 is @xmath7 mev , considering the errors of the results , it s close to the lower limit of the total width of @xmath1 .
however the branching ratios @xmath8 of @xmath4 is larger than the experimental data of @xmath1 .
so taking @xmath4 as the candidate of @xmath1 , the precision measurement of the total decay width and the ratio between @xmath9 and @xmath10 is needed in future experiments .
* keywords : * @xmath0 ; @xmath1 ; strong decay ; improved bethe - salpeter method . .
And you have already written the first three sentences of the full article: in the past few years , many more new charmmium - like states , so - called @xmath11 states , have been observed by the belle , babar and besiii collaborations @xcite .
the discovery of these states not only enriched the spectroscopy of charmmium - like states , but also provided us an opportunity to research the properties of charmmium - like states .
for example , the @xmath0 was observed in the inclusive process @xmath12 and had the decay mode @xmath13 by the belle collaboration at a mass of @xmath14 mev ..
Please generate the next two sentences of the article | the decay width of these state was less than 52 mev at the @xmath15 c.l . which has taken into the systematics @xcite .
later belle collaboration confirmed the observation of @xmath0 with a significance of @xmath16 , they got the mass and width of @xmath0 were @xmath17 mev , @xmath18 mev . at the same time , they also observed a new charmnium - like state @xmath1 in the process @xmath19 , the mass and width of @xmath1 were @xmath20 mev , @xmath21 mev @xcite . |
8,674 | Suppose that you have an abstract for a scientific paper: in this paper , we investigate the problem of spectrum access decision - making for the secondary users ( sus ) in the cognitive radio networks .
when the primary users ( pus ) are absent on certain frequency bandwidth , sus can formulate a queue and wait for the base station ( bs ) to serve .
the queue of the sus will be dismissed if the pu is emerging in the system . leveraging the queueing game approaches , the decision - making process of the sus that whether to queue or not is studied .
both individual equilibrium and social optimization strategies are derived analytically . moreover
, the optimal pricing strategy of the service provider is investigated as well .
our proposed algorithms and corresponding analysis are validated through simulation studies .
queueing game ; pricing ; nash equilibrium strategies ; social optimizations ; spectrum access ; cognitive radio .
And you have already written the first three sentences of the full article: in the fast growing wireless market , the frequency spectrum is one of the most scarce and valuable resources .
however , some surveys for actual measurements show that most of the allocated spectrum is largely under - utilized @xcite . cognitive radio ( cr ) is known as an efficient way to improve spectrum utilization and a promising technology to enable dynamic spectrum access by exploiting the unused spectrum in the wireless environments @xcite . in a cognitive radio network ( crn ) , there are two types of users , namely , licensed primary users ( pus ) who have the licensed spectrum access opportunities and unlicensed secondary users ( sus ) who can only utilize the spectrum which the pus do not occupy . to exploit limited spectrum efficiently , in a crn
, the sus are allowed to opportunistically to access licensed spectrum bands when pu transmission is not presented , which is able to significantly improve the spectrum utilization efficiency . during last decades.
Please generate the next two sentences of the article | , the technology of cr has attracted plenty of interests and has been investigated extensively , among which , how to explore the access opportunities and regular the spectrum access without harming the pus are of consistent research interests @xcite .
recently , there is a particular interest to apply the queueing theory @xcite which is a natural tool to analyze the transmission in the wireless networks or the game theory @xcite which is commonly used in developing optimization algorithms to address the spectrum access problems . |
8,675 | Suppose that you have an abstract for a scientific paper: the vla - cosmos large project has imaged the 2 deg@xmath0 cosmos field with a resolution of 1.5 arcsec and a sensitivity of about 11 @xmath1jy ( 1@xmath2 ) yielding to a catalog of @xmath3 radio sources . in this paper
we present a further analysis of the vla - cosmos large project catalog of radio sources aimed to : 1 ) quantify and correct for the effect of bandwidth smearing in the catalog , 2 ) determine the incompleteness produced by the noise bias and the resolution bias in the new catalog and 3 ) derive the radio source counts at 1.4 ghz .
the effect of bandwidth smearing on the radio sources in the catalog was quantified comparing the peak and total flux densities in the final mosaic and in each of the individual pointings where the source was closest to the center of the field .
we find that the peak flux densities in the original vla - cosmos large project catalog have to be divided by a factor about 0.8 or 0.9 , depending on the distance from the mosaic center .
the completeness of the radio catalog has been tested using samples of simulated radio sources with different angular size distributions .
these simulated sources have been added to the radio image and recovered using the same techniques used to produce the radio catalog .
the fraction of missed sources as a function of the total flux density is a direct measure of the incompleteness . finally , we derived the radio source counts down to 60 @xmath1jy with unprecedented good statistics .
comparison to the findings of other surveys shows good agreement in the flux density range 0.06 - 1 mjy confirming the upturn at @xmath4 mjy and a possible decline of the source counts below @xmath5 mjy . .
And you have already written the first three sentences of the full article: in recent years , we have experienced a renaissance of deep radio surveys , usually associated with multi - waveband observational programmes mainly designed to probe the formation and evolution of galaxies and super massive black holes ( smbh ) .
these surveys , mostly carried out at 1.4 ghz , have enabled the study of sub - mjy and @xmath1jy radio source populations ( hereafter @xmath1jy population ) and in particular the determination , with robust statistics , of the radio source counts down to a few tens of @xmath1jy ( e.g. * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* ; * ? ? ? |
8,676 | Suppose that you have an abstract for a scientific paper: we present a model for the distribution of void sizes and its evolution within the context of hierarchical scenarios of gravitational structure formation . for a proper description of the hierarchical buildup of the system of voids in the matter distribution , not only the _
void - in - void _ problem should be taken into account , but also that of the _ void - in - cloud _ issue . within the context of
the excursion set formulation of an evolving void hierarchy is one involving a _ two - barrier _ excursion problem , unlike the _ one - barrier _ problem for the dark halo evolution .
this leads to voids having a peaked size distribution at any cosmic epoch , centered on a characteristic void size that evolves self - similarly in time , in distinct contrast to the distribution of virialized halo masses in not having a small - scale cut - off . .
And you have already written the first three sentences of the full article: hierarchical scenarios of structure formation have been very succesfull in understanding the formation histories of gravitationally bound virialized haloes .
particularly compelling has been the formulation of a formalism in which the collapse and virialization of overdense dark matter halos within the context of hierarchical clustering can be treated on a fully analytical basis .
this approach was originally proposed by press & schechter ( 1974 ) , which found a particularly useful and versatile formulation and modification in the the _ excursion set formalism _.
Please generate the next two sentences of the article | ( bond et al .
1991 ) . |
8,677 | Suppose that you have an abstract for a scientific paper: we applied the recurrent variational approach to the two - leg hubbard ladder . at half - filling ,
our variational ansatz was a generalization of the resonating valence bond state . at finite doping
, hole pairs were allowed to move in the resonating valence bond background .
the results obtained by the recurrent variational approach were compared with results from density matrix renormalization group . 2 .
And you have already written the first three sentences of the full article: in the hope to get a better understanding of strongly interacting systems , there has been considerable interest in ladder systems .
@xcite these ladder systems have proven to be a theoretical wonderland , both analytically @xcite and numerically .
@xcite however , much of the analytic work done on ladders has been in weak coupling ( or perturbatively in some parameter ) , namely because there are very few analytic methods at strong coupling ..
Please generate the next two sentences of the article | exact diagonalization , monte carlo , and density matrix renormalization group methods have been the primary tools for studying these systems at strong coupling .
each of these methods has both strengths and weaknesses when considering the lattice sizes , temperatures , and couplings on can consider . with the ability to fabricate these materials , |
8,678 | Suppose that you have an abstract for a scientific paper: numerous methods for finding clusters at moderate to high redshifts have been proposed in recent years , at wavelengths ranging from radio to x - rays . in this paper
we describe a new method for detecting clusters in two - band optical / near - ir imaging data .
the method relies upon the observation that all rich clusters , at all redshifts observed so far , appear to have a red sequence of early - type galaxies .
the emerging picture is that all rich clusters contain a core population of passively evolving elliptical galaxies which are coeval and formed at high redshifts .
the proposed search method exploits this strong empirical fact by using the red sequence as a direct indicator of overdensity .
the fundamental advantage of this approach is that with appropriate filters , cluster elliptical galaxies at a given redshift are redder than all normal galaxies at lower redshifts .
a simple color cut thus virtually eliminates all foreground contamination , even at significant redshifts . in this paper ,
one of a series of two , we describe the underlying assumptions and basic techniques of the method in detail , and contrast the method with those used by other authors .
we provide a brief demonstration of the effectiveness of the technique using a real photometric sample with redshift data , and from this conclude that the method offers a powerful yet simple way of identify galaxy clusters .
we find that the method can reliably detect structures to masses as small as groups with velocity dispersions of only @xmath0 , with redshifts for all detected structures estimated to an accuray of @xmath110% . .
And you have already written the first three sentences of the full article: the detection and characterization of rich clusters of galaxies from low ( @xmath2 ) to high ( @xmath3 ) redshifts provides a crucial test of both cosmological models ( e.g. , carlberg et al .
1996 ; fan , bahcall , & cen 1997 ; oukbir , bartlett & blanchard 1997 ; eke et al .
1998 ; borgani et al . 1999 ; ledlow et al . 1999 ; reichart et al . 1999 ; viana & liddle 1999 ; henry 2000 , to list a recent subset of an extensive lterature ) and galaxy evolution ( see 3 for an extensive discussion ) . clusters trace structure in the universe to large scales ( e.g. , bahcall & soneira 1983 ; gramann et al . 1995 ; tadros , efstathiou , & dalton 1998 ; borgani , plionis & kolokotronis 1999 ) , and provide many examples of both strong and weak lensing ( see mellier 1999 for a recent review ) ..
Please generate the next two sentences of the article | the obvious importance of galaxy clusters has led to numerous galaxy cluster surveys in recent years , both optically ( e.g. , gunn , hoessel & oke 1986 ; abell , corwin & olowin 1989 ; couch et al .
1991 lumsden et al . |
8,679 | Suppose that you have an abstract for a scientific paper: the growing need for continuous processing capabilities has led to the development of multicore systems with a complex cache hierarchy .
such multicore systems are generally designed for improving the performance in average case , while hard real - time systems must consider worst - case scenarios .
an open challenge is therefore to efficiently schedule hard real - time tasks on a multicore architecture . in this work ,
we propose a mathematical formulation for computing a static scheduling that minimize @xmath0 data cache misses between hard real - time tasks on a multicore architecture using communication affinities . .
And you have already written the first three sentences of the full article: multicore processors have become the norm in many execution platforms in various fields .
such architectures come with a cache memory hierarchy made of several levels , shared or not between cores .
figure [ cache - archi ] represents the typical cache hierarchy that can be found in a multicore architecture with two levels of cache , noted @xmath1 and @xmath2 where @xmath3 is the number of the core ( in the figure @xmath3 ranges from 1 to 4 ) . in such architectures ,.
Please generate the next two sentences of the article | the @xmath2 cache is larger but provides slower access time than the @xmath0 cache .
generally , the @xmath4 cache is unified and shared among all cores , while at the @xmath5 level data and instruction caches are separated and private to each core . |
8,680 | Suppose that you have an abstract for a scientific paper: the cosmological ( upper ) limit on the peccei - quinn constant , related to the primordial oscillations of the axion field , can be relaxed for a mirror axion model .
the simple reason is that the mirror world is colder and so the behavior of the axion temperature - dependent mass is dominated by the contribution from the mirror sector .
so the coherent oscillations start earlier and correspondingly the axion mass density @xmath0 is reduced .
the cp violating term @xmath1 , in the qcd lagrangian , leads to observable effects ( e.g. non zero neutron electric dipole moment ) , experimentally not observed .
this fact is referred to as the strong cp problem ( for a general reference see ref . ) . in the peccei - quinn ( pq )
mechanism,@xcite which is the most appealing solution of this problem , the parameter @xmath2 becomes a dynamical field , the axion @xmath3 , whose potential is minimized for the cp even configuration @xmath4 .
the axion emerges as the pseudo - goldstone mode of a spontaneously broken global axial symmetry @xmath5 . here
@xmath6 is a constant , with dimension of energy , called the pq constant , and @xmath7 stands for the color anomaly of @xmath5 current.@xcite in the following , we will usually refer to the constant @xmath8 , which characterizes the axion phenomenology .
astrophysical considerations exclude all the value of @xmath9 up to @xmath10 gev.@xcite on the other hand , the cosmological limit , related to the primordial oscillations of the axion field , demands the upper bound @xmath11
gev.@xcite let us briefly review the origin of this last limit . in most axion models ,
the pq symmetry breaking occurs when a complex scalar field , @xmath12 , which carries pq charge , acquires a vacuum expectation value ( vev ) @xmath13 .
this occurs as the temperature of the universe cools down below the value of the pq temperature .
as said , the axion is identified with the angular degree of freedom @xmath14 . today
@xmath2 is settled in the cp - conserving....
And you have already written the first three sentences of the full article: this talk is based on the work in ref . .
i am grateful to the organizers of the sixth alexander friedmann international seminar on gravitation and cosmology , for inviting me to this interesting conference .
t. d. li and c. n. yang , _ phys ..
Please generate the next two sentences of the article | rev . _ * 104 * , 254 ( 1956 ) ; y. kobzarev , l. okun and i. pomeranchuk , _ yad . fiz . _ * 3 * , 1154 ( 1966 ) ; s. blinnikov and m. khlopov , _ astron .
* 60 * , 632 ( 1983 ) ; b. holdom , _ phys . |
8,681 | Suppose that you have an abstract for a scientific paper: we introduce a stochastic model of binary opinion dynamics in which the opinions are determined by the size of the neighbouring domains .
the exit probability here shows a step function behaviour indicating the existence of a separatrix distinguishing two different regions of basin of attraction .
this behaviour , in one dimension , is in contrast to other well known opinion dynamics models where no such behaviour has been observed so far .
the coarsening study of the model also yields novel exponent values .
a lower value of persistence exponent is obtained in the present model , which involves stochastic dynamics , when compared to that in a similar type of model with deterministic dynamics .
this apparently counter - intuitive result is justified using further analysis . based on these results
it is concluded that the proposed model belongs to a unique dynamical class . .
And you have already written the first three sentences of the full article: nonequilibrium dynamics has been a topic of intensive research over the last few decades .
the fact that models displaying identical equilibrium behaviour can be differentiated on the basis of critical relaxation , coarsening and persistence behaviour , has enhanced the interest in this field . traditionally critical and off critical
dynamical behaviour were studied for magnetic systems with different dynamical rules and constraints @xcite ..
Please generate the next two sentences of the article | more recently , physicists have been able to construct dynamical models in problems which are interdisciplinary in nature , where one can investigate how such models can be classified into different dynamical classes .
one very popular interdisciplinary topic is opinion dynamics , where a number of models @xcite have been proposed and studied by physicists , many of which can also be regarded as spin models . |
8,682 | Suppose that you have an abstract for a scientific paper: we present an analysis of a deep , 172 ks @xmath0 observation of the large area lyman alpha survey ( lala ) botes field , obtained with the advanced ccd imaging spectrometer ( acis - i ) on the @xmath0 x - ray observatory .
this is one of the deepest @xmath0 images of the extragalactic sky ; only the 2 ms cdf - n and 1 ms cdf - s are substantially deeper . in this paper
we present the x - ray source catalog obtained from this image , along with an analysis of source counts , and optical identifications .
the x - ray image is composed of two individual observations obtained in 2002 , and reaches 0.5 2.0 and 2.0 10.0 kev flux limits of 1.5 @xmath1 10@xmath2 and 1.0 @xmath1 10@xmath3 ergs @xmath4 s@xmath5 , respectively , for point sources near the aim point .
a total of 168 x - ray sources were detected : 160 in the 0.5 7.0 kev band , 132 in the 0.5 2.0 kev band , and 111 in the 2.0 7.0 kev band . the x - ray source counts were derived and compared with those from other @xmath0 deep surveys ; the hard x - ray source density of the lala botes field is 33% higher than that of cdf - s at the flux level of 2.0 @xmath1 10@xmath3 ergs @xmath4 s@xmath5 , confirming the field - to - field variances of the hard band source counts reported by previous studies .
the deep exposure resolves @xmath6 72% of the 2.0 10.0 kev x - ray background .
our primary optical data are @xmath7-band imaging from noao deep wide - field survey ( ndwfs ) , with limiting magnitude of @xmath7 = 25.7 ( vega , 3@xmath8 , 4 diameter aperture ) .
we have found optical counterparts for 152 of the 168 @xmath0 sources ( 90% ) ; 144 of these are detected on the @xmath7-band image , and 8 have optical counterparts in other bands ( either @xmath9,@xmath10,@xmath11,@xmath12 ) . among the @xmath7-band non - detected sources ,
not more than 11 of them can possibly be at @xmath13 5 , based on the hardness ratios of their x - ray emission and nondetections in bluer bands ( @xmath9,@xmath10 ) .
the majority ( @xmath14 76% ) of the....
And you have already written the first three sentences of the full article: a new era of x - ray astronomy has begun with the launch of the @xmath0 @xmath21-@xmath22 @xmath23 on 1999 july 23 , thanks to its very high sensitivity , broad energy range and high angular resolution ( weisskopf et al . 2002 ) .
the two deepest x - ray surveys ever conducted , 2 ms @xmath0 deep field north ( brandt et al .
2003 , alexander et al . 2003 ) and 1 ms @xmath0 deep field south ( giacconi et al . 2002 ; rosati et al ..
Please generate the next two sentences of the article | 2001 ) , were obtained using the advanced ccd imaging spectrometer detector ( acis ; garmire et al .
2003 ) on @xmath0 @xmath21-@xmath22 @xmath23 . |
8,683 | Suppose that you have an abstract for a scientific paper: the measurements of the @xmath0 and @xmath1 partial decay widths of an intermediate - mass standard model higgs boson are among the most important goals of a future photon linear collider . while in an initially polarized @xmath2 state
the background process @xmath3 is suppressed by @xmath4 , radiative corrections remove this suppression and are known to be very sizable at the one - loop level . in particular a new type of purely hard double logarithmic ( dl ) correction can even make the cross section negative at this order in perturbation theory .
the second order term of the series is also known and enters with a positive sign at the two loop level . from a theoretical as well as
a practical point of view it is clearly desirable to resum this series and to know its high energy behavior . in this paper , we derive the series of these novel `` non - sudakov '' logarithms to all orders and calculate the high energy limit analytically .
we also give explicit three loop corrections in the dl - approximation as a check of our results and show that the three loop structure also reveals the higher order behavior of mixed hard and soft double logarithms .
we are thus able to resum the virtual dl - corrections to @xmath5 to all orders .
hep - ph/9807332 + dtp/98/42 + july 1998 + * all - orders resummation of leading logarithmic + contributions to heavy quark production + in polarized @xmath0 collisions * + + .
And you have already written the first three sentences of the full article: among the many important physics processes which can be studied at a future high - energy photon linear collider ( plc ) @xcite , the production of higgs bosons , @xmath6 , stands out .
in particular , identification of an intermediate - mass standard model higgs boson via its ( dominant ) @xmath7 decay channels seems feasible and would provide an important measurement of the @xmath0 and @xmath1 partial decay widths . the dominant ( continuum )
background to @xmath8 comes from the standard model processes @xmath9 ..
Please generate the next two sentences of the article | various techniques can be used to suppress these .
the most effective appears to be to _ polarize _ the initial |
8,684 | Suppose that you have an abstract for a scientific paper: we study the geometric phase of a two - level atom coupled to an environment with lorentzian spectral density . the non - markovian effect on the geometric phase
is explored analytically and numerically . in the weak coupling limit the lowest - order correction to the geometric phase
is derived analytically and the general case is calculated numerically .
it is found that the correction to the geometric phase is significantly large if the spectral width is small and in this case the non - markovian dynamics has a significant impact to the geometric phase .
when the spectral width increases , the correction to the geometric phase becomes negligible , which shows the robustness of the geometric phase to the environmental white noises .
the result is significant to the quantum information processing based on the geometric phase . .
And you have already written the first three sentences of the full article: the concept of geometric phase ( gp ) in quantum system was originally introduced by berry @xcite when he studied the dynamics of a closed quantum system which undergoes an adiabatic cyclic evolution .
he found that besides the usual dynamical phase , the system also acquires an additional phase which only depends on the geometry of the path traversed by the system during its adiabatic evolution .
since then this important notion has attracted much attention @xcite ..
Please generate the next two sentences of the article | it has been generalized in various aspects , e.g. the gp for non - adiabatic evolution @xcite and for noncyclic evolution @xcite .
the gp has been observed experimentally in optical @xcite , nmr @xcite , and superconducting electronic circuit experiments @xcite . |
8,685 | Suppose that you have an abstract for a scientific paper: in this paper we systematically evaluate the variation in the reversal delay of a nanomagnet driven by a longitudinal spin current while under the influence of thermal noise .
we then use the results to evaluate the performance of an all - spin - logic ( asl ) circuit .
first , we review and expand on the physics of previously - published analytical models on stochastic nanomagnet switching .
the limits of previously established models are defined and it is shown that these models are valid for nanomagnet reversal times @xmath0 200 ps .
second , the insight obtained from previous models allows us to represent the probability density function ( pdf ) of the nanomagnet switching delay using the double exponential function of the frchet distribution .
the pdf of a single nanomagnet is extended to more complex nanomagnet circuit configurations .
it is shown that the delay - variation penalty incurred by nanomagnets arranged in parallel configuration is dwarfed by the average delay increase for nanomagnets arranged in a series configuration .
finally , we demonstrate the impact of device - level performance variation on the circuit behavior using asl logic gates .
while the analysis presented in this paper uses an asl - and gate as the prototype switching circuit in the spin domain , the physical concepts are generic and can be extended to any complex spin - based circuit . .
And you have already written the first three sentences of the full article: nanomagnets offer the ultimate thermodynamic limits of computation , as expressed by landauer s principle @xcite .
therefore , spintronics technology that uses electron spin for information processing and communication presents a favorable option to implement future low - power devices .
most compelling proposals of spintronic devices rely on either the spin - transfer torque ( stt ) or the dipolar coupling effects between nanomagnets to accomplish switching of the logic device @xcite ..
Please generate the next two sentences of the article | the analysis presented in this paper considers nanomagnet reversal through stt effect @xcite .
a major challenge for spintronics logic , in general , is the inherent stochasticity in nanomagnet dynamics resulting from ( i ) the presence of thermal noise and ( ii ) the existence of two basins of attraction that make the dynamic evolution of magnetization extremely sensitive to its initial state @xcite . |
8,686 | Suppose that you have an abstract for a scientific paper: we explore the cosmological implications of the angle - averaged correlation function , @xmath0 , and the clustering wedges , @xmath1 and @xmath2 , of the lowz and cmass galaxy samples from data release 10 and 11 of the sdss - iii baryon oscillation spectroscopic survey .
our results show no significant evidence for a deviation from the standard @xmath3cdm model .
the combination of the information from our clustering measurements with recent data from the cosmic microwave background is sufficient to constrain the curvature of the universe to @xmath4 , the total neutrino mass to @xmath5 ( 95% confidence level ) , the effective number of relativistic species to @xmath6 , and the dark energy equation of state to @xmath7 .
these limits are further improved by adding information from type ia supernovae and baryon acoustic oscillations from other samples . in particular , this data set combination is completely consistent with a time - independent dark energy equation of state , in which case we find @xmath8 .
we explore the constraints on the growth - rate of cosmic structures assuming @xmath9 and obtain @xmath10 , in agreement with the predictions from general relativity of @xmath11 .
cosmological parameters , large scale structure of the universe .
And you have already written the first three sentences of the full article: the large - scale distribution of galaxies contains the signature of acoustic waves that propagated through the universe prior to the epoch of recombination .
this signal , referred to as baryon acoustic oscillations ( bao ) , appears as a modulation in the amplitude of the galaxy power spectrum , @xmath12 , and a broad peak in the large - scale two - point correlation function , @xmath0 @xcite .
the wavelength of the oscillations in @xmath12 and the location of the peak in @xmath0 can be associated with the maximum distance that these acoustic waves can travel before the decoupling of matter and radiation , that is , the sound horizon at the drag redshift , @xmath13 . as this scale.
Please generate the next two sentences of the article | can be constrained with high accuracy from observations of the cosmic microwave background ( cmb ) , the acoustic scale inferred from the clustering of galaxy samples at different redshifts can be used as a standard ruler to measure the distance - redshift relation , providing a powerful and robust probe of the expansion history of the universe @xcite .
the bao signal was first detected in the clustering of the two - degree field galaxy redshift survey ( 2dfgrs , * ? ? ? |
8,687 | Suppose that you have an abstract for a scientific paper: the next generation of gamma - ray telescopes may be able to observe gamma - ray blazars at high redshift , possibly out to the epoch of reionization .
the spectrum of such sources should exhibit an absorption edge due to pair - production against uv photons along the line of sight .
one expects a sharp drop in the number density of uv photons at the lyman edge @xmath0 .
this implies that the universe becomes transparent after gamma - ray photons redshift below @xmath1 .
thus , there is only a limited redshift interval over which gev photons can pair produce .
this implies that any observed absorption will probe radiation fields in the very early universe , regardless of the subsequent star formation history of the universe .
furthermore , measurements of differential absorption between blazars at different redshifts can cleanly isolate the opacity due to uv emissivity at high redshift .
an observable absorption edge should be present for most reasonable radiation fields with sufficient energy to reionize the universe .
ly@xmath2 photons may provide an important component of the pair - production opacity .
observations of a number of blazars at different redshifts will thus allow us to probe the rise in comoving uv emissivity with time . .
And you have already written the first three sentences of the full article: our knowledge of uv radiation fields and energy injection into the igm at @xmath3 is fairly tenuous .
there are two main constraints : observations of the integrated background light ( madau & pozzetti 2000 , bernstein et al 1999 ) , and the fact that no gunn - peterson trough is observed in the spectra of the highest - redshift quasar to date ( fan et al 2000 ) , implying that the universe must be reionized by @xmath4
. the upcoming next generation space telescope ( ngst ) will be able to image high - redshift star clusters or agns in rest frame uv continuum emission ( haiman & loeb 1997,1998 ) , and their redshifts may be obtained via h@xmath2 observations ( oh 1999 ) ..
Please generate the next two sentences of the article | nonetheless , the redshift - binned number counts will be fairly sparse , and one is unlikely to probe sufficiently far down the luminosity function to get a good measure of the comoving emissivity as a function of redshift .
observations of gamma - ray blazars ( `` grazars '' ) probe extragalactic ir and uv radiation fields , by observing the pair production opacity to @xmath5 rays at the high energy end ( gould & schreder 1967 , stecker , de jager & salamon 1992 , madau & phinney 1996 , primack et al 1999 ) . |
8,688 | Suppose that you have an abstract for a scientific paper: a dynamical model for s and p wave correlated @xmath0 ( and @xmath1 ) exchange between a kaon and a nucleon is presented , starting from corresponding @xmath2 amplitudes in the pseudophysical region , which have been constructed from nucleon , @xmath3isobar and hyperon ( @xmath4 , @xmath5 ) exchange born terms and a realistic meson exchange model of the @xmath6 and @xmath7 amplitude .
the contribution in the s channel is then obtained by performing a dispersion relation over the unitarity cut . in the @xmath8channel ,
considerable ambiguities exist , depending on how the dispersion integral is performed .
our model , supplemented by short range interaction terms , is able to describe empirical @xmath9 data below pion production threshold in a satisfactory way . .
And you have already written the first three sentences of the full article: for quite some time , kaons have attracted the attention of nuclear physicists .
the reason is that strangeness , a quantum number conserved in strong interactions , attributes a special role to the kaons among the possible projectiles for investigating nuclear structure .
kaons have two properties which make them unique tools ..
Please generate the next two sentences of the article | firstly , they can transfer a new degree of freedom to the nucleus , and secondly , in contrast to pions they come in two forms , kaons ( @xmath10 ) and antikaons ( @xmath11 ) which differ substantially in their interaction with the nucleus .
kaons with their quark content @xmath12 ( @xmath13 ) have strangeness s=1 ; however , nuclear states involving strangeness can only contain hyperons ( @xmath14 , @xmath15 ) which have the same strangeness ( s=1 ) as antikaons ( quark content @xmath16 or @xmath17 ) . |
8,689 | Suppose that you have an abstract for a scientific paper: we study the nonequilibrium dynamics of a many - body bosonic system on a lattice , subject to driving and dissipation .
the time - evolution is described by a master equation , which we treat within a generalized gutzwiller mean field approximation for density matrices .
the dissipative processes are engineered such that the system , in the absence of interaction between the bosons , is driven into a homogeneous steady state with off - diagonal long range order .
we investigate how the coherent interaction affects qualitatively the properties of the steady state of the system and derive a nonequilibrium phase diagram featuring a phase transition into a steady state without long range order .
the phase diagram exhibits also an extended domain where an instability of the homogeneous steady state gives rise to a persistent density pattern with spontaneously broken translational symmetry . in the limit of small particle density
, we provide a precise analytical description of the time - evolution during the instability .
moreover , we investigate the transient following a quantum quench of the dissipative processes and we elucidate the prominent role played by collective topological variables in this regime . .
And you have already written the first three sentences of the full article: one major challenge in nonequilibrium many - body physics is to identify situations with a sufficient degree of universality , i.e. phenomena that occur independently of a precise microscopic realization and are largely insensitive to the specific choice of initial conditions .
several situations have been discussed in the literature , where many - body systems evolve in time towards nonequilibrium steady states .
the most prominent example in condensed matter is certainly the electron gas exposed to a bias voltage @xcite . in this context , truly many - body properties , such as the effect of nonequilibrium conditions on quantum critical points , have been investigated @xcite ..
Please generate the next two sentences of the article | further implementations of nonequilibrium many - body systems are discussed in the context of exciton - polariton bose - einstein condensates @xcite , or more recently using driven noisy systems of trapped ions or dipolar atomic gases @xcite .
as far as the time evolution of many - body systems is concerned , for closed systems we have seen a plethora of studies of quench dynamics @xcite , thermalization @xcite , and pre - thermalization @xcite , as well as transport @xcite . |
8,690 | Suppose that you have an abstract for a scientific paper: we report near - infrared spectroscopy of the gas giant planet hd 189733b in transit .
we used the _ hubble space telescope _ wide field camera 3 ( _ hst _
wfc3 ) with its g141 grism covering 1.1 to 1.7 and spatially scanned the image across the detector at 2@xmath0 . when smoothed to 75 nm bins ,
the local maxima of the transit depths in the 1.15 and 1.4 water vapor features respectively are @xmath1 ppm and @xmath2 ppm greater than the local minimum at 1.3 .
we compare the wfc3 spectrum with the composite transit spectrum of hd 189733b assembled by @xcite , extending from 0.3 to 24 .
although the water vapor features in the wfc3 spectrum are compatible with the model of non - absorbing , rayleigh - scattering dust in the planetary atmosphere @xcite , we also re - interpret the available data with a clear planetary atmosphere . in the latter interpretation
, the slope of increasing transit depth with shorter wavelengths from the near infrared , through the visible and into the ultraviolet is caused by unocculted star spots , with a smaller contribution of rayleigh scattering by molecular hydrogen in the planet s atmosphere . at relevant pressures along the terminator
, our model planetary atmosphere s temperature is @xmath3700 k , which is below the condensation temperatures of sodium- and potassium - bearing molecules , causing the broad wings of the spectral lines of na i and k i at 0.589 and 0.769 to be weak . .
And you have already written the first three sentences of the full article: the k1v star hd 189733 hosts the transiting gas giant planet hd 189733b , at an orbital distance of 0.03 au @xcite .
in some ways this system is nearly optimally suited for study with transmission spectroscopy .
its short planetary orbital period ( 2.2 days ) , its great stellar brightness ( k = 5.5 mag ) , and its large planet - to - star radius ratio ( 0.15 ) combine for convenient observations of high sensitivity and high contrast . on the other hand ,.
Please generate the next two sentences of the article | a significant negative is its intrinsic photometric variability , @xmath4% peak to valley , due to rotational modulation of star spots @xcite . as such , it is photometrically more variable than @xmath395% of stars in the kepler sample ( @xcite ; @xcite ; cf .
also figure 5 of @xcite ) . as |
8,691 | Suppose that you have an abstract for a scientific paper: we study a one - dimensional lattice flocking model incorporating all three of the flocking criteria proposed by reynolds [ _ computer graphics _ * 21 * 4 ( 1987 ) ] : alignment , centring and separation .
the model generalises that introduced by o. j. o loan and m. r. evans _ j. phys .
a. _ * 32 * l99 ( 1999 ) .
we motivate the dynamical rules by microscopic sampling considerations .
the model exhibits various flocking regimes : the alternating flock , the homogeneous flock and dipole structures .
we investigate these regimes numerically and within a continuum mean - field theory . *
pacs : * 05.70.fh 64.60.cn 87.10e .
And you have already written the first three sentences of the full article: flocking refers to a family of behaviours regularly seen in nature , including schooling of fish@xcite and flocking of birds and moths@xcite . whilst the features that are truly essential to flocks remain open to speculation@xcite
it is clear that the variety of biological@xcite and engineered@xcite systems in which flocking behaviour does , or could , prove useful is vast .
statistical mechanics has recently played an important role in uncovering and determining the source of many flocking phenomena@xcite ..
Please generate the next two sentences of the article | one of the pioneers in flocking research was reynolds@xcite . within his work
he determined three behaviours characteristic of flocking : the desire to match the velocity of flockmates ( alignment ) , the desire to stay close to flockmates ( centring ) , and the desire to avoid collisions ( separation ) . |
8,692 | Suppose that you have an abstract for a scientific paper: effects of strong electric fields on hopping conductivity are studied theoretically .
monte - carlo computer simulations show that the analytical theory of nguyen and shklovskii [ solid state commun .
38 , 99 ( 1981 ) ] provides an accurate description of hopping transport in the limit of very high electric fields and low concentrations of charge carriers as compared to the concentration of localization sites and also at the relative concentration of carriers equal to 0.5 . at intermediate concentrations of carriers between 0.1 and 0.5 computer simulations evidence essential deviations from the results of the existing analytical theories .
the theory of nguyen and shklovskii also predicts a negative differential hopping conductivity at high electric fields .
our numerical calculations confirm this prediction qualitatively .
however the field dependence of the drift velocity of charge carriers obtained numerically differs essentially from the one predicted so far .
analytical theory is further developed so that its agreement with numerical results is essentially improved . .
And you have already written the first three sentences of the full article: hopping conduction in solids governed by strong electric fields is in the focus of intensive theoretical and experimental study since several decades [ see , for instance , chapter 7 in ref . and references therein ] . in recent years
, particular interest to this research area has been caused by growing device applications of amorphous organic and inorganic materials in which the incoherent hopping transitions of charge carriers between spatially and energetically distributed localized states dominate the optoelectronic phenomena [ see , for instance , ref . and references therein ] .
one of the mostly discussed topics is whether the differential negative conductivity ( ndc ) , i.e. , the decreasing conductivity with increasing electric field , is possible in the hopping regime ..
Please generate the next two sentences of the article | the discussion was , to much extent , provoked by the reports on the apparent decrease of the drift mobility with rising electric field at relatively high temperatures and low field strengths in disordered organic materials.@xcite this apparent decrease of the mobility with increasing electric field was reported to be succeeded by the increase of the mobility at higher field strengths .
however , the self - consistent effective - medium theory for drift and diffusion at low electric fields@xcite does not show any decrease of the mobility with increasing field . |
8,693 | Suppose that you have an abstract for a scientific paper: we describe the results of a relativistic analysis of our observations of binary pulsar b1913 + 16 , up to the latest measurements in 2001 august . # 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: the relativistic binary pulsar b1913 + 16 , discovered by hulse & taylor ( 1975 ) , has now been observed for twenty seven years . after a several year hiatus due to the arecibo upgrading project
, we have resumed regular timing and profile measurements . in this paper , we describe the results of our relativistic analysis of these data .
in order to optimize timing data acquisition , we and colleagues have developed a number of specialized backends for recording binary and millisecond pulsar data , including a sweeping local oscillator system at 430 mhz ( mcculloch , taylor , & weisberg 1979 ) and a succession of wideband samplers and signal averagers for use at 21 cm ( taylor & weisberg 1982 ; rawley 1986 ; stinebring et al 1992 ) ..
Please generate the next two sentences of the article | most of our highest quality timing data were acquired with the princeton mark iii backend ( stinebring et al 1992 ) , which typically achieved time of arrival uncertainties @xmath0toa @xmath1s in five minute integrations of 40 mhz total bandwidth .
we have found that the quality of data acquired starting in 1981 are so much higher than earlier data that the previous measurements contribute negligibly to our fits . |
8,694 | Suppose that you have an abstract for a scientific paper: we report on the giant magnetoresistance ( gmr ) of multiwall carbon nanotubes with ultra small diameters .
in particular , we consider the effect of the inter - wall interactions and the lead / nanotube coupling .
comparative studies have been performed to show that in the case when all walls are well coupled to the electrodes , the so - called inverse gmr can appear .
the tendency towards a negative gmr depends on the inter - wall interaction and on the nanotube length .
if , however , the inner nanotubes are out of contact with one of the electrodes , the gmr remains positive even for relatively strong inter - wall interactions regardless of the outer nanotube length .
these results shed additional light on recently reported experimental data , where an inverse gmr was found in some multiwall carbon nanotube samples . .
And you have already written the first three sentences of the full article: carbon nanotubes belong to the most promising new materials for the future molecular electronics , they are believed to potentially replace in the near future the silicon - based conventional electronics . to illustrate the enormous scientific and technological progress that has been made since carbon nanotubes
were discovered it is worth to mention new concepts such as : the room temperature single electron transistor,@xcite the ballistic carbon nanotube field - effect transistor@xcite or the non - volatile random access memory for molecular computing.@xcite recently several both experimental@xcite and theoretical@xcite papers have been published on spin - dependent electrical transport in ferromagnetically contacted carbon nanotubes in an attempt to test their ability to operate as spintronic devices .
it has been found that carbon nanotubes though intrinsically nonmagnetic reveal quite a considerable gmr effect ..
Please generate the next two sentences of the article | however , it should be stated in this context that the experimental results are very diverse , and reflect to a great extent sample - specific features .
the poor reproducibility of experiments on carbon nanotubes , or more generally on molecular systems , is due to hardly controllable interface conditions between the molecule and external electrodes . |
8,695 | Suppose that you have an abstract for a scientific paper: self - similarity may originate from two origins , i.e. , the process memory and the process increments `` infinite '' variance . a distinction is attempted by employing the natural time @xmath0 . concerning the first origin , we analyze recent data on seismic electric signals , which support the view that they exhibit infinitely ranged _ temporal _ correlations . concerning the second , slowly driven systems that emit bursts of various energies @xmath1
obeying power - law distribution , i.e. , @xmath2 , are studied .
an interrelation between the exponent @xmath3 and the variance @xmath4(@xmath5 ) is obtained for the shuffled ( randomized ) data . in the latter ,
the most probable value of @xmath4 is approximately equal to that of the original data .
finally , it is found that the differential entropy associated with the probability @xmath6 maximizes for @xmath3 around @xmath7 1.6 to 1.7 , which is comparable to the value determined experimentally in diverse phenomena , e.g. , solar flares , icequakes , dislocation glide in stressed single crystals of ice e.t.c .
it also agrees with the @xmath8-value in the gutenberg - richter law of earthquakes . .
And you have already written the first three sentences of the full article: a large variety of natural systems exhibit irregular and complex behavior which at first looks erratic , but in fact possesses scale invariant structure ( e.g. , @xcite ) .
a process @xmath9 is called self - similar@xcite if for some @xmath10 , @xmath11 where the symbol of equality refers here to all finite - dimensional distributions of the process on the left and the right , and the parameter @xmath12 is called self - similarity index or exponent . equation ( [ eq1 ] )
means a `` scale invariance '' of the finite - dimensional distributions of @xmath13 , which does _ not _ imply , in stochastic processes , the same for the sample paths ( e.g.,@xcite ) ..
Please generate the next two sentences of the article | examples of self - similar processes are brownian , fractional brownian ( fbm ) , lvy stable and fractional lvy stable motion ( flsm ) .
lvy stable distributions ( which are followed by many natural processes , e.g. , @xcite ) differ greatly from the gaussian ones because they have heavy tails and their variance is infinite ( e.g.,@xcite ) . |
8,696 | Suppose that you have an abstract for a scientific paper: we give counterexamples to a question of bowditch that if a non - elementary type - preserving representation @xmath0 of a punctured surface group sends every non - peripheral simple closed curve to a hyperbolic element , then must @xmath1 be fuchsian .
the counterexamples come from relative euler class @xmath2 representations of the four - punctured sphere group .
we also show that the mapping class group action on each non - extremal component of the character space of type - preserving representations of the four - punctured sphere group is ergodic , which confirms a conjecture of goldman for this case .
the main tool we use is kashaev - penner s lengths coordinates of the decorated character spaces . .
And you have already written the first three sentences of the full article: let @xmath3 be an oriented closed surface of genus @xmath4 the @xmath5-representation space @xmath6 is the space of group homomorphisms @xmath7 from the fundamental group of @xmath3 into @xmath8 endowed with the compact open topology .
the euler class @xmath9 of @xmath1 is the euler class of the associated @xmath10-bundle on @xmath11 which satisfies the milnor - wood inequality @xmath12 in @xcite , goldman proved that equality holds if and only if @xmath1 is fuchsian , i.e. , discrete and faithful ; and in @xcite , he proved that the connected components of @xmath6 are indexed by the euler classes .
i.e. , for each integer @xmath13 with @xmath14 the representations of euler class @xmath13 exist and form a connected component of @xmath15 the lie group @xmath5 acts on @xmath6 by conjugation , and the quotient space @xmath16 is the character space of @xmath17 since the euler classes are preserved by conjugation , the connected components of @xmath18 are also indexed by the euler classes , i.e. , @xmath19 where @xmath20 is the space of conjugacy classes of representations of euler class @xmath13 . by the results of goldman@xcite , the extremal components @xmath21 are respectively identified with the teichmller space of @xmath3 and that of @xmath3 endowed with the opposite orientation ..
Please generate the next two sentences of the article | the mapping class group @xmath22 of @xmath3 is the group of isotopy classes of orientation preserving self - diffeomorphisms of @xmath17 by the dehn - nielsen theorem , @xmath22 is naturally isomorphic to the group of positive outer - automorphisms @xmath23 which acts on @xmath18 preserving the euler classes .
therefore , @xmath22 acts on each connected component of @xmath24 it is well known ( see e.g. fricke@xcite ) that the @xmath22-action is properly discontinuous on the extremal components @xmath25 i.e. , the teichmller spaces , and the quotients are the riemann moduli spaces of complex structures on @xmath17 on the non - extremal components @xmath26 @xmath27 goldman conjectured in @xcite that the @xmath22-action is ergodic with respect to the measure induced by the goldman symplectic form @xcite . |
8,697 | Suppose that you have an abstract for a scientific paper: ballistic transport through nanoscale devices with time - dependent rashba - type spin - orbit interaction ( soi ) can lead to spin - polarized wave packets that appear even for completely unpolarized input .
the soi that oscillates in a finite domain generates density and spin polarization fluctuations that leave the region as propagating waves .
particularly , spin polarization has space and time dependence even in regions without soi .
our results are based on an analytic solution of the time - dependent schrdinger equation .
the relevant floquet quasi - energies that are obtained appear in the energy spectrum of both the transmitted and reflected waves . .
And you have already written the first three sentences of the full article: the presence of rashba - type @xcite spin - orbit interaction @xcite ( soi ) in semiconducting materials can lead to spin - dependent quantum mechanical phenomena that are of both fundamental and practical interest . in rings and loop geometries
fundamental interference effects can be observed , and they can have important applications as well , mainly due to the fact that the strength of the soi has been proven to be experimentally tuneable @xcite .
the relevance of the physical system motivated extensive studiesbia84,ahiye12,nmt99,fr04,mpv04,fmbp05,szp05,sn05,kmga05,bo07,chr07,bo08,cpc08,kfbp08c , m10 , dmk11,fe12,nmmg11,neea13 of quantum rings or systems of them ..
Please generate the next two sentences of the article | since the strength of the soi that determines the spin sensitive behavior of the devices can be controlled by external gate voltages , the question what effects appear if these voltages are time dependent arise naturally .
this point is to be investigated in the current paper . |
8,698 | Suppose that you have an abstract for a scientific paper: we report the results of a @xmath0sc nuclear magnetic resonance ( nmr ) study on the quasi - one - dimensional compound cu@xmath1sc@xmath1ge@xmath2o@xmath3 at temperatures between 4 and 300 k. this material has been a subject of current interest due to indications of spin gap behavior .
the temperature - dependent nmr shift exhibits a character of low - dimensional magnetism with a negative broad maximum at @xmath4 @xmath5 170 k. below @xmath6 , the nmr shifts and spin lattice relaxation rates clearly indicate activated responses , confirming the existence of a spin gap in cu@xmath1sc@xmath1ge@xmath2o@xmath3 . the experimental nmr data can be well fitted to the spin dimer model , yielding a spin gap value of about 275 k which is close to the 25 mev peak found in the inelastic neutron measurement .
a detailed analysis further points out that the nearly isolated dimer picture is proper for the understanding of spin gap nature in cu@xmath1sc@xmath1ge@xmath2o@xmath3 . .
And you have already written the first three sentences of the full article: the physics of low - dimensional magnetic systems continues to attract attention because of the association with peculiar quantum effects.@xcite prominent examples like the spin - peierls transition and the spin ladder compounds have been characterized by ground states of the spin singlet with a finite spin gap.@xcite for a quasi - one - dimensional chain with half - integer spin ( @xmath7 = 1/2 ) , the gap can be opened via either frustration due to next nearest neighbor antiferromagnetic exchange or dimerization due to an alternating coupling to nearest neighbors along the chain.@xcite several @xmath7 = 1/2 chain systems such as ( vo)@xmath1p@xmath1o@xmath8 , bacu@xmath1v@xmath1o@xmath9 , and pbcu@xmath1(po@xmath2)@xmath1 have been reported to possess spin gaps and their characteristics have been interpreted in accordance with these scenarios.@xcite cu@xmath1sc@xmath1ge@xmath2o@xmath3 , which crystallizes in a monoclinic structure with the space group _ p_2@xmath10_/m _ , was recently synthesized by one of the present authors ( g.j.r.).@xcite a schematic picture of the crystal structure is illustrated in fig .
1 . taking into account the known oxidation states of o@xmath11 and ge@xmath12 , the remaining valences are nonmagnetic sc@xmath13 and cu@xmath14 ( @xmath7 = 1/2 ) .
the spin chain in cu@xmath1sc@xmath15ge@xmath2o@xmath3 can be described as an arrangement of spin dimers oriented along the crystallographic _.
Please generate the next two sentences of the article | b_-axis , separated by geo@xmath2 tetrahedra and crankshaft - like chains of sco@xmath16 octahedra ( fig .
each dimer consists of two cu@xmath14 ions in a cu@xmath1o@xmath1 plaquette and weak interdimer interactions could be possible to induce a quantum phase transition from a gapless state into a gapped state for cu@xmath1sc@xmath1ge@xmath2o@xmath3 . |
8,699 | Suppose that you have an abstract for a scientific paper: spacecraft observations of saturn s rings show evidence of an active aggregation - disaggregation process triggered by periodic influences from the nearby moons .
this leads to clumping and break - up of the ring particles at time - scales of the order of a few hours .
a mathematical model has been developed to explain these dynamics in the saturn s f - ring and b - ring @xcite , the implications of which are in close agreement with the empirical results . in this paper
, we conduct a rigorous analysis of the proposed forced dynamical system for a class of continuous , periodic and zero - mean forcing functions that model the ring perturbations caused by the moon flybys . in specific ,
we derive the existence of at least one periodic solution to the dynamic system with the period equal to the forcing period of the moon .
further , conditions for the uniqueness and stability of the solution and bounds for the amplitudes of the periodic solution are derived .
# 1tanh#1 # 1#2#1 ' '' '' to 0pt@xmath0 * keywords : * saturn ring , aggregation - disaggregation process , periodic solution , stability * ams2000 subject classification : 34c25 , 85a99*. .
And you have already written the first three sentences of the full article: in @xcite , esposito et .
al . have proposed a dynamical model to explain the aggregation and disaggregation processes observed in saturn s f ring and the b ring outer edge due to the perturbation caused by the saturn s moon , prometheus and mimas , respectively .
their numerical simulations demonstrate that the dynamical model explains certain spacecraft measurements corresponding to these regions in the saturn s ring ..
Please generate the next two sentences of the article | further , these numerical results strongly suggest the existence of a limit cycle for realistic values of the parameters . in this paper , we provide a rigorous mathematical proof of this fact as well as study other features that are relevant from a dynamical point of view .
the model under consideration relates the mean aggregate mass @xmath1 and the velocity dispersion @xmath2 of ring particles at the above mentioned locations in the saturn s ring , as follows @xmath3 in the first equation of ( [ model ] ) , the first term refers to the coagulation of the ring particles leading to a growth in the mean aggregate mass at an accretion rate @xmath4 ( @xmath5 is the accretion period ) and the second term refers to the erosion ( or break - up ) of the larger ring particles due to collisions with other ring particles at collisional rates @xmath6 ( @xmath7 is the collisional period ) when their velocity dispersion exceed @xmath8 , the threshold velocity for sticking . in the second equation of ( [ model ] ) |
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