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6,300 | Suppose that you have an abstract for a scientific paper: the role of neutrinos in stars is introduced for students with little prior astrophysical exposure .
we begin with neutrinos as an energy - loss channel in ordinary stars and conversely , how stars provide information on neutrinos and possible other low - mass particles .
next we turn to the sun as a measurable source of neutrinos and other particles .
finally we discuss supernova ( sn ) neutrinos , the sn 1987a measurements , and the quest for a high - statistics neutrino measurement from the next nearby sn . we also touch on the subject of neutrino oscillations in the high - density sn context . .
And you have already written the first three sentences of the full article: neutrinos were first proposed in 1930 by wolfgang pauli to explain , among other problems , the missing energy in nuclear beta decay . towards the end of that decade ,
the role of nuclear reactions as an energy source for stars was recognized and the hydrogen fusion chains were discovered by bethe @xcite and von weizscker @xcite .
it is intriguing , however , that these authors did not mention neutrinos for example , bethe writes the fundamental pp reaction in the form @xmath0 ..
Please generate the next two sentences of the article | it was gamow and schoenberg in 1940 who first stressed that stars must be powerful neutrino sources because beta processes play a key role in the hydrogen fusion reactions and because of the feeble neutrino interactions that allow them to escape unscathed @xcite .
moreover , the idea that supernova explosions had something to do with stellar collapse and neutron - star formation had been proposed by baade and zwicky in 1934 @xcite , and gamow and schoenberg ( 1941 ) developed a first neutrino theory of stellar collapse @xcite . |
6,301 | Suppose that you have an abstract for a scientific paper: a peer - to - peer network , enabling different parties to jointly store and run computations on data while keeping the data completely private .
enigma s computational model is based on a highly optimized version of secure multi - party computation , guaranteed by a verifiable secret - sharing scheme . for storage ,
we use a modified distributed hashtable for holding secret - shared data .
an external blockchain is utilized as the controller of the network , manages access control , identities and serves as a tamper - proof log of events .
security deposits and fees incentivize operation , correctness and fairness of the system .
similar to bitcoin , enigma removes the need for a trusted third party , enabling autonomous control of personal data . for the first time , users are able to share their data with cryptographic guarantees regarding their privacy . .
And you have already written the first three sentences of the full article: since early human history , centralization has been a major competitive advantage .
societies with centralized governance were able to develop more advanced technology , accumulate more resources and increase their population faster @xcite .
as societies evolved , the negative effects of centralization of power were revealed : corruption , inequality , preservation of the status quo and abuse of power ..
Please generate the next two sentences of the article | as it turns out , some ` separation of powers ' @xcite is necessary . in modern times
, we strive to find a balance between the models , maximizing output and efficiency with centralized control , guarded by checks and balances of decentralized governance . |
6,302 | Suppose that you have an abstract for a scientific paper: the imaging and slitless spectroscopy instrument ( issis ) will be flown as part of the science instrumentation in the world space observatory - ultraviolet ( wso - uv ) .
issis will be the first uv imager to operate in a high earth orbit from a 2 m class space telescope . in this contribution , the science driving to issis design , as well as main characteristics of issis are presented .
ultraviolet : general ; space vehicles : instruments = 0.5 cm .
And you have already written the first three sentences of the full article: the resonance transitions of the most abundant species in the universe as well as the electronic transitions of the most abundant molecules are in the ultraviolet ( uv ) range of the spectrum . hence , access to the uv range is instrumental for progress in astrophysics @xcite .
the world space observatory - ultraviolet ( wso - uv ) space telescope will grant this access in the post - hubble space telescope era .
wso - uv is a 170 cm diameter primary telescope with an efficient ritchey - chrtien configuration that will be operational in the 20172027 time frame ..
Please generate the next two sentences of the article | wso - uv is a russian - led mission and will be equipped with instrumentation for uv spectroscopy and imaging ( see * ? ? ?
* ; * ? ? ? |
6,303 | Suppose that you have an abstract for a scientific paper: this article provides a review of progress made in understanding inverse power law corrections @xmath0 where @xmath1 is the hard scale involved in a given qcd process .
particular attention will be paid to hera results . .
And you have already written the first three sentences of the full article: in order to test the theory of strong interactions ( qcd ) it has long been common practice to confront experimental data with perturbative predictions and then extract fundamental parameters such as the strong coupling @xmath2 . a consistent extraction of @xmath2 from different experiments and different observables points at the correctness of assuming qcd as the underlying theory .
since qcd is a theory where non - perturbative effects play a clear role one has to first question the feasibilty of such an approach and review the role of perturbative qcd ( pqcd ) . the fact that one can make perturbative predictions to any extent is indeed a blessing and in the case of many observables factorisation theorems allow the separation of pqcd from non - perturbative effects
. simply stated a factorisation theorem implies for an observable @xmath3 @xmath4 in the above we indicate by @xmath5 any set of phase space variables on which the observable may depend and by @xmath6 the hard momentum scale ..
Please generate the next two sentences of the article | @xmath7 is typically a universal operator matrix element which contains non - perturbative information and whose value can be extracted from experiment and tabulated , for example a parton distribution measure . @xmath8 and @xmath9 are perturbative coefficients calculated by using feynman graphs to represent the hard process .
the dots indicate the limitations of the perturbative approach . |
6,304 | Suppose that you have an abstract for a scientific paper: using a highly viscous magnetic fluid , the dynamics in the aftermath of the rosensweig instability can be slowed down by more than 2000 times . in this way
we expand the regime where the growth rate is predicted to scale linearly with the bifurcation parameter by six orders of magnitude , while this regime is tiny for standard ferrofluids and can not be resolved experimentally there .
we measure the growth of the pattern by means of a two - dimensional imaging technique , and find that the slopes of the growth and decay rates are not the same - a qualitative discrepancy to the theoretical predictions .
we solve this discrepancy by taking into account a viscosity which is assumed to be different for the growth and decay .
this may be a consequence of the measured shear thinning of the ferrofluid .
= 1 .
And you have already written the first three sentences of the full article: the `` pitch - drop - experiment '' @xcite , which received the ig - nobel price in physics 2005 , has brought to the attention that a fast process like drop formation @xcite can be retarded considerably if instead of a standard liquid like water it has a viscosity of @xmath0 at @xmath1c a material like pitch , with a viscosity around @xmath2 is selected .
the funnel was filled in 1930 @xcite , and today `` finally the ninth pitch drop has fallen from the world s longest running lab experiment '' @xcite and the 10th is awaited within the next 14 years . here the question arises whether those high viscosities may give access to so far not resolved phenomena . in a vessel with diameter of 120 mm .
the picture is taken from @xcite ..
Please generate the next two sentences of the article | a movie showing the formation of rosensweig patterns can be accessed at @xcite.,width=323 ] in the following we are investigating this question for the case of the well known rosensweig or normal field instability @xcite .
it is observed in a horizontal layer of magnetic fluid ( mf ) @xcite with a free surface , when a critical value @xmath3 of the vertically oriented magnetic induction is surpassed . |
6,305 | Suppose that you have an abstract for a scientific paper: we give explicit calculations of the algebraic theory of power operations for a specific morava @xmath0-theory spectrum and its @xmath1-localization .
these power operations arise from the universal degree-3 isogeny of elliptic curves associated to the @xmath0-theory . .
And you have already written the first three sentences of the full article: suppose @xmath0 is a commutative @xmath2-algebra , in the sense of @xcite , and @xmath3 is a commutative @xmath0-algebra .
we want to capture the properties and underlying structure of the homotopy groups @xmath4 of @xmath3 , by studying operations associated to the cohomology theory that @xmath0 represents . an important family of cohomology operations , called _ power operations _ ,
is constructed via the extended powers . specifically , consider the _ @xmath5th extended power _.
Please generate the next two sentences of the article | functor @xmath6 on the category of @xmath0-modules , which sends an @xmath0-module to its @xmath5-fold smash product over @xmath0 modulo the action by the symmetric group on @xmath5 letters .
the @xmath7 s assemble together to give the _ free commutative @xmath0-algebra _ |
6,306 | Suppose that you have an abstract for a scientific paper: this chapter is intended to provide a general presentation of the atomic and nuclear processes responsible for x - ray line and gamma - ray line emission in various astrophysical environments .
i consider line production from hot plasmas , from accelerated particle interactions , from the decay of radioactive nuclei synthesized in stars and from positron annihilation .
spectroscopic properties of these emissions are discussed in the light of the detection capabilities of modern space instruments . .
And you have already written the first three sentences of the full article: x- and gamma - ray emission lines are valuable signatures of various high - energy processes at work in the universe , including heating of astrophysical gas to very high temperatures , particle acceleration and nucleosynthesis .
perhaps the most important realization of pioneering high - energy astronomy was that hot plasmas are found essentially everywhere in the universe .
more and more detailed observations of thermal x - ray lines provide detailed and often unique information on a wide variety of astrophysical sites , including stellar environments , supernova explosions , accreting compact objects , interstellar and intergalactic media and active galactic nuclei ..
Please generate the next two sentences of the article | particle acceleration is believed to occur in most of these sites .
our understanding of acceleration mechanisms should greatly benefit from the detection of lines produced through atomic and nuclear interactions of energetic particles with ambient matter . |
6,307 | Suppose that you have an abstract for a scientific paper: the icecube collaboration has recently reported the observation of two events with energies in excess of 1 pev . while an atmospheric origin of these events can not be ruled out at this time
, this pair of showers may potentially represent the first observation of high - energy astrophysical neutrinos . in this paper
, we argue that if these events are neutrino - induced , then the neutrinos are very likely to have been produced via photo - meson interactions taking place in the same class of astrophysical objects that are responsible for the acceleration of the @xmath0@xmath1 ev cosmic ray spectrum . among the proposed sources of such cosmic rays , gamma - ray bursts stand out as particularly capable of generating pev neutrinos at the level implied by icecube s two events .
in contrast , the radiation fields in typical active galactic nuclei models are likely dominated by lower energy ( uv ) photons , and thus feature higher energy thresholds for pion production , leading to neutrino spectra which peak at eev rather than pev energies ( models with significant densities of x - ray emission , however , could evade this problem ) .
cosmogenic neutrinos generated from the propagation of ultra - high energy cosmic rays similarly peak at energies that are much higher than those of the events reported by icecube . .
And you have already written the first three sentences of the full article: very recently , the icecube collaboration announced their observation of two events which could potentially represent the first detection of high - energy astrophysical neutrinos @xcite .
the analysis under consideration was designed to search for very high - energy ( @xmath2 pev ) and high - quality shower events over a period of 615.9 live days between 2010 and 2012 . over this time , the icecube experiment was in its nearly complete ( 79 string ) and complete ( 86 string ) configurations .
the two showers in question were observed on august 8 , 2011 and january 3 , 2012 , and each have an energy of approximately 1 pev ( 1.04 and 1.14 pev `` with a combined and statistical uncertainty of @xmath3 each '' @xcite ) ..
Please generate the next two sentences of the article | both showers were fully contained within the volume of the detector , and there are no indications of any instrumental problems , or of any connection with atmospheric muons . at energies below @xmath01 pev ,
atmospheric neutrinos constitute icecube s primary background . |
6,308 | Suppose that you have an abstract for a scientific paper: it is well known that quantum mechanics is incompatible with local realistic theories .
svetlichny showed , through the development of a bell - like inequality , that quantum mechanics is also incompatible with a restricted class of _ nonlocal _ realistic theories for three particles where any two - body nonlocal correlations are allowed @xcite . in the present work ,
we experimentally generate three - photon ghz states to test svetlichny s inequality .
our states are fully characterized by quantum state tomography using an overcomplete set of measurements and have a fidelity of @xmath0 with the target state .
we measure a convincing , @xmath1 , violation of svetlichny s inequality and rule out this class of restricted nonlocal realistic models . .
And you have already written the first three sentences of the full article: quantum mechanics can not be described by local hidden - variable ( lhv ) theories .
this is the conclusion of bell s seminal work , in which he derived a strict limit to the strength of correlations achievable by all lhv models that is violated by quantum predictions @xcite .
bell s original inequality did not allow for imperfections and thus it was not accessible to experimental tests ..
Please generate the next two sentences of the article | clauser , horne , shimony and holt ( chsh ) addressed this issue and developed the chsh inequality @xcite , which allowed for tests in actual experiments . since then a growing number of experiments have been reported ( for examples , see @xcite ) , and the overwhelming experimental evidence from these tests is in favour of quantum mechanics , ruling out lhv theories . it should be noted that , while no _ loophole - free _ bell test has been performed , the most significant potential loopholes , relating to detection efficiency and space - like separation of the choices of measurements settings , have both separately been closed @xcite .
both bell s inequality and the chsh inequality were formulated for testing the correlations between just two particles . for more than two particles , greenberger , horne and zeilinger ( ghz ) showed @xcite that a contradiction between lhv theories and quantum mechanics can be seen directly in perfect correlations , as opposed to statistically in imperfect ones . soon thereafter bell - type inequalities for more than two particles were developed @xcite . |
6,309 | Suppose that you have an abstract for a scientific paper: results obtained from 9 x - ray observations of 3c 273 performed by _ asca _ are presented ( for a total exposure time of about 160 000 s ) .
the analysis and interpretation of the results is complicated by the fact that 4 of these observations were used for on - board calibration of the ccds spectral response . in particular , we had to pay special attention to the low energy band and 56 kev energy range where systematic effects could distort a correct interpretation of the data .
the present standard analysis shows that , in agreement with official recommendations , a conservative systematic error ( at low energies ) of @xmath0 23 @xmath1 10@xmath2 @xmath3 must be assumed when analyzing _ asca _ sis data .
a soft - excess , with variable flux and/or shape , has been clearly detected as well as flux and spectral variability that confirm previous findings with other observatories .
an anti - correlation is found between the spectral index and the flux in the 2 - 10 kev energy range . with the old response
matrices , an iron emission line feature with ew @xmath0 50100 ev was initially detected at @xmath0 5.6 - 5.7 kev ( @xmath0 6.5 - 6.6 kev in the quasar frame ) in 6 observations and , in two occasions , the line was resolved ( @xmath4 0.2 - 0.6 kev ) .
comparison with the crab spectrum indicates however that this feature was mostly due to remaining calibration uncertainties between 56 kev .
indeed , fitting the data with the latest publicly available calibration matrices , we find that the line remains unambiguously significant in ( only ) the two observations with lowest fluxes where it is weak ( ew @xmath0 20 - 30 ev ) , narrow and consistent with being produced by fe k@xmath5 emission from neutral matter .
overall , the observations are qualitatively consistent with a variable , non - thermal x - ray continuum emission , i.e. , a power law with @xmath6 @xmath0 1.6 ( possibly produced in the innermost regions of the radio - optical jet ) , plus underlying `` seyfert - like ''....
And you have already written the first three sentences of the full article: the remarkable discovery by egret on - board _ cgro _ that blazars ( i.e. bl lacertae objects and flat - spectrum radio quasars ) are strong @xmath7-ray emitters has drawn in recent years the attention of the astronomical community to this class of objects .
observations indicate that the overall energy distribution of blazars shows the signature of two different types of emission mechanisms : beamed non - thermal jet radiation producing the overall broad band ( from radio to @xmath7-rays ) continuum emission common to all blazars , and quasi - isotropic thermal radiation by an accretion - disk producing a `` uv bump '' observed in a large number of quasars and seyfert galaxies but absent in bl lac objects ( e.g. sambruna , maraschi & urry , 1996 , elvis et al .
the non - thermal continuum consists of ir - optical and @xmath7-ray peaks ..
Please generate the next two sentences of the article | the first peak is interpreted in terms of synchrotron emission and the second peak in terms of inverse compton emission ( see urry & padovani 1995 for a review on the subject ) . from object
to object , the observed different spectral characteristics may be due to the relative importance of one emission mechanism to the other which , in turn , is likely to be related to the amount of beaming in one object or the other ( e.g. dondi & ghisellini 1995 ) . |
6,310 | Suppose that you have an abstract for a scientific paper: we propose a quantum implementation of a capital - dependent parrondo s paradox that uses @xmath0 qubits , where @xmath1 is the number of parrondo games .
we present its implementation in the quantum computer language ( qcl ) and show simulation results . .
And you have already written the first three sentences of the full article: quantum game theory @xcite is a new field of science having its roots in both game theory and quantum information theory . for about a decade
quantum computer scientists have been searching for new methods of quantum algorithm design .
thorough investigation of different quantum games may bring new insight into the development of quantum algorithms ..
Please generate the next two sentences of the article | it was shown that grover s algorithm @xcite can be treated as an example of a quantum parrondo s paradox @xcite .
operators used in grover s algorithm can be treated as parrondo games having separately zero expected values , however , if they are interwired , the expected value fluctuates . |
6,311 | Suppose that you have an abstract for a scientific paper: strong - coupling expansion is performed for the lattice @xmath0 model in @xmath1 dimensions .
because the strong - coupling limit itself is not solvable , we employed numerical calculations so as to set up unperturbed eigensystems . restricting the number of hilbert - space bases , we performed linked - cluster expansion up to eleventh order .
we carried out alternative simulation by means of the density - matrix renormalization group .
thereby , we confirmed that our series - expansion data with a convergence - acceleration trick are in good agreement with the simulation result . through the analytic continuation to the domain of negative biquadratic interaction , we obtain the false - vacuum decay rate .
contrary to common belief that tunnelling phenomenon lies out of perturbative treatments , our series expansion reproduces the instanton - theory behaviour for high potential barrier .
for shallow barrier , on the contrary , our result tells that the relaxation is no more described by instanton , but the decay rate acquires notable enhancement . .
And you have already written the first three sentences of the full article: suppose that a system is placed at a certain metastable state surrounded by local potential minimum , the system would be unstable to decay to a global minimum assisted by either quantum or thermal fluctuations .
such processes are called false - vacuum decay and metastability relaxation , and they are considered to be non - perturbative in nature . hence , in order to calculate the decay rate ( life time ) , ingenious treatments have been invented so far @xcite .
those treatments rely on semi - classical approximation ..
Please generate the next two sentences of the article | that is , the treatments take into account quadratic fluctuations around the field configuration which extremizes the euclidean action .
such field configurations are called instanton , bounce and ( critical ) droplet . |
6,312 | Suppose that you have an abstract for a scientific paper: micromesh gas amplification structures ( micromegas ) are being used in an increasing number of particle physics applications since their conception fourteen years ago .
more recently , they are being used or considered as readout of time projection chambers ( tpcs ) in the field of rare event searches ( dealing with dark matter , axions or double beta decay ) . in these experiments ,
the radiopurity of the detector components and surrounding materials is measured and finely controlled in order to keep the experimental background as low as possible . in the present paper ,
the first measurement of the radiopurity of micromegas planes obtained by high purity germanium spectrometry in the low background facilities of the canfranc underground laboratory ( lsc ) is presented .
the obtained results prove that micromegas readouts of the _ microbulk _ type are currently manufactured with radiopurity levels below 30 for th and u chains and @xmath060 for @xmath1k , already comparable to the cleanest detector components of the most stringent low background experiments at present .
taking into account that the studied readouts were manufactured without any specific control of the radiopurity , it should be possible to improve these levels after dedicated development .
time projection chamber , micromegas , radiopurity , rare event searches .
And you have already written the first three sentences of the full article: the quest for the direct detection of dark matter in the form of weakly interacting massive particles ( wimps ) @xcite , the search for the neutrinoless double beta decay ( @xmath2 ) @xcite or other experiments involving very low rate processes ( the so - called rare event searches ) impose very challenging experimental requirements .
the most important of these requirements is the reduction of experimental backgrounds down to ever - decreasing levels .
the fight against backgrounds is performed in several ways , including active and passive shielding , operation in underground sites , event discrimination and especially selecting carefully the materials composing the detector and those in the surroundings so that they have the lowest radioactive traces that could induce background in the experiment ..
Please generate the next two sentences of the article | all these practices have evolved toward a technical field itself , usually called _ ultra - low background techniques _
@xcite . |
6,313 | Suppose that you have an abstract for a scientific paper: we show that open quantum systems of two - level atoms symmetrically coupled to a single - mode photon field can be efficiently simulated by applying a _
su_(4 ) group theory to quantum master equations .
this is important since many foundational examples in quantum optics fall into this class .
we demonstrate the method by finding exact solutions for many - atom open quantum systems such as lasing and steady state superradiance .
although quantum mechanics actually describes the behavior of isolated and closed quantum systems , in practice most physical situations to which it is applied are open .
the open nature is necessary to treat basic irreversible processes such as the energy transfer with a heat bath , the particle or charge exchange with a reservoir , and quantum measurements .
open quantum systems can be treated under the born and markov approximations by the quantum master equation in the lindblad form @xcite , which has been applied across many fields of physics , including quantum optics and quantum information science @xcite , atomic and molecular physics @xcite , solid state physics @xcite , and optomechanics @xcite .
here we focus on a novel group - theoretic approach to find an efficient solution of the quantum master equation for an important class of quantum optical systems .
even though we focus on these systems , the methods we present could be more generally applied to other fields .
we consider specifically the symmetric coupling of a single - mode cavity field to an ensemble of @xmath0 two - level atoms ( analogous to pseudo - spin-1/2 systems or qubits ) .
the hamiltonian that describes this situation in the interaction picture is given by @xmath1 where the first term is the free energy , with @xmath2 being the detuning of the light field from the atomic transition , and the second term is the reversible atom - field coupling with strength @xmath3 .
the photon annihilation operator is @xmath4 , and @xmath5 and @xmath6 are pauli operators for the....
And you have already written the first three sentences of the full article: in this section , we give explicit expressions for the _
su_(4 ) superoperators for @xmath0 two - level atoms in terms of the pauli spin - operators . following hartmann @xcite , 18 superoperators @xmath15 , @xmath16 and @xmath17 are defined , where @xmath18 , @xmath109 although this list , eq .
( [ super ] ) , contains 18 operator definitions , only 15 of them are independent ( it is possible to write @xmath110 , @xmath111 , @xmath112 in terms of the others ) ..
Please generate the next two sentences of the article | one can demonstrate that the 15 remaining superoperators are linear combinations of the familiar gell - mann matrices that are the generators of the _
su_(4 ) group , @xmath113 @xcite . in order to see this , consider first the fundamental one atom case , where we interpret the @xmath114 density matrix as a @xmath115 vector in the representing vector space ( _ i.e. _ liouville space ) . |
6,314 | Suppose that you have an abstract for a scientific paper: in this paper , we empirically investigate correlations among four centrality measures , originated from the social science , of various complex networks . for each network
, we compute the centrality measures , from which the partial correlation as well as the correlation coefficient among measures is estimated .
we uncover that the degree and the betweenness centrality are highly correlated ; furthermore , the betweenness follows a power - law distribution irrespective of the type of networks .
this characteristic is further examined in terms of the conditional probability distribution of the betweenness , given the degree .
the conditional distribution also exhibits a power - law behavior independent of the degree which explains partially , if not whole , the origin of the power - law distribution of the betweenness .
a similar analysis on the random network reveals that these characteristics are not found in the random network . .
And you have already written the first three sentences of the full article: the network ( or graph ) is a useful way of expressing and investigating quantitatively the characteristics of complex systems in various disciplines .
it consists of a set of vertices representing entities , and edges associated with connections between vertices @xcite .
numerous complex systems can be and have been expressed in terms of networks , and they are often classified by the research field , such as social @xcite , technological @xcite , and biological networks @xcite , to name just a few ..
Please generate the next two sentences of the article | early researches on the network focused mainly on the regular and the random networks from which many mathematical results for general structural characteristics have been extracted @xcite .
recently , due to the availability of computers and the internet , study on large - scale statistical properties of complex networks has been possible . |
6,315 | Suppose that you have an abstract for a scientific paper: we study the possibility of brane - world generalization of the einstein - straus swiss - cheese cosmological model .
we find the modifications induced by the brane - world scenario . at a first glance
only the motion of the boundary is modified and the fluid in the exterior region is allowed to have pressure .
the general relativistic einstein - straus model emerges in the low density limit . by imposing that
the brane is static , a combination of the junction conditions and modified cosmological evolution leads to the conclusion that the brane is flat .
thus no static swiss - cheese universe can exist on the brane .
the conclusion is not altered by the introduction of a cosmological constant in the flrw regions .
this result mimics a similar general relativistic result : static einstein - straus universes do not exist . .
And you have already written the first three sentences of the full article: brane - world scenarios introduced by arkani - hamed , dimopoulos and dvali add and randall and sundrum ( rs ) @xcite are motivated by string theory , where open strings end on branes . in the generalized rs scenario our 4-dimensional friedmann - lematre - robertson - walker ( flrw ) universe is a hypersurface of codimension one ( the brane ) embedded into a 5-dimensional charged vaidya - anti de sitter or reissner - nordstrm - anti de sitter space - time ( the bulk ) .
the radiation in the bulk , the charge and mass of the central bulk black hole can be switched off independently ( for a detailed discussion see @xcite ) , however the bulk will always have a negative cosmological constant , which balances the brane tension in such a way that the 4-dimensional ( 4d ) cosmological constant can be fine - tuned .
branes with various other symmetries were also examined , like the einstein brane einbrane , a kantowski - sachs type brane @xcite and the gdel brane @xcite ..
Please generate the next two sentences of the article | all these cases bear in common unusual properties or exotic matter .
there were also various attemps to find black hole solutions on the brane ( for a recent review see @xcite ) . |
6,316 | Suppose that you have an abstract for a scientific paper: the scalar isovector meson propagator is studied in quenched qcd . for the lightest quark masses
used , this propagator is dominated by a quenched chiral loop effect associated with the @xmath0-@xmath1 two - meson intermediate state . both the time dependence and the pion mass dependence of the effect are well - described by quenched chiral perturbation theory . .
And you have already written the first three sentences of the full article: recent calculations in quenched qcd at light valence quark mass have been refined to sufficient accuracy to allow detailed comparison with the predictions of quenched chiral perturbation theory @xcite .
the identification of quenched chiral loop effects in lattice data serves several purposes .
it allows one to perform sensible chiral extrapolations of quenched data and to extract the parameters of the qcd chiral lagrangian in the quenched approximation ..
Please generate the next two sentences of the article | it also provides a standard of comparison for future studies of chiral behavior in full and partially quenched qcd , which will be crucial for obtaining complete control over chiral extrapolations in full qcd .
in particular , the study of quenched chiral loop ( qcl ) effects has identified several quantities for which the effects of quenching are clearly observable in the lattice data and in detailed agreeement with quenched chiral perturbation theory . |
6,317 | Suppose that you have an abstract for a scientific paper: we study a system of three coherently coupled states , where one state is shifted periodically against the other two .
we discover such a system possesses a dark floquet state at zero quasi - energy and always with negligible population at the intermediate state .
this dark floquet state manifests itself dynamically in terms of the suppression of inter - state tunneling , a phenomenon known as coherent destruction of tunneling .
we suggest to call it dark coherent destruction of tunneling ( dcdt ) . at high frequency limit for the periodic driving
, this floquet state reduces to the well - known dark state widely used for stirap .
our results can be generalized to systems with more states and can be verified with easily implemented experiments within current technologies .
two - state and three - state models are the simplest quantum systems . despite their simplicity
, they often provide very good approximations to describe realistic physical systems and are capable of revealing a variety of fascinating quantum effects .
the understanding of their ubiquitous features are nowadays being exploited for the manipulation and control of quantum states of small systems involving single atoms , photons , or nano - devices @xcite .
coherent destruction of tunneling ( two - state models ) and dark state ( three - state models ) are two of the elegant prototype examples where deep understanding gained from quantum coherent effects in these simple systems are impacting the development of quantum technology in communication and computation
. coherent destruction of tunneling ( cdt ) was discovered in a periodically - driving double well system @xcite .
it describes a fascinating phenomenon whereby coherent tunneling between two wells ( or the rabi oscillation between two states ) is turned off by an externally enforced periodic level shift .
its understanding is related to dynamical localization @xcite , which occurs at isolated degenerate points of the quasienergies @xcite .
cdt has....
And you have already written the first three sentences of the full article: the @xmath75 tridiagonal matrix @xmath71 has the following non - zero matrix elements : @xmath83 , @xmath73 for @xmath84 .
@xmath74 is tunable and @xmath85 is fixed .
the eigenvalues and eigenvectors of @xmath71 have the following properties ..
Please generate the next two sentences of the article | + let @xmath86 be all the eigenvalues of matrix @xmath71 , then @xmath87 .
it is easy to verify that @xmath88 , @xmath89 , and the relation @xmath90 . |
6,318 | Suppose that you have an abstract for a scientific paper: we study the kondo lattice model with additional attractive interaction between the conduction electrons within the dynamical mean - field theory using the numerical renormalization group to solve the effective quantum impurity problem .
in addition to normal - state and magnetic phases we also allow for the occurrence of a superconducting phase . in the normal phase we observe a very sensitive dependence of the low - energy scale on the conduction - electron interaction .
we discuss the dependence of the superconducting transition on the interplay between attractive interaction and kondo exchange . .
And you have already written the first three sentences of the full article: heavy fermion ( hf ) compounds with elements from the lanthanide or actinide series share some rather general features in the fermi liquid phase , namely a strong enhancement of the effective carrier mass and a similarly enhanced pauli susceptibility with a wilson ratio typically of the order , but larger than one @xcite .
in addition to this well - understood fermi liquid phase @xcite , hf systems also exhibit a variety of phase transitions , among them magnetic and superconducting phases .
this aroused the strong interest of both experimentalists and theorists , as @xmath0-electrons conventionally tend to suppress superconductivity ..
Please generate the next two sentences of the article | the discovery of quantum critical phenomena @xcite eventually showed the intimate link between the latter two . in spite of the rather large collection of experimental results ,
an accepted theoretical description of superconductivity has not yet been established . moreover , |
6,319 | Suppose that you have an abstract for a scientific paper: rotne - prager - yamakawa approximation is one of the most commonly used methods of including hydrodynamic interactions in modelling of colloidal suspensions and polymer solutions .
the two main merits of this approximation is that it includes all long - range terms ( i.e. decaying as @xmath0 or slower in interparticle distances ) and that the diffusion matrix is positive definite , which is essential for brownian dynamics modelling . here , we extend the rotne - prager - yamakawa approach to include both translational and rotational degrees of freedom , and derive the regularizing corrections to account for overlapping particles .
additionally , we show how the rotne - prager - yamakawa approximation can be generalized for other geometries and boundary conditions . .
And you have already written the first three sentences of the full article: particles moving in a viscous fluid induce a local flow field that affects other particles . these long - range , many - body interactions , mediated by the solvent are commonly called hydrodynamic interactions ( hi ) . the presence of hi
is known to affect the dynamic properties of soft matter : they modify the values of diffusion coefficients in colloidal suspensions @xcite , affect the characteristics of the coil - stretch transition in polymers @xcite , change the kinetic pathways of phase separation in binary mixtures @xcite , alter the kinetics of macromolecule adsorption on surfaces @xcite or cause the polymer migration in microchannels @xcite .
they are also important in the dynamics of biological soft matter , such as dna @xcite , proteins @xcite or lipid membranes @xcite ..
Please generate the next two sentences of the article | the proper account of hydrodynamic interactions is thus essential in simulation studies of soft matter in the flow .
unfortunately , hi depend in a complicated nonlinear way on the instantaneous positions of all particles in the system . for a system of spheres , exact explicit expressions for the hydrodynamic interaction tensors exist in the form of the power series in interparticle distances , which may be incorporated into the simulation scheme @xcite . |
6,320 | Suppose that you have an abstract for a scientific paper: we study the exclusive @xmath0 decay in the appelquist , chang , dobrescu model within one universal extra dimension .
we investigate the sensitivity of the branching ratio , lepton polarization and forward backward asymmetry @xmath1 to the compactification parameter @xmath2 we obtain that the branching ratio changed about @xmath3 compared to the sm value , when @xmath4 and zero position of the forward backward asymmetry is shifted to the left compared to the sm result .
therefore measurement of the branching ratio of @xmath5 decay and determination of zero position of @xmath6 are very useful in looking for new physics in the framework of the ued models . 0^*0
5_5 s_s^ ? ?
o _ ^0
_ pacs numbers : 12.60.i , 13.30.a , 14.20.mr .
And you have already written the first three sentences of the full article: flavor changing neutral current ( fcnc ) @xmath7 transitions are forbidden in the standard model ( sm ) at tree level that occur at loop level , and therefore provide consistency check of the sm at quantum level .
these decays induced by the fcnc are also very sensitive to the new physics beyond the sm . new physics embedded into rare decays through the wilson coefficients which can take values different from their sm counterpart or through the new operator structures in an effective hamiltonian ( see @xcite and references therein ) . among the hadronic , leptonic and semileptonic decays , the last decay channels are very significant , since they are theoretically , more or less , clean , and they have relatively larger branching ratio .
from theoretical side there are many works in which the semileptonic decay channels due to @xmath7 transitions are investigated ..
Please generate the next two sentences of the article | these decays contain many observables like forward backward asymmetry @xmath1 , lepton polarization asymmetries , etc .
, which are very useful and serve as a testing ground for the sm and looking for new physics beyond the sm @xcite . from experimental side , |
6,321 | Suppose that you have an abstract for a scientific paper: using alma observations of the c@xmath0o(2 - 1 ) line emission of the gas envelope of protostar l1527 , we have reconstructed its morphology and kinematics under the assumption of axisymmetry about the west - east axis . the main original contribution to our understanding of the formation process of l1527 is the presentation of a simple 3d parameterisation based solely on regions that are not dominated by absorption . in the explored range ( @xmath10.7 to 5 arcsec from the star )
the model reproduces observations better than earlier attempts .
the main results include : a measurement of the rotation velocity that confirms its evolution to keplerian toward short distances ; a measurement of the mean in - fall velocity , [email protected] kms@xmath3 , lower than free fall velocity , with no evidence for the significant @xmath4-dependence suggested by an earlier analysis ; a measurement of the central mass , [email protected] m@xmath5 within a distance of 1.5 arcsec from the star , in agreement with earlier estimates obtained from a different range of distances ; evidence for a strong disc plane depression of the in - falling flux resulting in an @xmath6 shaped flow possibly caused by the freeze - out of co molecules on dust grains ; a measurement of the accretion rate , [email protected] 10@xmath7m@xmath5yr@xmath3at a distance of 1 arcsec ( 140 au ) from the star ; evidence for a 10@xmath8 tilt of the symmetry plane of the envelope about the line of sight , cancelling below @xmath13 arcsec from the star , but matching infrared observations and being also apparent on the sky map of the mean doppler velocity . [ firstpage ] circumstellar matter stars : individual ( l1527 irs ) stars : low - mass stars : protostars radio lines : stars . .
And you have already written the first three sentences of the full article: l1527 irs is a class 0 protostar , at a distance of @xmath1140 pc , in its earliest stages of formation .
it has a mass of @xmath10.2 solar masses and is surrounded by a flared rotating envelope of about one solar mass , as recently reported by @xcite who observed it in the continuum ( at 1.3 and 3.4 mm wavelength ) and on the @xmath9co(2 - 1 ) line using the submillimeter array ( sma ) and the combined array for research in millimeter astronomy ( carma ) .
these observations suggest a mass accretion rate of and a disc diameter at the arcsecond scale ..
Please generate the next two sentences of the article | they were followed by measurements and analyses of the 1.3 mm dust polarization by @xcite and @xcite , which reveal a toroidal magnetic field configuration .
alma observations of molecular lines have been reported very recently : of c@xmath0o and so by @xcite , of cyclic - c@xmath10h@xmath11 and so by @xcite and of cch , cs , h@xmath11co and ch@xmath10oh by @xcite . |
6,322 | Suppose that you have an abstract for a scientific paper: wild poliovirus type 3 ( wpv3 ) has not been seen anywhere since the last case of wpv3-associated paralysis in nigeria in november 2012 . at the time of writing ,
the most recent case of wild poliovirus type 1 ( wpv1 ) in nigeria occurred in july 2014 , and wpv1 has not been seen in africa since a case in somalia in august 2014 .
no cases associated with circulating vaccine - derived type 2 poliovirus ( cvdpv2 ) have been detected in nigeria since november 2014 .
has wpv1 been eliminated from africa ?
has wpv3 been eradicated globally ? has nigeria interrupted cvdpv2 transmission ?
these questions are difficult because polio surveillance is based on paralysis and paralysis only occurs in a small fraction of infections .
this report provides estimates for the probabilities of poliovirus elimination in nigeria given available data as of march 31 , 2015 .
it is based on a model of disease transmission that is built from historical polio incidence rates and is designed to represent the uncertainties in transmission dynamics and poliovirus detection that are fundamental to interpreting long time periods without cases .
the model estimates that , as of march 31 , 2015 , the probability of wpv1 elimination in nigeria is @xmath0 , and that if wpv1 has not been eliminated , a new case will be detected with @xmath1 probability by the end of 2015 .
the probability of wpv3 elimination ( and thus global eradication ) is @xmath2 .
however , it is unlikely that the ongoing transmission of cvdpv2 has been interrupted ; the probability of cvdpv2 elimination rises to @xmath3 if no new cases are detected by april 2016 .
* added july 10 , 2015 * : on june 26 , 2015 , a paralytic polio case caused by ongoing circulation of established cvdpv2 lineage was confirmed by the global polio laboratory network .
the date of paralysis onset was may 16 , 2015 , 181 days after the previous case .
the case provides new information about the prevalence of cvdpv2 in nigeria that can be used to both assess the....
And you have already written the first three sentences of the full article: since the world health assembly announced the intention to eradicate polio worldwide in 1988 , all countries except pakistan , afghanistan , and nigeria have [ line - through]*certified elimination*interrupted indigenous transmission of all three wild poliovirus ( wpv ) serotypes at least once @xcite .
nigeria may be the next country to achieve wild - type polio elimination .
the most recent case of wild - type 1 ( wpv1 ) in nigeria occurred in july 2014 @xcite ..
Please generate the next two sentences of the article | the most recent case of wild - type 3 ( wpv3 ) seen globally occurred in nigeria in november 2012 @xcite .
is nigeria wild - polio - free ? |
6,323 | Suppose that you have an abstract for a scientific paper: in this paper we derive three equations of motion for a supernova remnant ( snr ) in the framework of the thin layer approximation using the pad approximant .
the circumstellar medium is assumed to follow a density profile of either an exponential type , a gaussian type , or a lane
emden ( @xmath0 ) type .
the three equations of motion are applied to four snrs : tycho , cas a , cygnus loop , and sn 1006 .
the percentage error of the pad approximated solution is always less than @xmath1 .
the theoretical decrease of the velocity over ten years for snrs is evaluated .
_ keywords _ : supernovae : general ism : supernova remnants supernovae : individual ( tycho ) supernovae : individual ( cas a ) supernovae : individual ( cygnus loop ) supernovae : individual ( sn 1006 ) .
And you have already written the first three sentences of the full article: the equation of motion for a supernova remnant ( snr ) can be modeled by a single law of motion or multiple laws of motion when the appropriate boundary conditions are provided .
examples of a single law of motion are : the sedov expansion in the presence of a circumstellar medium ( csm ) with constant density where the radius , @xmath2 , scales as @xmath3 , see @xcite , and the momentum conservation in the framework of the thin layer approximation with csm at constant density where @xmath4 , see @xcite .
examples of piece - wise solutions for an snr can be found in @xcite : a first energy conserving phase , @xmath3 followed by a second adiabatic phase where @xmath5 . at the same time.
Please generate the next two sentences of the article | it has been shown that in the first ten years of 1993j @xmath6 , which means an observed exponent larger than the previously suggested exponents , see @xcite .
the previous analysis allows posing a basic question : ` is it possible to find an analytical solution for snrs given the three observable astronomical parameters , age , radius and velocity ? ' . in order to answer the above question , |
6,324 | Suppose that you have an abstract for a scientific paper: gaia is esa s ambitious space astrometry mission with a main objective to astrometrically and spectro - photometrically map not less than 1000 million celestial objects in our galaxy with unprecedented accuracy .
the announcement of opportunity ( ao ) for the data processing will be issued by esa late in 2006 .
the gaia data processing and analysis consortium ( dpac ) has been formed recently and is preparing an answer to this ao .
the satellite will downlink around 100 tb of raw telemetry data over a mission duration of 56 years . to achieve its required accuracy of a few tens of microarcseconds in astrometry , a highly involved processing of this data
is required .
in addition to the main astrometric instrument gaia will host a radial - velocity spectrometer and two low - resolution dispersers for multi - colour photometry .
all instrument modules share a common focal plane made of a ccd mosaic about 1 square meter in size and featuring close to 1 giga pixels .
each of the various instruments requires a relatively complex processing while at the same time being interdependent .
we describe the composition and structure of the dpac and the envisaged overall architecture of the system .
we shall delve further into the core processing - one of the nine , so - called coordination units comprising the gaia processing system . .
And you have already written the first three sentences of the full article: this paper is sub - divided in four sections : we give a brief overview of the gaia satellite and introduce the data processing and analysis consortium ( dpac ) .
following on from this we describe the overall system architecture for gaia processing and finally take a more detailed look at the core processing .
the gaia payload consists of three distinct instruments for astrometric , photometric and spectroscopic measurements , mounted on a single optical bench ..
Please generate the next two sentences of the article | unlike hst and sim , which are pointing missions observing a preselected list of objects , gaia is a scanning satellite that will repeatedly survey in a systematic way the whole sky .
the main performances of gaia expressed with just a few numbers are just staggering and account for the vast scientific harvest awaited from the mission : a complete survey to 20th magnitude of all point sources amounting to more than one thousand million objects , with an astrometric accuracy of 12@xmath0 at 15th magnitude and @xmath1 for the few million stars brighter than 13th magnitude ; radial velocities down to 17th magnitude , with an accuracy ranging from 1 to @xmath2 ; multi - epoch spectrophotometry for every observed source sampling from the visible to the near ir . beyond its sheer measurement accuracy |
6,325 | Suppose that you have an abstract for a scientific paper: results are presented from the atlas collaboration from the 2010 lhc heavy ion run , during which nearly 10 inverse microbarns of luminosity were delivered .
soft physics results include charged particle multiplicities and collective flow .
the charged particle multiplicity , which tracks initial state entropy production , increases by a factor of two relative to the top rhic energy , with a centrality dependence very similar to that already measured at rhic .
measurements of elliptic flow out to large transverse momentum also show similar results to what was measured at rhic , but no significant pseudorapidity dependence .
extensions of these measurements to higher harmonics have also been made , and can be used to explain structures in the two - particle correlation functions that had long been attributed to jet - medium interactions .
new hard probe measurements include single muons , jets and high @xmath0 hadrons .
single muons at high momentum are used to extract the yield of @xmath1 bosons and are found to be consistent within statistical uncertainties with binary collision scaling .
conversely , jets are found to be suppressed in central events by a factor of two relative to peripheral events , with no significant dependence on the jet energy .
fragmentation functions are also found to be the same in central and peripheral events .
finally , charged hadrons have been measured out to 30 gev , and their centrality dependence relative to peripheral events is similar to that found for jets . .
And you have already written the first three sentences of the full article: the atlas detector at the lhc @xcite , shown in fig .
[ atlas ] , was designed primarily for precise measurements in the highest - energy proton - proton collisions , particularly to discover new high - mass particle states .
however , it is also a very capable detector for the measurement of heavy ion collisions at the highest energies achieved to date , already a factor of 14 higher than available at the relativistic heavy ion collider ..
Please generate the next two sentences of the article | the atlas inner detector is immersed in a 2 tesla solenoid magnetic field and provides precise reconstruction of particle trajectories typically with three pixel layers and four double sided silicon strip detectors out to @xmath2 , as well as a transition radiation tracker , out to @xmath3 .
the longitudinally segmented atlas calorimeter provides electromagnetic and hadronic measurements out to @xmath4 , with particularly high spatial precision in the @xmath5 direction . finally , the atlas muon spectrometer is located outside the calorimeters ( which range out most of the hadronic backgrounds ) and measures muon tracks out to @xmath6 . the lhc provided lead - lead collisions to the three large experiments in november and december 2010 , and atlas accumulated almost ten inverse microbarns of luminosity , as shown in the right panel of fig . |
6,326 | Suppose that you have an abstract for a scientific paper: we derive the most general seiberg - witten maps for noncommutative gauge theories in second order of the noncommutative parameter @xmath0 .
our results reveal the existence of more ambiguities than previously known .
in particular , we demonstrate that some of these ambiguities enter observables like scattering cross sections and enlarge the parameter space of the noncommutative standard model beyond @xmath1 . .
And you have already written the first three sentences of the full article: with the start of data taking at the large hadron collider ( lhc ) , particle physics will , for the first time , directly probe the tera scale , i.e. the scale of electroweak symmetry breaking according to the standard model ( sm ) , around @xmath2 . while the sm has been confirmed experimentally to be a very precise effective description of the physics below the tera scale ,
there are many serious contenders for the more fundamental theory beneath the sm .
for quite some time , superstring theory has been a leading candidate for the fundamental theory unifying all known interactions ..
Please generate the next two sentences of the article | there are certain solutions of superstring theory with additional spatial dimensions , where the characteristic string scales are low enough to allow experimental tests at the lhc and the planned international @xmath3 linear collider ( ilc ) .
one spectacular prediction @xcite of superstring theory is the emergence of a noncommutative ( nc ) structure of spacetime at a scale @xmath4 associated with nonvanishing commutators @xmath5 = { \mathrm{i}}\theta_{\mu\nu } = { \mathrm{i}}\frac{1}{\lambda_{\text{nc}}^2}c_{\mu\nu}\ ] ] of spacetime coordinates that correspond to oriented minimal resolvable areas of size @xmath6 . while a nonvanishing commutator like ( [ eq : nc - geometry ] ) had been proposed much earlier @xcite as a regulator of divergencies in quantum field theory ( qft ) and quantum gravity , the observation of @xcite caused intense renewed interest in qft on nc spacetimes ( ncqft ) . |
6,327 | Suppose that you have an abstract for a scientific paper: the quantum state of a system of @xmath0 qubits can be represented by a wigner function on a discrete phase space , each axis of the phase space taking values in the finite field @xmath1 . within this framework
, we show that one can make sense of the notion of a `` rotationally invariant state '' of any collection of qubits , and that any such state is , in a well defined sense , a state of minimum uncertainty . .
And you have already written the first three sentences of the full article: a quantum state can not be squeezed down to a point in phase space .
but there are quantum states that closely approximate classical states , such as the coherent states of a harmonic oscillator
. one characterization of the coherent states is based on the wigner function : they are the only states for which the wigner function is both strictly positive and rotationally symmetric around its center ( here we assume a specific scaling of the axes appropriate for the given oscillator ).
Please generate the next two sentences of the article | . one can also express the quantum mechanics of _ discrete _ systems in terms of phase space . in this paper
we consider a system of @xmath0 qubits described in the framework of ref . |
6,328 | Suppose that you have an abstract for a scientific paper: the status of the precision tests of the electroweak interactions is reviewed in this paper .
an emphasis is put on the standard model analysis based on measurements at lep / slc and the tevatron .
the results of the measurements of the electroweak mixing angle in the nutev experiment and the future prospects are discussed .
= 18pt .
And you have already written the first three sentences of the full article: the unification of the electromagnetic and weak interactions in 1968 @xcite , the discoveries of the neutral currents in 1973 @xcite , of the charm quark in 1974 @xcite , of the and bosons in 1983 @xcite were very successful steps for the theory of the electroweak ( ew ) interactions , the standard model ( sm ) @xcite .
after the discoveries of the top quark in 1995 @xcite and the tau neutrino in 2000 @xcite the electroweak sm became the commonly accepted theory of the fundamental electroweak interactions .
it is a gauge invariant quantum field theory based on the symmetry group @xmath0 , which is spontaneously broken by the higgs mechanism ..
Please generate the next two sentences of the article | the renormalizability of the sm @xcite allows us to make precise predictions for measurable quantities at higher orders of the perturbative expansion , in terms of a few input parameters .
the higher - order terms , radiative corrections ( rc ) or quantum corrections , contain the self - coupling of the vector bosons as well their interactions with the higgs field and the top quark . |
6,329 | Suppose that you have an abstract for a scientific paper: the present paper deals with quantization of perfect fluid anisotropic cosmological models .
bianchi type v and ix models are discussed following schutz s method of expressing fluid velocities in terms of six potentials .
the wave functions are found for several examples of equations of state . in one case
a complete wave packet could be formed analytically .
the initial singularity of a zero proper volume can be avoided in this case , but it is plagued by the usual problem of non - unitarity of anisotropic quantum cosmological models .
it is seen that a particular operator ordering alleviates this problem .
* perfect fluid quantum anisotropic universe : merits and challenges * + barun majumder and narayan banerjee + department of physical sciences , + indian institute of science education and research - kolkata , + mohanpur campus , p.o .
bckv main office , district nadia , + west bengal 741252 , india .
_ pacs numbers : 04.20.cv . , 04.20.me_ .
And you have already written the first three sentences of the full article: the basic motivation behind a quantum cosmological model is two - fold .
one is the fact that when the linear dimension of the universe reaches the planck scale ( @xmath0 cm ) , the universe is indeed governed by a quantum picture .
the second is the hope that a quantum description might be able to produce a singularity free birth of our universe ..
Please generate the next two sentences of the article | the quantum state of the universe is described by a wave function @xmath1 which is the solution of the wheeler dewitt equation on a minisuperspace . for a comprehensive review
, we refer to @xcite . |
6,330 | Suppose that you have an abstract for a scientific paper: the efficiency of heat engines is limited by the carnot bound , attained when the engine cycle is reversible .
quantum engines fuelled by non - thermal ( e.g. , squeezed - thermal ) baths have been shown to surpass this bound . yet , their maximum efficiency can not be determined by the reversibility condition , which may yield an unachievable efficiency bound above @xmath0 .
this prompts the question : what does really limit the efficiency ? we identify the fraction of the exchanged energy between a quantum system and a bath that necessarily causes an entropy change and derive a new inequality for the latter .
this formulation reveals a universal efficiency bound for quantum engines which is invariably attained for the least dissipation over the engine cycle but does not imply reversibility , unless the baths are thermal .
this bound thus can not be solely deduced from the laws of thermodynamics .
we illustrate these results for the practically - relevant carnot- and otto cycles energised by non - thermal baths , which are both shown to be restricted by our new efficiency bound . .
And you have already written the first three sentences of the full article: engines are machines that convert some form of energy ( e.g. , thermal or electrical energy ) into work .
their efficiency , defined as the ratio of the extracted work to the invested energy , is restricted to @xmath0 at most by the energy - conservation law .
while mechanical engines may reach this bound , carnot showed @xcite that the efficiency of any heat engine that cyclically operates between two thermal baths is universally limited by the ratio of the bath temperatures , regardless of the concrete design @xcite ..
Please generate the next two sentences of the article | the universality of this bound led to the formalisation of the second law of thermodynamics and the introduction of the notion of entropy by clausius @xcite . in terms of entropy
, the carnot bound is attained by ( idealised ) heat engines that operate reversibly , so that the total entropy of the engine and the baths is unaltered over a cycle @xcite . |
6,331 | Suppose that you have an abstract for a scientific paper: two compounds , tetragonal yb@xmath0 and cubic yb@xmath1 , have been investigated by electric - field gradient ( efg ) and knight shift measurements at the boron sites using the @xmath2b nuclear magnetic resonance ( nmr ) technique and by performing first - principles calculations . in yb@xmath1 @xmath2b ( @xmath3 )
nmr spectra reveal patterns typical for an axially symmetric field gradient with a quadrupole coupling frequency of @xmath4 khz . in the second boride ( yb@xmath0 ) three different efgs were observed corresponding to the three inequivalent crystallographic sites for the boron atoms ( @xmath5 , @xmath6 , and @xmath7 ) .
they correspond to : @xmath8 khz with an asymmetry parameter @xmath9 , @xmath10 khz , @xmath11 , and @xmath12 khz , @xmath13 .
the knight shifts measured by magic - angle spinning ( mas ) nmr at room temperature are very small being @xmath14 ppm and @xmath15 ppm for yb@xmath0 and yb@xmath1 , respectively . for the theoretical calculations structure optimizations were performed as a first step . for the obtained structural parameters
the efgs were computed within the local - density approximation .
very satisfactory agreement between experimental and theoretical results is obtained both for the structural parameters and the b efgs thus confirming the underlying structural models .
in addition to the efgs , band structures , densities of states , and valence - electron densities are presented and the bonding situation in the two yttrium borides is discussed .
the band - structure results are compatible with the very low values for the knight shifts mentioned above .
metal borides ; electronic band structure ; electric field gradient ; chemical bonding ; nmr .
And you have already written the first three sentences of the full article: through their specific properties , transition metal borides became attractive both from scientific and technical point of view .
for instance , yb@xmath1 , like some other rare - earth and actinide hexaborides , shows superconductivity below 7.1 k @xcite and has been considered as a possible candidate for high - temperature thermoelectric materials @xcite .
detailed knowledge of the electronic structure of a material is a key ingredient for an in - depth understanding of many of its macroscopic features ..
Please generate the next two sentences of the article | a combination of experimental methods as well as computations on an _ ab - initio _ level has proved very efficient , in particular relating electronic structure calculations to results of nuclear magnetic resonance ( nmr ) technique .
the value of the electric field gradient ( efg ) , measured by nmr quadrupole interaction , is directly determined by the charge distribution around the nucleus . |
6,332 | Suppose that you have an abstract for a scientific paper: we present a comparative theoretical and experimental study of dynamic structure factors ( momentum - dependent loss functions ) of the noble metals cu , ag , and au in the energy range of 0@xmath060 ev .
the emphasis is on theoretical results that are compared with new as well as available experimental data .
dynamic structure factors are calculated within the linear - response formalism of time - dependent density - functional theory , using the full - potential linearized augmented plane - wave ( fp - lapw ) method . for the studied energy range , local - field effects
are found to be very important for ag and au and only marginally relevant for cu .
we present an explanation for this surprising behavior .
loss functions of all three metals possess a complex multi - peak structure .
we classify the features in the loss function as being related to collective excitations , interband transitions , or mixed modes .
the impact of short - range correlations on the dynamic response functions are evaluated by comparing the results of the random - phase approximation to those of the time - dependent local - density approximation .
exchange correlation effects are found to be weak for small momentum transfers , but increasingly important for larger momenta .
the calculated structure factors agree well with experiments . .
And you have already written the first three sentences of the full article: electron energy loss spectroscopy ( eels ) in the transmission electron microscope ( tem ) is a well - established experimental technique to study the electronic structure of materials .
@xcite energy loss is directly linked to the imaginary part of the inverse dielectric function , and therefore many other properties of interest can be extracted from these measurements . combined with the imaging capabilities of the microscope , as well as optical and x - ray emission spectroscopies that can be performed in the tem ,
eels is an excellent tool for materials characterization . in the past decades.
Please generate the next two sentences of the article | , the tem has experienced an impressive improvement in its performance .
modern microscopes equipped with field - emission guns and monochromators routinely achieve an energy resolution of 0.5 ev or even 0.1 ev , @xcite while the resolution in the momentum transfer is better than 0.1 @xmath1 . |
6,333 | Suppose that you have an abstract for a scientific paper: we investigate a soliton cellular automaton ( box - ball system ) with periodic boundary conditions .
since the cellular automaton is a deterministic dynamical system that takes only a finite number of states , it will exhibit periodic motion .
we determine its fundamental cycle for a given initial state . .
And you have already written the first three sentences of the full article: a cellular automaton ( ca ) is a discrete dynamical system consisting of a regular array of cells@xcite .
each cell takes only a finite number of states and is updated in discrete time steps .
although the updating rules are simple , cas often exhibit very complicated time evolution patterns which resemble natural phenomena such as chemical reactions , turbulent flow , nonlinear dispersive waves and solitons ..
Please generate the next two sentences of the article | a typical ca exhibiting a solitonic behaviour is the box and ball system ( bbs ) which is a reinterpretation of the ca proposed by takahashi and satsuma@xcite .
the bbs is _ integrable _ in the sense that it is obtained from the kdv equation through a limiting procedure called ultradiscretization@xcite . |
6,334 | Suppose that you have an abstract for a scientific paper: radio continuum observations of barred galaxies revealed strong magnetic fields of @xmath0 g in the circumnuclear starbursts .
such fields are dynamically important and give rise to magnetic stress that causes inflow of gas towards the center at a rate of several solar masses per year , possibly along the spiral field seen in radio polarization and as optical dust lanes .
this may solve the long - standing question of how to feed active nuclei , and explain the relation between the bolometric luminosity of agn nuclei and the star - formation rate of their hosts .
the strong magnetic fields generated in young galaxies may serve as the link between star formation and accretion onto supermassive black holes .
magnetic fields of @xmath1 g strength were measured in the central region of the almost edge - on starburst galaxy ngc 253 .
four filaments emerging from the inner disk delineate the boundaries of the central outflow cone of hot gas .
strong faraday rotation of the polarized emission from the background disk indicates a large - scale helical field in the outflow walls . .
And you have already written the first three sentences of the full article: magnetic fields are a major agent in the ism and also control the density and propagation of cosmic rays .
the radio infrared correlation indicates that turbulent fields are strongest in star - forming regions .
magnetic fields and cosmic rays can provide the pressure to drive galactic outflows ..
Please generate the next two sentences of the article | outflows from starburst galaxies in the early universe may have magnetized the intergalactic medium . in spite of our increasing knowledge of cosmic magnetic fields , many important questions ,
especially their origin , strength in intergalactic space , first occurrence in young galaxies and their dynamical importance for galaxy evolution remain unanswered . |
6,335 | Suppose that you have an abstract for a scientific paper: * for the vast majority of naturally occurring , small , single domain proteins folding is often described as a two - state process that lacks detectable intermediates .
this observation has often been rationalized on the basis of a nucleation mechanism for protein folding whose basic premise is the idea that after completion of a specific set of contacts forming the so - called folding nucleus the native state is achieved promptly . here
we propose a methodology to identify folding nuclei in small lattice polymers and apply it to the study of protein molecules with chain length n=48 . to investigate the extent to which protein topology is a robust determinant of the nucleation mechanism we compare the nucleation scenario of a native - centric model with that of a sequence specific model sharing the same native fold . to evaluate the impact of the sequence s finner details in the nucleation mechanism we consider the folding of two non- homologous sequences .
we conclude that in a sequence - specific model the folding nucleus is , to some extent , formed by the most stable contacts in the protein and that the less stable linkages in the folding nucleus are solely determined by the fold s topology .
we have also found that independently of protein sequence the folding nucleus performs the same ` topological ' function .
this unifying feature of the nucleation mechanism results from the residues forming the folding nucleus being distributed along the protein chain in a similar and well - defined manner that is determined by the fold s topological features . * .
And you have already written the first three sentences of the full article: proteins do not appear to fold by means of a unique mechanism and over the years several phenomenological models have been proposed for protein folding @xcite .
the framework model , for example , is based on the idea that the formation of the hydrogen - bonded secondary structural elements precedes the formation of tertiary structure @xcite , and the diffusion - collision model assumes that part of the protein folding process involves the interaction of metastable regions of structure which , when in contact , may provide additional stabilization @xcite .
chymotrypsin inhibitor 2 , a small , single domain , two - state folder with 64 residues , epitomizes the so - called nucleation - condensation ( nc ) mechanism for protein folding ..
Please generate the next two sentences of the article | the latter was firstly investigated by shakhnovich , in the context of monte carlo lattice simulations @xcite , and by fersht through extensive protein engineering studies @xcite termed @xmath0-value analysis .
the nc mechanism can be viewed as a modified version of the nucleation - growth mechanism originally proposed by wetlaufer @xcite . |
6,336 | Suppose that you have an abstract for a scientific paper: cosmic reionization progresses as h ii regions form around sources of ionizing radiation .
their average size grows continuously until they percolate and complete reionization .
we demonstrate how this typical growth can be calculated around the largest , biased sources of uv emission such as quasars by further developing an analytical model based on the excursion set formalism .
this approach allows us to calculate the sizes and growth of the hii regions created by the progenitors of any dark matter halo of given mass and redshift with a minimum of free parameters .
statistical variations in the size of these pre - existing hii regions are an additional source of uncertainty in the determination of very high redshift quasar properties from their observed hii region sizes .
we use this model to demonstrate that the transmission gaps seen in very high redshift quasars can be understood from the radiation of only their progenitors and associated clustered small galaxies . the fit sets a lower limit on the redshift of overlap of @xmath0 .
this interpretation makes the transmission gaps independent of the age of the quasars observed .
if this interpretation were correct it would raise the prospects of using radio interferometers currently under construction to detect the epoch of reionization .
[ firstpage ] galaxies : formation intergalactic medium quasars : general cosmology : theory .
And you have already written the first three sentences of the full article: recent observations are just beginning to reveal the epoch of cosmological reionization , which defines a fundamental transition in the universe , separating the cosmic dark ages ( e.g. rees 1997 ) from the epoch of galaxy formation and evolution .
the appearance of a gunn - peterson trough ( gunn & peterson 1965 ) in quasar spectra indicates that reionization was ending at @xmath1 ( e.g. becker et al .
2001 ; fan et al ..
Please generate the next two sentences of the article | 2002 ; white et al . 2003 ) , while the large - angle polarization anisotropy of the cosmic microwave background observed by the wilkinson microwave anisotropy probe ( spergel et al .
2006 ) indicates the universe may have been significantly reionized by @xmath2 ( page et al . |
6,337 | Suppose that you have an abstract for a scientific paper: it has been observed that most manifolds in the callahan - hildebrand - weeks census of cusped hyperbolic @xmath0-manifolds are obtained by surgery on the minimally twisted 5-chain link ; a full classification of the exceptional surgeries on the 5-chain link has recently been completed . in this article , we provide a complete classification of the sets of exceptional slopes and fillings for all cusped hyperbolic surgeries on the minimally twisted 5-chain link , thereby describing the sets of exceptional slopes and fillings for most hyperbolic manifolds of small complexity and providing supporting evidence for some well - known conjectures . .
And you have already written the first three sentences of the full article: the set of exceptional slopes on a boundary component of a cusped hyperbolic manifold has generated a lot of interest in the literature ; there are many restrictions on the set of exceptional slopes on a boundary component of a hyperbolic 3-manifold @xmath1 and its corresponding fillings , for example , no such @xmath1 has two distinct @xmath2 fillings @xcite or more than 10 exceptional slopes @xcite .
however , it is still not known if a hyperbolic knot exterior in @xmath2 can have a reducible filling , or if @xmath1 can have a pair of exceptional slopes @xmath3 and @xmath4 corresponding to a lens space and toroidal space so that the _ distance _ ( minimal number of intersections ) between @xmath3 and @xmath4 is 4 .
conjecturally , neither are possible , see @xcite and @xcite respectively ..
Please generate the next two sentences of the article | moreover , it is conjecturally the case that the figure - eight knot exterior is the unique one - cusped hyperbolic manifold with 10 exceptional slopes @xcite and that the figure - eight knot exterior and its sister are the unique one - cusped hyperbolic manifolds having two exceptional slopes at distance 8 , see @xcite . in this article , by classifying the sets of exceptional slopes and the corresponding fillings for all manifolds obtained by surgery on the minimally twisted 5-chain link ( see the rightmost link in figure [ sequence : fig ] ) , we provide experimental evidence that supports these conjectures : [ flash ] if @xmath1 is a cusped hyperbolic manifold obtained by surgery on the minimally twisted 5-chain link then : * @xmath1 is not the exterior of a knot with a reducible filling ; * @xmath1 does not have a lens space and toroidal filling at distance 4 ; * if @xmath1 has 10 exceptional slopes then @xmath1 is the figure-8 knot exterior ; * if @xmath1 has exceptional slopes at distance 8 then @xmath1 is either the figure-8 knot exterior or the figure-8 knot exterior sister .
a notable collection of chain links is described in @xcite ; they are the figure-8 knot , the whitehead link , the 3-chain link , the 4-chain link with a half twist , and the minimally twisted 5-chain link . |
6,338 | Suppose that you have an abstract for a scientific paper: we compare the cumulative star formation histories ( sfhs ) of local group ( lg ) dwarf galaxies with those in the volume - limited acs nearby galaxy survey treasury ( angst ) sample ( d @xmath0 4 mpc ) , in order to understand how typical the lg dwarf galaxies are relative to those in the nearby universe .
the sfhs were derived in a uniform manner from high quality optical color - magnitude diagrams constructed from hubble space telescope imaging .
we find that the _ mean _ cumulative sfhs of the lg dwarfs are comparable to the mean cumulative sfhs of the angst sample for the three different morphological types ( dwarf spheroidals / ellipticals : dsph / de ; dwarf irregulars : di ; transition dwarfs : dtrans ) .
we also discuss effects such as population gradients and systematic uncertainties in the stellar models that may influence the derived sfhs . both the angst and local group dwarf galaxies show a consistent and strong morphology - density relationship , emphasizing the importance of environment in the evolution of dwarf galaxies .
specifically , we confirm that dis are found at lower densities and higher luminosities than dsphs , within this large sample .
we also find that dtrans are located in similar environments to those occupied by dwarf irregular galaxies , but have systematically lower luminosities that are more comparable to those of dwarf spheroidals .
the similarity of the sfhs and morphology - density relationships of the lg and angst dwarf galaxies suggests that the lg dwarfs are a good representation of dwarf galaxies in the local universe . .
And you have already written the first three sentences of the full article: dwarf galaxies in the local group ( lg ) are among the most well - studied galaxies in the universe .
detailed determinations of their kinematics , metallicities , and stellar contents serve as a basis for much of what we understand about the formation and evolution of both individual and groups of galaxies ( see reviews by * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
in particular , we can directly determine the history of star formation and chemical evolution for individual galaxies using hubble space telescope ( hst ) observations of resolved stellar populations in nearby and lg galaxies ( e.g. , * ? ? ? |
6,339 | Suppose that you have an abstract for a scientific paper: lvy flights represent the best strategy to randomly search for a target in an unknown environment , and have been widely observed in many animal species . here , we inspect and discuss recent results concerning human behavior and cognition .
different studies have shown that human mobility can be described in terms of lvy flights , while fresh evidence indicates that the same pattern accounts for human mental searches in online gambling sites .
thus , lvy flights emerge as a unifying concept with broad cross - disciplinary implications .
we argue that the ubiquity of such a pattern , both in behavior and cognition , suggests that the brain regions responsible for this behavior are likely to be evolutionarily old ( i.e. no frontal cortex is involved ) , and that fmri techniques might help to confirm this hypothesis .
lvy flights , human mobility , behavior , cognition .
And you have already written the first three sentences of the full article: lvy flights describe a class of random walks whose step lengths follow a power - law tailed distribution @xcite . in a lvy flight , the probability @xmath0 that the walker performs a jump of length @xmath1 is given by @xmath2 with @xmath3 .
lvy flights have been proven to be the best strategy that can be adopted in random searches @xcite .
in particular , viswanathan and collaborators proved that , independently of the dimensions of the space where the search is performed , the optimal exponent is @xmath4 if ( i ) the target sites are sparse , ( ii ) they can be visited multiple times , and ( iii ) the searcher can detect the target only when it is in its close vicinity @xcite . an important case where these conditions are naturally fulfilled concerns foraging animals looking for scarce preys , and in fact lvy flights have been observed in the patterns of movement of different species ranging from albatrosses @xcite to marine predators @xcite , and from monkeys @xcite to mussels @xcite ..
Please generate the next two sentences of the article | although in some cases further analysis is needed @xcite , the overall pattern appears to be robust @xcite .
the evidence for lvy strategies in humans has become manifest in the last few years . |
6,340 | Suppose that you have an abstract for a scientific paper: skew product systems with monotone one - dimensional fibre maps driven by piecewise expanding markov interval maps may show the phenomenon of intermingled basins @xcite . to quantify the degree of intermingledness the uncertainty exponent @xcite and the stability index @xcite
were suggested and characterized ( partially ) . here
we present an approach to evaluate / estimate these two quantities rigorously using thermodynamic formalism for the driving markov map . .
And you have already written the first three sentences of the full article: motivated by numerical observations by alexander , yorke , you and kan @xcite and sommerer and ott @xcite , the term _ intermingled basins _ was introduced to the mathematics literature by kan in @xcite : `` [ ] any open set which intersects one basin in a set of positive measure also intersects each of the other basins in a set of positive measure '' , and he showed the existence of an open set of diffeomorphisms with two intermingled basins on a three - dimensional manifold .
the degree of intermingledness was soon quantified by the _ uncertainty exponent _
@xcite originally introduced in @xcite . in @xcite this exponent.
Please generate the next two sentences of the article | is calculated numerically for a certain model of point particle motion subject to friction and periodic forcing in a two - dimensional potential ( which does not display intermingled but riddled basins ) , and the authors support their findings theoretically by calculations carried out for a simple piecewise linear model , that has the form of a skew product over two - leg base map with two full linear branches and for which the dynamics are essentially equivalent to that of a random walk with two regimes of transition probabilities .
later , a related quantity denoted _ stability index _ was introduced in @xcite and further studied in @xcite . while the uncertainty exponent measures the degree of intermingledness averaged over points that are equidistant to one of the attractors , the stability index measures intermingledness close to individual points , so it resembles a local dimension . in the present paper we provide rigorous derivations of the two exponents mentioned before for nonlinear generalizations of the piecewise linear system . |
6,341 | Suppose that you have an abstract for a scientific paper: the stellar halos of spiral galaxies bear important chemo dynamical signatures of galaxy formation .
we present here the analysis of 89 semi cosmological spiral galaxy simulations , spanning @xmath0 4 magnitudes in total galactic luminosity . these simulations sample a wide variety of merging histories and
show significant dispersion in halo metallicity at a given total luminosity - more than a factor of ten in metallicity .
our preliminary analysis suggests that galaxies with a more extended merging history possess halos which have younger and more metal rich stellar populations than the stellar halos associated with galaxies with a more abbreviated assembly . a correlation between halo metallicity and
its surface brightness has also been found , reflecting the correlation between halo metallicity and its stellar mass .
our simulations are compared with recent hubble space telescope observations of resolved stellar halos in nearby spirals .
[ firstpage ] galaxies : halos galaxies : formation galaxies : evolution galaxies : structure numerical methods .
And you have already written the first three sentences of the full article: understanding the formation history of stellar halos is one of the classical pursuits of galactic astronomy .
the problem is generally framed within the context of two competing scenarios : one of `` rapid collapse '' ( eggen , lynden bell & sandage 1962 ) , in which the stellar halo is formed by the rapid collapse of a proto galaxy within a dynamical timescale ( @xmath0 10@xmath1 yr ) , and one of `` galactic assembly '' @xcite , whereby the stellar halo is assembled on a longer timescale ( @xmath0 10@xmath2 yr ) by the accretion of `` building
blocks '' , each with separate enrichment histories ..
Please generate the next two sentences of the article | both scenarios have their strengths and weaknesses , and it would appear that a hybrid model is the most plausible option consistent with extant data ( e.g. : @xcite ; @xcite ) . an intriguing piece of the halo formation `` puzzle '' is provided by comparing the stellar halo of our own milky way with that of its neighbour , m31 .
first , despite their comparable total galactic luminosities , the stellar halo of m31 is _ apparently _ much more metal rich than that of the milky way ( e.g. : @xcite ; @xcite ; durrell , harris & pritchet 2001 ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite ) . |
6,342 | Suppose that you have an abstract for a scientific paper: the spin dynamics of rare earth ions ( er , nd , sm and gd ) in heavily doped phosphate glasses have been investigated using @xmath0p nmr .
correlation times in the range 10@xmath1 to 10@xmath2 s have been obtained for temperatures between 4 k and 100 k. no evidence of spin - spin coupling between the ions has been found and spin relaxation occurs via conventional phonon processes , including the orbach process . a model involving inhomogeneous broadening of the nmr resonance lines , with distinct sample regions corresponding to the presence or absence of nuclear spin diffusion , has been used in extracting the electron spin correlation times from the nmr measurements . .
And you have already written the first three sentences of the full article: novel magnetic and magneto - optic phenomena , of interest for optoelectronic applications , have been found in the rare earth ( r ) metaphosphate glasses ( remg ) with compositions in the vicinity ( r@xmath30@xmath4)@xmath5(p@xmath30@xmath6)@xmath7 . for example , these paramagnetic materials exhibit the largest known magnetic contributions to the low temperature specific heats in oxide glasses @xmath8 x - ray diffraction and exafs studies@xmath9 have shown that the structure of remg comprises a 3-d network of corner - linked po@xmath10 tetrahedra , with the rare - earth ions , which in several instances are known to be trivalent r@xmath11 occupying sites within the po@xmath10 skeleton . in recent work @xmath12
we have shown that it is possible to study the spin dynamics of rare earth ions in metaphosphate glasses using @xmath0p nmr as a probe .
the present investigation has extended the nmr measurements to a number of remg systems containing er , nd , sm and gd ions . for some of these systems , la or y ions have been used as a buffer in order to lower the concentration of magnetic ions while preserving the metaphosphate glass structure ..
Please generate the next two sentences of the article | information on the dynamics of the rare earth ions has been obtained using the model developed previously @xmath13 .
the local fields set up by paramagnetic ions lead to nuclear resonance frequency shifts and the establishment of an exclusion barrier of radius @xmath14 , inside which spins are excluded from the observed nmr signal , together with a diffusion barrier of radius @xmath15 inside which nuclear spin diffusion does not operate@xmath13 . in highly paramagnetic systems of the type studied here , nuclear spin systems are thus composed of three distinct spatial regions corresponding to spin diffusive , non - diffusive and exclusion zones . |
6,343 | Suppose that you have an abstract for a scientific paper: open quantum systems are studied from the thermodynamical point of view unifying the principle of maximum informational entropy and the hypothesis of relaxation times hierarchy .
the result of the unification is a non - markovian and local in time master equation that provides a direct connection of dynamical and thermodynamical properties of open quantum systems .
the power of the approach is illustrated with the application to the damped harmonic oscillator and the damped driven two - level system resulting in analytical expressions for the non - markovian and non - equilibrium entropy and inverse temperature . .
And you have already written the first three sentences of the full article: open quantum systems attract attention in both theoretical @xcite and experimental @xcite research .
the theoretical investigation of open quantum systems uses a great variety of different tools @xcite .
typically , these methods allow the determination of a reduced density matrix @xcite or a quantum state vector @xcite of an open quantum system ..
Please generate the next two sentences of the article | usually , the reduced density operator carries also unnecessary information about different correlations in the open quantum system that are inaccessible to experimental observation . to study only the relevant information about an open quantum system it is appropriate to use methods of non - equilibrium thermodynamics .
as for the theoretical study of open quantum systems , several approaches to non - equilibrium thermodynamics have been proposed . |
6,344 | Suppose that you have an abstract for a scientific paper: in the paper we present an isothermal model for describing damage and fatigue by the use of the ginzburg - landau ( g - l ) equation .
fatigue produces progressive damage , which is related with a variation of the internal structure of the material .
the g - l equation studies the evolution of the order parameter , which describes the constitutive arrangement of the system and , in this framework , the evolution of damage . the thermodynamic coherence of the model is proved . in the last part of the work
, we extend the results of the paper to a non - isothermal system , where fatigue contains thermal effects , which increase the damage of materials .
keywords : damage , fatigue , phase transition , thermodynamics . .
And you have already written the first three sentences of the full article: the fatigue notion was founded on the concept of degraded or tired material and linked to the observation of material damage subjected to cyclic loading , which never reaches a level sufficient to cause failure in a single application ( see @xcite , @xcite , @xcite , @xcite and schu ) .
it is apparent that fatigue produces progressive damage involving plastic deformation , crack nucleation , creep rupture and finally rapid fracture .
material damage is the gradual process of mechanical deterioration , that basically results in a structural component failure ( see @xcite kork and @xcite ) . among the first and most important mathematical models of fatigue , we recall.
Please generate the next two sentences of the article | caputo s papers @xcite , @xcite and @xcite , where he proposes a definition of fatigue using the fractional derivative defined by him in @xcite .
this model estimates fatigue as function of the maximum strain applied , related to the number of cycles and of their frequency . |
6,345 | Suppose that you have an abstract for a scientific paper: the departure of a granular gas in the instable region of parameters from the initial homogeneous cooling state is studied .
results from molecular dynamics and from direct monte carlo simulation of the boltzmann equation are compared .
it is shown that the boltzmann equation accurately predicts the low density limit of the system . the relevant role played by the parallelization of the velocities as time proceeds and the dependence of this effect on the density
is analyzed in detail . .
And you have already written the first three sentences of the full article: the study of granular systems has attracted much interest in the last years .
the practical importance of these systems , which are present in many situations in daily life , together with the richness and complexity of their behavior@xcite , have motivated many researches trying to describe and understand the physical mechanisms governing granular flows .
of course , the variety of what we call granular media makes it necessary to use different theoretical descriptions depending on the problem we wish to address . in the context of rapid , low density , granular flows ,.
Please generate the next two sentences of the article | the application of the methods of the kinetic theory for molecular ( elastic ) systems has proven to be a very useful tool .
the starting point for this description has been in many cases the extension to inelastic collisions of the boltzmann equation , which is derived under the same hypothesis as in elastic systems . from this kinetic equation , |
6,346 | Suppose that you have an abstract for a scientific paper: josephson parametric amplifiers ( jpa ) are promising devices for applications in circuit quantum electrodynamics ( qed ) and for studies on propagating quantum microwaves because of their good noise performance . in this work ,
we present a systematic characterization of a flux - driven jpa at millikelvin temperatures .
in particular , we study in detail its squeezing properties by two different detection techniques . with the homodyne setup
, we observe squeezing of vacuum fluctuations by superposing signal and idler bands . for a quantitative analysis
we apply dual - path cross - correlation techniques to reconstruct the wigner functions of various squeezed vacuum and thermal states . at @xmath0 signal gain , we find @xmath1 squeezing below vacuum .
in addition , we discuss the physics behind squeezed coherent microwave fields . finally , we analyze the jpa noise temperature in the degenerate mode and find a value smaller than the standard quantum limit for phase - insensitive amplifiers . .
And you have already written the first three sentences of the full article: the tremendous progress in the field of quantum electrodynamics ( qed ) with solid - state superconducting circuits @xcite has recently triggered massive efforts aiming at the investigation of propagating quantum microwaves @xcite . towards this end ,
the analysis of propagating microwave light at frequencies of a few gigahertz and with power levels below a single photon on average has become an important task .
however , due to the low signal energy of typically only a few attowatt per megahertz bandwidth , the measurement of such signals requires amplification . for a long time , phase - insensitive high electron mobility transistor ( hemt ) amplifiers are considered as a good choice ..
Please generate the next two sentences of the article | they feature a broad operation bandwidth , high gain , but still add 10 - 20 noise photons @xcite to the signal .
this noise can be significantly reduced by using josephson parametric amplifiers ( jpa ) @xcite , which achieve amplification via a high - frequency modulation of a josephson inductance . in the phase - insensitive or non - degenerate operation mode , |
6,347 | Suppose that you have an abstract for a scientific paper: we propose a copula based method to handle missing values in multivariate data of mixed types in multilevel data sets .
building upon the extended rank likelihood of @xcite and the multinomial probit model , our model is a latent variable model which is able to capture the relationship among variables of different types as well as accounting for the clustering structure .
we fit the model by approximating the posterior distribution of the parameters and the missing values through a gibbs sampling scheme .
we use the multiple imputation procedure to incorporate the uncertainty due to missing values in the analysis of the data .
our proposed method is evaluated through simulations to compare it with several conventional methods of handling missing data .
we also apply our method to a data set from a cluster randomized controlled trial of a multidisciplinary intervention in acute stroke units .
we conclude that our proposed copula based imputation model for mixed type variables achieves reasonably good imputation accuracy and recovery of parameters in some models of interest , and that adding random effects enhances performance when the clustering effect is strong . .
And you have already written the first three sentences of the full article: multivariate analysis often involves understanding the relationship among variables of different types .
our motivating data set is from the quality in acute stroke care ( qasc ) study , which implemented a multidisciplinary intervention to manage fever , hyperglycaemia and swallowing dysfunction in acute stroke patients @xcite .
this study was one of the largest rigorously evaluated clinical trials which showed that organised stroke unit care significantly reduced death and disability among stroke patients ..
Please generate the next two sentences of the article | there were 19 acute stroke units in new south wales , australia that participated in the study , and they were randomly assigned to an intervention group ( 10 units ) and a control group ( 9 units ) .
a pre - intervention and a post - intervention cohort of patients were recruited , their demographic variables such as age , gender and marital status were obtained , and process of care variables such as temperature , time from onset to hospital and length of stay in hospital were recorded . |
6,348 | Suppose that you have an abstract for a scientific paper: we present the discovery of an object in the pleiades open cluster , named teide 2 , with optical and infrared photometry which place it on the cluster sequence slightly below the expected substellar mass limit .
we have obtained low- and high - resolution spectra that allow us to determine its spectral type ( m6 ) , radial velocity and rotational broadening ; and to detect h@xmath0 in emission and lii 670.8 nm in absorption .
all the observed properties strongly support the membership of teide 2 into the pleiades .
this object has an important role in defining the reappearance of lithium below the substellar limit in the pleiades .
the age of the pleiades very low - mass members based on their luminosities and absence or presence of lithium is constrained to be in the range 100120 myr .
e - mail addresses : [email protected] , [email protected] [email protected],[email protected],[email protected],[email protected] .
And you have already written the first three sentences of the full article: the pleiades open cluster has become a favorite location for brown dwarf ( bd ) searches .
this privilege is due to its proximity , young age , low extinction and compactness ( the same properties that make it easily recognized to the naked eye ) .
such advantages were recognized over ten years ago , when the first ccd surveys of the cluster began ( jameson & skillen @xcite ; stauffer et al ..
Please generate the next two sentences of the article | since then , there has been many efforts to reach fainter magnitudes and cover more area ( see hambly @xcite for a review ) , which have revealed many bd candidates .
a breakthrough in our understanding of bds has come from the successful application of the lithium test ( rebolo , martn & magazz @xcite ; magazz , martn & rebolo @xcite ) , which is an efficient observational method for distinguishing young bds from very low - mass ( vlm ) stars . |
6,349 | Suppose that you have an abstract for a scientific paper: i briefly review standard top quark physics at hadron colliders and summarize the contributions to this conference .
the possibility of new mechanisms for @xmath0 production are also discussed .
fermilab - conf-94/322-t + hep - ph/9409312 + september 13 , 1994 + .
And you have already written the first three sentences of the full article: in hadron colliders the dominant mode of top quark production is via quark - antiquark annihilation or gluon - gluon fusion , @xmath1 however there are other modes , @xmath2 in this list i have not included processes which pick a @xmath3-quark out of the hadron .
these processes are approximately ordered according to their rates in hadron colliders .
1(a ) has the rates for the first three processes at the tevatron assuming that the dominant decay model for the top quark is @xmath4 ..
Please generate the next two sentences of the article | the channel , positron plus jets , was chosen so that the final state for all three processes is positron , @xmath5 plus jets .
the qcd , @xmath6-gluon and @xmath7 processes have two , one and zero non-@xmath3-quark jets , respectively . |
6,350 | Suppose that you have an abstract for a scientific paper: superconducting quantum interference filters ( sqifs ) are arrays of superconducting loops of different sizes including josephson junctions ( jj ) . for a random distribution of sizes
, they present a non - periodic response to an applied magnetic field , with a large transfer function and a magnetic field sensitivity potentially improved with respect to that of a single squid .
such properties make sqifs interesting devices to detect the magnetic component of electromagnetic waves at microwave frequencies .
we have used the highly scalable technique of ion irradiation to make squids and sqifs based on commercial @xmath0films , and studied their properties .
both display optimum performances as a function of temperature and bias current , that can be understood in the frame of numerical simulations that we developed .
the role of asymmetries and dispersion in jj characteristics ( routinely found in high tc superconductors technologies ) is also studied .
we have found that both do not impede the existence of a sqif effect but play a role on the emergence of the optimal point .
we finally present results on sqif made with 2000 squid in series , showing a transfer function @xmath1 . .
And you have already written the first three sentences of the full article: since the pioneering works of carelli et al@xcite and oppenlnder et al@xcite , a lot of work has been devoted to the development of superconducting quantum interference filters ( sqifs ) for sensitive absolute magnetometry or for rf applications . indeed ,
since the response of the sqif is non - periodic in magnetic field , there is no need of a feed - back loop to maintain a fixed functioning point
. not only the absolute value of the magnetic field can be therefore measured , but the band - width of the device is not limited by the feed - back electronics anymore ( typically a few mhz usually @xcite ) ..
Please generate the next two sentences of the article | in addition , one can chose the arrangement of the squids in the array to match the impedance of the device to the read - out system .
this paves the way for rf applications of sqifs , such as compact low noise amplifiers and sub - wavelength broad band antennas ( for a review see mukhanov et al@xcite ) . in the recent years , different architectures and geometries of sqifs |
6,351 | Suppose that you have an abstract for a scientific paper: our recent work on starbursts , particularly in the ultraviolet ( uv ) , is summarized .
the intrinsic uv fluxes of uv selected starbursts can be derived from uv data alone because , to first order , their dust behaves like a foreground screen .
this allows a comparison of the bolometric effective surface brightness @xmath0 of uv selected starbursts to other starburst samples .
starbursts have a robust ( 90th percentile ) upper limit @xmath1 , which strongly suggest that their global star formation intensities are regulated .
the mechanism(s ) involved in the regulation are not yet clear .
the dust attenuation corrections for high-@xmath2 starbursts are significant . calculations of the rate of evolution in the early universe based on zero dust interpretations are probably underestimated by about an order of magnitude .
hence the early universe was not quiescent , but obscured . .
And you have already written the first three sentences of the full article: the pace of cosmic evolution is marked out by the condensation of stars from the ism .
starbursts , regions of intense massive star formation which can dominate the bolometric output of galaxies , are crucial to our understanding of this evolution at all redshifts . in the local universe about 25% of high mass star formation
is contained within starburst galaxies ( heckman , 1997 ; gallego _ et al._1995 ) . at high redshift ( @xmath3 ) , starbursts are the the easiest galaxies to detect , and can be used to directly trace the rate of evolution ( madau _ et al . _.
Please generate the next two sentences of the article | so , to understand the cosmological pace of evolution , we must understand starbursts .
we would like to know how to derive intrinsic star formation rates and the physics that determines these rates . |
6,352 | Suppose that you have an abstract for a scientific paper: we present amalgamated free products satisfying coupling rigidity with respect to the automorphism group of the associated bass - serre tree . as an application
, we obtain orbit equivalence rigidity for amalgamated free products of mapping class groups . .
And you have already written the first three sentences of the full article: measure equivalence is an equivalence relation between discrete countable groups and is defined so that two such groups are equivalent if there exists a measure space , called a coupling , equipped with certain measure - preserving actions of those groups ( see definition [ defn - me ] ) .
this is closely related to orbit equivalence between measure - preserving actions of discrete countable groups on probability measure spaces .
we refer to @xcite , @xcite , @xcite , @xcite and @xcite for recent developments and related topics on measure and orbit equivalence . in @xcite , given two discrete countable groups @xmath0 , @xmath1 satisfying rigidity in the sense of measure equivalence , we present a construction of an amalgamated free product @xmath2 satisfying rigidity of the same kind ..
Please generate the next two sentences of the article | the first step for the proof of this result is to show the coupling rigidity of @xmath3 with respect to the automorphism group of the bass - serre tree @xmath4 associated to the decomposition of @xmath3 , which is proved on the assumption that @xmath0 and @xmath1 satisfy property ( t ) . as a consequence , for any discrete countable group @xmath5 that is measure equivalent to @xmath3
, we can find a simplicial action of @xmath5 on @xmath4 and obtain information on the structure of @xmath5 through the bass - serre theory . |
6,353 | Suppose that you have an abstract for a scientific paper: we describe a code designed for hot media ( t @xmath0 a few 10@xmath1 k ) , optically thick to compton scattering .
it computes the structure of a plane - parallel slab of gas in thermal and ionization equilibrium , illuminated on one side or on both sides by a given spectrum .
this code has been presented in a previous paper ( dumont , abrassart & collin 2000 ) , where several aspects were already discussed .
so we focus here mainly on the recent developments .
presently the code solves the transfer of the continuum with the accelerated lambda iteration method ( ali ) and that of the lines in a two stream eddington approximation , without using the local escape probability formalism to approximate the line transfer .
this transfer code is coupled with a monte carlo code which allows to take into account direct and inverse compton diffusions , and to compute the spectrum emitted up to mev energies , in any geometry .
the influence of a few physical parameters is shown , and the importance of the density and pressure distribution ( constant density , pressure equilibrium , or hydrostatic equilibrium ) is stressed .
recent improvements in the treatment of the atomic data are described , and foreseen developments are mentioned .
# 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 average continuum observed in active galactic nuclei ( agn ) is shown in fig . 1 from the optical to x - ray range , as obtained from a composite optical - uv spectrum of francis et al .
( 1991 ) and zheng et al .
( 1997 ) , and from an average ( slightly modified ) soft x - ray spectrum of laor et al ..
Please generate the next two sentences of the article | it is widely admitted since several years that the optical - uv part of this continuum is produced by a warm ( temperature of the order of @xmath2 k ) , optically thick or effectively thick medium , most likely an accretion disc .
moreover , one deduces from the spectral distribution in the hard x - ray range , in particular the 30 kev hump observed in many seyfert 1 galaxies , and from the presence of other features like the iron k line around 7 kev , that this medium is irradiated by a hard x - ray source , which is partly reprocessed and reemitted ( improperly named reflected " ) . |
6,354 | Suppose that you have an abstract for a scientific paper: i review recent progress in numerically simulating the formation and evolution of galaxies in hierarchically clustering universes .
special emphasis is given to results based on high - resolution gas dynamical simulations using the n - body hardware integrator grape .
applications address the origin of the spin of disk galaxies , the structure and kinematics of damped ly-@xmath0systems , and the origin of galaxy morphology and of galaxy scaling laws .
# 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: motivated by the increasing body of evidence that most of the mass in the universe consists of invisible `` dark '' matter , and by the particle physicist s inference that this dark matter is made of exotic non - baryonic particles , a new and on the long run more fruitful approach to study the formation of galaxies has been developed : rather than to model the formation and evolution of galaxies from properties of present day galaxies , it is attempted to prescribe a set of reasonable initial conditions .
the evolution of galaxies is then modeled starting from these initial conditions .
physical processes are taken into account that are considered to be relevant such as gravity , gas dynamics , radiative cooling and star formation ..
Please generate the next two sentences of the article | the outcome at different epochs is then confronted against observational data .
one scenario that has been extensively tested in that way is the model of hierarchical clustering , currently the most successful paradigm of structure formation in the universe . in this scenario , |
6,355 | Suppose that you have an abstract for a scientific paper: we present an analysis of the constraining power of future measurements of the integrated sachs - wolfe ( isw ) effect on models of the equation of state of dark energy as a function of redshift , @xmath0 . to achieve this
, we employ a new parameterization of @xmath1 , which utilizes the mean value of @xmath0 ( @xmath2 ) as an explicit parameter .
this helps to separate the information contained in the estimation of the distance to the last scattering surface ( from the cmb ) from the information contained in the isw effect .
we then use fisher analysis to forecast the expected uncertainties in the measured parameters from future isw observations for two models of dark energy with very different time evolution properties .
for example , we demonstrate that the cross correlation of planck cmb data and lsst galaxy catalogs will provide competitive constraints on @xmath0 , compared to a snap like sne project , for models of dark energy with a rapidly changing equation of state ( e.g. `` kink '' models ) .
our work confirms that , while sne measurements are more suitable for constraining variations in @xmath0 at low redshift , the isw effect can provide important independent constraints on @xmath0 at high @xmath3 . .
And you have already written the first three sentences of the full article: there is now a substantial amount of observational evidence that the universe is dominated by a dark component which is causing its expansion rate to accelerate .
the analysis of the cosmic microwave background ( cmb ) anisotropy power spectra @xcite combined with results from large scale structure ( lss ) surveys @xcite strongly suggest that about @xmath4 of the energy in the universe is in an exotic form of matter which we refer to as dark energy ( de ) .
measurements of the luminosity distance to supernova type ia ( snia ) independently confirm these conclusions by showing that high redshift supernovae are dimmer than in a matter dominated universe @xcite.
Please generate the next two sentences of the article | . further evidence , which has recently become available , is the detection of the integrated sachs - wolfe ( isw ) effect using the cmb / lss cross - correlation @xcite .
this evidence is complementary in nature to the snia data . rather than probing the overall expansion of the universe |
6,356 | Suppose that you have an abstract for a scientific paper: in a recent article , this author proposed a program for physics beyond the standard model , solely based on modifying the twin pillars of fundamental physics by replacing lorentz structure with euclidean jordan algebra while keeping quantum theory .
this program predicts not only quarks and leptons but also a short - range 5th fundamental force accompanying gravity .
this 5th force predicts quark mixing and the related cp violation , which in fact was a phenomena observed in labs about fifty years ago .
thus , there are two conflicting theories as of now , the one based on the 5th force which _ predicts _ this phenomena and the established cabibbo - kobayashi - maskawa ( ckm ) theory which was invented to _
explain _ this phenomena . in this article
a test of these two theories against the recent experimental data is presented .
it is found in this test that the ckm theory fares poorly , whereas the one based on the 5th force withstands the test well , in both accuracy and precision .
for example , for the ckm matrix entry @xmath0 , we have @xmath1 .
And you have already written the first three sentences of the full article: it was experimentally observed in the 1960s that a quark of high generation can decay into a quark of low generation : a diagram of the mixed quark decay .
( http://en.wikipedia.org/wiki/user:army1987/quark ) this phenomenon , referred to as _ the mixed quark decay _ in this article , has been thought to be explained by the ckm theory @xcite in which it is assumed that the weak interaction pairs are @xmath2 , @xmath3 and @xmath4 rather than the more natural pairs @xmath5 , @xmath6 and @xmath7 , where @xmath8=v\left[\begin{matrix } d\cr s \cr b \end{matrix}\right]\ ] ] with @xmath9 being the ckm matrix @xmath10.\ ] ] for example , via weak interaction , instead of decaying into @xmath11 , @xmath12 decays into @xmath13 , and hence decays into @xmath14 , @xmath15 or @xmath11 with the relative probability @xmath16 , @xmath17 and @xmath18 respectively . in this theory , the ckm matrix @xmath9 is simply an input parameter whose actual value must be determined by experiments , but one thing is clear : @xmath9 has to be unitary _ exactly_. a great success of this theory is the prediction of the third generation of quarks , for which kobayashi and maskawa shared one half of the 2008 nobel physics prize in physic @xcite . from the particle data group @xcite , the best experimental determination for the magnitudes of the ckm matrix elements
is @xmath19 @xmath20 . }.
Please generate the next two sentences of the article | \end{aligned}\ ] ] it is worth to mention that , the values of @xmath21 and @xmath22 quoted here ( the highlighted matrix entries ) are obtained under the theoretical assumption that @xmath23 , see equation ( 11.13 ) of page 159 in ref . @xcite and the line above this equation .
if we took the experimentally determined value of @xmath24 , i.e. , @xmath25 , we would have @xmath26 the phases of the ckm matrix elements determine the amount of cp violation . with the observed amount of cp violation taken into account , the currently best known standard |
6,357 | Suppose that you have an abstract for a scientific paper: the nonlinear hausdorff young inequality follows from the work of christ and kiselev .
later muscalu , tao , and thiele asked if the constants can be chosen independently of the exponent .
we show that the nonlinear hausdorff young quotient admits an even better upper bound than the linear one , provided that the function is sufficiently small in the @xmath0 norm .
the proof combines perturbative techniques with the sharpened version of the linear hausdorff young inequality due to christ . .
And you have already written the first three sentences of the full article: in this paper , we investigate the hausdorff young inequality for a nonlinear version of the fourier transform , and establish theorem [ thm : main ] below . before stating it
precisely , we briefly discuss the linear case . given a complex - valued integrable function @xmath1 on the real line , we normalize its fourier transform as follows : @xmath2 in this way , the fourier transform is a contraction from @xmath3 to @xmath4 and it extends to a unitary operator on @xmath5 .
standard interpolation tools can then be used to show that , for any @xmath6 $ ] , the fourier transform is also a contraction from @xmath7 to @xmath8 , where @xmath9 denotes the exponent conjugate to @xmath10 ..
Please generate the next two sentences of the article | this is the content of the classical hausdorff young inequality .
its sharp version was first established by babenko @xcite in the case when the exponent @xmath11 is an even integer , and then by beckner @xcite for general exponents . |
6,358 | Suppose that you have an abstract for a scientific paper: we study and compare the shannon capacity region and the stable throughput region for a random access system in which source nodes multicast their messages to multiple destination nodes . under an erasure channel model which accounts for interference and
allows for multipacket reception , we first characterize the shannon capacity region .
we then consider a queueing - theoretic formulation and characterize the stable throughput region for two different transmission policies : a retransmission policy and random linear coding .
our results indicate that for large blocklengths , the random linear coding policy provides a higher stable throughput than the retransmission policy .
furthermore , our results provide an example of a transmission policy for which the shannon capacity region strictly outer bounds the stable throughput region , which contradicts an unproven conjecture that the shannon capacity and stable throughput coincide for random access systems .
wireless multicast , random access , aloha , queueing , stability , throughput , capacity , retransmissions , random linear coding .
And you have already written the first three sentences of the full article: a fundamental question of communication theory is : at what rate can information be transmitted reliably over a noisy channel ? there is more than one way to go about answering this question .
for instance , consider an erasure channel where the parameter @xmath0 denotes the probability with which a transmission on the channel is lost ; with probability @xmath1 the transmission is received without error .
the traditional approach for describing the rate of reliable communication for the erasure channel is to cite its shannon capacity , which is @xmath1 bits per channel use for a channel with binary inputs and outputs ..
Please generate the next two sentences of the article | if feedback is available to notify the sender when a channel input is erased , then the capacity can be achieved by retransmitting lost inputs @xcite .
alternatively , the rate of reliable communication can be described by the _ |
6,359 | Suppose that you have an abstract for a scientific paper: we present the results from a _ hubble space telescope / acs _ study of the supernovae associated with gamma - ray bursts 040924 ( @xmath0 ) and 041006 ( @xmath1 ) .
we find evidence that both grbs were associated with a sn1998bw - like supernova dimmed by @xmath2 and @xmath3 magnitudes , respectively , making grb040924 the faintest grb - associated sn ever detected .
we study the luminosity dispersion in grb / xrf - associated sne and compare to local type ibc supernovae from the literature .
we find significant overlap between the two samples , suggesting that grb / xrf - associated sne are not necessarily more luminous nor produce more @xmath4ni than local sne .
based on the current ( limited ) datasets , we find that the two samples may share a similar @xmath4ni production mechanism .
# 1#2#3#1@xmath5#2@xmath6#3@xmath7 # 1#2#3@xmath8 .
And you have already written the first three sentences of the full article: gamma - ray burst ( grb ) explosions harbor both spherical supernova ( sn ) ejecta and highly collimated engine - driven jets @xcite .
this `` spherical+jet '' paradigm for the geometry of grbs implies that both explosion components must be studied independently .
early ( @xmath9 few days ) optical observations trace the synchrotron radiation produced from the engine - driven relativistic jets , while late - time ( @xmath10 days ) observations probe the optical emission from the non - relativistic spherical sn ejecta , powered by the decay of @xmath4ni ..
Please generate the next two sentences of the article | such observations allow us to address the following fundamental questions regarding the grb / sn connection : what is the diversity among grb - associated sne , and how does the sample compare to local type ibc supernovae ( sne ibc ) ?
three of the best studied events , sne 1998bw , 2003dh 2003lw ( associated with grbs 980425 , 030329 and 031203 , respectively ) were strikingly similar , with brighter optical luminosities and faster photospheric velocities than local sne ibc @xcite . |
6,360 | Suppose that you have an abstract for a scientific paper: we systematically investigate the topological band structures of half - heusler compounds using first - principles calculations .
the modified becke - johnson exchange potential together with local density approximation for the correlation potential ( mbjlda ) has been used here to obtain accurate band inversion strength and band order .
our results show that a large number of half - heusler compounds are candidates for three - dimensional topological insulators .
the difference between band structures obtained using the local density approximation ( lda ) and mbjlda potential is also discussed . .
And you have already written the first three sentences of the full article: motivated by their potential applications in spintronics and quantum computing @xcite , the search for three - dimensional topological insulators ( 3dti ) has attracted considerable theoretical and experimental interest @xcite .
these materials are called `` topological '' because they are distinguished from ordinary insulators by the so - called @xmath0 topological invariants associated with the bulk band structure @xcite . on the theory side , the state - of - the - art first - principles calculations guided by topological band theory @xcite has provided a powerful tool for uncovering new families of 3dti . based on this approach , it has been recently predicted that ternary half - heusler compounds can realize the topological insulating phase with proper strain engineering @xcite .
there are several ways to determine the band topology of an insulator ..
Please generate the next two sentences of the article | intuitively , one can count the number of band inversions within the entire brillouin zone an _ odd _ number indicates that the material may be a 3dti @xcite .
this method depends on an accurate interpretation of the atomic origin of the bands and is better suited for crystals with a high - symmetry lattice . a more rigorous method is to directly evaluate the @xmath0 topological invariants . for materials with inversion symmetry |
6,361 | Suppose that you have an abstract for a scientific paper: there is a large body of work that has used the excellent chandra observations of nearby galaxies with neglible low mass x - ray binary ( lmxb ) populations .
this has culminated in a `` universal '' x - ray luminosity function ( xlf ) for high mass x - ray binaries ( hmxbs ) . however , a number of methods have been used to convert from source intensities to luminosities when creating these xlfs .
we have taken advantage of the xmm - newton observations of the nearby starbursting spiral galaxy ngc 253 to test some of these methods .
we find the luminosities derived from these various methods to vary by a factor of @xmath03 .
we also find the most influential factor in the conversion from intensity to luminosity to be the absorption .
we therefore conclude that a more consistent approach is required for determining the true universal xlf for hmxbs .
ideally , this would involve individual spectral fitting of each x - ray source .
certainly , the line - of - sight absorption should be determined from the observations rather than assuming galactic absorption .
we find the best approach for obtaining an xlf from low - count data to be the splitting of the x - ray sources into two or more intensity intervals , and obtaining a conversion from intensity to flux for each group from spectral modelling of the summed spectrum of that group . .
And you have already written the first three sentences of the full article: the x - ray populations of external galaxies have been well studied for the last @xmath020 years .
historically , studies of the individual sources have been severely limited by low count rates and signal to noise , and several methods have been used to derive the x - ray luminosity of a source from its intensity .
grimm et al . ( 2003 , hereafter known as g03 ) used chandra and asca surveys of nearby starburst galaxies , along with asca , mir - kvant / ttm and rxte / asm observations of hmxbs in our galaxy and the magellanic clouds to obtain a correlation between the x - ray properties of hmxbs and the star formation rate ( sfr ) of their host galaxies ..
Please generate the next two sentences of the article | they chose their sample of galaxies to have sufficiently high sfr to total mass ratios so that their x - ray populations would be dominated by hmxbs , with negligible lmxb contributions .
g03 used published chandra x - ray luminosity functions ( xlfs ) , scaled assuming the hubble constant to be 70 km s@xmath1 mpc@xmath1 . |
6,362 | Suppose that you have an abstract for a scientific paper: a recently reported phase sensitive brillouin light scattering technique is improved by use of a magnetic modulator .
this modulator is based on brillouin light scattering in a thin ferrite film . using this magnetic modulator in time- and space brillouin light scattering measurements
we have increased phase contrast and excluded influence of optical inhomogeneities in the sample .
we also demonstrate that the quality of the resulting interference patterns can be improved by data postprocessing using the simultaneously recorded information about the reference light . .
And you have already written the first three sentences of the full article: space- and time - resolved brillouin light scattering ( bls ) spectroscopy is a well established technique to investigate the spin - wave dynamics in thin magnetic films @xcite .
however , this method is based on a simple counting of inelastically scattered photons .
thus it only allows for the spatial and temporal mapping of spin - wave intensities ..
Please generate the next two sentences of the article | no phase information about magnetic excitations is accessible by conventional bls . at the same time the phase information is crucial to answer questions concerning problems such as formation of coherent states in a magnon gas and evolution of nonlinear spin - wave eigenmodes
@xcite as well as nonlinear phase accumulation @xcite , peculiarities of spin - wave excitation process @xcite , 2-dimensional phase structure of spin - wave beams in magnetically anisotropic media , etc . + the first realization of a phase - sensitive bls setup as well as the results obtained by means of phase - sensitive bls spectroscopy have been presented by us in ref . |
6,363 | Suppose that you have an abstract for a scientific paper: we study a very specific type of neutrino mass and mixing structure based on the idea of strong scaling ansatz ( ssa ) where the ratios of neutrino mass matrix elements belonging to two different columns are equal .
there are three such possibilities , all of which are disfavored by the latest neutrino oscillation data .
we focus on the specific scenario which predicts vanishing reactor mixing angle @xmath0 and inverted hierarchy with vanishing lightest neutrino mass . motivated by several recent attempts to explain non - zero @xmath0 by incorporating corrections to a leading order neutrino mass or mixing matrix giving @xmath1 , here we study the origin of non - zero @xmath0 as well as leptonic dirac cp phase @xmath2 by incorporating two different corrections to scaling neutrino mass and mixing : one where type ii seesaw acts as a correction to scaling neutrino mass matrix and the other with charged lepton correction to scaling neutrino mixing .
although scaling neutrino mass matrix originating from type i seesaw predicts inverted hierarchy , the total neutrino mass matrix after type ii seesaw correction can give rise to either normal or inverted hierarchy .
however , charged lepton corrections do not disturb the inverted hierarchy prediction of scaling neutrino mass matrix .
we further discriminate between neutrino hierarchies , different choices of lightest neutrino mass and dirac cp phase by calculating baryon asymmetry and comparing with the observations made by the planck experiment . .
And you have already written the first three sentences of the full article: origin of tiny neutrino masses and mixing is one of the most widely studied problems in modern day particle physics . since the standard model ( sm ) of particle physics fails to provide an explanation to neutrino masses and mixing , several well motivated beyond standard model ( bsm ) frameworks
have been proposed to account for the tiny neutrino mass observed by several neutrino oscillation experiments @xcite .
more recently , the neutrino oscillation experiments t2k @xcite , double chooz @xcite , daya - bay @xcite and reno @xcite have also confirmed the earlier results and also made the measurement of neutrino parameters more precise . the latest global fit values for @xmath3 range of neutrino oscillation parameters @xcite.
Please generate the next two sentences of the article | are shown in table [ tab : data1 ] .
another global fit study @xcite reports the 3@xmath4 values as shown in table [ tab : data2 ] . |
6,364 | Suppose that you have an abstract for a scientific paper: point - contact ( pc ) andreev - reflection ( ar ) measurements of the superconducting gap in iron - oxipnictide @xmath0feaso@xmath1f@xmath2 ( @xmath0=la , sm ) films have been carried out .
the value of the gap is distributed in the range @xmath3 510mev ( for @xmath0=sm ) with a maximum in the distribution around 6mev .
temperature dependence of the gap @xmath4 can be fitted well by bcs curve giving reduced gap ratio @xmath5 ( here @xmath6 is the critical temperature from the bcs fit ) . at the same time , an expected second larger gap feature was difficult to resolve distinctly on the ar spectra making determination reliability of the second gap detection questionable .
possible reasons for this and the origin of other features like clear - cut asymmetry in the ar spectra and current regime in pcs are discussed . .
And you have already written the first three sentences of the full article: discovering a few years ago a new family of iron based superconductors gave rise both to intensive investigation of the fundamental properties of these materials ( see reviews @xcite and refs . therein ) and to seeking for their potential application .
the fabrication of high - quality thin films is of great importance for potential applications of these new materials in superconducting devices as well as for a deeper fundamental study of their superconducting properties .
numerous experiments were undertaken to study the superconducting state of iron based superconductors , however less attention was paid to the investigation of films , due to the more complicated preparation . in this paper.
Please generate the next two sentences of the article | we present first point - contact andreev reflection ( pcar ) spectroscopy investigation of lafeaso@xmath1f@xmath2 and smfeaso@xmath1f@xmath2 films .
the main goal was to measure of the superconducting gap(s ) and its temperature dependence for the mentioned films to compare these data with existing similar measurements on bulk samples @xcite and to clarify some issues as to the presence of multiband structure on pcar spectra and pcar spectra asymmetry . |
6,365 | Suppose that you have an abstract for a scientific paper: we estimate the couplings in the heavy hadron chiral theory ( hhct ) lagrangian from the qcd sum rules in an external axial field . we take into account the perturbative correction to the meson correlator in the infinite mass limit . with the perturbative correction and three successive power corrections ,
the meson correlator in an axial field becomes one of the best known correlators . in spite of this , the corresponding sum rule is not very stable .
it yields the result @xmath0 , where @xmath1 is the central value of the heavy meson decay constant with the perturbative correction @xcite .
this result is surprisingly low as compared with the constituent quark model estimate @xmath2 .
the sum rules for @xmath3 following from nondiagonal @xmath4 and diagonal @xmath5 baryon correlators in an external axial field suggest @xmath6 , while diagonal @xmath4 and nondiagonal @xmath5 baryon sum rules have too large uncertainties .
wue / itp97016 + hep - ph/9706421 couplings of heavy hadrons with soft pions + from qcd sum rules + a. g. grozin@xmath7 + _ institut fr physik , johannes gutenberg universitt , _ + _ staudinger weg 7 , d55099 mainz , germany _ + o. i. yakovlev@xmath7 + _ institut fr theoretische physik ii , bayrische maximilians universitt _ , + _ am hubland , d97074 wrzburg , germany
_ @xmath7 on leave from budker institute of nuclear physics , novosibirsk 630090 , russia . .
And you have already written the first three sentences of the full article: it is well known that the qcd lagrangian with @xmath8 massless flavours has the @xmath9 symmetry spontaneously broken to @xmath10 giving the @xmath11plet of pseudoscalar massless goldstone mesons ( pions ) @xmath12 ( @xmath13 ) .
their interactions at low momenta are described by the chiral lagrangian ( see e. g. @xcite ) @xmath14 where the pion constant @xmath15mev is defined by @xmath16 ( @xmath17 is the pion flavour wave function ) , and dots mean terms with more derivatives .
light quark masses can be included perturbatively , and lead to extra terms in ( [ lpi ] ) ..
Please generate the next two sentences of the article | @xmath9 transformations act as @xmath18 .
let s define @xmath19 , @xmath20 ; it transforms as @xmath21 where @xmath22 is a @xmath23 matrix depending on @xmath24 . |
6,366 | Suppose that you have an abstract for a scientific paper: we provide the classification of real forms of complex d=4 euclidean algebra @xmath0 as well as ( pseudo)real forms of complex d=4 euclidean superalgebras @xmath1 for n=1,2 .
further we present our results : n=1 and n=2 supersymmetric d=4 poincar and euclidean r - matrices obtained by using d= 4 poincar r - matrices provided by zakrzewski @xcite for n=2 we shall consider the general superalgebras with two central charges . .
And you have already written the first three sentences of the full article: the classification of quantum deformations of lorentz symmetries described by classical r - matrices was given firstly by zakrzewski @xcite ( see also @xcite ) , and has been further extended to the classification of classical r - matrices for poincar algebra in @xcite .
the classification of dual hopf - algebraic quantum deformations of poincar group were presented in @xcite .
subsequently , the infinitesimal r - matrix description of the deformations of poincar algebra presented in @xcite has been extended in several papers to finite hopf - algebraic deformations , with conclusive results obtained in @xcite ..
Please generate the next two sentences of the article | because majority of studied deformations were triangular , i.e. described by the twist deformations , they permitted ( see e.g. @xcite ) to derive explicit formulas for the non - commutative algebra of deformed space - time coordinates by the use of so - called star product realizations .
the study of deformations of spacetime supersymmetries and the corresponding deformed superspaces were less systematic , related mostly either with the supersymmetrization of simplest abelian canonical twist deformation of poincar symmetries @xcite@xcite or with the supersymmetric extension of @xmath2-deformation @xcite . |
6,367 | Suppose that you have an abstract for a scientific paper: ic 310 has recently been identified as a gamma - ray emitter based on observations at gev energies with fermi - lat and at very high energies ( vhe , @xmath0 gev ) with the magic telescopes . despite ic 310 having been classified as a radio galaxy with
the jet observed at an angle @xmath1 degrees , it exhibits a mixture of multiwavelength properties of a radio galaxy and a blazar , possibly making it a transitional object . on the night of 12/13@xmath2 of november 2012 the magic telescopes observed a series of violent outbursts from the direction of ic 310 with flux - doubling time scales faster than 5 min and a peculiar spectrum spreading over 2 orders of magnitude .
such fast variability constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole , challenging the shock acceleration models , commonly used in explanation of gamma - ray radiation from active galaxies . here
we will show that this emission can be associated with pulsar - like particle acceleration by the electric field across a magnetospheric gap at the base of the jet . .
And you have already written the first three sentences of the full article: the nearby lenticular ( s0 , @xmath3 ) galaxy ic310 located in the perseus cluster exhibits an active galactic nucleus ( agn ) .
this object has been detected at high energies ( above 30gev ) with _
fermi_/lat @xcite as well as at tev energies @xcite ..
Please generate the next two sentences of the article | the jet of ic310 , extending in the outward direction from the center of the cluster led to early assignment of this object as a head - tail radio galaxy @xcite .
however , using the very - long - baseline interferometry ( vlbi ) technique , a parsec - scale one - sided jet was found to follow the large - scale jet within about @xmath4 @xcite . |
6,368 | Suppose that you have an abstract for a scientific paper: we compute the universal generic corrections to the power spectrum in slow - roll inflation due to unknown high - energy physics .
we arrive at this result via a careful integrating out of massive fields in the `` in - in '' formalism yielding a consistent and predictive low - energy effective description in time - dependent backgrounds .
the density power spectrum is universally modified at leading order in @xmath0 , the ratio of the scale of inflation to the scale of new physics ; the tensor power spectrum receives only subleading corrections . in doing so ,
we show how to make sense of a physical momentum - cut - off in loop integrals despite dynamical redshifts , and how the result can be captured in a combined effective action / effective density matrix , where the latter contains non - adiabatic terms which modify the boundary conditions . .
And you have already written the first three sentences of the full article: the dawning of the era of precision cosmology demands that we understand the history of our universe theoretically with the same accuracy as experiment .
the _ wmap _ determination of acoustic peaks in the cmb spectrum to 1% accuracy has given strong support to the existence of an era of inflation @xcite .
inflation , famously , predicts the primordial power spectrum of density fluctuations underlying all structure in the universe ..
Please generate the next two sentences of the article | this ability of _ wmap _ and future _ planck _ data @xcite to constrain theoretical models of the early universe has set off a scramble to delineate a theoretically controlled computation of the primordial inflationary power spectrum .
the textbook approach makes a number of explicit and implicit assumptions , each of which can affect the power spectrum at the accuracy measured . |
6,369 | Suppose that you have an abstract for a scientific paper: macronovae ( kilonovae ) that arise in binary neutron star mergers are powered by radioactive beta decay of hundreds of @xmath0-process nuclides .
we derive , using fermi s theory of beta decay , an analytic estimate of the nuclear heating rate .
we show that the heating rate evolves as a power law ranging between @xmath1 to @xmath2 .
the overall magnitude of the heating rate is determined by the mean values of nuclear quantities , e.g. , the nuclear matrix elements of beta decay .
these values are specified by using nuclear experimental data .
we discuss the role of higher order beta transitions and the robustness of the power law .
the robust and simple form of the heating rate suggests that observations of the late - time bolometric light curve @xmath3 would be a direct evidence of a @xmath0-process driven macronova .
such observations could also enable us to estimate the total amount of @xmath0-process nuclei produced in the merger .
[ firstpage ] stars : neutron@xmath4gamma - ray burst : general .
And you have already written the first three sentences of the full article: @xcite proposed that neutron star mergers will be accompanied by macronovae ( kilonovae ) , which are optical infrared transients powered by radioactive decay of the merger s debris .
these macronovae are among the most promising electromagnetic counterparts to gravitational - wave merger events ( e.g. @xcite ) .
recently , macronova candidates have been discovered in the afterglows of several short gamma - ray bursts @xcite ..
Please generate the next two sentences of the article | @xcite re - analyzed the afterglow light curves of historical nearby short gamma - ray bursts and suggested that macronovae are ubiquitous in short grbs afterglows .
the radioactive heat generated by @xmath0-process nuclei play an essential role in powering macronovae . |
6,370 | Suppose that you have an abstract for a scientific paper: by using the enskog - boltzmann approach , we study the steady - state dynamics of a granular discorectangle placed in a two - dimensional bath of thermalized hard disks . hard core collisions are assumed elastic between disks and inelastic between the discorectangle and the disks , with a normal restitution coefficient @xmath0 . assuming a gaussian ansatz for the probability distribution functions , we obtain analytical expressions for the granular temperatures .
we show the absence of equipartition and investigate both the role of the anisotropy of the discorectangle and of the relative ratio of the bath particles to the linear sizes of the discorectangle .
in addition , we investigate a model of a discorectangle with two normal restitution coefficients for collisions along the straight and curved surfaces of the discorectangle . in this case
one observes equipartition for a non trivial ratio of normal restitution coefficients . .
And you have already written the first three sentences of the full article: granular matter is characterized by the existence of dissipative forces between particles . in order to sustain a collective motion ,
it is necessary to provide energy continuously .
when power supply is sufficiently copious , the assembly of granular particles attains a non equilibrium steady state ( ness)@xcite ..
Please generate the next two sentences of the article | it is customary to define the granular temperature as the second moment of the velocity distribution .
it is a source of both fascination and inconvenience that the well - know properties of temperatures characterizing thermal systems are not necessarily transferable to granular temperatures . in particular |
6,371 | Suppose that you have an abstract for a scientific paper: ehrenborg and jung @xcite recently related the order complex for the lattice of @xmath0-divisible partitions with the simplicial complex of _ pointed ordered set partitions _ via a homotopy equivalence .
the latter has top homology naturally identified as a specht module .
their work unifies that of calderbank , hanlon , robinson @xcite , and wachs @xcite . by focusing on the underlying geometry ,
we strengthen and extend these results from type @xmath1 to all real reflection groups and the complex reflection groups known as _ shephard groups_. [ section ] [ theorem]proposition [ theorem]lemma [ theorem]corollary [ theorem]conjecture [ theorem]definition [ theorem]example [ theorem]observation [ theorem]convention [ theorem]observations [ theorem]question [ theorem]remark l .
And you have already written the first three sentences of the full article: the aim of this paper is to elucidate a phenomenon that has been studied for the symmetric group @xmath2 by studying the underlying geometry .
here we sketch the phenomenon , along with our geometric interpretation and generalization . for @xmath3 divisible by @xmath0 , recall that the @xmath0-divisible partition lattice @xmath4 is the poset of partitions of the set @xmath5 with parts divisible by @xmath0 , together with a unique minimal element @xmath6 when @xmath7 . in @xcite ,
calderbank , hanlon and robinson showed that for @xmath7 the top homology of the order complex @xmath8 , when restricted from @xmath9 to @xmath2 , carries the _ ribbon representation _ of @xmath2 corresponding to a ribbon with row sizes @xmath10 ..
Please generate the next two sentences of the article | wachs @xcite gave a more explicit proof of this fact .
their results generalized stanley s @xcite result for the mbius function of @xmath11 , which generalized g. s. sylvester s @xcite result for 2-divisible partitions @xmath12 . |
6,372 | Suppose that you have an abstract for a scientific paper: some physical results in four dimensional large n gauge theories on a periodic torus are summarized . .
And you have already written the first three sentences of the full article: the large n limit of four dimensional non - abelian gauge theories is interesting from the view point of qcd phenomenology @xcite and string theory @xcite .
lattice qcd is a useful technique for extracting fundamental results in the large n limit of qcd .
fermions are naturally quenched in the t hooft limit of large n qcd and this significantly reduces the computational cost in a lattice calculation ..
Please generate the next two sentences of the article | in addition , there is a concept of continuum reduction @xcite , namely , physics does not depend on the size of box @xmath0 for @xmath1 and @xmath2 is a physical critical size .
these two observations have been used to extract physical results in the large n limit of qcd using numerical techniques on the lattice . |
6,373 | Suppose that you have an abstract for a scientific paper: we calculate by means of the press - schechter formalism the density profile developed by dark - matter halos during accretion , i.e. , the continuous aggregation of small clumps .
we find that the shape of the predicted profile is similar to that shown by halos in high - resolution cosmological simulations .
furthermore , the mass - concentration relation is correctly reproduced at any redshift in all the hierarchical cosmologies analyzed , except for very large halo masses .
the role of major mergers , which can cause the rearrangement of the halo structure through violent relaxation , is also investigated .
we show that , as a result of the boundary conditions imposed by the matter continuously infalling into the halo during the violent relaxation process , the shape of the density profile emerging from major mergers is essentially identical to the shape the halo would have developed through pure accretion .
this result explains why , according to high - resolution cosmological simulations , relaxed halos of a given mass have the same density profile regardless of whether they have had a recent merger or not , and why both spherical infall and hierarchical assembly lead to very similar density profiles . finally , we demonstrate that the density profile of relaxed halos is not affected either by the capture of clumps of intermediate mass . .
And you have already written the first three sentences of the full article: the dominant dark component of matter in the universe is clustered in bound halos which form the skeleton of all astronomical objects of cosmological interest , from dwarf galaxies to rich galaxy clusters .
the determination of the inner structure of such halos has been addressed both analytically and by numerical simulations .
the analytical approach to this problem was pioneered by gunn & gott ( 1972 ) , who adopted the simplifying assumption that halos grow through spherical infall , i.e. , the monolithic collapse of a density fluctuation of isotropically distributed , cold , collisionless matter in an otherwise homogeneous expanding universe ..
Please generate the next two sentences of the article | this allowed them to derive the density profile resulting from self - similar initial conditions in an einstein - de sitter universe up to the onset of shell crossing .
the effects of shell crossing and of adopting more and more realistic initial conditions were addressed and the whole treatment was refined in a series of subsequent papers @xcite . according to these studies , after the collapse of some initial seed , a stationary regime is reached , the so - called secondary infall , in which the system grows inside - out . |
6,374 | Suppose that you have an abstract for a scientific paper: the rational design of molecules and materials is becoming more and more important . with the advent of powerful computer systems and sophisticated algorithms ,
quantum chemistry plays a decisive role in the design process . while traditional quantum chemical approaches predict the properties of a predefined molecular structure , the goal of inverse quantum chemistry is to find a structure featuring one or more desired properties . herein , we review inverse quantum chemical approaches proposed so far and discuss their advantages as well as their weaknesses . *
inverse quantum chemistry : concepts and strategies for rational compound design * thomas weymuth and markus reiher + eth zrich , laboratorium fr physikalische chemie , + vladimir - prelog - weg 2 , 8093 zrich , switzerland date : = march 9 , 2014 + status : printed in _ int .
j. quantum chem . _ _ 114 _ * 2014 * 823837 + .
And you have already written the first three sentences of the full article: the last decades have witnessed the fast - paced development of a wide range of quantum chemical methods@xcite .
examples are highly accurate but also computationally demanding wave - function - based approaches like coupled cluster and configuration interaction@xcite and density functional theory@xcite .
the latter allows for the description of large molecular systems consisting of hundreds of atoms usually at reduced accuracy , however ..
Please generate the next two sentences of the article | today , these computational approaches are firmly established in chemistry , and they are crucial for basically all areas of chemical research . underlying all these methods is the time - independent schrdinger equation , @xmath0 where @xmath1 is the sought - for wave function characterizing the system under investigation , @xmath2 the energy associated with this wave function , and @xmath3 is the hamiltonian operator . in nonrelativistic quantum chemistry ,
the hamiltonian of an assembly of ( point - like ) atomic nuclei and electrons is given by @xmath4 ( in hartree atomic units , in which the elementary charge , the mass of the electron , the reduced planck constant , and @xmath5 take a value of one used throughout this work , unless otherwise stated ) . |
6,375 | Suppose that you have an abstract for a scientific paper: we investigate the elementary excitations of quasi one - dimensional @xmath0 systems built up from zig - zag chains with general isotropic exchange constants , using exact ( lanczos ) diagonalization for 24 spins and series expansions starting from the decoupled dimer limit .
for the ideal one - dimensional zig - zag chain we discuss the systematic variation of the basic ( magnon ) triplet excitation with general exchange parameters and in particular the presence of practically flat dispersions in certain regions of phase space .
we extend the dimer expansion in order to include the effects of 3d interactions on the spectra of weakly interacting zig - zag chains . in an application to @xmath1
we show that this approach allows to determine the exchange interactions between individual pairs of spins from the spectra as determined in recent neutron scattering experiments . 1000 0.5 cm .
And you have already written the first three sentences of the full article: spin systems consisting of chain- or ladderlike structures as basic building blocks have recently attracted much attention .
these systems are of interest on the one hand as one - dimensional ( 1d ) model systems allowing to study quantum phase transitions related to the existence of a spin gap and their dependence on the exchange parameters @xcite ; on the other hand they describe an increasing number of real materials when an additional ( small ) exchange coupling in the remaining two dimensions is introduced @xcite .
a material of particular recent experimental interest is @xmath1 @xcite ..
Please generate the next two sentences of the article | we have performed an investigation of the dynamics of such systems with a twofold aim : ( i ) we discuss the spectrum @xmath2 of the low - lying triplet excitations in the ideal 1d system over a wide range of exchange parameters using both series expansions and exact diagonalization , in order to determine the range of applicability of the series expansion approach and to study the validity of using an effective interaction between dimers . we find and discuss in particular a regime in phase space with extremely small dispersion and a minimum of @xmath2 at finite wavevector @xmath3 .
( ii ) we extend the dimer expansion to include 3d couplings and apply this method in particular to a discussion of the dynamics of the quasi zigzag - ladder material kcucl@xmath4 in terms of microscopic exchange parameters . of particular interest as an 1d building block for this type of materials is the @xmath5 zig - zag chain , as shown in fig . |
6,376 | Suppose that you have an abstract for a scientific paper: quantitative understanding of human behaviors provides elementary comprehension of the complexity of many human - initiated systems . in this paper
, we investigate the behavior of people on the @xmath0 forum by the statistical analysis of the amounts of view and reply of posts . according to our statistics , we find that the amounts of view and reply of posts follow the power law distributions with different power exponent .
furthermore , we discover that the amounts of view and reply of posts have nonlinear relationship .
they are related by power function and show us straight line in log - log plot .
based on the estimation of slope and intercept of the line , we can characterize the behaviors quantitatively and know that people of chinese forum and those of foreign forum have different preference towards replying to and viewing the posts . at last ,
we analyze the burstiness and memory in replying time series .
they show some universal properties among different forum .
all of them locate themselves in the high-@xmath1 , low-@xmath2 region .
* keyword * : human dynamics , @xmath0 forum , burstiness and memory * pacs * : 89.75.da - systems obeying scaling laws ; 89.20.hh - world wide web , internet ; 89.65.-s - social and economic systems .
And you have already written the first three sentences of the full article: human behavior , as an academic issue in science , has a history about one century from watson @xcite . as a joint interest of sociology , psychology and economics ,
human behavior has been extensively investigated during the last decades .
a basic assumption embedded in the previous analysis on human dynamics is that its temporal statistics are uniform and stationary , which can be properly described by a poisson process ..
Please generate the next two sentences of the article | accordingly , the interevent time distribution should have an exponential tail @xcite .
however , through studying the distributions of interevent time of the human behavior such as the people to send out or reply e - mail and surface mail , albert barabsi discovered that these human behaviors present obvious deviation to the poisson process : long time silent and short time high frequency eruption simultaneously present in these human behaviors , and their distributions of interevent time have power law fat tail @xcite . from e - mail communications @xcite to surface mail communications @xcite and short message communications @xcite , from financial activities to library loans @xcite , from web browsing @xcite to on - line |
6,377 | Suppose that you have an abstract for a scientific paper: optically thin and geometrically thick accretion flows are known to be responsible for the observed radio / x - ray luminosity relation of the x - ray bright galactic nuclei .
it has also been suggested that supermassive black hole masses can be estimated from measurements of the core radio luminosity and the x - ray luminosity by using the advection - dominated accretion flow ( adaf ) model . in this study
we increase the number of data available by compiling the radio / x - ray fluxes and the mass in published literatures , and compare the observed ratio of the luminosities with predictions from various models of optically thin accretion flows .
semi - analytically derived relations of the luminosities are presented in cases of the standard adaf model and modified adaf models , in which a truncation of inner parts of the flows and winds causing a reduction of the infalling matter are included .
we show that the observed relation can be used indeed to estimate the supermassive black hole mass , provided that properties of such accretion flows are known . having investigated sensitivities of the method on modifications of the standard adaf model
, we find that a general trend of model predictions from the standard adaf , the truncated adaf and the windy adaf are somewhat indistinguishable .
we also find , however , that the extreme case of the windy model is inconsistent with currently available observational data , unless microphysics parameters are to be substantially changed .
high resolution radio observations , however , are required to avoid the contamination of non - disk components , such as , a jet component , which , otherwise , results in the over - estimated smbh mass . .
And you have already written the first three sentences of the full article: supermassive black holes ( smbhs ) have been considered as the most likely power sources of the activity in quasars and active galactic nuclei ( lynden - bell 1969 ; rees 1984 ) .
smbhs at the centers of all galaxies are now recognized as ubiquitous , whose mass @xmath0 is proportional to the spheroidal bulge mass of the host galaxy or the galactic bulge luminosity ( kormendy & richstone 1995 ; magorrian et al .
1998 ; richstone et al . 1998 ) and is strongly correlated with the velocity dispersion of the host galaxy ( ferrarese & merritt 2000 ; gebhardt et al . 2000a ; ferrarese 2002 ) ..
Please generate the next two sentences of the article | recently , evidence for the existence of a smbh in the center of our galaxy has been added ( eckart & genzel 1997 ; genzel et al .
1997 ; ghez et al . |
6,378 | Suppose that you have an abstract for a scientific paper: advances in vlbi instrumentation now allow wideband recording that significantly increases the sensitivity of short wavelength vlbi observations .
observations of the super - massive black hole candidate at the center of the milky way , sgra * , with short wavelength vlbi reduces the scattering effects of the intervening interstellar medium , allowing observations with angular resolution comparable to the apparent size of the event horizon of the putative black hole .
observations in april 2007 at a wavelength of 1.3 mm on a three station vlbi array have now confirmed structure in sgra * on scales of just a few schwarzschild radii . when modeled as a circular gaussian ,
the fitted diameter of sgra * is 37@xmath0as ( @xmath1,@xmath2 ; @xmath3 ) , which is smaller than the expected apparent size of the event horizon of the galactic center black hole .
these observations demonstrate that mm / sub - mm vlbi is poised to open a new window onto the study of black hole physics via high angular resolution observations of the galactic center . .
And you have already written the first three sentences of the full article: at a distance of @xmath4kpc ( @xcite ) , sgra * , the compact radio , nir and x - ray source at the galactic center , is thought to mark the position of a super - massive black hole of mass @xmath5 ( @xcite,@xcite ) .
proper motions of sgra * ( @xcite ) confirm that it traces a significant amount of the mass that is inferred by stellar motions and orbits .
due to its proximity , sgra * is the only galactic nucleus that can be studied with vlbi on sub - au linear scales ( @xmath6 ) ..
Please generate the next two sentences of the article | the ionized ism , however , scatter - broadens images of sgra * with a @xmath7 dependence , and vlbi at the highest frequencies is the only available means to set important limits on intrinsic structures near the event horizon .
vlbi at 7 mm and 3.5 mm has detected evidence for intrinsic structure of sgra * , but these observations remain dominated by scattering effects , and the intrinsic sizes at these wavelengths ( set by the optical depth of the emission ) are much larger than the apparent size of the event horizon ( @xcite , @xcite ) . |
6,379 | Suppose that you have an abstract for a scientific paper: in an experiment with a 65 mev / nucleon polarized deuteron beam on a liquid - deuterium target at kvi , several multi - body final states in deuteron - deuteron scattering were identified . for these measurements , a unique and advanced detection system , called bina ,
was utilized .
we demonstrate the feasibility of measuring vector and tensor polarization observables of the deuteron break - up reaction leading to a three - body final - state .
the polarization observables were determined with high precision in a nearly background - free experiment . the analysis procedure and some results are presented . .
And you have already written the first three sentences of the full article: the physics phenomena of nuclei are largely understood by considering the interaction between their building blocks , the nucleons . in 1935 , yukawa described the nucleon - nucleon ( nn ) force by the exchange of massive mesons @xcite in analogy to the electromagnetic interaction which can be represented by the exchange of a massless photon .
several phenomenological nucleon - nucleon potentials have been derived based on yukawa s theory and are able to reproduce data points in neutron - proton and proton - proton scattering with extremely high precision .
these so - called high - quality nn potentials are used in faddeev equations @xcite to give an exact solution of the scattering problem for the three - nucleon system ..
Please generate the next two sentences of the article | already , for the simplest three - nucleon system , the triton , an exact solution of the three - nucleon faddeev equations employing two - nucleon forces ( 2nfs ) underestimates the experimental binding energy @xcite , showing that 2nfs are not sufficient to describe the three - nucleon system accurately .
the existence of an additional force , the three - nucleon ( 3n ) interaction , was predicted a long time ago by primakov @xcite and confirmed by a comparison between precision data and state - of - the - art calculations @xcite . |
6,380 | Suppose that you have an abstract for a scientific paper: in characterizing the quark - hadron phase structure , determining various thermodynamic quantities and investigating their temperature dependencies on vanishing and finite magnetic field , su(3 ) polyakov linear - sigma model ( plsm ) is utilized .
the dependence of the chiral order - parameter on vanishing and finite magnetic field is calculated in mean - field approximation . in a wide range of temperatures and magnetic field strengths ,
the thermodynamic observables including trace anomaly , speed of sound squared , entropy density , specific heat and magnetization are presented .
an excellent agreement is found when these are confronted to recent lattice qcd calculations .
the temperature dependence of these quantities confirms our previous result that the transition temperature is reduced with magnetic field .
furthermore , the temperature dependence of magnetization verifies the conclusion that the qcd matter has paramagnetic properties near and far above the critical temperature .
the excellent agreement with recent lattice calculations means that plsm possesses the correct degrees of freedom in both hadronic and partonic phases and describes well dynamics deriving confined hadrons to deconfined quark - gluon plasma .
the magnetic field seems to enhance the occurrence of chiral phase - transition due to its contributions to the landau quantizations and contribute to the suppression in the chiral condensates relevant to the restoration of the chiral symmetry - breaking .
the inverse magnetic catalysis leads to a decrease in the chiral critical temperature with increasing magnetic field .
we remark that plsm has a temperature - limited applicability depending on the temperature - applicability of its chiral and deconfinement order - parameters . only within this limit
the conclusions about equation of state , chiral phase - structure and magnetic properties , etc
. can be relatively certain . .
And you have already written the first three sentences of the full article: the structure of quantum chromodynamic ( qcd ) matter at very high temperatures [ much higher than the critical temperature ( @xmath0 ) , which characterizes the hadron - quark deconfinement phase - transition ] is well understood by perturbation theory , for instance . but the entire quark - hadron phase structure still represents a great challenge to lattice qcd and particle scientists . on one hand , it is difficult to draw predictions for the properties of qcd matter , especially the partonic matter , at arbitrary finite temperatures and chemical potentials .
the reason is that qcd under extreme conditions of temperatures and densities remains strongly coupled . on the other hand , non - perturbative approaches , such as lattice qcd simulations , the only available first - principles calculation - tools ,
turn to be very reliable , especially at vanishing chemical potential ..
Please generate the next two sentences of the article | this predicts that the crossover to the quark - gluon plasma ( qgp ) occurs at @xmath1 and might be tolerated to be implemented at finite chemical potentials but much less than the temperatures .
however , this approach ca nt be used at higher chemical potentials and lower temperatures which characterize the color - superconducting phase structure , for instance . |
6,381 | Suppose that you have an abstract for a scientific paper: in a recent publication , we proposed two possible wave functions for the elementary excitations of the su(3 ) haldane shastry model ( hsm ) , but argued on very general grounds that only one or the other can be a valid excitation . here
we provide the explicit details of our calculation proving that the wave function describing a coloron excitation which transforms according to representation @xmath0 under su(3 ) rotations if the spins of the original model transform according to representation 3 , is exact .
we further provide an explicit construction of the exact color - polarized two - coloron eigenstates , and thereby show that colorons are free but that their relative momentum spacings are shifted according to fractional statistics with parameter @xmath1 .
we evaluate the su(3 ) spin currents .
finally , we interpret our results within the framework of the asymptotic bethe ansatz and generalize some of them to the case of su(@xmath2 ) . .
And you have already written the first three sentences of the full article: in recent years , there has been substantial interest in models in condensed matter physics with symmetry groups larger than su(2 ) , the group underlying the usual spin algebra . in particular ,
transition - metal oxides @xcite , where the electron spin is coupled to orbital degrees of freedom , have been described theoretically by models with su(4 ) symmetry @xcite . furthermore , there has been a growing interest in the su(@xmath2 ) generalization of the hubbard model @xcite motivated by possible experimental realizations in systems of ultracold atoms @xcite . in a previous paper @xcite
, we have used the su(@xmath2 ) haldane shastry model to make the case that the elementary excitations of su(@xmath2 ) spin chains transform under the representation _ conjugate _ to the representation of the su(@xmath2 ) spins on the chain , and only exist in one n@xmath3 of the brillouin zone . in this article , we will present for one thing the detailed calculations underlying our line of argumentation in @xcite . to this end , we focus on the su(3 ) haldane shastry model ( hsm ) @xcite , which serves as a paradigm for not only the su(3 ) spin chain , but , as we shall see , also illustrates some very general properties of su(@xmath2 ) chains ..
Please generate the next two sentences of the article | in particular , we derive the quantum numbers of the elementary , fractionally quantized excitations , the analogs of the spinon excitations for su(2 ) , which we call colorons for su(3 ) .
as already mentioned , the key result is that these excitations transform under the su(@xmath2 ) representation conjugate to the representation of the original su(@xmath2 ) spins localized at the sites of the chain . in the case of su(3 ) , if a basis for the original spins is spanned by the colors blue , red , and green , a basis for the coloron excitations is given by the complementary colors yellow , cyan , and magenta ( see fig . |
6,382 | Suppose that you have an abstract for a scientific paper: we present the spatial correlation function analysis of non - stellar x - ray point sources in the _ chandra _ large area synoptic x - ray survey of lockman hole northwest ( clasxs ) .
our 9 acis - i fields cover a contiguous solid angle of 0.4 deg@xmath0 and reach a depth of @xmath1 in the 28 kev band .
we supplement our analysis with data from the chandra deep field north ( cdfn ) .
the addition of this field allows better probe of the correlation function at small scales .
a total of 233 and 252 sources with spectroscopic information are used in the study of the clasxs and cdfn fields respectively .
we calculate both redshift - space and projected correlation functions in comoving coordinates , averaged over the redshift range of @xmath2 , for both clasxs and cdfn fields for a standard cosmology with @xmath3 , and @xmath4 ( @xmath5 km s@xmath6 mpc@xmath6 ) .
the correlation function for the clasxs field over scales of 3 mpc@xmath7 200 mpc can be modeled as a power - law of the form @xmath8 , with @xmath9 and @xmath10 mpc .
the redshift - space correlation function for cdfn on scales of 1 mpc@xmath7 100 mpc is found to have a similar correlation length @xmath11 mpc , but a shallower slope ( @xmath12 ) .
the real - space correlation functions derived from the projected correlation functions , are found to be @xmath13 mpc , and @xmath14 for the clasxs field , and @xmath15 mpc , @xmath16 for the cdfn field . by comparing the real- and redshift - space correlation functions in the combined clasxs and cdfn samples ,
we are able to estimate the redshift distortion parameter @xmath17 at an effective redshift @xmath18 .
we compare the correlation functions for hard and soft spectra sources in the clasxs field and find no significant difference between the two groups .
we have also found that the correlation between x - ray luminosity and clustering amplitude is weak , which , however , is fully consistent with the expectation using the simplest relations between x - ray....
And you have already written the first three sentences of the full article: structure formation and evolution in the universe and the formation and growth of supermassive black holes ( smbhs ) are two fundamental problems in astronomy which are still not fully understood . while recent progresses in the cosmic microwave background , the high redshift type ia supernovae survey , and the large optical surveys have significantly improved our understanding of the evolution of large scale structure , there are still several gaps in the picture of structure formation . the data at redshift of @xmath23 , where most of the cosmic star formation might have taken place , is still very limited . on scales of galaxies and cluster of galaxies ,
the feed back process from galaxies or agns could significantly alter structure formation models where gravitation is the only driving force .
the clustering of active galactic nuclei ( agns ) provides unique path to the solution of these problems because ( 1 ) the agns are often bright compared to normal galaxies and are easily seen at large cosmological distance ; ( 2 ) agns trace the violent growth phase of smbhs and hence their clustering properties provide a link between the dark matter halo to the agn activity ..
Please generate the next two sentences of the article | large scale agn surveys have been traditionally carried out in the optical band with dedicated telescopes .
the most recent of these are the sloan digital sky survey ( sdss , schneider et al . |
6,383 | Suppose that you have an abstract for a scientific paper: we summarize and extend previous results on the comparison of threshold resummation , performed , using soft - collinear effective theory ( scet ) , in the becher - neubert approach , to the standard perturbative qcd formalism based on factorization and resummation of mellin moments of partonic cross sections .
we show that the logarithmic accuracy of this scet result can be extended by half a logarithmic order , thereby bringing it in full agreement with the standard qcd result if a suitable choice is made for the soft scale @xmath0 which characterizes the scet result .
we provide a master formula relating the two approaches for other scale choices .
we then show that with the becher - neubert scale choice the landau pole , which in the perturbative qcd approach is usually removed through power- or exponentially suppressed terms , in the scet approach is removed by logarithmically subleading terms which break factorization .
such terms may become leading for generic choices of parton distributions , and are always leading when resummation is used far enough from the hadronic threshold .
qcd , soft - gluon , threshold , resummation , soft - collinear effective theory .
And you have already written the first three sentences of the full article: threshold resummation @xcite plays an important role in extending and stabilizing the accuracy of perturbative results , and it may be of some relevance even for hadronic processes which are quite far from threshold @xcite , due to the fact that the underlying partonic process can be rather closer to threshold than the hadronic one @xcite .
all - order resummed results are known to lead to a divergent series when expanded out in powers of the strong coupling : this is physically due to the fact that resummation is obtained by choosing as a scale of the parton - level process the maximum energy of the radiated partons @xcite , which tends to zero in the threshold limit .
the divergence can be tamed by introducing suitable subleading contributions , such as exponentially suppressed terms outside the physical kinematic region @xcite , or power - suppressed terms @xcite . in ref ..
Please generate the next two sentences of the article | @xcite it was suggested , within the context of a scet approach to threshold resummation , that the divergence can be tamed by making a hadronic choice of scale . in scet
this is possible because resummed results are characterized by a `` soft scale '' @xmath0 : the becher - neubert ( bn ) scale choice consists of expressing @xmath0 in terms of kinematic variables of the hadronic scattering process . |
6,384 | Suppose that you have an abstract for a scientific paper: cosmology enters precision testing period with the observational experiments advancement .
we have not arrived to decipher the origin of the dominant dark energy component of our universe , although we have located some of its characters . in such a situation
the possibilities of a simple four - fermion interaction model are investigated to describe dark energy characters .
we explicitly calculate the vacuum expectation value of the energy - momentum tensor and discuss the results with comparison to the equation of state for dark energy requirement .
it is found that the negative pressure is realized at low temperature .
it is an appropriate property as a dark energy candidate .
we also investigate some cosmological tests for the dark energy via its equation of state . .
And you have already written the first three sentences of the full article: cosmological problems are as old as human history , but cosmology is a relatively new science . in recent years two main observational results have revealed a profound implication in our current knowledge of the universe .
these are the confirmation of the flat geometry and its accelerating expansion of our universe in the relatively recent epoch , i.e. , with redshift of roughly 0.5 or less , driving by an unidentified component as coined dark energy by m. turner @xcite .
the recent observations have dramatically changed our previous intuition ..
Please generate the next two sentences of the article | the evolution of the universe was slowing down due to gravitational attractive force and also alleviated the universe age crisis problem with respect to the oldest stars and globular clusters in our milk way galaxy .
respectively , the first acoustic peak of the temperature fluctuations on the cosmic microwave background radiation ( cmbr ) is observed by the experiments of boomerang , maxima and wmap @xcite . |
6,385 | Suppose that you have an abstract for a scientific paper: we measure the transverse thermoelectric coefficient @xmath0 in simulations of type - ii superconductors in the vortex liquid regime , using the time - dependent ginzburg - landau ( tdgl ) equation with thermal noise .
our results are in reasonably good quantitative agreement with experimental data on cuprate samples , suggesting that this simple model contains much of the physics behind the large nernst effect due to superconducting fluctuations observed in these materials . .
And you have already written the first three sentences of the full article: the nernst effect in the cuprate superconductors has recently become a focus of attention both experimentally @xcite and theoretically @xcite .
the nernst effect is the electric field induced when the sample has a temperature gradient , @xmath1 , perpendicular to the magnetic field , @xmath2 ; this electric field is perpendicular to both @xmath1 and @xmath2 .
for some cuprate superconductors the nernst effect due to superconducting fluctuations is detectable at temperatures far above the transition temperature , @xmath3 @xcite ..
Please generate the next two sentences of the article | @xcite calculated the low - field nernst effect for @xmath4 due to superconducting fluctuations , obtaining results in reasonable agreement ( in absolute units ) with experimental data .
they used the linearized time - dependent ginzburg - landau ( tdgl ) equation , which is identical to the aslamazov - larkin @xcite approximation for the microscopics . |
6,386 | Suppose that you have an abstract for a scientific paper: given a link @xmath0 , a representation @xmath1 is _ tracefree _ if the image of each meridian has trace zero .
we determine the conjugacy classes of tracefree representations when @xmath0 is a montesinos link . .
And you have already written the first three sentences of the full article: given a link @xmath2 and a linear group @xmath3 , a _ tracefree _
( or _ traceless _ ) @xmath3-representation of @xmath0 means a homomorphism @xmath4 sending each meridian to an element of trace zero . dated back to 1980 ,
magnus @xcite used tracefree @xmath5-representations to prove the faithfulness of a representation of braid groups in the automorphism groups of the rings generated by the characters functions on free groups ..
Please generate the next two sentences of the article | lin @xcite used tracefree @xmath6-representations to define a casson - type invariant of a knot @xmath7 , and showed it to equal half of the signature of @xmath7 .
more interestingly , kronheimer and mrowka @xcite observed that for some knots @xmath7 , its khovanov homology is isomorphic to the ordinary homology of the space @xmath8 of conjugacy classes of tracefree representations of @xmath7 . in this context , |
6,387 | Suppose that you have an abstract for a scientific paper: discovery of new transition metal compounds with large spin orbit coupling ( soc ) coexisting with strong electron - electron correlation among the @xmath0 electrons is essential for understanding the physics that emerges from the interplay of these two effects . in this study , we predict a novel class of @xmath1 mott insulators in a family of fluoride compounds that are previously synthesized , but not characterized extensively .
first principles calculations in the level of all electron density functional theory + dynamical mean field theory ( dft+dmft ) indicate that these compounds have large mott gaps and some of them exhibit unprecedented proximity to the ideal , @xmath2 symmetric @xmath1 limit .
interest in @xmath3 compounds has been blossoming in the recent years in response to the scientific advances and applications in the areas of topological insulators , multiferroics , and thermoelectrics . at the forefront of this activity
are the ir compounds , because of the interesting interplay between itinerancy , the electronic correlations and strong spin - orbit coupling ( soc).@xcite this strong coupling between the spin and orbital degrees of freedom gives rise to various interesting phases , such as the exotic spin - liquid phase predicted in honeycomb iridates , or the recently observed fermi arcs and the spin - orbit induced mott insulating phase in the perovskite - related ir - oxides.@xcite in these latter systems , the soc splits the six - fold degenerate ir t@xmath4 states into 4 occupied @xmath5 and 2 half - occupied @xmath1 states .
the bands formed by the @xmath1 states are much narrower than the width of the whole @xmath6 manifold in the absence of soc , and as a result , the system can be easily drawn to a mott - insulating phase with even a modest amount of correlations on the 5d ir atom . @xcite
the most widely studied soc induced correlated insulator is sr@xmath7iro@xmath8 , which is an antiferromagnetic insulator below 240 k.@xcite there are numerous studies that....
And you have already written the first three sentences of the full article: the action of the auxiliary impurity problem that we minize in our calculations is @xmath74 where @xmath75 is the imaginary time , @xmath76 is the annihilation operator for the impurity electrons , @xmath77 and @xmath78 are the orbital and spin indices , and @xmath49 is the impurity hybridization function .
the on site electron - electron coulomb interaction between the d electrons is represented by the slater form : @xmath79 and @xmath80 here , @xmath81 are the radial part of the spherical harmonics , the index @xmath77 denotes @xmath82 , and @xmath83 are the slater integrals .
the explicit form of the frequency dependent hybridization @xmath84 can be written in terms of the projector @xmath85 , the kohn - sham hamiltonian ( without the spin - orbit coupling ) @xmath86 , the spin - orbit coupling hamiltonian @xmath87 , the self - energy @xmath88 , the local green s function @xmath89 and the double counting energy @xmath90.
Please generate the next two sentences of the article | as@xcite @xmath91 the small latin indices @xmath92 enumerate the kohn - sham bands and include the spin as well .
@xmath93 is the crystal momentum . |
6,388 | Suppose that you have an abstract for a scientific paper: we prove the analogue of helly s theorem for systolic complexes .
namely , we show that @xmath0-systolic complexes have helly dimension less or equal to @xmath1 , whereas @xmath2-systolic complexes have helly dimension bounded from the above by @xmath3 . .
And you have already written the first three sentences of the full article: eduard helly proved his classical theorem concerning convex subsets of euclidean spaces .
namely , suppose that @xmath4 is a collection of convex subsets of @xmath5 ( where @xmath6 ) such that the intersection of every @xmath7 of these sets in nonempty .
then the whole family has a nonempty intersection ..
Please generate the next two sentences of the article | this result gave rise to the concept of helly dimension .
for a geodesic metric space @xmath8 we define its _ helly dimension _ |
6,389 | Suppose that you have an abstract for a scientific paper: successful soft leptogenesis ( sl ) requires a relatively low mass scale for the su(2 ) singlet neutrinos of @xmath0 gev .
however , conventional sl ( unflavoured ) requires an unnaturally small soft supersymmetry(susy)-breaking bilinear @xmath1 coupling for successful leptogenesis . on the other hand ,
in this regime , the interactions mediated by @xmath2 , @xmath3 ( and even @xmath4 ) charged lepton yukawa interactions are in equilibrium , making the lepton number asymmetries and the washouts flavour dependent .
hence , it is crucial to take into account the flavour effects . considering a general soft susy - breaking trilinear @xmath5 couplings
, it is possible to enhance the efficiency up to @xmath6 compared to the unflavoured case . with the enhanced efficiency
, we can raise the @xmath7 up to tev scale for successful leptogenesis .
taking into account the low energy constraints , we verify that the fast lepton flavour violation processes induced by the soft susy - breaking slepton masses would not destroy the enhancement .
= 11.6pt .
And you have already written the first three sentences of the full article: the type - i susy seesaw model can be described by the superpotential : @xmath8 where @xmath9 is the superpotential for the minimal supersymmetric standard model ( mssm ) , @xmath10 are the lepton flavour indices , @xmath11 are the majorana masses of the right - handed singlet neutrinos with generation indices @xmath12 , and @xmath13 , @xmath14 , @xmath15 are the chiral superfields for the right - handed singlet neutrinos , the left - handed lepton doublets and the higgs doublets , with @xmath16 and @xmath17 .
the relevant soft susy - breaking terms are given by @xmath18 the singlet sneutrino and anti - sneutrino states mix , giving rise to the mass eigenstates : @xmath19 where @xmath20 , that correspond to the mass eigenvalues @xmath21
for simplicity , we will concentrate on sl arising from a single sneutrino generation @xmath22 and in what follows we will drop that index ..
Please generate the next two sentences of the article | after superfield phase rotations , we have three independent physical phases , they are @xmath23 eq . ( [ eq : soft_terms ] ) leads to cp asymmetries @xmath24 arising from self - energy diagrams induced by the bilinear @xmath7 term , @xmath25 where @xmath26 is the thermal factor associated to the difference between the phase - space , bose - enhancement and fermi - blocking factors for the scalar and fermionic channels , that vanishes in the zero temperature limit @xmath27@xcite .
regarding the flavour structure of the soft terms relevant for flavoured sl , we can distinguish two general possibilities : \1 . _ |
6,390 | Suppose that you have an abstract for a scientific paper: we summarize new x - ray detections of four nitrogen - type wolf - rayet ( wr ) stars obtained in a limited survey aimed at establishing the x - ray properties of wn stars across their full range of spectral subtypes .
none of the detected stars is so far known to be a close binary .
we report _ chandra _ detections of wr 2 ( wn2 ) , wr 18 ( wn4 ) , and wr 134 ( wn6 ) , and an _ xmm - newton _ detection of wr79a ( wn9 ha ) .
these observations clearly demonstrate that both wne and wnl stars are x - ray sources .
we also discuss _ chandra _ archive detections of the wn6h stars wr 20b , wr 24 , and wr 136 and _ rosat _ non - detections of wr 16 ( wn8h ) and wr 78 ( wn7h ) .
the x - ray spectra of all wn detections show prominent emission lines and an admixture of cool ( kt @xmath0 1 kev ) and hot ( kt @xmath1 2 kev ) plasma .
the hotter plasma is not predicted by radiative wind shock models and other as yet unidentified mechanisms are at work .
most stars show x - ray absorption in excess of that expected from visual extinction ( a@xmath2 ) , likely due to their strong winds or cold circumstellar gas .
existing data suggest a falloff in x - ray luminosity toward later wn7 - 9 subtypes , which have higher l@xmath3 but slower , denser winds than wn2 - 6 stars .
this provides a clue that wind properties may be a more crucial factor in determining emergent x - ray emission levels than bolometric luminosity . .
And you have already written the first three sentences of the full article: x - ray observations of wolf - rayet ( wr ) stars provide an important means of determining physical conditions in their powerful metal - rich winds and in hot wind - blown bubbles which can surround the star .
x - ray observations yield information on the temperature , emission measure , and luminosity of hot plasma that can be used to test models of wr x - ray emission , which are largely based on the idea that the x - rays arise in shocked winds .
photoelectric absorption of low - energy x - rays can reveal the presence of gas along the line - of - sight toward the star that is difficult to detect by other means ..
Please generate the next two sentences of the article | high - resolution grating spectra can be obtained for the brightest wr x - ray sources and are capable of constraining the location of the x - ray emittng plasma relative to the star , wind parameters , and wind element abundances .
it has been nearly three decades since wr stars were discovered to be x - ray sources by the _ einstein observatory _ |
6,391 | Suppose that you have an abstract for a scientific paper: we study , using a gravity dual , the finite temperature dynamics of @xmath0 gauge theory for large @xmath1 , with fundamental quark flavours in a quenched approximation , in the presence of a fixed charge under a global current .
we observe several notable phenomena .
there is a first order phase transition where the quark condensate jumps discontinuously at finite quark mass , generalizing similar transitions seen at zero charge .
we find a non zero condensate at zero quark mass above a critical value of the charge , corresponding to an analogue of spontaneous chiral symmetry breaking at finite number density .
we find that the spectrum of mesons contains the expected associated goldstone ( `` pion '' ) degrees of freedom with a mass dependence on the quark mass that is consistent with the gell - mann oakes renner relation .
our tool in these studies is holography , the string dual of the gauge theory being the geometry of @xmath1 spinning d3branes at finite temperature , probed by a d7brane . * global currents , phase transitions * * and * * chiral symmetry breaking in large @xmath1 gauge theory * * tameem albash , veselin filev , clifford v. johnson , arnab kundu * _ department of physics and astronomy _
_ university of southern california _ _ los angeles , ca 90089 - 0484 , u.s.a . _ albash , filev , johnson1 , akundu @usc.edu .
And you have already written the first three sentences of the full article: there is great interest in understanding the phase structure of quantum chromodynamics ( qcd ) .
there are various regions of the @xmath2 phase diagram ( @xmath3 is temperature and @xmath4 is a chemical potential for baryon number ) which are extremely hard to model theoretically using traditional field theory techniques .
some of these regimes are being probed experimentally , and so there is additional interest in obtaining better theoretical understanding from an immediate phenomenological point of view . for almost a decade , progress in understanding the dynamics of extended objects in string theory has enabled several new techniques and a fresh and powerful new perspective to be brought to the study of strongly coupled gauge theory ..
Please generate the next two sentences of the article | the techniques were sharpened further ( for large number of colours , @xmath1 , ) with holographic examples such as the ads / cft correspondence , and the study of gauge / gravity duals ( or , more properly , gauge / string duals ) has proven to be a fruitful and often elegant pursuit .
not long after the birth of ads / cft@xcite , where the finite temperature phase structure of @xmath5 @xmath0 ( at large @xmath1 ) was understood in terms of the thermodynamics of schwarzschild black holes in ads@xcite , it was recognized@xcite that progress could be made in understading the properties of gauge theories in the presence of a global current , akin to a chemical potential for baryon number or isospin , by studying the physics of charged black holes , such as riessner |
6,392 | Suppose that you have an abstract for a scientific paper: we use three samples ( 3crr , 6ce and 6c * ) to investigate the radio luminosity function ( rlf ) for the ` most powerful ' low - frequency selected radio sources .
we find that the data are well fitted by a model with a constant co - moving space density at high redshift as well as by one with a declining co - moving space density above some particular redshift .
this behaviour is very similar to that inferred for steep - spectrum radio quasars by willott et al(1998 ) in line with the expectations of unified schemes .
we conclude that there is as yet no evidence for a ` redshift cut - off ' in the co - moving space densities of powerful classical double radio sources , and rule out a cut - off at @xmath0 . .
And you have already written the first three sentences of the full article: it is well - known that the ( co - moving ) space densities of the rarest , most powerful quasars and radio galaxies were much higher at epochs corresponding to @xmath1 than they are now ( longair 1966 ) .
the behaviour of the space density beyond these redshifts is the subject of this paper .
dunlop & peacock ( 1990 ) found evidence for a ` redshift cut - off ' ( a decline in the co - moving space density ) in the distribution of flat - spectrum radio sources over the redshift range @xmath2 . through failing to find any flat - spectrum radio quasars at @xmath3 in a large ( @xmath440 per cent of the sky ) survey ,.
Please generate the next two sentences of the article | shaver et al ( 1996 , hereafter sh96 ) argued for an order - of - magnitude drop in space density between @xmath5 and @xmath6 , for this class of object .
as emphasised by sh96 , the crucial advantage of any radio - selected survey is that with sufficient optical follow - up , it can be made free of optical selection effects , such as increasing dust obscuration at high redshift . |
6,393 | Suppose that you have an abstract for a scientific paper: we study the backwards - in - time stability of the schwarzschild singularity from a dynamical pde point of view .
more precisely , considering a spacelike hypersurface @xmath0 in the interior of the black hole region , tangent to the singular hypersurface @xmath1 at a single sphere , we study the problem of perturbing the schwarzschild data on @xmath0 and solving the einstein vacuum equations backwards in time .
we obtain a local well - posedness result for small perturbations lying in certain weighted sobolev spaces .
no symmetry assumptions are imposed .
the perturbed spacetimes all have a singularity at a `` collapsed '' sphere on @xmath0 , where the leading asymptotics of the curvature and the metric match those of their schwarzschild counterparts to a suitably high order .
as in the schwarzschild backward evolution , the pinched initial hypersurface @xmath0 ` opens up ' instantly , becoming a smooth spacelike ( cylindrical ) hypersurface .
this result thus yields classes of examples of non - symmetric vacuum spacetimes , evolving forward - in - time from smooth initial data , which form a schwarzschild type singularity at a collapsed sphere .
we rely on a precise asymptotic analysis of the schwarzschild geometry near the singularity which turns out to be at the threshold that our energy methods can handle .
= 8 pt .
And you have already written the first three sentences of the full article: it is well - known ( cf .
birkhoff s theorem @xcite ) that the only spherically symmetric solution @xmath2 to the einstein vacuum equations ( eve ) @xmath3 is the celebrated schwarzschild spacetime .
it was in fact the first non - trivial solution to the einstein field equations to be discovered @xcite ..
Please generate the next two sentences of the article | in kruskal ( null ) @xmath4 coordinates the maximally extended metric reads @xmath5 where @xmath6 , @xmath7 , and the radius function @xmath8 is given implicitly by @xmath9 here the underlying manifold @xmath10 is endowed with the differential structure of @xmath11 , where @xmath12 is the open subset @xmath13 in the @xmath14 plane ; see figure [ krusk ] .
the spacetime has an essential curvature singularity at @xmath15 , ( the future component of ) which is contained in the interior of the black hole region , the quadrant @xmath16 . |
6,394 | Suppose that you have an abstract for a scientific paper: we prove the large deviation principle for the joint empirical measure of pairs of random variables which are coupled by a totally symmetric " interaction .
the rate function is given by an explicit bilinear expression , which is finite only on product measures and hence is non - convex .
= 7000 .
And you have already written the first three sentences of the full article: [ [ section ] ] large deviations of empirical measures have been widely studied in the literature since the celebrated sanov s theorem , which gives the large deviations principle in the scale of @xmath0 of the empirical measures of i. i. d. random variables with the relative entropy @xmath1 as the rate function .
another entropy , voiculescu s non - commutative entropy @xmath2 , arises in the study of fluctuations of eigenvalues of random matrices , see hiai & petz@xcite and the references therein .
chan @xcite interprets empirical measures of eigenvalues of random matrices as a system of interacting diffusions with singular interactions ..
Please generate the next two sentences of the article | [ [ section-1 ] ] in this paper we study empirical measures which can be thought of as a decoupled version of the empirical measures generated by random matrices .
we are interested in empirical measures on @xmath3 generated by pairs of random variables that are tied together by a totally symmetric , and hence non - local , interaction , see formula ( [ f ] ) for the ( unnormalized ) joint density . under certain assumptions , we prove that the large deviation principle in the scale @xmath4 holds for the joint empirical measures , and the rate function is non - convex . as a corollary , we derive a large deviations principle for the univariate average empirical measures with a rate function that superficially resembles the rate function of random matrices , see corollary [ c2 ] ; an interesting feature here is the emergence of concave rate functions , see remark [ rc2 ] . |
6,395 | Suppose that you have an abstract for a scientific paper: we have developed a method for measuring higher - order weak lensing distortions of faint background galaxies , namely the weak gravitational flexion , by fully extending the kaiser , squires & broadhurst method to include higher - order lensing image characteristics ( holics ) introduced by okura , umetsu , & futamase .
we take into account explicitly the weight function in calculations of noisy shape moments and the effect of higher - order psf anisotropy , as well as isotropic psf smearing .
our holics formalism allows accurate measurements of flexion from practical observational data in the presence of non - circular , anisotropic psf .
we test our method using mock observations of simulated galaxy images and actual , ground - based subaru observations of the massive galaxy cluster a1689 ( @xmath0 ) . from the high - precision measurements of spin-1 first flexion
, we obtain a high - resolution mass map in the central region of a1689 .
the reconstructed mass map shows a bimodal feature in the central @xmath1 region of the cluster .
the major , pronounced peak is associated with the brightest cluster galaxy and central cluster members , while the secondary mass peak is associated with a local concentration of bright galaxies . the refined , high - resolution mass map of a1689 demonstrates the power of the generalized weak lensing analysis techniques for quantitative and accurate measurements of the weak gravitational lensing signal . .
And you have already written the first three sentences of the full article: propagation of light rays from a distant source to the observer is governed by the gravitational field of intervening mass fluctuations as well as by the global geometry of the universe .
the images of background sources hence carry the imprint of the gravitational potential of intervening cosmic structures , and their statistical properties can be used to test the background cosmological models .
weak gravitational lensing is responsible for the weak shape - distortion and magnification of the images of background sources due to the gravitational field of intervening matter ( e.g. , bartelmann & schneider 2001 ; umetsu , futamase , & tada 1999 ) . to the first order ,.
Please generate the next two sentences of the article | weak lensing gives rise to a few @xmath2 levels of elliptical distortions in images of background sources , responsible for the second - order derivatives of the gravitational lensing potential .
thus , the weak lensing signal , measured from tiny but coherent quadrupole distortions in galaxy shapes , can provide a direct measure of the projected mass distribution of cosmic structures . however , practical weak lensing observations subject to the effects of atmospheric seeing , isotropic / anisotropic psf , and ( residual ) camera distortion across the field of view , which must be examined from the stellar shape measurements and corrected for in the weak lensing analysis . |
6,396 | Suppose that you have an abstract for a scientific paper: we study the fine tuning in the parameter space of the semi - constrained nmssm , where most soft susy breaking parameters are universal at the gut scale .
we discuss the dependence of the fine tuning on the soft susy breaking parameters @xmath0 and @xmath1 , and on the higgs masses in nmssm specific scenarios involving large singlet - doublet higgs mixing or dominant higgs - to - higgs decays . whereas these latter scenarios allow _ a priori _ for considerably less fine tuning than the constrained mssm , the early lhc results rule out a large part of the parameter space of the semi - constrained nmssm corresponding to low values of the fine tuning .
lpt orsay 11 - 63 + l2c 11- + lupm 11 - 002 + + * ulrich ellwanger@xmath2 , grgory espitalier - nol@xmath3 and cyril hugonie@xmath4 * + _ @xmath2 lpt , umr 8627 , cnrs , universit de paris sud , 91405 orsay , france + _
@xmath5 l2c , umr 5221 , cnrs , universit de montpellier ii , 34095 montpellier , france + _ @xmath4 lupm , umr 5299 , cnrs , universit de montpellier ii , 34095 montpellier , france + _ _ _ .
And you have already written the first three sentences of the full article: the first motivation for supersymmetric extensions of the standard model ( sm ) stems from the solution of the naturalness or fine tuning problem in the higgs sector of the sm @xcite ( besides the unification of the gauge couplings and the possibility to explain dark matter ) : in the sm with an ultraviolet cutoff @xmath6 much larger than the electroweak scale @xmath7 , the bare higgs mass squared @xmath8 must satisfy roughly @xmath9
. hence @xmath8 must be of the order @xmath10 , but must be finetuned relative to @xmath10 with a precision of the order @xmath11 .
this fine tuning is enormous for @xmath6 of the order of a gut scale , but only a tuning of @xmath12 is considered as natural . within supersymmetric ( susy ) extensions of the sm with susy breaking terms of the order @xmath13 , the necessary tuning between the parameters is of the order of @xmath14 , and hence independent from an ultraviolet cutoff @xmath6 ..
Please generate the next two sentences of the article | first results of searches for susy by the atlas and cms collaborations at the lhc , based on @xmath15 fb@xmath16 of data taken at 7 tev center - of - mass energy , imply lower bounds on susy breaking gluino and up / down squark masses in the 1 tev range @xcite ( for the latest publications , see the atlas and cms notes on the web pages @xcite ) .
these bounds reduce the phenomenologically viable range of parameters in susy extensions of the sm . however , an obviously interesting question is the impact of these negative results on the necessary tuning between the parameters in the remaining parameter region . |
6,397 | Suppose that you have an abstract for a scientific paper: a complete physical approach to quantum information requires a robust interface among flying qubits , long - lifetime memory and computational qubits . here
we present a unified interface for microwave and optical photons , potentially connecting engineerable quantum devices such as superconducting qubits at long distances through optical photons .
our approach uses an ultracold ensemble of atoms for two purposes : quantum memory and to transduce excitations between the two frequency domains . using coherent control techniques
, we examine an approach for converting and storing quantum information between microwave photons in superconducting resonators , ensembles of ultracold atoms , and optical photons as well as a method for transferring information between two resonators . controlling
the interaction between quantum bits and electromagnetic fields is a fundamental challenge underlying quantum information science .
ideally , control allows storage , communication , and manipulation of the information at the level of single quanta .
unfortunately , no single degree of freedom satisfies all these criteria simultaneously @xcite . instead
, a hybrid approach may take advantage of each system s most attractive properties .
for example , optical photons provide a robust long - distance quantum bus @xcite , while microwave ( mw ) photons can be easily manipulated using superconducting qubits @xcite , and atoms can store quantum information for seconds or even minutes @xcite .
we propose an interface between optical , microwave photons and atomic excitations that takes advantage of each of these properties . in a recent proposal ,
the possibility of coupling ultracold atoms to a nanofibre in the vicinity of a superconducting waveguide / resonator was suggested [ fig.1(a ) ] @xcite .
the evanescent tail of the two - color laser field propagating in the fiber provides the necessary potential to trap atoms close to the nanofibre in the form of a 1d lattice , which has recently been....
And you have already written the first three sentences of the full article: here we study the dispersive effect of atoms when they are trapped in a one dimensional optical lattice , as expected for the tapered fiber trap given in the paper .
we consider a situation where the atoms are not saturated with few photons @xmath91 , and therefore , the system is in the linear regime and the electric field operator can be presented by its expectation value , i.e. , @xmath92 . furthermore , since the atoms are periodically spaced , we can discretize the propagation of the electric field ( as shown in fig . 2 of the main text ) and
use the transfer matrix formalism to study multiple scattering events to all order @xcite . in the @xmath93th cell.
Please generate the next two sentences of the article | , we define the forward ( backward)-propagating field as @xmath94 , respectively .
the fields in two consecutive cells are related by : @xmath95 where @xmath96 is the transfer matrix and the corresponding transmission ( reflection ) coefficient is given by : @xmath97 , respectively . |
6,398 | Suppose that you have an abstract for a scientific paper: we present a method to measure the spectrally - resolved transmission matrix of a multiply scattering medium , thus allowing for the deterministic spatiospectral control of a broadband light source by means of wavefront shaping . as a demonstration
, we show how the medium can be used to selectively focus one or many spectral components of a femtosecond pulse , and how it can be turned into a controllable dispersive optical element to spatially separate different spectral components to arbitrary positions . .
And you have already written the first three sentences of the full article: wave propagation through a multiply scattering medium is an important problem for different disciplines , from optics to acoustics and microwaves @xcite , since it finds important applications from fundamental physics to biomedical imaging @xcite . for a monochromatic coherent input beam ,
the medium typically generates a speckle pattern @xcite - the result of complex interference between the scattered waves - that is usually considered a major drawback for imaging and focusing . in optics ,
wavefront shaping by spatial light modulators ( slms ) has emerged as a powerful tool to control the speckle and thus light propagation through such complex media @xcite ..
Please generate the next two sentences of the article | different approaches have been proposed , in particular via optimization methods @xcite , to focus light through @xcite or into @xcite a complex medium . however
, a more general way to understand light propagation is to describe it via its transmission matrix ( tm ) @xcite , which in essence describes the fact that propagation through a disordered medium , however complex , remains a linear process , and therefore can be described by a linear operator @xmath0 linking input to output modes , i.e. it can be described as @xmath1 . |
6,399 | Suppose that you have an abstract for a scientific paper: we present a new public archive of light - motion curves in sloan digital sky survey ( sdss ) stripe 82 , covering 99@xmath0 in right ascension from @xmath1 to 3.3@xmath2 and spanning 252 in declination from @xmath3126 to 126 , for a total sky area of @xmath4249 deg@xmath5 .
stripe 82 has been repeatedly monitored in the @xmath6 , @xmath7 , @xmath8 , @xmath9 and @xmath10 bands over a seven - year baseline .
objects are cross - matched between runs , taking into account the effects of any proper motion .
the resulting catalogue contains almost 4 million light - motion curves of stellar objects and galaxies .
the photometry are recalibrated to correct for varying photometric zeropoints , achieving @xmath420 mmag and @xmath430 mmag root - mean - square ( rms ) accuracy down to 18 mag in the @xmath7 , @xmath8 , @xmath9 and @xmath10 bands for point sources and extended sources , respectively .
the astrometry are recalibrated to correct for inherent systematic errors in the sdss astrometric solutions , achieving @xmath432 mas and @xmath435 mas rms accuracy down to 18 mag for point sources and extended sources , respectively . for each light - motion curve ,
229 photometric and astrometric quantities are derived and stored in a higher - level catalogue . on the photometric side ,
these include mean exponential and psf magnitudes along with uncertainties , rms scatter , @xmath11 per degree of freedom , various magnitude distribution percentiles , object type ( stellar or galaxy ) , and eclipse , stetson and vidrih variability indices . on the astrometric side ,
these quantities include mean positions , proper motions as well as their uncertainties and @xmath11 per degree of freedom .
the here presented light - motion curve catalogue is complete down to @xmath12 and is at present the deepest large - area photometric and astrometric variability catalogue available .
[ firstpage ] catalogues - stars : photometry , astrometry , variables - galaxy : stellar content - galaxies : photometry .
And you have already written the first three sentences of the full article: [ cols="<,<,<,<",options="header " , ] [ tab : hlc2 ]
the hlc supplies a set of 229 derived quantities for each light - motion curve in the lmcc .
these quantities are aimed at describing the mean magnitudes , photometric variability and astrometric motion of the objects in the lmcc , and they are calculated using only light - motion curve entries that satisfy the quality constraints from section 2.3 . those quantities in the hlc related to photometry.
Please generate the next two sentences of the article | are described in table [ tab : hlc1 ] , while those related to astrometry are described in table [ tab : hlc2 ] . in table
[ tab : hlc1 ] , if a tag name is associated with a 5-element array , then the 5 values represent the described quantity for each of the five sdss wave bands in the order @xmath6 , @xmath7 , @xmath8 , @xmath9 and @xmath10 . when a certain wave band has insufficent `` good '' light - motion curve entries to calculate a particular quantity , a value of zero is stored ( this also applies to table [ tab : hlc2 ] ) . for instance , the first value in the array mean_psfmag is set to zero for any light - motion curves with no `` good '' entries for the @xmath6 band . all quantities in table [ tab : hlc1 ] with clip at the end of the tag name |
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