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4,700 | Suppose that you have an abstract for a scientific paper: based on a course presented at the international school of physics enrico fermi , clxi course,.``polarons in bulk materials and systems with reduced dimensionality '' , varenna , italy , 21.6 .
- 1.7.2005 .
in the present course , an overview is presented of the fundamentals of continuum - polaron physics , which provide the basis of the analysis of polaron effects in ionic crystals and polar semiconductors .
these lecture notes deal with large , or continuum , polarons , as described by the frhlich hamiltonian .
the emphasis is on the polaron optical absorption , with detailed mathematical derivations . .
And you have already written the first three sentences of the full article: a charge placed in a polarizable medium is screened .
dielectric theory describes the phenomenon by the induction of a polarization around the charge carrier .
the induced polarization will follow the charge carrier when it is moving through the medium ..
Please generate the next two sentences of the article | the carrier together with the induced polarization is considered as one entity ( see fig.[fig_scheme1 ] ) .
it was called a _ polaron _ by l. d. landau @xcite . |
4,701 | Suppose that you have an abstract for a scientific paper: we have studied a dissipative version of a one - dimensional fermi accelerator model .
the dynamics of the model is described in terms of a two - dimensional , nonlinear area - contracting map .
the dissipation is introduced via innelastic collisions of the particle with the walls and we consider the dynamics in the regime of high dissipation .
for such a regime , the model exhibits a route to chaos known as period doubling and we obtain a constant along the bifurcations so called the feigenbaum s number @xmath0 . .
And you have already written the first three sentences of the full article: the origin of cosmic radiation and a mechanism trough which it could acquire enormous energies has intrigued many physicists and mathematicians along the last decades . in particular
, in the year of 1949 enrico fermi @xcite proposed a very simple model that qualitatively describes a process in which charged particles were _ bounced _ via interaction with moving magnetic fields .
this heuristic idea was then later modified to encompass in a suitable model that could give quantitative results on the original fermi s model ..
Please generate the next two sentences of the article | after that , many different versions of the model were proposed @xcite and studied in different context and considering many approaches and modifications @xcite .
one of them is the well known fermi - ulam model ( fum ) . |
4,702 | Suppose that you have an abstract for a scientific paper: the electronic and optical properties of polycyclic aromatic hydrocarbons ( pahs ) present a strong dependence on their size and geometry .
we tackle this issue by analyzing the spectral features of two prototypical classes of pahs , belonging to @xmath0 and @xmath1 symmetry point groups and related to coronene as multifunctional seed .
while the size variation induces an overall red shift of the spectra and a redistribution of the oscillator strength between the main peaks , a lower molecular symmetry is responsible for the appearance of new optical features .
along with broken molecular orbital degeneracies , optical peaks split and dark states are activated in the low - energy part of the spectrum . supported by a systematic analysis of the composition and the character of the optical transitions , our results contribute in shedding light to the mechanisms responsible for spectral modifications in the visible and near uv absorption bands of medium - size pahs .
* keywords * : astrochemistry , coronene , configuration interaction , graphene nanoribbons , transition density , zindo polycyclic aromatic hydrocarbons ( pahs ) are the focus of research in significantly diverse fields , ranging from biochemistry @xcite to theoretical chemistry @xcite , from molecular electronics @xcite to astrochemistry @xcite , where pahs are assigned an important role @xcite due to their chemical composition and spectral features @xcite . in this framework , a theoretical identification of the absorption and emission features of these molecules assumes a significant relevance @xcite , since they might drastically vary both upon small structural modifications @xcite and as a consequence of ionization @xcite or dehydrogenation @xcite . in the field of molecular electronics ,
the interest in medium- and large - sized pahs is intrinsically connected to graphene , as they are viewed as highly stable graphene molecules @xcite .
their intriguing and versatile optical properties @xcite , combined with their facile....
And you have already written the first three sentences of the full article: the results presented in this paper are obtained within the framework of hartree - fock based semi - empirical methods .
this methodology is well tested and reliable to compute the electronic and optical properties of c - conjugated low - dimensional systems @xcite , including pahs themselves @xcite .
the am1 model @xcite is adopted for structural optimization [ 0.4 @xmath3/(mol @xmath4 ) threshold for the forces ] , whereas the zindo / s model @xcite , based on configuration interaction ( ci ) including single excitations only , is employed for the optical spectra . to better characterize the optical excitations ,.
Please generate the next two sentences of the article | we introduce the _ transition density _
@xcite , which is defined as : @xmath5 where @xmath6 ( @xmath7 ) indicates the occupied ( unoccupied ) molecular orbitals ( mos ) and @xmath8 are the ci coefficients of the @xmath9 excited - state configuration @xcite . |
4,703 | Suppose that you have an abstract for a scientific paper: we investigate yang - lee zeros of grand partition functions as truncated fugacity polynomials of which coefficients are given by the canonical partition functions @xmath0 up to @xmath1 .
such a partition function can be inevitably obtained from the net - baryon number multiplicity distribution in relativistic heavy ion collisions , where the number of the event beyond @xmath2 has insufficient statistics , as well as canonical approaches in lattice qcd .
we use a chiral random matrix model as a solvable model for chiral phase transition in qcd and show that the closest edge of the distribution to real chemical potential axis is stable against cutting the tail of the multiplicity distribution . the similar behavior is also found in lattice qcd at finite temperature for roberge - weiss transition .
in contrast , such a stability is found to be absent in the skellam distribution which does not have phase transition .
we compare the number of @xmath2 to obtain the stable yang - lee zeros with those of critical higher order cumulants . .
And you have already written the first three sentences of the full article: phase transition in quantum chromodynamics ( qcd ) is one of the central subjects in high energy nuclear physics both theoretically and experimentally .
first principle lattice qcd ( lqcd ) calculations have shown that the transition from quark - gluon plasma ( qgp ) to hadronic matter is of crossover type at physical quark masses @xcite , in which order parameters and thermodynamic quantities change smoothly as functions of temperature . at finite baryon density
, one expects that the nature of the transition can change ..
Please generate the next two sentences of the article | unfortunately , little is known about the state of matter at high baryon density from lqcd calculations because of the difficulty in numerical simulation at finite baryon chemical potential @xmath3 @xcite .
various approximation methods applied so far seem to work only @xmath4 or a small volume or heavy quark mass region . |
4,704 | Suppose that you have an abstract for a scientific paper: we perform an asteroseismological study on the dav star g117@xmath0b15a on the basis of a modern set of fully evolutionary da white dwarf models that have consistent chemical profiles at the core and the envelope .
we found an asteroseismological model for g117@xmath0b15a that closely reproduces its observed pulsation periods .
then , we use the most recently measured value of the rate of period change for the dominant mode of this pulsating star to impose a preliminary upper limit to the mass of the axion . .
And you have already written the first three sentences of the full article: pulsating da ( h - rich atmospheres ) white dwarfs , also called zz ceti or dav stars , are the most numerous class of degenerate pulsators , with over 148 members known today . they are characterized by multiperiodic brightness variations caused by spheroidal , non - radial @xmath1-modes of low degree with periods between 70 and 1500 s ( winget & kepler , althaus et al .
g117@xmath0b15a is the most well - studied star of this class of variables .
the rate of change of its 215.2 s period is very small : @xmath2 s / s ( kepler 2009 ) , with a stability comparable to that of the most stable millisecond pulsars ..
Please generate the next two sentences of the article | the _ axion _ is a hypothetical particle that appears as a consequence of the symmetry postulated by peccei & quinn ( 1977 ) to solve the strong cp ( charge - parity ) problem in quantum chromodynamics .
axions are considered as candidates for dark matter of the universe , and their contribution depends on their mass ( raffelt 2007 ) . |
4,705 | Suppose that you have an abstract for a scientific paper: we consider the motion of classical spinning test particles in schwarzschild and kerr metrics and investigate innermost stable circular orbits ( isco ) .
the main goal of this work is to find analytically the small - spin corrections for the parameters of isco ( radius , total angular momentum , energy , orbital angular frequency ) of spinning test particles in the case of vectors of black hole spin , particle spin and orbital angular momentum being collinear to each other .
we analytically derive the small - spin linear corrections for arbitrary kerr parameter @xmath0 .
the cases of schwarzschild , slowly rotating and extreme kerr black hole are considered in details . for a slowly rotating black hole
the isco parameters are obtained up to quadratic in @xmath0 and particle s spin @xmath1 terms . from the formulae
obtained it is seen that the spin - orbital coupling has attractive character when spin and angular momentum are parallel and repulsive when they are antiparallel . for the case of the extreme kerr black hole with co - rotating particle we succeed to find the exact analytical solution for the limiting isco parameters for arbitrary spin .
it has been shown that the limiting values of isco radius and frequency do not depend on the particle s spin while values of energy and total angular momentum depend on it .
we have also considered circular orbits of arbitrary radius and have found small - spin linear corrections for the total angular momentum and energy at given radius .
system of equations for numerical calculation of isco parameters for arbitrary @xmath0 and @xmath1 is also explicitly written .
pacs numbers : : 04.20.-q .
And you have already written the first three sentences of the full article: in general relativity the presence of a rotation ( intrinsic angular momentum , or spin ) of the central body influences motion of a particle orbiting it . due to this reason the orbits of test particles differ in the schwarzschild and kerr backgrounds .
when , in turn , a test particle has spin as well , it will also influence the particle s orbit .
in particular , the motion of a spinning particle will differ from the non - spinning one even in the schwarzschild background ..
Please generate the next two sentences of the article | let us consider a massive non - spinning test particle orbiting a central black hole ( bh ) .
there exists a minimal radius at which stable circular motion is still possible , it defines the so - called innermost stable circular orbit ( isco ) in given background . for the schwarzschild background |
4,706 | Suppose that you have an abstract for a scientific paper: lots of research focuses on the combinatorics behind various bases of cluster algebras .
this paper studies the natural basis of a type @xmath0 cluster algebra , which consists of all cluster monomials .
we introduce a new kind of combinatorial formulas for the cluster monomials in terms of the so - called globally compatible collections .
we give bijective proofs of these formulas by comparing with the well - known combinatorial models of the @xmath1-paths and of the perfect matchings in a snake diagram . for cluster variables of a type @xmath0 cluster algebra
, we give a bijection that relates our new formula with the theta functions constructed by gross , hacking , keel and kontsevich . .
And you have already written the first three sentences of the full article: cluster algebras were first introduced by s. fomin and a. zelevinsky in @xcite to design an algebraic framework for understanding total positivity and canonical bases for quantum groups .
a cluster algebra is a subring of a rational function field generated by a distinguished set of laurent polynomials called cluster variables .
the long - standing positivity conjecture , now proved in @xcite and @xcite , asserts that the coefficients in any cluster variable are positive integers . from the combinatorial point of view.
Please generate the next two sentences of the article | , the positivity conjecture suggests that these coefficients should count some combinatorial objects .
lots of research focuses on building such combinatorial models . |
4,707 | Suppose that you have an abstract for a scientific paper: we undertook a time - series photometric multi - site campaign for the rapidly oscillating ap star hd 99563 and also acquired mean light observations over two seasons .
the pulsations of the star , that show flatter light maxima than minima , can be described with a frequency quintuplet centred on 1557.653 @xmath0hz and some first harmonics of these .
the amplitude of the pulsation is modulated with the rotation period of the star that we determine with @xmath1 d from the analysis of the stellar pulsation spectrum and of the mean light data .
we break the distorted oscillation mode up into its pure spherical harmonic components and find it is dominated by the @xmath2 pulsation , and also has a notable @xmath3 contribution , with weak @xmath4 and 2 components .
the geometrical configuration of the star allows one to see both pulsation poles for about the same amount of time ; hd 99563 is only the fourth roap star for which both pulsation poles are seen and only the third where the distortion of the pulsation modes was modelled .
we point out that hd 99563 is very similar to the well - studied roap star hr 3831 .
finally , we note that the visual companion of hd 99563 is located in the @xmath5 scuti instability strip and may thus show pulsation .
we show that if the companion was physical , the roap star would be a 2.03 @xmath6 object , seen at a rotational inclination of @xmath7 , which then predicts a magnetic obliquity @xmath8 .
stars : variables : other stars : oscillations techniques : photometric stars : individual : hd 99563 stars : individual : xy crt .
And you have already written the first three sentences of the full article: where the lower part of the classical instability strip intersects the main sequence , three distinct classes of multiperiodically pulsating variables can be found . the @xmath9 doradus stars pulsate in gravity modes of high radial order and have periods of the order of one day ( kaye et al .
the @xmath5 scuti stars have periods of the order of a few hours ( breger 1979 ) and are thus pressure and gravity mode pulsators of low radial order .
the fastest pulsations in this domain in the hr diagram are however excited in the rapidly oscillating ap ( roap ) stars ( kurtz 1982 , kurtz & martinez 2000 ) , with typical periods around 10 minutes , indicating pressure modes of high radial overtones ..
Please generate the next two sentences of the article | the photometric semi - amplitudes associated with these pulsations are in most cases only a few mmag , which makes them difficult to detect .
the roap stars are also remarkable due to their spectral peculiarities , since they are pulsating representatives of cool magnetic ap stars of the srcreu subtype . |
4,708 | Suppose that you have an abstract for a scientific paper: we address the problem of long - time asymptotics for the solutions of the korteweg - de vries equation under low regularity assumptions .
we consider decreasing initial data admitting only a finite number of moments .
for the so - called `` soliton region '' , an improved asymptotic estimate is provided , in comparison with the one in @xcite .
our analysis is based on the dbar steepest descent method proposed by p. miller and k. t. d. -r .
mclaughlin . .
And you have already written the first three sentences of the full article: let us consider the initial - boundary value problem for the korteweg - de vries ( kdv ) equation with a decaying initial datum @xmath0 existence and uniqueness of real - valued , classical solutions can be proved via the inverse scattering transform , introduced by green , gardner , kruskal and miura in their seminal work @xcite .
the long time behavior of these last ones has been extensively investigated in the literature ( @xcite@xcite@xcite@xcite@xcite@xcite@xcite@xcite ) .
the solutions are known to eventually decompose into a certain number of solitons , travelling to the right , plus a radiation part , propagating to the left . in this paper.
Please generate the next two sentences of the article | we wish to consider the so - called _ soliton region _
, formed by those points of the @xmath1-plane satisfying @xmath2 , for some fixed constant @xmath3 . in order to detail more about existing results , |
4,709 | Suppose that you have an abstract for a scientific paper: the grist project is developing a grid - technology based system as a research environment for astronomy with massive and complex datasets .
this knowledge extraction system will consist of a library of distributed grid services controlled by a workflow system , compliant with standards emerging from the grid computing , web services , and virtual observatory communities .
this new technology is being used to find high redshift quasars , study peculiar variable objects , search for transients in real time , and fit sdss qso spectra to measure black hole masses .
grist services are also a component of the `` hyperatlas '' project to serve high - resolution multi - wavelength imagery over the internet . in support of these science and outreach objectives
, the grist framework will provide the enabling fabric to tie together distributed grid services in the areas of data access , federation , mining , subsetting , source extraction , image mosaicking , statistics , and visualization . .
And you have already written the first three sentences of the full article: the grist project ( ) is enabling astronomers and the public to interact with the grid projects that are being constructed worldwide , and bring to flower the promise of easy , powerful , distributed computing .
our objectives are to understand the role of service - oriented architectures in astronomical research , to bring the astronomical community to the grid particularly teragrid , and to work with the national virtual observatory ( nvo ) to build a library of compute - based web services . the scientific motivation for grist derives from creation and mining of wide - area federated images , catalogs , and spectra
. an astronomical image collection may include multiple pixel layers covering the same region on the sky , with each layer representing a different waveband , time , instrument , observing condition , etc ..
Please generate the next two sentences of the article | the data analysis should combine these multiple observations into a unified understanding of the physical processes in the universe .
the familiar way to do this is to cross - match source lists extracted from different images . |
4,710 | Suppose that you have an abstract for a scientific paper: the average formation lengths of the hadrons produced during the deep inelastic scattering ( dis ) of leptons on protons are studied in the framework of the symmetric lund model .
it is shown that these formation lengths essentially depend on the electric charges of the hadron .
for electro - production and charged current ( cc ) neutrino - production , the average formation lengths of positively charged particles are larger than those of negatively charged antiparticles .
this situation is reversed for cc antineutrino - production . in all the mentioned cases , the main mechanism is the direct production of hadrons .
the additional mechanism of hadron production , through the decay of resonances , is essential only for pions and leads to a decrease in the average formation lengths . * formation lengths of hadrons in lepto - production
* l. grigoryan alikhanyan national science laboratory ( yerevan physics institute ) , br.alikhanian 2 , 375036 yerevan , armenia .
And you have already written the first three sentences of the full article: the study of the space - time evolution of hadronization during lepto - production on nuclear targets is relatively straightforward because in this case , only one string ( two jets of hadrons ) is produced .
the possible influence of the two string mechanism was studied in ref .
@xcite , in which its contribution was determined to be small ..
Please generate the next two sentences of the article | another important issue is the selection of conditions under which cascading processes in a nucleus do not occur , i.e. , the hadronization occurs beyond the nucleus .
consequently , for the investigation of the hadronization process , it is very important to know the formation lengths of hadrons in lepto - production on the elementary nuclear target ( nucleon ) . |
4,711 | Suppose that you have an abstract for a scientific paper: transient wave forms in neural networks with diffusive and nonlocal coupling have attracted particular interest because they may mediate recruitment of healthy cortical tissue into a pathological state during migraine . to investigate this process
, we use a reaction - diffusion system of inhibitor - activator type as a generic model of pathological wave propagation and set it close to bifurcation in the sub - excitable regime .
we report the influence of various nonlocal connectivity schemes on wave propagation .
wave propagation can be suppressed with cross coupling inhibitor and activator for both positive and negative coupling strength @xmath0 , depending on the connection length @xmath1 .
the area in the parameter plane @xmath2 where this control goal is achieved resembles a mexican - hat - type network connectivity .
our results suggest that nonlocal synaptic transmission can control wave propagation , which may be of therapeutic value .
nonlinear dynamical systems , excitability , control , nonlocal and time delay coupling m. a. dahlem , f. m. schneider , a. panchuk , g. hiller , e. schll [email protected],2 [email protected] [email protected],3 [email protected] [email protected] .
And you have already written the first three sentences of the full article: during migraine attacks , localized pathological excitation can spread through cortical tissue and invade large areas before it abates .
this activity causes migraine aura , that is , neurological symptoms preceding the headache phase @xcite .
the underlying process is a phenomenon called cortical spreading depression ( sd ) ..
Please generate the next two sentences of the article | it is assumed to be a reaction - diffusion process in the cortex , although reactions and diffusion processes that provide the mechanism of propagtion are still under debate @xcite . however , the generic dynamics of reaction - diffusion systems are largely independent of the interaction details and shared among various biological systems @xcite . therefore , to describe the spatio - temporal patterns of sd ,
the cortex can be approximated as a continuous excitable media supporting reaction diffusion waves @xcite . |
4,712 | Suppose that you have an abstract for a scientific paper: we investigate the hypothesis that @xmath0-ray - quiet agn have a larger tendency for jet bending than @xmath0-ray - loud agn , revisiting the analysis of @xcite . we perform a statistical analysis using a large sample of 351 radio - loud agn along with @xmath0-ray identifications from the fermi large area telescope ( lat ) .
our results show no statistically significant differences in jet - bending properties between @xmath0-ray - loud and @xmath0-ray - quiet populations , indicating that jet bending is not a significant factor for @xmath0-ray detection in agn . .
And you have already written the first three sentences of the full article: the energetic gamma - ray experiment telescope ( egret ) detected 66 active galactic nuclei ( agn ) with @xmath0-ray emission at energies greater than 100 mev @xcite .
almost all of the agn identified were blazars , triggering immense interest and prompting a series of studies focused on the multi - wavelength properties of these agn .
egret s successor , the large area telescope ( lat , onboard the _ fermi gamma - ray space telescope _ ) , has identified over 1000 @xmath0-ray sources with energies greater than 100 mev @xcite , revealing the @xmath0-ray sky in detail ..
Please generate the next two sentences of the article | the lat instrument presents the opportunity to revisit questions first examined in the egret era with far superior data .
egret s discovery opened a new direction in investigating the nature and physical processes of blazars . |
4,713 | Suppose that you have an abstract for a scientific paper: results from an ongoing study of baryon - baryon systems with strangeness @xmath0 and @xmath1 within chiral effective field theory are reported .
the investigations are based on the scheme proposed by weinberg which has been applied rather successfully to the nucleon - nucleon interaction in the past .
results for the hyperon - nucleon and hyperon - hyperon interactions obtained to leading order are reviewed .
specifically , the issue of extrapolating the binding energy of the @xmath2-dibaryon , extracted from recent lattice qcd simulations , to the physical point is addressed .
furthermore , first results for the hyperon - nucleon interaction at next - to - leading order are presented and discussed .
hyperon - nucleon interaction , hyperon - hyperon interaction , lattice qcd , effective field theory .
And you have already written the first three sentences of the full article: chiral effective field theory ( eft ) as proposed in the pioneering works of weinberg @xcite is a powerful tool for the derivation of nuclear forces . in this scheme
there is an underlying power counting which allows to improve calculations systematically by going to higher orders in a perturbative expansion .
in addition , it is possible to derive two- and corresponding three - nucleon forces as well as external current operators in a consistent way . over the last decade or.
Please generate the next two sentences of the article | so it has been demonstrated that the nucleon - nucleon ( @xmath3 ) interaction can be described to a high precision within the chiral eft approach @xcite . following the original suggestion of weinberg , in these works the power counting
is applied to the @xmath3 potential rather than to the reaction amplitude . |
4,714 | Suppose that you have an abstract for a scientific paper: k 4 - 47 is an unusual planetary nebula composed of a compact high - ionization core and a pair of low - ionization knots .
long - slit medium - resolution spectra of the knots and core are analyzed in this paper .
assuming photoionization from the central star , we have derived physical parameters for all the nebular components , and the ( _ icf _ ) chemical abundances of the core , which appear similar to type - i pne for he and n / o but significantly deficient in oxygen .
the nebula has been further modelled using both photoionization ( cloudy ) and shock ( mappings ) codes . from the photoionization modelling of the core , we find that both the strong auroral 4363 and 5755 emission lines observed and the optical size of the core can not be accounted for if a homogeneus density is adopted .
we suggest that a strong density stratification , matching the high - density core detected at radio wavelengths and the much lower density of the optical core , might solve the problem . from the bow - shock modelling of the knots , on the other hand , we find that knots chemistry is also represented by type - i pn abundances , and that they would move with velocities of 250 - 300 .
[ firstpage ] planetary nebulae : individual ( k 4 - 47 ) - ism : kinematics and dynamics - ism : jets and outflows .
And you have already written the first three sentences of the full article: planetary nebulae ( pne ) are known to possess a variety of small - scale structures that are usually in a lower ionization state than the main body of the nebulae .
the morphological and kinematic properties of these low - ionization structures ( liss , gonalves , corradi & mampaso , 2001 ) vary from type to type , in the sense that liss can appear in the form of pairs of knots , filaments , jets , and isolated features moving with velocities that either do not differ substantially from that of the ambient nebula , or instead move supersonically through the environment . the total number of pne that are known to possess liss is 55 , i.e. about 10% of all the 527 galactic pne imaged in filters of high- and low - ionization emission lines ( balick 1987 ; schwarz , corradi & melnick 1992 ; manchado et al .
the different types of liss may be easily seen in corradi et al ..
Please generate the next two sentences of the article | ( 1996 ) . at present
, the origin of jets and pairs of knots in pne is not completely clear . from the theoretical point of view |
4,715 | Suppose that you have an abstract for a scientific paper: we study one - dimensional lvy processes with lvy - khintchine exponent @xmath0 , where @xmath1 is a complete bernstein function .
these processes are subordinate brownian motions corresponding to subordinators , whose lvy measure has completely monotone density ; or , equivalently , symmetric lvy processes whose lvy measure has completely monotone density on @xmath2 .
examples include symmetric stable processes and relativistic processes .
the main result is a formula for the generalized eigenfunctions of transition operators of the process killed after exiting the half - line .
a generalized eigenfunction expansion of the transition operators is derived . as an application , a formula for the distribution of the first passage time ( or the supremum functional )
is obtained . .
And you have already written the first three sentences of the full article: in a recent paper @xcite , spectral problem for the one - dimensional cauchy process ( that is , the symmetric @xmath3-stable process ) killed upon exiting a half - line or an interval was studied . for the half - line , an explicit formula for generalized eigenfunctions of transition operators
was obtained using methods developed in the theory of linear water waves .
the argument of @xcite relies on some properties specific to the cauchy process , and it does not easily generalize to other lvy processes ..
Please generate the next two sentences of the article | the purpose of this article is to derive a similar formula for generalized eigenfunctions in a more general setting , using a modified method .
the class of processes considered here consists of symmetric ( one - dimensional ) lvy processes @xmath4 with lvy measure having completely monotone density function on @xmath2 . |
4,716 | Suppose that you have an abstract for a scientific paper: higgs boson couplings with gauge bosons are probed through @xmath0 in an effective lagrangian framework . for this study the beam polarization facility at the ilc along with the typical center - of - mass energy of 500 gev is considered .
the reach of the ilc with an integrated luminosity of 300 fb@xmath1 in the determination of @xmath2-conserving parameters is obtained .
sensitivity of the probe of each of these couplings in the presence of other couplings is investigated .
the most influential coupling parameters are @xmath3 .
other parameters of significant effect are @xmath4 and @xmath5 .
a detailed study of the various kinematic distributions represents possibilities to disentangle the effect of some of these couplings .
# 1phys .
rev .
* d#1 * .
And you have already written the first three sentences of the full article: with the discovery of the new resonance of mass around 125 gev by the atlas and cms collaborations at the lhc in 2012 , a change of paradigm has taken @xcite .
the discovery has unambiguously established the role of the higgs mechanism in electroweak symmetry breaking ( ewsb ) .
all the properties of the new particle measured so far are consistent with that of the standard higgs boson ..
Please generate the next two sentences of the article | thus , one may be tempted to conclude that for all practical purposes , the newly found particle is like that of the standard model ( sm ) higgs boson , and new physics effects are decoupled as far as the higgs sector is concerned . at the same time , it is well known that there are difficulties associated with the higgs sector of the sm that need to be addressed .
the main difficulty is the hierarchy problem associated with the quadratically diverging quantum corrections to the mass of the higgs boson when computed in the sm . |
4,717 | Suppose that you have an abstract for a scientific paper: a detailed investigation of phonon excitations and charge carrier dynamics in single crystals of fe@xmath0cu@xmath1cr@xmath2s@xmath3 ( @xmath4 ) has been performed by using infrared spectroscopy . in fecr@xmath2s@xmath3
the phonon eigenmodes are strongly affected by the onset of magnetic order . despite enhanced screening effects , a continuous evolution of the phonon excitations can be observed in the doped compounds with @xmath5 ( metallic ) and @xmath6 ( bad metals ) , but the effect of magnetic ordering on the phonons is strongly reduced compared to @xmath7 . the drude - like charge - carrier contribution to the optical conductivity in the doped samples indicates that the colossal magneto - resistance effect results from the suppression of spin - disorder scattering . .
And you have already written the first three sentences of the full article: the discovery of colossal magnetoresistance ( cmr ) in perovskite - type manganites has attracted considerable attention.@xcite double - exchange ( de ) mechanism , @xcite strong electron - phonon coupling , @xcite phase separation scenarios @xcite or a griffiths singularity @xcite were suggested to clarify the origin of the cmr effect , but a conclusive microscopic model has not yet been established .
ever since , the occurrence of cmr effects has been reported for various other classes of materials , such as pyrochlores,@xcite rare - earths based compounds like gdi@xmath8,@xcite and ternary chalcogenide spinels @xmath9cr@xmath8s@xmath10.@xcite these cmr materials have been classified in terms of spin - disorder scattering and a universal dependence of the magnetoresistence vs. carrier density has been suggested on theoretical grounds.@xcite ramirez _ et al .
_ drew attention to the spinel system in 1997.@xcite in polycrystalline with @xmath11 k , the cmr effect reaches values comparable to those observed in perovskite oxides . the substitution of fe by cu increases @xmath12 to temperatures above room temperature , and the cmr effect remains relatively strong ( @xmath137 % ) .@xcite in addition , solid solutions of the ferrimagnetic semiconductor fecr@xmath8s@xmath10 and the metallic ferromagnet cucr@xmath8s@xmath10 show a number of puzzling properties : from the very beginning , a controversial discussion has been arising whether the cu ions are mono- or divalent for @xmath14.@xcite for @xmath15 it was established that only monovalent and hence diamagnetic ( @xmath16 ) cu exists in the mixed crystals.@xcite moreover , fe@xmath0cu@xmath17cr@xmath8s@xmath10 shows two metal - to - insulator transitions as a function of @xmath18 , as the room - temperature resistivity reveals two minima at @xmath19 and @xmath20 and concomitantly the seebeck coefficient changes sign two times.@xcite additionally , band - structure calculations predicted that the fe@xmath0cu@xmath17cr@xmath8s@xmath10 system should exhibit....
Please generate the next two sentences of the article | single crystals of were grown using a chemical transport - reaction method with chlorine as transport agent and the ternary polycrystals as starting material .
details of the sample preparation are described elsewhere.@xcite no indication for the existence of secondary phases was found by x - ray diffraction analysis of powdered single crystals . |
4,718 | Suppose that you have an abstract for a scientific paper: we provide a straightforward demonstration of a fundamental difference between classical and quantum mechanics for a single local system ; namely the absence of a joint probability distribution of the position @xmath0 and momentum @xmath1 . elaborating on a recently reported criterion by bednorz and belzig [ phys .
rev .
a * 83 * , 52113 ] we derive a simple criterion that must be fulfilled for any joint probability distribution in classical physics .
we demonstrate the violation of this criterion using homodyne measurement of a single photon state , thus proving a straightforward signature of the breakdown of a classical description of the underlying state .
most importantly , the criterion used does not rely on quantum mechanics and can thus be used to demonstrate non - classicality of systems not immediately apparent to exhibit quantum behavior .
the criterion is directly applicable any system described by the continuous canonical variables x and p , such as a mechanical or an electrical oscillator and a collective spin of a large ensemble .
the conceptual differences between classical and quantum physics have intrigued and sometimes bewildered the physics community since the early days of quantum mechanics .
this has led to a search for indisputable manifestations of the quantum world through observations of non - classical behavior in experiments .
a field of particular curiosity is that of identifying the quantum to classical cross - over for ever larger systems , thereby eventually identifying non - classical effects in macroscopic systems .
recently this has led to the observation of , e.g. , macroscopic entangled atomic ensembles @xcite , interference of large molecules @xcite and experiments pushing toward observing non - classical effects in mechanical oscillators @xcite . in parallel to this fundamental interest , non - classicality is of central importance to quantum information processing , the essence of which is to advance computation beyond what is classically possible....
And you have already written the first three sentences of the full article: the authors would like to thank w. vogel for his valuable comments and discussions .
this work was support by the villum kann rasmussen foundation ( denmark ) , the eu projects q - essence and malicia , and danish national research foundation .
ngj is grateful for generous support from danmarks nationalbank ( denmark ) ..
Please generate the next two sentences of the article | |
4,719 | Suppose that you have an abstract for a scientific paper: we study the quantum rabi model within the framework of the analytical solution developed in phys .
rev . lett . * 107 * , 100401 ( 2011 ) .
in particular , through time - dependent correlation functions , we give a quantitative criterion for classifying two regions of the quantum rabi model , involving the jaynes - cummings , the ultrastrong , and deep strong coupling regimes .
in addition , we find a stationary qubit - field entangled basis that governs the whole dynamics as the coupling strength overcomes the mode frequency . .
And you have already written the first three sentences of the full article: the light - matter interaction has been subject of central interest since the early years of quantum mechanics . in @xmath0 , one of the first attempts to explain the results coming from experiments was the rabi model , that describes the simplest dipole semiclassical interaction between light and matter @xcite , and is reduced to a pseudospin-@xmath1 system driven by a monochromatic classical radiation field .
however , the advent of quantum technologies such as cavity qed @xcite , have allowed us to access the quantum regime of the radiation field , where the dynamical description is given by the celebrated jaynes - cummings model ( jcm ) @xcite .
this model predicts collapses and revivals of the population inversion , the appearance of jaynes - cummings doublets as a consequence of the excitation number conservation , and it has found a testbed in several hybrid setups such as trapped ions @xcite , quantum dots @xcite , and circuit quantum electrodynamics ( circuit qed ) @xcite ..
Please generate the next two sentences of the article | circuit qed has been growing both theoretically and experimentally , and their complex proposals such as the generation of multipartite entanglement @xcite rely on the fundamentals of the jcm and the tavis - cummings model @xcite .
this can be justified because ratios between the coupling strength @xmath2 and the resonator frequency @xmath3 may grow from typical quantum optical values of @xmath4 to circuit qed values of @xmath5 . |
4,720 | Suppose that you have an abstract for a scientific paper: we perform the bifurcation analysis of the kepler problem on @xmath0 and @xmath1 .
an analogue of the delaunay variables is introduced .
we investigate the motion of a point mass in the field of the newtonian center moving along a geodesic on @xmath2 and @xmath3 ( the restricted two - body problem ) .
when the curvature is small , the pericenter shift is computed using the perturbation theory .
we also present the results of the numerical analysis based on the analogy with the motion of rigid body .
keywords and phrases : kepler problem , bifurcation analysis , perihelion shift , delaunay variables , restricted problem . .
And you have already written the first three sentences of the full article: we start with the equations of motion for a particle of unit mass on a three - dimensional sphere @xmath0 or in a lobachevsky space @xmath1 ( pseudosphere ) .
the sphere @xmath0 ( pseudosphere @xmath1 ) can be parameterized using the cartesian ( redundant ) coordinates of the four - dimensional euclidean space @xmath4 ( the minkovsky space @xmath5 ) with the constraint @xmath6 where @xmath7 ( @xmath8 ) is the corresponding metrics .
hereinafter , an upper sign in @xmath9 is used for the sphere and a lower sign is used for the pseudosphere ..
Please generate the next two sentences of the article | the metrics in @xmath4 ( @xmath5 ) generates a metrics in the sphere @xmath0 ( the lobachevsky metrics in the pseudosphere @xmath1 ) . in terms of the cartesian
coordinates , the lagrangian for the particle s motion in the field of the potential @xmath10 is @xmath11 with the constraint [ e1 ] . using the hamiltonian formalism for systems with constraints ( arnold et al . |
4,721 | Suppose that you have an abstract for a scientific paper: we present a study based on several advanced first - principles methods , of the recently synthesized pbnio@xmath0 [ j. am .
chem .
soc * 133 * , 16920 ( 2011 ) ] , a rhombohedral antiferromagnetic insulator which crystallizes in the highly distorted @xmath1 crystal structure .
we find this compound electrically polarized , with a very large electric polarization of @xmath2 100 @xmath3c/@xmath4 , thus even exceeding the polarization of well - known bifeo@xmath0 .
pbnio@xmath0 is a proper ferroelectric , with polarization driven by large pb - o polar displacements along the [ 111 ] direction .
contrarily to naive expectations , a definite ionic charge of 4 + for pb ion can not be assigned , and in fact the large pb 6@xmath5-o 2@xmath6 hybridization drives the ferroelectric distortion through a lone - pair mechanism similar to that of other pb- and bi - based multiferroics . _
introduction _ multiferroics are materials in which different ferroic orders such as ferromagnetism , ferroelectricity and/or ferroelasticity may coexist in one single phase @xcite . in the last few years , there has been a tremendous boom of interest in these materials , due to the potential applications in memory devices or in novel type of magnetic switching in magnetoelectric multiferroics , based on the cross - coupling between ferroelectric and magnetic channels @xcite .
furthermore , these materials offer a rich and fascinating playground for the complex physical mechanisms underlying the processes involved in the observed properties.@xcite it is obvious that the search and the prediction by material design of new multiferroics is of great importance for both fundamental physics and technological applications @xcite .
relatively few multiferroics have been identified so far .
@xcite without doubt , the most studied and well characterized multiferroic is bifeo@xmath0 @xcite .
it crystallizes in the polar space group _ r3c _ ( no . 161 ,
point group _ c_@xmath7@xmath8 ) , and is predicted to have a g....
And you have already written the first three sentences of the full article: support by european community ( fp7 eu - india grant athena and erc starting grant no.203523 bismuth ) is gratefully acknowledged .
x.h . thanks claude ederer and chung - yuan ren for their helpful advices and comments .
thanks j.m ..
Please generate the next two sentences of the article | perez - mato for useful discussions .
the calculations have been performed on the vienna scientific cluster ( vsc ) and , partially , in caspur supercomputing center in rome . |
4,722 | Suppose that you have an abstract for a scientific paper: in this work we include electron - electron interaction beyond hartree - fock level in our non - equilibrium green s function approach by a crude form of gw through the single plasmon pole approximation .
this is achieved by treating all conduction band electrons as a single effective band screening the coulomb potential .
we describe the corresponding self - energies in this scheme for a multi - subband system . in order to apply the formalism to heterostructures we discuss the screening and plasmon dispersion in both 2d and 3d systems .
results are shown for a four well quantum cascade laser with different doping concentration where comparisons to experimental findings can be made . + _ accepted for publication in * journal of physics : conference series * by iop publishing ltd .
, as a proceeding of the pngf6 workshop in lund , sweden , 2015 . .
And you have already written the first three sentences of the full article: since the quantum cascade laser ( qcl ) was introduced more than 20 years ago @xcite it has continuously been improved and redesigned to operate from the mid - infrared all the way down to the terahertz ( thz ) range .
compact laser sources at these wavelengths are valuable for spectroscopic applications @xcite but a major problem is that thz qcls do not operate at room temperature .
this can be overcome via difference frequency generation which recently has been demonstrated at powers in the milli - watt range @xcite ..
Please generate the next two sentences of the article | direct thz - qcls still generate a lot of interest in the research community due to the promise of higher wall - plug efficiency and the prospects of miniaturization of cryo - coolers .
the main temperature degrading mechanism of the thz qcls is currently not fully understood and is still debated by the community @xcite . |
4,723 | Suppose that you have an abstract for a scientific paper: one of the key predictions of modeling from the ir excess of herbig ae stars is that for protoplanetary disks , where significant grain growth and settling has occurred , the dust disk has flattened to the point that it can be partially or largely shadowed by the innermost material at or near the dust sublimation radius .
when the self - shadowing has already started , the outer disk is expected to be detected in scattered light only in the exceptional cases that the scale height of the dust disk at the sublimation radius is smaller than usual .
high - contrast imaging combined with the ir spectral energy distribution allow us to measure the degree of flattening of the disk , as well as to determine the properties of the outer disk .
we present polarimetric differential imaging in @xmath0 band obtained with subaru / hiciao of one such system , mwc 480 .
the hiciao data were obtained at a historic minimum of the nir excess .
the disk is detected in scattered light from 02 - 10 ( 27.4 - 137au ) .
together with the marginal detection of the disk from 1998 february 24 by hst / nicmos , our data constrain the opening half angle for the disk to lie between [email protected]@xmath2 . when compared with similar measures in co for the gas disk from the literature , the dust disk subtends only @xmath330% of the gas disk scale height ( h / [email protected] ) .
such a dust disk is a factor of 5 - 7 flatter than transitional disks , which have structural signatures that giant planets have formed . .
And you have already written the first three sentences of the full article: for the vast majority of protoplanetary disks , modeling of the ir spectral energy distribution has been the principal tool for characterizing the properties of the dust disk .
models for disks derived from such data are non - unique since the viewing geometry ( inclination ) , assumed grain opacity model , and the presence or absence of structure in the disk can combine to produce similar seds .
moreover , disks are not static : iso and spitzer studies of t tauri stars have shown that variability in the 3 - 4.5 micron range is ubiquitous @xcite ..
Please generate the next two sentences of the article | at least some higher mass analogs to t tauri stars , the herbig ae stars , also exhibit striking variability in the ir sed which has been interpreted as reflecting changes in the scale height of the dust disk at or near the sublimation radius @xcite . for protoplanetary disks where
there has been significant dust grain growth and settling , the dust disk may have flattened sufficiently to be partially or largely shadowed @xcite by material at or near the dust sublimation radius . under these circumstances , |
4,724 | Suppose that you have an abstract for a scientific paper: we report the detection with the rossi x - ray timing explorer of a compton reflection signature in the seyfert galaxy mcg@xmath05 - 23 - 16 .
@xmath1 also resolves the fe k@xmath2 fluorescence line with fwhm @xmath3 48,000 km s@xmath4 .
this measurement provides the first _ independent _ confirmation of @xmath5 detections in seyfert galaxies of broad fe k@xmath2 lines that are thought to be the signature of emission from the inner regions of an accretion disk orbiting a black hole . under the assumption that reflection arises from an isotropic source located above a neutral accretion disk , and using a theoretical model that accounts for the dependence of the reflected spectrum on inclination angle ,
we derive a 90% confidence range for the disk inclination of @xmath6 = 50@xmath7 .
the large inclination is consistent with that expected from the unified model for mcg@xmath05 - 23 - 16 based on its seyfert 1.9 classification .
if we assume that the high - energy cutoff in the incident spectrum lies at energies larger than a few hundred kev , then the equivalent width of the fe k@xmath2 line is much larger than predicted for the amount of reflection .
this implies either an enhanced iron abundance , a covering factor of reflecting material @xmath8 , or a cutoff in the incident spectrum at energies between @xmath360 and @xmath3200 kev . .
And you have already written the first three sentences of the full article: at the heart of an active galactic nucleus lies the putative black - hole `` monster '' that supplies its power .
much of this power emerges in the form of x - rays , which are in turn efficient probes of the immediate regions surrounding the nucleus .
the fuel supply for the massive central engine is thought to arise from a disk of dense , accreting matter with column densities @xmath9 well in excess of @xmath10 @xmath11 . in the presence of such matter , the reflected x - ray spectrum has two distinct features ..
Please generate the next two sentences of the article | one is the fe k@xmath2 fluorescence emission line at 6.4 kev ( fabian et al .
1989 , george & fabian 1991 ) . |
4,725 | Suppose that you have an abstract for a scientific paper: pagerank centrality is used by google for ranking web - pages to present search result for a user query . here , we have shown that pagerank value of a vertex also depends on its intrinsic , non - network contribution . if the intrinsic , non - network contributions of the vertices are proportional to their degrees or zeros , then their pagerank centralities become proportion to their degrees . some simulations and empirical data
are used to support our study .
in addition , we have shown that localization of pagerank centrality depends upon the same intrinsic , non - network contribution . .
And you have already written the first three sentences of the full article: complex network tools have been used in different fields from social , technological and biological networks @xcite , to analyze the structure and dynamics of the network .
different centrality measures have been used to find the important vertices in a network e.g. , degree centrality , eigenvector centrality , katz centrality , vertex betweenness centrality , edge betweenness centrality , closeness centrality@xcite , etc . among them ,
the simplest measure is the degree centrality ..
Please generate the next two sentences of the article | degree of a vertex is the number of edges connected to it .
pagerank is another important measure and is used in network tasks like , information retrieval , link prediction and community detection@xcite . in 1998 , brin and page @xcite developed the pagerank algorithm to rank websites in their search engine . |
4,726 | Suppose that you have an abstract for a scientific paper: the escape fraction at infinity is evaluated for massless particles produced in collisions of weakly interacting particles accreted into a density spike near the particle horizon of an extremal kerr black hole , for the case of equatorial orbits .
we compare with the schwarzschild case , and argue that in the case of extremal black holes , redshifted signatures can be produced that could potentially explore the physics of particle collisions at centre of mass energies that extend beyond those of any feasible terrestrial accelerator . .
And you have already written the first three sentences of the full article: some of us have recently argued that rotating black holes surrounded by relic cold dark matter ( dm ) density spikes may act as particle accelerators @xcite . in the limit of maximally rotating ,
extremal kerr black holes , we showed that collisions between particles , e.g. weakly interacting massive dm particles , may reach arbitrarily high center - of - mass energies .
for some related works see @xcite . in this sequel.
Please generate the next two sentences of the article | , we compute the escape fraction and flux at infinity of the highly blue - shifted particles .
we demonstrate that the escape fraction is finite and of interest for any value of @xmath0 although the price one pays for sub - extremality is that the achievable centre - of - mass frame ( cmf ) collision energy is limited . our earlier work attracted considerable comment with regard to the fact that extremality for a kerr black hole might not be achievable in nature @xcite , although not all authors concur on this point @xcite . |
4,727 | Suppose that you have an abstract for a scientific paper: we infer the central mass distributions within 0.41.2 disc scale lengths of 18 late - type spiral galaxies using two different dynamical modelling approaches the asymmetric drift correction ( adc ) and axisymmetric jeans anisotropic multi - gaussian expansion ( jam ) model .
adc adopts a thin disc assumption , whereas jam does a full line - of - sight velocity integration .
we use stellar kinematics maps obtained with the integral - field spectrograph @xmath0 to derive the corresponding circular velocity curves from the two models . to find their best - fit values , we apply markov chain monte carlo ( mcmc ) method .
adc and jam modelling approaches are consistent within 5% uncertainty when the ordered motions are significant comparable to the random motions , i.e , @xmath1 is locally greater than 1.5 . below this value ,
the ratio @xmath2 gradually increases with decreasing @xmath1 , reaching @xmath3 .
such conditions indicate that the stellar masses of the galaxies in our sample are not confined to their disk planes and likely have a non - negligible contribution from their bulges and thick disks .
[ firstpage ] galaxies : bulge galaxies : disc galaxies : kinematics and dynamics galaxies : structure .
And you have already written the first three sentences of the full article: the non - keplerian rotation curves of spiral galaxies provided the first observational evidence that galaxies are embedded in extensive dark matter haloes ( @xcite ) .
historically , the 21-cm emission from atomic neutral hydrogen gas ( hi ) has been the main tool to derive galaxy rotation curves , because of its capability to trace the gravitational field beyond the optical stellar disc .
however , hi is less useful in constraining the rotation curve in the central parts of discs usually due to insufficient spatial resolution and the lack of hi gas in the inner parts of galaxies ( e.g. , @xcite ) . the interstellar medium in the centre is instead dominated by gas in the molecular and ionised phases ( e.g. , @xcite ) ..
Please generate the next two sentences of the article | unfortunately , the rotation curves derived through co emission , the common tracer for the molecular gas distribution , often show non - axisymmetric signatures such as wiggles ( @xcite ) .
hot ionised gas has the additional disadvantage that the observed rotation alone is often insufficient to trace the total mass distribution and that its velocity dispersion needs to be included . |
4,728 | Suppose that you have an abstract for a scientific paper: the algebraic structures related with integrable structure of superconformal field theory ( scft ) are introduced .
the scft counterparts of baxter s q - operator are constructed .
the fusion - like relations for the transfer - matrices in different representations and their truncations are obtained .
superconformal field theory , super - kdv , quantum superalgebras , q - operator 11.25.hf ; 11.30.pb ; 02.20.uw ; 02.20.tw .
And you have already written the first three sentences of the full article: during last decade the integrable structures associated with conformal field theory ( cft ) and its @xmath0 extension were studied @xcite-@xcite . the main problem to which these papers were addressed is the simultaneous diagonalization of the corresponding infinite family of the integrals of motion ( i m ) .
the method used for this purpose is the continuous version of the quantum inverse scattering method ( qism ) @xcite .
the most successful results were obtained by means of the generalization of the baxter s @xmath1-operator relation @xcite . in this paper.
Please generate the next two sentences of the article | we will follow this way constructing the @xmath1-operator for analysis of the integrable structure arising in the superconformal field theory ( scft ) .
this cft includes both usual left and right components of the energy - momentum tensor @xmath2 , @xmath3 and spin-@xmath4 local fields @xmath5 , @xmath6 where variable @xmath7 lies on a cylinder of circumference @xmath8 . |
4,729 | Suppose that you have an abstract for a scientific paper: we determine the distribution of nearest neighbour spacings between the tangencies to a fixed circle in a class of circle packings generated by reflections .
we use a combination of geometric tools and the theory of automorphic forms .
320755 ] .
And you have already written the first three sentences of the full article: in recent years , there has been increasing interest in the quantitative study of aspects of circle packings , in particular for apollonian packings .
for instance , the asymptotic count of the number of circles with bounded curvature has been determined @xcite , as well as several questions concerning the arithmetic of apollonian packings , see @xcite . in this paper
, we investigate local statistics for the distribution of tangencies to a fixed circle in a circle packing , in a class of packings generated by reflections ..
Please generate the next two sentences of the article | the packings that we study are formed by starting with an initial finite configuration @xmath0 of circles in the plane with disjoint interiors , and such that the gaps between circles are curvilinear triangles , as in figure [ fig configurations ] .
we then form the group @xmath1 generated by reflections in the dual circles defined by the triangular gaps of the configuration , see [ sec : construct ] , and by applying the elements of @xmath1 to the initial configuration @xmath0 , we obtain an infinite circle packing @xmath2 , see figure [ fig configurations ] for an example . |
4,730 | Suppose that you have an abstract for a scientific paper: hyper - kamiokande is a proposed next - generation water cherenkov detector .
if a galactic supernova happens , it will deliver a high event rate ( @xmath0 neutrino events in total ) as well as event - by - event energy information .
recent supernova simulations exhibit the standing accretion shock instability ( sasi ) which causes oscillations in the number flux and mean energy of neutrinos .
the amplitude of these oscillations is energy - dependent , so the energy information available in hyper - kamiokande could be used to improve the detection prospects of these sasi oscillations . to determine whether this can be achieved in the presence of detector effects like backgrounds and finite energy uncertainty , we have started work on a detailed simulation of hyper - kamiokande s response to a supernova neutrino burst .
And you have already written the first three sentences of the full article: hyper - kamiokande ( hk , @xcite ) is a proposed next - generation water cherenkov detector consisting of two cylindrical tanks with a fiducial volume of @xmath1kt each . the first tank is expected to start data - taking in 2026 , with the second tank following six years later .
hk has a broad physics programme covering many areas of particle and astroparticle physics , including oscillation of accelerator and atmospheric neutrinos , nucleon decay , solar neutrinos , supernova burst and relic neutrinos , indirect detection of dark matter through wimp annihilation and neutrino geophysics . for a galactic supernova at a fiducial distance of @xmath2kpc
, hk will detect @xmath0 neutrinos within 10s ..
Please generate the next two sentences of the article | this high event rate enables hk to resolve fast time variations of the event rate , which could give us information on properties of the progenitor ( like its rotation ) or on details of the supernova explosion mechanism which are currently still unclear . in section [ sec :
sasi ] of this paper , we will describe a feature of supernova explosions that causes such fast time variations and we introduce a method of using this energy information . to determine whether this method can be successful in the presence of detector effects , we have started work on a detailed detector simulation , which is described in section [ sec : simulation ] . |
4,731 | Suppose that you have an abstract for a scientific paper: we study parallel symmetric @xmath0-user interference channels when the interference is bursty and feedback is available from the respective receivers .
presence of interference in each subcarrier is modeled as a memoryless bernoulli random state .
the states across subcarriers are drawn from an arbitrary joint distribution with the same marginal probability for each subcarrier and instantiated i.i.d . over time .
for the linear deterministic setup , we give a complete characterization of the capacity region . for the setup with gaussian noise , we give outer bounds and a tight generalized degrees of freedom characterization .
we propose a novel helping mechanism which enables subcarriers in very strong interference regime to help in recovering interfered signals for subcarriers in strong and weak interference regimes .
depending on the interference and burstiness regime , the inner bounds either employ the proposed helping mechanism to code across subcarriers or treat the subcarriers separately .
the outer bounds demonstrate a connection to a subset entropy inequality by madiman and tetali @xcite . .
And you have already written the first three sentences of the full article: the temporal nature of interference in wireless networks depends on the underlying traffic as well as the subcarrier allocations of neighbouring base stations ( which usually employ multicarrier systems like ofdm ) . in practice ,
due to the bursty nature of data traffic and uncoordinated subcarrier allocations across base stations , the resulting interference at the physical layer tends to be bursty .
in addition to the potential for harnessing such burstiness , feedback from the receivers is another resource available in wireless networks . with these motivations , in this paper.
Please generate the next two sentences of the article | we study parallel ( multicarrier ) interference channels with bursty interference links and output feedback from the receivers . in @xcite and @xcite ,
the problem of harnessing bursty interference was studied for a single carrier setup without feedback . |
4,732 | Suppose that you have an abstract for a scientific paper: a semi microscopic model for the low energy photodisintegration of the @xmath0be nucleus is constructed , and the experimental data are analyzed with its help .
the older radioactive isotope data are supported by this analysis .
the theoretical photodisintegration cross section is derived .
the astrophysical rates for the reaction @xmath1be@xmath2 and the reverse photodisintegration of @xmath0be are calculated .
the new reaction rate for @xmath3be@xmath2 is compared with previous estimations . .
And you have already written the first three sentences of the full article: recently fully microscopic calculations of nuclei with @xmath4 have become feasible @xcite .
the @xmath0be nucleus is such a system of special interest , as it allows tests of theories of interaction of composite particles @xcite .
the properties of low energy continuum of @xmath0be are of particular importance in this connection . however , the corresponding experimental data on the low energy photodisintegration of @xmath0be are not in mutual agreement ( see fig . 1 ) . in the present work we develop a semi microscopic model to describe the process , and we analyze the experimental data with its help ..
Please generate the next two sentences of the article | the model accounts simultaneously for both resonant and non resonant contributions to the cross section .
an estimation of the reliability of various data is obtained and a theoretical photodisintegration cross section is derived . |
4,733 | Suppose that you have an abstract for a scientific paper: we obtain new bounds for the magnetic dipole moments of the tau lepton .
these limits on the magnetic couplings of the tau to the electroweak gauge bosons ( @xmath0 ) are set in a model independent way using the most general effective lagrangian with the @xmath1 symmetry .
comparison with data from the most precise experiments at high energies shows that the present limits are more stringent than the previous published ones . for the anomalous magnetic moment the bounds are , for the first time , within one order of magnitude of the standard model prediction . .
And you have already written the first three sentences of the full article: the fermion dipole moments are some of the best measured quantities in physics .
while the limits for the cp - violating ones , the electric dipole moments , are impressive@xcite ( @xmath2 e - cm for the electron and the neutron ) , the agreement between the measurement of the anomalous magnetic dipole moments of the electron and of the muon and its theoretical prediction is such that provides the best determination of the fine structure constant .
since the first prediction for the electron anomalous magnetic moment computed by schwinger@xcite , the magnetic properties of the leptons played a central role in testing symmetries and the quantum prediction of the theory ..
Please generate the next two sentences of the article | this could be done thanks to the relativity long lifetime of the muon and the stability of the electron in ordinary atoms .
for the heavy fermions the situation is very different . as short lived - particles , there is no possibility of such high precision experiments . |
4,734 | Suppose that you have an abstract for a scientific paper: there are different approaches for the hadronic b decay calculations , recently . in this paper
, we upgrade three of them , namely factorization , qcd factorization and the perturbative qcd approach based on @xmath0 factorization , by using new parameters and full wave functions . although they get similar results for many of the branching ratios , the direct cp asymmetries predicted by them are different , which can be tested by recent experimental measurements of b factories . .
And you have already written the first three sentences of the full article: the hadronic b decays are important for testing the standard model ( sm ) , and also for uncovering the signal of new physics .
understanding non - leptonic @xmath1 meson decays is crucial for the ckm matrix elements measurements and cp violation detection .
especially the direct cp violation is expected to be measured in hadronic b decays ..
Please generate the next two sentences of the article | recently , both belle and babar claimed to find direct cp asymmetry in @xmath2 and @xmath3 decays @xcite .
it is the start of direct cp measurement in b physics . in the theoretical side , there are much more complication in direct cp asymmetry predictions . |
4,735 | Suppose that you have an abstract for a scientific paper: in this letter we demonstrate that the two claims of @xmath0 ovii k@xmath1 absorption lines from warm hot intergalactic medium ( whim ) along the lines of sight to the blazars h 2356 - 309 ( buote et al . , 2009 ; fang et al . , 2010 ) and mkn 501 ( ren , fang & buote , 2014 ) are likely misidentifications of the @xmath2 oii k@xmath3 line produced by a diffuse low - ionization metal medium in the galaxy s interstellar and circum - galactic mediums .
we perform detailed modeling of all the available high signal - to - noise chandra letg and xmm - newton rgs spectra of h 2356 - 309 and mkn 501 and demonstrate that the @xmath0 whim absorption along these two sightlines is statistically not required .
our results , however , do not rule out a small contribution from the @xmath0 ovii k@xmath1 absorber along the line of sight to h 2356 - 309 . in our model
the temperature of the putative @xmath4 whim filament is t@xmath5 k and the ovii column density is n@xmath6 @xmath7 , twenty times smaller than the ovii column density previously reported , and now more consistent with the expectations from cosmological hydrodynamical simulations .
absorption lines , ism , galaxy , whim .
And you have already written the first three sentences of the full article: according to all hydro - dynamical simulation for structure formation run in the framework of a @xmath8cdm cosmology , large concentrations of galaxies are the best tracers of the filamentary web of dark - matter that our local universe is made of .
embedded into these filaments of shining ordinary matter ( stars in galaxies ) , should be hidden the , still to be found , largest reservoir of baryons in the local universe : the so called warm - hot intergalactic medium ( whim : e.g cen & ostriker , 2006 ) .
this , metal enriched ( through galaxy - igm feedback ) , otherwise primordial , medium should have temperatures in the range logt@xmath9 ( in k ) , and very low baryon densities @xmath10 @xmath11 . at such temperatures , h.
Please generate the next two sentences of the article | and he are mostly fully ionized ( and so very difficult to detect ) , and the most abundant metal , oxygen , is mainly present in its stable he - like form : ovii .
the strongest bound - bound transition of the ovii ion is the k@xmath1 at @xmath12 , and should thus imprint absorption lines in the soft x - ray spectra of background objects whose lines of sight cross one or more whim filaments between us and the target . |
4,736 | Suppose that you have an abstract for a scientific paper: beams of @xmath0he and @xmath1o nuclei are considered for ion - beam cancer therapy as alternative options to protons and @xmath2c nuclei . spread - out bragg peak ( sobp ) distributions of physical dose and relative biological effectiveness for 10% survival are calculated by means of our geant4-based monte carlo model for heavy ion therapy ( mchit ) and the modified microdosimetric kinetic model .
the depth distributions of cell survival fractions are calculated for @xmath3h , @xmath0he , @xmath2c and @xmath1o for tissues with normal ( hsg cells ) , low and high radiosensitivity . in each case
the cell survival fractions were compared separately for the target volume , behind and in front of it . in the case of normal radiosensitivity @xmath0he and
@xmath2c better spare tissues in the entrance channel compared to protons and @xmath1o .
the cell survival fractions calculated , respectively , for the entrance channel and target volume are similar for @xmath0he and @xmath2c .
when it is important to spare healthy tissues located after the distal edge of the sobp plateau , @xmath0he can be recommended due to reduced nuclear fragmentation of these projectiles .
no definite advantages of @xmath1o with respect to @xmath2c were found , with the except of an enhanced impact of these heavier projectiles on radioresistant tumors . .
And you have already written the first three sentences of the full article: the advantage of charged particles , in particular , protons and carbon nuclei , used for radiation therapy of cancer consists in elevated dose delivered at the end of projectile range in tissues .
the plateau of the depth - dose distribution at the entrance of a monoenergetic beam terminates with a sharp bragg peak which can be targeted at the tumor .
such a dose profile helps to spare healthy tissues located in front of the tumor as well as beyond the projectile range . since a set of beam energies.
Please generate the next two sentences of the article | is typically used in treatments to cover the whole tumor volume , the resulting dose distribution is characterized by a spread - out bragg peak ( sobp ) @xcite with a wide domain of elevated dose . the damage of healthy tissues during therapy can be essentially reduced if the ratio between the relative biological effectiveness ( rbe ) values at the sobp region and plateau is favorable . as recognized almost 40 years ago in radiobiological experiments with sobp beams of light nuclei performed at berkeley @xcite , this rbe ratio is greater than 1 and increases with ion charge up to carbon .
it was also found that this ratio decreases for ne and becomes less than 1 . in 1994 |
4,737 | Suppose that you have an abstract for a scientific paper: results are presented on @xmath0 radiative decays to @xmath1 and @xmath2 based on a sample of 58 m @xmath3 events taken with the besii detector .
partial wave analyses are carried out using the relativistic covariant tensor amplitude method in the 1.0 to 2.3 gev/@xmath4 @xmath5 mass range .
there are conspicuous peaks due to the @xmath6 and two @xmath7 states in the 1.45 and 1.75 gev/@xmath4 mass regions .
the first @xmath7 state has a mass of @xmath8 mev/@xmath4 , a width of @xmath9 mev/@xmath4 , and a branching fraction @xmath10 .
spin 0 is strongly preferred over spin 2 .
the second @xmath7 state peaks at @xmath11 mev/@xmath4 with a width of @xmath12 mev/@xmath4 .
if this @xmath7 is interpreted as coming from @xmath13 , the ratio of its branching fractions to @xmath14 and @xmath15 is @xmath16
. 0.2 cm .
And you have already written the first three sentences of the full article: qcd predicts the existence of glueballs , the bound states of gluons , and the observation of glueballs would provide a direct test of qcd . in the quenched approximation ,
lattice qcd calculations predict the lightest glueball to be a @xmath7 with the mass being in the region from 1.4 to 1.8 gev/@xmath4 @xcite .
although the identification of a glueball is very complicated , there are several glueball candidates , including the @xmath17 and @xmath13 ..
Please generate the next two sentences of the article | the properties of the @xmath17 and @xmath13 are reviewed in detail in the latest issue of the particle data group ( pdg ) @xcite .
@xmath3 radiative decays have been suggested as promising modes for glueball searches . |
4,738 | Suppose that you have an abstract for a scientific paper: let @xmath0 be the set of all non - negative integers .
an integer additive set - indexer of a graph @xmath1 is an injective function @xmath2 such that the induced function @xmath3 defined by @xmath4 is also injective .
an iasi is said to be _ @xmath5-uniform _ if @xmath6 for all @xmath7 . in this paper
, we introduce the notions of strong integer additive set - indexers and initiate a study of the graphs which admit strong integer additive set - indexers .
keywords : set - indexers ; integer additive set - indexers ; strong integer additive set - sndexers ; strongly uniform integer additive set - indexers .
mathematics subject classification 2010 : 05c78 .
And you have already written the first three sentences of the full article: for all terms and definitions , not defined specifically in this paper , we refer to @xcite . unless mentioned otherwise , all graphs considered here are simple , finite and have no isolated vertices .
the researches in the field of graph labeling commenced with the introduction of the notion of graceful labeling of graphs in @xcite .
analogous to the number valuations of graphs , the notion of set - valuations of graphs was introduced in @xcite ..
Please generate the next two sentences of the article | let us first consider the following notions of a set - labeling and a set - indexer of a given graph @xmath1 .
[ d0 ] [ d1 ] . |
4,739 | Suppose that you have an abstract for a scientific paper: we report the detection of a 22ghz water maser line in the nearest ( @xmath0mpc ) radio galaxy centaurusa using the australia telescope compact array ( atca ) .
the line is centered at a velocity of @xmath1 km s@xmath2 , which is redshifted by about @xmath3 km s@xmath2 from the systemic velocity .
such an offset , as well as the width of @xmath4 km s@xmath2 , could be consistent with either a nuclear maser arising from an accretion disk of the central supermassive black hole , or for a jet maser that is emitted from the material that is shocked near the base of the jet in centaurusa .
the best spatial resolution of our atca data constrains the origin of the maser feature within @xmath5pc from the supermassive black hole .
the maser exhibits a luminosity of @xmath6l@xmath7 , which classifies it as a kilomaser , and appears to be variable on timescales of months .
a kilomaser can also be emitted by shocked gas in star forming regions .
given the small projected distance from the core , the large offset from systemic velocity , as well as the smoothness of the line feature , we conclude that a jet maser line emitted by shocked gas around the base of the agn is the most likely explanation .
for this scenario we can infer a minimum density of the radio jet of @xmath8@xmath9 , which indicates substantial mass entrainment of surrounding gas into the propagating jet material . .
And you have already written the first three sentences of the full article: centaurusa ( cena ) is by far the most nearby radio galaxy and one of the brightest radio sources in the sky .
its proximity of only @xmath10mpc @xcite makes it a unique target for studies of supermassive black hole ( smbh ) accretion , jet formation and acceleration , as well as the interaction of the jets and lobes with the interstellar and intergalactic media .
centaurusa ( see * ? ? ?.
Please generate the next two sentences of the article | * for a review of the properties of cena ) is embedded in the giant elliptical host ngc5128 .
unlike most other elliptical galaxies , ngc5128 displays very prominent dust lanes that are likely due to merger activity in the past ( see e.g. * ? ? ? |
4,740 | Suppose that you have an abstract for a scientific paper: fuzzy set theory opens new vistas in computability theory and here i show this by defining a new computational metaphor the fuzzy chemical metaphor .
this metaphor is an extension of the chemical metaphor .
in particular , i introduce the idea of a state of a system as a solution of fuzzy molecules , that is molecules that are not just different but rather similar , that react according to a set of fuzzy reaction rules .
these notions become precise by introducing fuzzy labeled transition systems .
solutions of fuzzy molecules and fuzzy reaction rules are used to define the general notion of a fuzzy chemical abstract machine , which is a _ realization _ of the fuzzy chemical metaphor .
based on the idea that these machines can be used to describe the operational semantics of process calculi and algebras that include fuzziness as a fundamental property , i present a toy calculus that is a fuzzy equivalent of the @xmath0-calculus . .
And you have already written the first three sentences of the full article: the gamma model of parallel programming was introduced by jean - pierre bentre and daniel le mtayer in @xcite ( see also @xcite for a more accessible account of the model and @xcite for a recent account of it ; also see @xcite for a thorough presentation of the field of multiset processing ) . at the time of its introduction ,
parallel programming as a mental activity was considered more difficult ( one might also say cumbersome ) than sequential programming , something that even today it is still valid to a certain degree .
bentre and le mtayer designed gamma in order to ease the design and specification of parallel algorithms ..
Please generate the next two sentences of the article | thus , making a parallel programming task easier compared to previously available approaches .
gamma was inspired by the chemical reaction model . according to this metaphor |
4,741 | Suppose that you have an abstract for a scientific paper: two triplet vector - like quarks ( vlqs ) with hypercharges of @xmath0 and one singlet scalar boson are embedded in the standard model ( sm ) to resolve the 750 gev diphoton excess .
the constraints on the tree - level higgs- and @xmath1-mediated flavor - changing neutral currents are discussed in detail . besides the resolution of excess , it is found that the signal strength of diphoton higgs decay can have a @xmath2 deviation from the sm prediction and that the upper limits of the branching ratios for rare top - quark decays are @xmath3 .
we find that the production cross section of a single vlq by electroweak processes is larger than that of vlq - pair by qcd processes .
to explore the signals of the heavy vlqs at the lhc , we throughly analyze the production of single @xmath4 and @xmath5 via @xmath6 annihilations in @xmath7 collisions at @xmath8 tev .
it is found that the electroweak production cross sections for @xmath9 , @xmath10 , and @xmath11 channels with @xmath12 tev can be @xmath13 , @xmath14 , and @xmath15 fb , respectively ; and the dominant decay modes are @xmath16 and @xmath17 . with adopting kinematic cuts , the significance for @xmath18 channel can be over @xmath19 .
kias - p16026 .
And you have already written the first three sentences of the full article: with the discovery of the standard model ( sm ) higgs in the atlas @xcite and cms @xcite experiments , we have taken one step further toward understanding the electroweak symmetry breaking ( ewsb ) through the spontaneous symmetry breaking ( ssb ) mechanism in the scalar sector .
the next mission for the high - luminosity large hadron collider ( lhc ) is to explore not only the detailed properties of the sm higgs , but also the new physics effects .
since problems related to the origin of neutrino mass , dark matter ( dm ) , and matter - antimatter asymmetry can not be resolved in the sm , it is believed that the sm of particle physics is an effective theory at the electroweak scale ..
Please generate the next two sentences of the article | if new physics exists at the tev scale , the lhc can detect it .
some potential events indicating the existence of new effects indeed have been observed in the recent atlas and cms experiments . |
4,742 | Suppose that you have an abstract for a scientific paper: we present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit . for the continuum calculation we use the skorniakov - ter - martirosian ( stm ) integral equation to determine the scattering length and effective range parameter to high precision . for the lattice calculation we use the finite - volume method of lscher .
we take into account topological finite - volume corrections to the dimer binding energy which depend on the momentum of the dimer . after subtracting these effects
, we find from the lattice calculation @xmath0 and @xmath1 .
these results agree well with the continuum values @xmath2 and @xmath3 obtained from the stm equation .
we discuss applications to cold atomic fermi gases , deuteron - neutron scattering in the spin - quartet channel , and lattice calculations of scattering for nuclei and hadronic molecules at finite volume . .
And you have already written the first three sentences of the full article: in this paper , we perform the first benchmark of finite - volume lattice methods for the low - energy scattering of composite objects .
our results will have immediate applications to lattice studies of elastic neutron - nucleus scattering . in the analysis presented here we consider scattering between a fermion and a bound dimer composed of two fermions . in order to test the precision of our lattice calculations
, we also repeat the same calculations using the skorniakov - ter - martirosian ( stm ) integral equation @xcite . along the way we also provide the most accurate calculation to date for the fermion - dimer effective range parameter ..
Please generate the next two sentences of the article | some of the results presented were summarized in a letter publication @xcite , and we present the full details of the calculations here .
we consider two component fermions . |
4,743 | Suppose that you have an abstract for a scientific paper: we propose an interpolation formula for the distribution of the reflection coefficient in the presence of time reversal symmetry for chaotic cavities with absorption .
this is done assuming a similar functional form as that when time reversal invariance is absent .
the interpolation formula reduces to the analytical expressions for the strong and weak absorption limits .
our proposal is compared to the quite complicated exact result existing in the literature . .
And you have already written the first three sentences of the full article: in recent years there has been a great interest in the study of absorption effects on transport properties of classically chaotic cavities @xcite ( for a review see ref .
this is due to the fact that for experiments in microwave cavities @xcite , elastic resonators @xcite and elastic media
@xcite absorption always is present ..
Please generate the next two sentences of the article | although the external parameters are particularly easy to control , absorption , due to power loss in the volume of the device used in the experiments , is an ingredient that has to be taken into account in the verification of the random matrix theory ( rmt ) predictions . in a microwave experiment of a ballistic chaotic cavity connected to a waveguide supporting one propagating mode , doron _
@xcite studied the effect of absorption on the @xmath0 sub - unitary scattering matrix @xmath1 , parametrized as @xmath2 where @xmath3 is the reflection coefficient and @xmath4 is twice the phase shift . |
4,744 | Suppose that you have an abstract for a scientific paper: metasurfaces are nano - structured devices composed of arrays of subwavelength scatterers ( or meta - atoms ) that manipulate the wavefront , polarization , or intensity of light . like other diffractive optical devices ,
metasurfaces suffer from significant chromatic aberrations that limit their bandwidth . here
, we present a method for designing multiwavelength metasurfaces using unit cells with multiple meta - atoms , or meta - molecules .
transmissive lenses with efficiencies as high as 72@xmath0 and numerical apertures as high as 0.46 simultaneously operating at 915 nm and 1550 nm are demonstrated . with proper
scaling , these devices can be used in applications where operation at distinct known wavelengths is required , like various fluorescence microscopy techniques . over the last few years
, a new wave of interest has risen in nano - structured diffractive optical elements due to advances in nano - fabrication technology @xcite . from the multiple designs proposed so far ,
dielectric transmitarrays @xcite are some of the most versatile metasurfaces because they provide high transmission and subwavelength spatial control of both polarization and phase .
several diffractive optical elements , including high numerical aperture lenses and simultaneous phase and polarization controllers have recently been demonstrated with high efficiencies @xcite .
these devices are based on subwavelength arrays of high refractive index dielectric nano - resonators ( scatterers ) with different geometries , fabricated on a planar substrate .
scatterers with various geometries impart different phases to the transmitted light , shaping its wavefront to the desired form
. one main drawback of almost all of metasurface devices , particularly the ones with spatially varying phase profiles like lenses and gratings , is their chromatic aberration : their performance changes as the wavelength is varied @xcite .
refractive optical elements also suffer from chromatic aberrations ; however , their....
And you have already written the first three sentences of the full article: * simulation . * to find the transmission amplitude and phase of a multi - element metasurface , the rigorous coupled wave analysis technique was used @xcite .
a normally incident plane wave at each wavelength was used as the excitation , and the amplitude and phase of the transmitted wave were extracted . since the lattice is subwavelength for normal incidence at both wavelengths , only the zeroth order diffracted light is nonzero .
this justifies the use of only one transmission value at each wavelength to describe the behavior of meta - atoms ..
Please generate the next two sentences of the article | the lattice constant was chosen as 720 nm , and the a - si posts were 718-nm tall .
refractive indices of 3.56 and 3.43 were assumed for a - si at 915 nm and 1550 nm , respectively . |
4,745 | Suppose that you have an abstract for a scientific paper: the search for a canonical set of eigenvectors of the discrete fourier transform has been ongoing for more than three decades .
the goal is to find an orthogonal basis of eigenvectors which would approximate hermite functions
the eigenfunctions of the continuous fourier transform .
this eigenbasis should also have some degree of analytical tractability and should allow for efficient numerical computations . in this paper we provide a partial solution to these problems .
first , we construct an explicit basis of ( non - orthogonal ) eigenvectors of the discrete fourier transform , thus extending the results of @xcite . applying the gramm - schmidt orthogonalization procedure we obtain an orthogonal eigenbasis of the discrete fourier transform .
we prove that the first eight eigenvectors converge to the corresponding hermite functions , and we conjecture that this convergence result remains true for all eigenvectors .
0.15 cm _ keywords _ : eigenvectors , discrete fourier transform , orthogonal basis , hermite functions , q - binomial theorem + _ 2010 mathematics subject classification _ : primary 42a38 , secondary 65t50 .
And you have already written the first three sentences of the full article: the fractional fourier transform is becoming increasingly more important due to an ever - growing list of applications in signal processing , optics and quantum mechanics and in other areas of science @xcite . in order to define this object
one needs first to diagonalize the fourier transform operator @xmath0 , and that is where hermite functions @xmath1 become indispensable .
it is well - known that hermite functions are the eigenfunctions of the fourier transform operator @xmath2 and that they form a complete orthonormal basis of @xmath3 . in other words ,.
Please generate the next two sentences of the article | the orthogonal basis of hermite functions diagonalizes the fourier transform operator @xmath0 and this allows us to define the fractional power @xmath4 the fractional fourier transform .
of course , there are infinitely many ways to choose an eigenbasis of the fourier transform , each of them would lead to a different version of the fractional fourier transform . |
4,746 | Suppose that you have an abstract for a scientific paper: we investigate a communication setup where a source output is sent through a free noisy channel first and an additional codeword is sent through a noiseless but expensive channel later . with the help of the second message the decoder should be able to decide with zero - error whether its decoding of the first message was error - free .
this scenario leads to the definition of a digraph parameter that generalizes witsenhausen s zero - error rate for directed graphs .
we investigate this new parameter for some specific directed graphs and explore its relations to other digraph parameters like sperner capacity and dichromatic number .
when the original problem is modified to require zero - error decoding of the whole message then we arrive back to the witsenhausen rate of an appropriately defined undirected graph .
keywords : zero - error , graph products , sperner capacity , dichromatic number , witsenhausen rate .
And you have already written the first three sentences of the full article: consider the following situation .
alice writes a message to bob consisting of the numbers of several bank accounts to which bob has to send some money .
she writes in a hurry ( she just got to know that the transfers are urgent if they do not want to pay delay punishment , but currently she has little time ) ..
Please generate the next two sentences of the article | therefore her characters are not very well legible , so bob may misread some numbers .
however , there are some rules for the possible mistakes , e.g. , a @xmath0 may be thought to be a @xmath1 but never a @xmath2 . |
4,747 | Suppose that you have an abstract for a scientific paper: we show that describing the screened electrostatic interactions in a periodic stack of rigid parallel identical charged plate - like colloids within a local density functional theory approach , generically leads to a swelling behaviour . within the same framework
, we find that the effective potential between a pair of such plates immersed in an electrolyte is repulsive at all distances .
this general result is in contradiction with a theory put forward by sogami , shinohara and smalley , that we criticize and thoroughly reconsider to show how the two approaches can be reconciled . .
And you have already written the first three sentences of the full article: the counter - intuitive phenomenon of effective attractions between like - charges immersed in an electrolyte has recently attracted considerable attention , and questions one of the fundamental tenets of colloid science @xcite .
the understanding of the underlying mechanism is crucial for a correct description of a vast variety of industrial and natural processes , in particular the stability and phase behaviour of colloidal dispersions . in this article
, we investigate the stability of electrostatically swollen stacks of regularly spaced planar colloids or membranes of infinite lateral extension in an electrolyte ..
Please generate the next two sentences of the article | such a one - dimensional geometry describes the early stages of clay swelling @xcite but is also relevant for lamellar phases of charged bilayers @xcite . at the simplest level of mean - field description , with neglect of excluded volume and coulomb correlation effects ,
the inhomogeneous density profiles of microscopic co- and counter - ions forming the electric double layers around the planar macroions can be obtained analytically @xcite . |
4,748 | Suppose that you have an abstract for a scientific paper: we study the implementation of quantum phase measurement in a superconducting circuit , where two josephson phase qubits are coupled to the photon field inside a resonator .
we show that the relative phase of the superposition of two fock states can be imprinted in one of the qubits .
the qubit can thus be used to probe and store the quantum coherence of two distinguishable fock states of the single - mode photon field inside the resonator .
the effects of dissipation of the photon field on the phase detection are investigated .
we find that the visibilities can be greatly enhanced if the kerr nonlinearity is exploited .
we also show that the phase measurement method can be used to perform the gauss sum factorization of numbers ( @xmath0 ) into a product of prime integers , as well as to precisely measure both the resonator s frequency and the nonlinear interaction strength .
the largest factorizable number is mainly limited by the coherence time .
if the relaxation time of the resonator were to be @xmath1 @xmath2s ( @xmath3 ms ) , then the largest factorizable number can be @xmath4 ( @xmath5 ) , where @xmath6 is the number of photons in the resonator . .
And you have already written the first three sentences of the full article: the superposition of states is a fundamental feature of quantum mechanics . recently
, the arbitrary superposition of fock states @xcite has been produced in a superconducting resonator with a josephson phase qubit @xcite .
this offers novel ways to directly study the quantum coherence of the photon field , i.e. , superposition of number states ..
Please generate the next two sentences of the article | also , this strongly coupled qubit - resonator system @xcite , may be useful for quantum information processing ( qip ) .
we theoretically study the quantum phase measurement of the photon field in a superconducting resonator coupled to two phase qubits . |
4,749 | Suppose that you have an abstract for a scientific paper: we have studied the influence of the patterning procedure on the critical current density of high-@xmath0 yba@xmath1cu@xmath2o@xmath3 thin rings using the nonlinear ac susceptibility method . at no applied dc magnetic field
we have found that laser ablation degrades strongly the critical current density whereas ion beam etching has only a weak influence on it . from the measurements at different frequencies and
dc magnetic fields we analyzed the influence of flux creep and obtained the field dependence of the flux creep exponent .
our data reconfirm the recently observed scaling relation for the nonlinear susceptibility response of type - ii superconductors . .
And you have already written the first three sentences of the full article: in a recently published letter we have shown that the measurement of the magnetic moment of samples with ring geometry enables the identification of regions with degraded superconducting regions and can be used as a sensitive method to investigate the critical current density @xmath4 of high temperature superconducting thin films @xcite .
the ac field amplitude dependence of the ac susceptibility of structured narrow rings provides the experimental foundation for this method . within the bean model and via the determination of the so - called penetration field @xmath5 ( at which the perfect diamagnetic shielding is lost ) and geometry parameters we obtain @xmath4 . in this work
we have exploited this technique at zero dc magnetic field @xmath6 to investigate the influence of the structuring method used to fabricate the high - temperature superconducting rings on @xmath4 ..
Please generate the next two sentences of the article | our results indicate clearly that ion beam etching is a far less destructive structuring technique than laser ablation . we have also obtained the dc field dependence of @xmath4 and analysed the effects of flux creep with an extended bean model which enables the interpretation of the frequency dependence of the ac susceptibility associated with a finite resistivity due to flux motion @xcite . we have analyzed the shift of the ac susceptibility with frequency and applied a scaling relation which has been predicted by brandt @xcite . within this theory
we have determined the flux creep exponent @xmath7 and compared it with the one determined by relaxation measurements with a squid . |
4,750 | Suppose that you have an abstract for a scientific paper: the avalanche mechanism " has been used to relate efimov trimer states to certain enhanced atom loss features observed in ultracold atom gas experiments .
these atom loss features are argued to be a signature of resonant atom - molecule scattering that occurs when an efimov trimer is degenerate with the atom - molecule scattering threshold .
however , observation of these atom loss features has yet to be combined with the direct observation of atom - molecule resonant scattering for any particular atomic species .
in addition , recent monte - carlo simulations were unable to reproduce a narrow loss feature .
we experimentally search for enhanced atom loss features near an established scattering resonance between @xmath0k@xmath1rb feshbach molecules and @xmath1rb atoms .
our measurements of both the three - body recombination rate in a gas of @xmath0k and @xmath1rb atoms and the ratio of the number loss for the two species do not show any broad loss feature and are therefore inconsistent with theoretical predictions that use the avalanche mechanism . .
And you have already written the first three sentences of the full article: evidence for efimov three - body bound states , which were proposed originally in the context of nuclear physics @xcite , has been observed in a number of ultracold atom gas experiments @xcite . in principle , near a magnetic - field feshbach resonance @xcite there exists an infinite number of three - body bound states that follow a discrete scaling law .
the primary signature of these three - body states in cold atom gases has been resonantly enhanced three - body loss of trapped atoms .
a loss resonance occurs at a negative value of the two - body scattering length @xmath2 , which is denoted @xmath3 , where the energy of the efimov state coincides with the scattering threshold energy for three atoms @xcite , as shown schematically in fig ..
Please generate the next two sentences of the article | [ fig : efimov ] ( a ) .
several experiments have observed multiple efimov loss features whose locations follow discrete scaling , with each @xmath3 larger than that of the last by a factor of @xmath4 , where @xmath5 is a universal parameter @xcite . |
4,751 | Suppose that you have an abstract for a scientific paper: we have studied the nucleation and the physical properties of a -1/2 wedge disclination line near the free surface of a confined nematic liquid crystal .
the position of the disclination line has been related to the material parameters ( elastic constants , anchoring energy and favored anchoring angle of the molecules at the free surface ) .
the use of a planar model for the structure of the director field ( whose predictions have been contrasted to those of a fully three - dimensional model ) has allowed us to relate the experimentally observed position of the disclination line to the relevant properties of the liquid crystals .
in particular , we have been able to observe the collapse of the disclination line due to a temperature - induced anchoring angle transition , which has allowed us to rule out the presence of a real disclination line near the nematic / isotropic front in directional growth experiments . .
And you have already written the first three sentences of the full article: disclination lines @xcite are characteristic defects of uniaxial nematic phases .
these lines break the orientational order of the director field .
they can easily form , for instance by stirring a nematic drop deposited on a glass plate ..
Please generate the next two sentences of the article | observation in the microscope reveals a _ threaded texture _ composed of thin and thick threads which are primarily @xmath0 and @xmath1 wedge disclination lines .
the former have singular cores whereas the latter form continuous configurations since the director can escape along the disclination axis ( the so - called _ escape in the third dimension _ @xcite ) . |
4,752 | Suppose that you have an abstract for a scientific paper: the central two - pion exchange @xmath0 potential at large distances is studied in the framework of relativistic chiral symmetry and related directly to the nucleon scalar form factor , which describes the mass density of its pion cloud .
this relationship is well supported by phenomenology and allows the dependence of the asymptotic potential on the nucleon mass to be assessed .
results in the heavy baryon limit are about 25% larger than those corresponding to the empirical nucleon mass in the region of physical interest .
this indicates that it is very important to keep this mass finite in precise descriptions of the @xmath0 system and supports the efficacy of the relativistic chiral framework .
one also estimates the contribution of subleading effects and presents a simple discussions of the role of the quark condensate in this problem .
m.r .
robilotta _ _ .
And you have already written the first three sentences of the full article: qcd is nowadays the main theoretical framework for understanding hadronic processes , but its non - abelian character makes low energy calculations unfeasible . the usual strategy for overcoming this difficulty consists in working with effective theories , constructed in such a way as to include , as much as possible , the main features of qcd . as in nuclear physics
most processes involve only the quarks @xmath1 and @xmath2 , one requires these theories to be poincar invariant and to possess approximate @xmath3 chiral symmetry .
the breaking of the latter , due to the quark masses , is parametrized by the small pion mass @xmath4 at the effective level . in the last twenty years.
Please generate the next two sentences of the article | , effective theories incorporating chiral symmetry have been successfully applied to hadronic interactions , including or not electro - weak probes . as far as the hadronic sector is concerned it
is useful to distinguish two classes of processes , involving only mesons or both mesons and baryons . in the case of purely pionic systems , effective lagrangians |
4,753 | Suppose that you have an abstract for a scientific paper: it is evident that models of the knee should match the observational phenomenology . in this talk
i discuss a few aspects of phenomenology , which are important not only for the understanding of the knee origin , but also for the general problem of the origin of cosmic rays . among them
are the shape of the energy spectrum , its irregularity , the sharpness of the knee and its fine structure .
the classification of models is given and some examples of the most recent models are discussed .
the most probable conclusion deduced from this examination is that the knee has an astrophysical origin and the so called source models of the knee are most likely among them . .
And you have already written the first three sentences of the full article: the total number of models pretending to explain the origin of the knee exceeds twenty and the number of people who propose these models is about thirty .
the number of ideas is definitely larger , but i deliberately distinguish _ ideas _ and _ models _ , because sometimes the ideas are not developed at all to be considered as a model .
the quality of the development is also quite different for different models . to the great extent.
Please generate the next two sentences of the article | it is due to the lack of astrophysical or particle physics data which could constrain the models , but there are also some evident subjective reasons . certainly it is our duty to examine as much consequences of the proposed idea as we can and to some extent it is our fault that we ignore some evident experimental or observational facts which contradict the proposed idea .
there is a tradition in our p.n.lebedev physical institute that if you propose the idea you should also propose the test which can * kill * your idea . |
4,754 | Suppose that you have an abstract for a scientific paper: we describe an experimental technique to generate a quasi - monochromatic field with any arbitrary spatial coherence properties that can be described by the cross - spectral density function , @xmath0 .
this is done by using a dynamic binary amplitude grating generated by a digital micromirror device ( dmd ) to rapidly alternate between a set of coherent fields , creating an incoherent mix of modes that represent the coherent mode decomposition of the desired @xmath0 .
this method was then demonstrated experimentally by interfering two plane waves and then spatially varying the coherence between them .
it is then shown that this creates an interference pattern between the two beams whose fringe visibility varies spatially in an arbitrary and prescribed way . .
And you have already written the first three sentences of the full article: the transverse degree of freedom of an optical field is the fundamental aspect of light that contains spatial information .
utilization of this information is the basic resource in traditional imaging systems and in applications such as microscopy , lithography , holography or metrology .
in addition , use of the transverse modes of light has recently been demonstrated to be an important resource in optical communication @xcite , high - dimensional entanglement studies @xcite , and quantum key distribution @xcite ..
Please generate the next two sentences of the article | having control of the spatial coherence properties of a light beam provides an additional degree of control compared to using fully coherent light only , and has been shown to be advantageous for a number of applications .
beams of decreased coherence allow access to spatial frequencies that are twice those available in a purely coherent system @xcite . |
4,755 | Suppose that you have an abstract for a scientific paper: we estimate black hole masses in narrow line seyfert 1 ( nls1 ) galaxies at the basis of their x - ray excess variance .
we apply the standard approach appropriate for broad line seyfert 1 ( bls1 ) galaxies . in general
, we find that the obtained masses are by a factor @xmath0 20 too small to agree with values obtained from other methods ( reverberation , stellar dispersion )
. however , a small subset of our nls1 objects does not require that multiplication , or the correction factor is less than 4 .
we find that this subset have a soft x - ray photon index , @xmath1 , smaller than 2 .
we thus postulate that this subclass of nls1 actually belongs to bls1 . .
And you have already written the first three sentences of the full article: nls1 sources are defined as a subclass of broad line objects at the basis of the optical spectra , as sources with the full width at half maximum ( fwhm ) of h@xmath2 line , produced in broad line region , smaller than 2100 kms@xmath3 . in bls1s fwhm(h@xmath2 ) is @xmath4 2100 kms@xmath3 .
it was later found that nls1 generally have smaller black hole masses for a given luminosity , and strong soft x - ray excesses ( mathur et al .
2001 ; crummy et al , 2006 ) ..
Please generate the next two sentences of the article | soft x - ray photon indices , @xmath1 , of nls1 sources have a mean value 3.1 , while bls1 sources are harder , with a mean of 2.1 ( e.g. boller et al .
it suggests that nls1 and bls1 differ with respect to the accretion pattern . |
4,756 | Suppose that you have an abstract for a scientific paper: we present fir[@xmath0@xmath1co luminosity relations ( i.e. , @xmath2 ) for the full co rotational ladder from @xmath3 up to @xmath4 for a sample of 62 local ( @xmath5 ) ( ultra ) luminous infrared galaxies ( lirgs ; @xmath6 } > 10^{11}\,{\mbox{$l_{\odot}\,$}}$ ] ) using data from _ herschel _ spire - fts and ground - based telescopes .
we extend our sample to high redshifts ( @xmath7 ) by including 35 ( sub)-millimeter selected dusty star forming galaxies from the literature with robust co observations , and sufficiently well - sampled fir / sub - millimeter spectral energy distributions ( seds ) so that accurate fir luminosities can be deduced .
the addition of luminous starbursts at high redshifts enlarge the range of the fir@xmath1co luminosity relations towards the high - ir - luminosity end while also significantly increasing the small amount of mid-@xmath8/high-@xmath8 co line data ( @xmath9 and higher ) that was available prior to _
herschel_. this new data - set ( both in terms of ir luminosity and @xmath8-ladder ) reveals linear fir@xmath1co luminosity relations ( i.e. , @xmath10 ) for @xmath3 up to @xmath9 , with a nearly constant normalization ( @xmath11 ) .
in the simplest physical scenario this is expected from the ( also ) linear fir@xmath1(molecular line ) relations recently found for the dense gas tracer lines ( hcn and cs ) , as long as the dense gas mass fraction does not vary strongly within our ( merger / starburst)-dominated sample .
however from @xmath12 and up to the @xmath4 transition we find an increasingly sub - linear slope and higher normalization constant with increasing @xmath8 .
we argue that these are caused by a warm ( @xmath13 ) and dense ( @xmath14 ) gas component whose thermal state is unlikely to be maintained by star formation powered far - uv radiation fields ( and thus is no longer directly tied to the star formation rate ) .
we suggest that mechanical heating ( e.g. , supernova driven turbulence and shocks ) , and not cosmic rays , is the more likely....
And you have already written the first three sentences of the full article: early empirical correlations between the preponderance of young stars and gas in galaxies ( e.g. , @xcite ) confirmed in a qualitative sense the simple power - law dependence between star formation rate surface density ( @xmath15 ) and gas surface density ( @xmath16 ) first suggested by @xcite who found @xmath17 for hi gas . once the h@xmath18 component as traced by co lines was identified in galaxies , the gas surface density could be related to both hi and h@xmath18 , i.e. , @xmath19 @xcite . in a seminal paper , @xcite established this relation , hereafter called the schmidt - kennicutt ( s - k ) relation , to be : @xmath20 , averaged over entire galaxy disks .
further studies by @xcite and @xcite found a nearly linear s - k relation for the molecular gas on kpc scales ( see also @xcite and @xcite ) , with the sfr surface density having a much closer correspondence with the molecular gas surface density reflecting the well - established fact that stars form out of molecular rather than atomic gas . much theoretical effort has gone into obtaining the exponents and normalization of this relation as unique outcomes of various physical processes occurring in star forming galaxies , with various models capable of yielding ( s - k)-type relations ( e.g. , @xcite ) . it became evident that , while no deterministic microphysics of the interstellar medium ( ism ) and star formation ( sf ) can be linked to a given s - k relation , the high - density gas component ( @xmath21 ) plays a crucial role in ultimately anchoring such relations to the star formation taking place deep inside supersonically turbulent molecular clouds in disks .
the s - k relations for high - density gas are particularly challenging to establish since determining the dense gas mass fraction within a galaxy requires observations of co from @xmath3 ( a total molecular gas mass tracer ) up to at least @xmath22 along with the much fainter lines of _ bona fide _ dense gas tracers like cs and heavy - rotor molecules such as hcn . a multi -....
Please generate the next two sentences of the article | can then yield dense gas masses , @xmath23 ( e.g. , @xcite ) .
however , to do so for a large number of galaxies in order to obtain even a surface - integrated sfr@xmath24 s - k relation has been prohibitively expensive in telescope time . at high redshifts |
4,757 | Suppose that you have an abstract for a scientific paper: in this note , we introduce a new method for constructing graphs with high chromatic number and small clique . indeed , via this method ,
we present a new proof for the well - known kneser s conjecture . borsuk - ulam theorem , chromatic number , @xmath0-tucker lemma , triangle - free graphs .
And you have already written the first three sentences of the full article: in this note , all graphs are finite , simple and undirected .
the complete graph on @xmath1 vertices is denoted by @xmath2 .
the number of graph vertices in the largest complete subgraph of @xmath0 , denoted by @xmath3 is called the clique number of @xmath0 ..
Please generate the next two sentences of the article | the girth of a graph is the number of edges in its shortest cycle .
a proper ( vertex ) coloring is an assignment of labels or colors to each vertex of a graph so that no edge connects two identically colored vertices . |
4,758 | Suppose that you have an abstract for a scientific paper: we present a new pseudospectral code , ` bamps ` , for numerical relativity written with the evolution of collapsing gravitational waves in mind .
we employ the first order generalized harmonic gauge formulation . the relevant theory is reviewed and the numerical method is critically examined and specialized for the task at hand . in particular
we investigate formulation parameters , gauge and constraint preserving boundary conditions well - suited to non - vanishing gauge source functions .
different types of axisymmetric twist - free moment of time symmetry gravitational wave initial data are discussed . a treatment of the axisymmetric apparent horizon condition is presented with careful attention to regularity on axis .
our apparent horizon finder is then evaluated in a number of test cases . moving on to evolutions ,
we investigate modifications to the generalized harmonic gauge constraint damping scheme to improve conservation in the strong field regime .
we demonstrate strong - scaling of our pseudospectral penalty code .
we employ the cartoon method to efficiently evolve axisymmetric data in our @xmath0 dimensional code .
we perform test evolutions of schwarzschild perturbed by gravitational waves and by gauge pulses , both to demonstrate the use of our blackhole excision scheme and for comparison with earlier results .
finally numerical evolutions of supercritical brill waves are presented to demonstrate durability of the excision scheme for the dynamical formation of a blackhole . .
And you have already written the first three sentences of the full article: this is the first in a series of papers about the numerical treatment of collapsing gravitational waves using a new pseudospectral code developed for the problem . in the early @xmath1s critical phenomena
were discovered in gravitational collapse @xcite , in spherical symmetry , with general relativity minimally coupled to a massless scalar field .
one aspect of the finding was that , amazingly , the critical solution dividing the formation of a blackhole from dissipation of the field , was unique , in the sense that if one takes any one parameter family of initial data , with the parameter controlling somehow the strength of the data , and tunes this parameter to the threshold of blackhole formation , one finds that the same solution is always obtained , regardless of the family ! shortly thereafter similar phenomenology was reported in axisymmetric , vacuum general relativity @xcite , or in other words in the collapse of gravitational waves . since then.
Please generate the next two sentences of the article | multiple studies have been performed to reproduce this finding , albeit with different initial data and numerical approaches , but without success . perhaps most strikingly , in @xcite , numerical evidence of a different critical solution was presented .
even if one completely accepts the available evidence for criticality in vacuum collapse , this obviously begs the question whether or not the naive expectation of uniqueness of the critical solution in axisymmetric , rather than spherical , collapse holds . |
4,759 | Suppose that you have an abstract for a scientific paper: the calice @xcite si - w electromagnetic calorimeter @xcite has been tested with electron beams ( 1 to 6 gev ) at desy in may 2006 , as well as electrons ( 6 to 45 gev ) and hadrons ( 6 to 80 gev ) at cern in august and october 2006 .
several millions of events have been taken at different incident angles ( from 0@xmath0 to 45@xmath0 ) and three beam impact positions .
the ecal calibration is performed with muon beams and shows a good uniformity for nearly all channels .
the large statistics available allows not only to characterise the ecal physics performance , but also to identify subtle hardware effects . .
And you have already written the first three sentences of the full article: the si - w ecal physics prototype is composed of 30 layers of @xmath1 wafers , each wafer having an array of @xmath2 pixels of @xmath3 @xmath4 .
the two top rows of wafers are completed for the full depth in july 2006 .
the mechanical structure consists of tungsten sheets wrapped in carbon fibre , providing 15 alveola where slabs are inserted ..
Please generate the next two sentences of the article | one slab is made of two pcbs on each side of a tungsten layer , with the wafers conductively glued to the pcb .
the very front end electronics ( vfe ) provide preamplification and are located outside the active area , but mounted on the same pcb as the silicon wafers . |
4,760 | Suppose that you have an abstract for a scientific paper: we consider ( generalized ) kolakoski sequences on an alphabet with two even numbers . they can be related to a primitive substitution rule of constant length @xmath0
. using this connection , we prove that they have pure point dynamical and pure point diffractive spectrum , where we make use of the strong interplay between these two concepts .
since these sequences can then be described as model sets with @xmath0-adic internal space , we add an approach to `` visualize '' such internal spaces . .
And you have already written the first three sentences of the full article: a one - sided infinite sequence @xmath1 over the alphabet @xmath2 is called a ( classical ) _ kolakoski sequence _ ( named after w. kolakoski who introduced it in 1965 , see @xcite ) , if it equals the sequence defined by its run lengths , e.g. : @xmath3 here , a _ run _ is a maximal subword consisting of identical letters .
the sequence @xmath4 is the only other sequence which has this property .
one way to obtain @xmath1 of ( [ eq : kol ] ) is by starting with @xmath5 as a seed and iterating the two substitutions @xmath6 alternatingly , i.e. , @xmath7 substitutes letters on even positions and @xmath8 letters on odd positions ( we begin counting at @xmath9 ) : @xmath10 clearly , the iterates converge to the kolakoski sequence @xmath1 ( in the obvious product topology ) , and @xmath1 is the unique ( one - sided ) fixed point of this iteration.
Please generate the next two sentences of the article | . one can generalize this by choosing a different alphabet @xmath11 ( we are only looking at alphabets with @xmath12 ) .
such a ( generalized ) kolakoski sequence , which is also equal to the sequence of its run lengths , can be obtained by iterating the two substitutions @xmath13 alternatingly . here , the starting letter of the sequence is @xmath14 . |
4,761 | Suppose that you have an abstract for a scientific paper: the vortex dynamics in a low temperature superconductor deposited on top of a rectangular array of micrometer size permalloy triangles is investigated experimentally .
the rectangular unit cell is such that neighboring triangles physically touch each other along one direction .
this design stabilizes remanent states which differ from the magnetic vortex state typical of individual non - interacting triangles .
magnetic force microscopy images have revealed that the magnetic landscape of the template can be switched to an ordered configuration after magnetizing the sample with an in - plane field .
the ordered phase exhibits a broad flux flow regime with relatively low critical current and a highly anisotropic response .
this behavior is caused by the spontaneous formation of two separated rows of vortices and antivortices along each line of connected triangles .
the existence of a clear flux flow regime even for zero external field supports this interpretation .
the density of induced vortex - antivortex pairs is directly obtained using a high frequency measurement technique which allows us to resolve the discrete motion of vortices .
strikingly , the presence of vortex - antivortex rows gives rise to a self organized synchronized motion of vortices which manifests itself as field independent shapiro steps in the current - voltage characteristics . .
And you have already written the first three sentences of the full article: the dynamics and pinning of vortices in type - ii superconductors is arguably one of the most widely investigated phenomena in the field of superconductivity . recently
, particular attention has been devoted to the possibility of controlling the strength of the vortex pinning using different magnetic templates@xcite . within the london formalism , the interaction between a vortex line and a finite size permanent magnet
is given by@xcite , @xmath0 where the integration is carried out over the volume of the ferromagnet , @xmath1 indicates the position of the vortex line , @xmath2 its spatial dependent magnetic moment , and @xmath3 is the field generated by the vortex line ..
Please generate the next two sentences of the article | this equation shows that the pinning potential not only depends on the size of the dots@xcite but also on their exact magnetic state@xcite .
in particular , if the superconducting penetration depth @xmath4 is on the order of the lateral size of the dot , a weak average pinning is expected when the magnetic dot contains multiple domains . |
4,762 | Suppose that you have an abstract for a scientific paper: we analyze the electronic green s functions in the superconducting ground state of the @xmath0-@xmath1 model using gutzwiller - projected wave functions , and compare them to the conventional bcs form .
some of the properties of the bcs state are preserved by the projection : the total spectral weight is continuous around the quasiparticle node and approximately constant along the fermi surface . on the other hand ,
the overall spectral weight is reduced by the projection with a momentum - dependent renormalization , and the projection produces electron - hole asymmetry in renormalization of the electron and hole spectral weights .
the latter asymmetry leads to the bending of the effective fermi surface which we define as the locus of equal electron and hole spectral weight .
address = institute of theoretical physics , ecole polytechnique fdrale de lausanne ( epfl ) , ch-1015 lausanne , switzerland .
And you have already written the first three sentences of the full article: high temperature superconductivity ( htsc ) is one of the most intriguing phenomena in modern solid state physics .
experimentally , htsc is observed in layered cuprate compounds .
the undoped cuprates are antiferromagnetically ordered insulators which develop the characteristic superconducting `` dome '' upon doping with charge carriers ..
Please generate the next two sentences of the article | htsc is interesting not only for promising technological applications , but also from a theoretical point of view .
the relevant ingredients for htsc are believed to be the following . * |
4,763 | Suppose that you have an abstract for a scientific paper: lepton flavor violation ( lfv ) has been observed in neutrino oscillations . for charged lepton
fv decays only upper limits are known , but sizable branching ratios are expected in many neutrino mass models .
high scale models , such as the classical supersymmetric seesaw , usually predict that decays @xmath0 are roughly a factor @xmath1 maller than the corresponding decays @xmath2 . here
we demonstrate that the @xmath3-penguin diagram can give an enhancement for decays @xmath0 in many extensions of the minimal supersymmetric standard model ( mssm ) .
we first discuss why the @xmath3-penguin is not dominant in the mssm with seesaw and show that much larger contributions from the @xmath3-penguin are expected in general .
we then demonstrate the effect numerically in two example models , namely , the supersymmetric inverse seesaw and r - parity violating supersymmetry .
_ introduction : _ neutrino oscillation experiments @xcite have firmly established that lepton flavor is violated in the neutrino sector , with two of the three measurable mixing angles being surprisingly large .
observation of the characteristic `` neutrino dip '' leaves no doubt that neutrinos have mass @xcite and quite accurate values for the mass squared differences are known now @xcite . in the charged lepton sector , however , only upper limits on lfv branching ratios , such as @xmath4 @xcite or @xmath5 @xcite , exist .
extending the standard model ( sm ) only by neutrino masses does not automatically lead to measurable charged lfv ( clfv ) , but sizable branching ratios are expected in many models .
in fact , on quite general grounds one expects large clfv , if physics beyond the sm exists at the tev scale . a prime example for this observation is supersymmetry ( susy ) . here
, the mass matrices of the new scalar particles need not ( and in general will not ) be aligned with those of the sm fermions .
clfv decays will occur and one can estimate roughly the branching ratios for radiative decays as @xcite....
And you have already written the first three sentences of the full article: we thank werner porod , debottam das and daniel e. lopez - fogliani for fruitful discussions . a.v .
acknowledges support from the anr project cpv - lfv - lhc nt09 - 508531 .
this work was supported by the spanish micinn under grants fpa2008 - 00319/fpa and fpa2011 - 22975 by the multidark consolider csd2009 - 00064 , by the generalitat valenciana grant prometeo/2009/091 and by the eu grant unilhc pitn - ga-2009 - 237920 ..
Please generate the next two sentences of the article | y. fukuda _ et al .
_ [ super - kamiokande collaboration ] , phys . |
4,764 | Suppose that you have an abstract for a scientific paper: we study the group of interval exchange transformations and obtain several characterizations of its commutator group . in particular
, it turns out that the commutator group is generated by elements of order @xmath0 . .
And you have already written the first three sentences of the full article: let @xmath1 be an interval of the real line and @xmath2 be a finite collection of points that split @xmath1 into subintervals @xmath3 , @xmath4 .
a transformation @xmath5 of the interval @xmath1 that rearranges the subintervals by translation is called an _ interval exchange transformation _ ( see figure [ fig1 ] ) . to be precise , the restriction of @xmath5 to any @xmath3 is a translation , the translated subinterval remains within @xmath1 and does not overlap with the other translated subintervals .
the definition is still incomplete as values of @xmath5 at the points @xmath6 are not specified ..
Please generate the next two sentences of the article | the standard way to do this , which we adopt , is to require that @xmath5 be right continuous .
that is , we consider the half - closed interval @xmath7 partitioned into smaller half - closed intervals @xmath8 . |
4,765 | Suppose that you have an abstract for a scientific paper: in these lectures we give an overview of nonequilibrium stochastic systems .
in particular we discuss in detail two models , the asymmetric exclusion process and a ballistic reaction model , that illustrate many general features of nonequilibrium dynamics : for example coarsening dynamics and nonequilibrium phase transitions . as a secondary theme
we shall show how a common mathematical structure , the @xmath0-deformed harmonic oscillator algebra , serves to furnish exact results for both systems .
thus the lectures also serve as a gentle introduction to things @xmath0-deformed . and nonequilibrium dynamics , stochastic processes , phase transition , asymmetric exclusion process , reaction kinetics 02.50.-r , 05.40.-a , 05.70.fh .
And you have already written the first three sentences of the full article: in these lectures we explore the subject of nonequilibrium dynamics . before getting into any kind of detail
let us first establish what we mean by a nonequilibrium system .
this is best done by taking stock of our understanding of an equilibrium system ..
Please generate the next two sentences of the article | consider the canonical ( boltzmann ) distribution for a systems with configurations labelled @xmath1 each with energy @xmath2 : @xmath3 where @xmath4 .
the task is to calculate the partition function @xmath5 from which all thermodynamic properties , in principle , can be computed . |
4,766 | Suppose that you have an abstract for a scientific paper: in this paper we consider the classical relativistic motion of charged particles in a knotted electromagnetic field . after reviewing how to construct electromagnetic knots from maps between the three - sphere and the two - sphere ,
we introduce a mean quadratic radius of the energy density distribution in order to study some properties of this field .
we study the classical relativistic motion of electrons in the electromagnetic field of the hopf map , and compute their trajectories .
it is observed that these electrons initially at rest are strongly accelerated by the electromagnetic force , becoming ultrarelativistic in a period of time that depends on the knot energy and size . .
And you have already written the first three sentences of the full article: as pointed out in a recent paper by irvine and bouwmeester @xcite , electromagnetic knots are exact solutions of the classical maxwell equations of electromagnetism in vacuum .
they appeared firstly in a paper by raada @xcite in 1989 .
raada himself @xcite has used these solutions as the basic elements of a topological model of electromagnetism which is locally equivalent to maxwell s standard theory but implies furthermore some topological quantization conditions with interesting physical meaning @xcite ..
Please generate the next two sentences of the article | electromagnetic knots are defined through two fundamental complex scalar fields @xmath0 whose level curves coincide with the magnetic and electric lines respectively , each one of these lines being labelled by the constant value of the corresponding scalar .
both scalars are assumed to have only one value at infinity , which is equivalent to compactify the physical three - space to the sphere @xmath1 . |
4,767 | Suppose that you have an abstract for a scientific paper: we present preliminary results for the topological charge and susceptibility determined from the low - lying eigenmodes of the wilson - dirac operator .
these modes have been computed on dynamical configurations with @xmath0 non - perturbatively improved wilson fermions .
we compare our results with the eigenmodes of fermions in the quenched approximation . .
And you have already written the first three sentences of the full article: for several reasons there is particular interest in the low - lying eigenmodes of the dirac operator in qcd . from phenomenological models
it is expected that for sufficiently light quark masses physics , e.g. hadron correlators , is dominated by these modes .
calculations on the lattice enable us to study the relevance of low - lying eigenmodes for various observables directly . furthermore , the eigenmodes of the dirac operator carry information about the topological content of the background gauge field ..
Please generate the next two sentences of the article | the topological properties can also be probed using gluonic methods .
these however typically suffer from large fluctuations on very short scales and therefore require some sort of smoothing procedures . |
4,768 | Suppose that you have an abstract for a scientific paper: we consider the effective hamiltonian of an open quantum system , its biorthogonal eigenfunctions @xmath0 and define the value @xmath1 that characterizes the phase rigidity of the eigenfunctions @xmath0 . in the scenario with avoided level crossings
, @xmath2 varies between 1 and 0 due to the mutual influence of neighboring resonances .
the variation of @xmath2 may be considered as an internal property of an _ open _ quantum system . in the literature ,
the phase rigidity @xmath3 of the scattering wave function @xmath4 is considered .
since @xmath4 can be represented in the interior of the system by the @xmath0 , the phase rigidity @xmath3 of the @xmath4 is related to the @xmath2 and therefore also to the mutual influence of neighboring resonances . as a consequence ,
the reduction of the phase rigidity @xmath3 to values smaller than 1 should be considered , at least partly , as an internal property of an open quantum system in the overlapping regime .
the relation to measurable values such as the transmission through a quantum dot , follows from the fact that the transmission is , in any case , resonant with respect to the effective hamiltonian .
we illustrate the relation between phase rigidity @xmath3 and transmission numerically for small open cavities . .
And you have already written the first three sentences of the full article: the advances in the nanotechnology make it possible to produce small quantum dots with desired controllable properties .
the analogy between such a system and an atom has proved to be quite close @xcite . since however
no natural restrictions for choosing the control parameters exist , the quantum dots may show new properties that we can not obtain from studies on atoms ..
Please generate the next two sentences of the article | for example , fano resonances have been observed experimentally in quantum dots @xcite , and the fano parameters may be complex @xcite .
theoretically , the fano parameter expresses the interference between the resonant part of the transmission and a smooth ( direct ) nonresonant part . |
4,769 | Suppose that you have an abstract for a scientific paper: hadronic observables in z+jet events can be subject to large nlo corrections at tev scales , with @xmath0-factors that even reach values of order 50 in some cases .
we develop a method , loopsim , by which approximate nnlo predictions can be obtained for such observables , supplementing nlo z+jet and nlo z+2-jet results with a unitarity - based approximation for missing higher loop terms .
we first test the method against known nnlo results for drell - yan lepton @xmath1 spectra .
we then show our approximate nnlo results for the z+jet observables .
finally we examine whether the loopsim method can provide useful information even in cases without giant @xmath0-factors , with results for observables in dijet events that can be compared to early lhc data . .
And you have already written the first three sentences of the full article: at cern s large hadron collider ( lhc ) , it is widely anticipated that signals of new physics , for example supersymmetry , may manifest themselves as large excesses of data compared to expected qcd and electroweak backgrounds at high momentum scales @xcite .
the estimation of these backgrounds will be one of the elements in ascertaining the presence of any new physics from such signals .
consequently , considerable effort is being invested across the particle physics community in the development of methods to understand and predict backgrounds ( some of the issues involved are described nicely in ref ..
Please generate the next two sentences of the article | @xcite ) . given the qcd methods that are available today , some of the best prospects for obtaining systematic , accurate predictions of backgrounds involve next - to - leading order ( nlo ) qcd calculations . by carrying out a systematic expansion in the strong coupling and obtaining the first two terms ( leading order ( lo ) and nlo ) for a given process , one often obtains predictions that are accurate to @xmath2 .
the importance of nlo predictions in the lhc programme has motivated a large calculational effort destined to extend the range of processes known at nlo ( for reviews , see refs . |
4,770 | Suppose that you have an abstract for a scientific paper: classical and quantum theories of time - symmetric smoothing , which can be used to optimally estimate waveforms in classical and quantum systems , are derived using a discrete - time approach , and the similarities between the two theories are emphasized .
application of the quantum theory to homodyne phase - locked loop design for phase estimation with narrowband squeezed optical beams is studied .
the relation between the proposed theory and aharonov _ et al . _ s weak value theory is also explored . .
And you have already written the first three sentences of the full article: , the time at which the signal is to be estimated.,scaledwidth=48.0% ] estimation theory is the science of determining the state of a system , such as a dice , an aircraft , or the weather in boston , from noisy observations @xcite . as shown in fig .
[ classes ] , estimation problems can be classified into four classes , namely , prediction , filtering , retrodiction , and smoothing . for applications that do not require real - time data , such as sensing and communication , smoothing is the most accurate estimation technique .
i have recently proposed a time - symmetric quantum theory of smoothing , which allows one to optimally estimate classical diffusive markov random processes , such as gravitational waves or magnetic fields , coupled to a quantum system , such as a quantum mechanical oscillator or an atomic spin ensemble , under continuous measurements @xcite . in this paper ,.
Please generate the next two sentences of the article | i shall demonstrate in more detail the derivation of this theory using a discrete - time approach , and how it closely parallels the classical time - symmetric smoothing theory proposed by pardoux @xcite .
i shall apply the theory to the design of homodyne phase - locked loops ( pll ) for narrowband squeezed optical beams , as previously considered by berry and wiseman @xcite . |
4,771 | Suppose that you have an abstract for a scientific paper: a spherical two - distance set is a finite collection of unit vectors in @xmath0 such that the distances between any two distinct vectors assume only two values .
we use the semidefinite programming method to compute improved estimates of the maximum size of spherical two - distance sets .
exact answers are found for dimensions @xmath1 and @xmath2 where previous results gave divergent bounds .
dept . of electrical and computer engineering and institute for systems research ,
university of maryland , college park , md 20742 , and institute for information transmission problems , russian academy of sciences , moscow , russia .
email : [email protected] . ] dept . of mathematics and
institute for systems research , university of maryland , college park , md 20742 .
email : [email protected] ] .
And you have already written the first three sentences of the full article: this paper is devoted to the application of the semidefinite programming method to estimates of the size of the largest possible two - distance set on the sphere @xmath3 .
a spherical two - distance set is a finite collection @xmath4 of unit vectors in @xmath0 such that the set of distances between any two distinct vectors in @xmath4 has cardinality two . estimating the maximum size @xmath5 of such a set is a classical problem in distance geometry that has been studied for several decades .
we begin with an overview of known results ..
Please generate the next two sentences of the article | a lower bound on @xmath5 is obtained as follows .
let @xmath6 be the standard basis in @xmath7 . |
4,772 | Suppose that you have an abstract for a scientific paper: we study the relationship between the collective phenomena of super and subradiance and spontaneous synchronization of quantum systems . to this aim
we revisit the case of two detuned qubits interacting through a pure dissipative bosonic environment , which contains the minimal ingredients for our analysis . by using the liouville formalism ,
we are able to find analytically the ultimate connection between these phenomena .
we find that dynamical synchronization is due to the presence of long standing coherence between the ground state of the system and the subradiant state .
we finally show that , under pure dissipation , the emergence of spontaneous synchronization and of subradiant emission occur on the same time scale .
this reciprocity is broken in the presence of dephasing noise . .
And you have already written the first three sentences of the full article: superradiance , the collective emission of a sample of atoms , is one of the most celebrated examples of cooperative quantum phenomena , while synchronization is a widespread and paradigmatic emergent behavior in complex systems ( see @xcite and @xcite , respectively , for comprehensive reviews ) . in the most idealized form of superradiance , as first described by dicke in his seminal paper @xcite , the atoms identically interact with the electromagnetic field , a situation encountered , e.g. , when these are confined in a region of space smaller than the wavelength of the resonant modes .
when the initial atomic state is a highly entangled symmetric state , the emission is cooperative and takes place in a rapid burst at a rate proportional to the square of the number of atoms .
this is a clear signature of the presence of constructive quantum interference . if the emission starts from the state in which all the atoms are in their excited state , the collective atomic state acts as an antenna amplifying at a macroscopic level the quantum field fluctuation which trigger the emission . during the last years @xcite , superradiance in the presence of a small number of emitters.
Please generate the next two sentences of the article | was observed by employing trapped ions @xcite and superconducting qubits @xcite .
superradiant emission has been shown to be a useful resource towards the realization of single - photon sources @xcite , quantum memories @xcite , and laser cooling @xcite . |
4,773 | Suppose that you have an abstract for a scientific paper: in this article we investigate the casimir effect in the presence of a medium by quantizing the electromagnetic ( em ) field in the presence of a magnetodielectric medium by using the path integral formalism . for a given medium with definite electric and magnetic susceptibilities , explicit expressions for the casimir force
are obtained which are in agree with the original casimir force between two conducting parallel plates immersed in the quantum electromagnetic vacuum . .
And you have already written the first three sentences of the full article: one of the most remarkable and fundamentally important result of the field quantization is the casimir effect which is a force arising from the change of the zero point energy caused by imposing the boundary conditions ( bc ) @xcite .
this force is the macroscopic aspect of the quantum electrodynamics that provides a direct line between quantum field theory and the macroscopic world .
the original calculation of the casimir force between two perfectly conducting parallel plates immersed in the quantum electromagnetic vacuum is based on the definition of the casimir energy in the presence and the absence of boundary surfaces @xcite that leads to an attractive observable force @xmath0 between the plates , where @xmath1 is the planck constant , @xmath2 is the speed of light and @xmath3 is the distance between the plates ..
Please generate the next two sentences of the article | in other way one can consider this effect by evaluating the radiation pressure on macroscopic objects @xcite . as the magnitude of the casimir force is substantial at @xmath4
this effect is relevant in nano - technology @xcite and should be take into account to design and actuate microelectromechanical ( mems ) systems . moreover the possibility of transducing the energy from the vacuum is investigated by means of mems @xcite . |
4,774 | Suppose that you have an abstract for a scientific paper: in this article we have solved an hypothetical problem related to the stability and gross properties of two dimensional self - gravitating stellar objects using thomas - fermi model .
the formalism presented here is an extension of the standard three - dimensional problem discussed in the book on statistical physics , part - i by landau and lifshitz .
further , the formalism presented in this article may be considered as class problem for post - graduate level students of physics or may be assigned as a part of their dissertation project . .
And you have already written the first three sentences of the full article: the study of gross properties of bulk self - gravitating objects using thomas - fermi model has been discussed in a very lucid manner in the text book on statistical physics by landau and lifshitz @xcite . in this book
the model has also been extended for the bulk system with ultra - relativistic electrons as one of the constituents .
analogous to the conventional white dwarf model , these electrons in both non - relativistic and ultra - relativistic cases provide degeneracy pressure to make the bulk system stable against gravitational collapse ..
Please generate the next two sentences of the article | the results are therefore an alternative to lane - emden equation or chandrasekhar equation @xcite .
the mathematical formalism along with the numerical estimates of various parameters , e.g. , mass , radius , etc . for white dwarf stars |
4,775 | Suppose that you have an abstract for a scientific paper: we consider plane waves propagating in quadratic nonlinear slab waveguides with nonlinear quasi - phase - matching gratings .
we predict analytically and verify numerically the complete gain spectrum for transverse modulational instability , including hitherto undescribed higher order gain bands . .
And you have already written the first three sentences of the full article: with the maturing of the quasi - phase - matching ( qpm ) technique , in particular by electric - field poling of ferro - electric materials , such as linbo@xmath0 @xcite , by poling of polymers @xcite and quantum - well disordering in semiconductors @xcite , the number of applications of quadratic nonlinear ( or @xmath1 ) materials has increased significantly .
even complicated qpm grating structures are now commercially available in periodically poled linbo@xmath0 ( ppln ) .
it is therefore more important than ever to have complete knowledge of the effects a qpm grating has on the properties of @xmath1 materials ..
Please generate the next two sentences of the article | the most fundamental effect of a qpm grating , with a certain spectrum of spatial wave vectors , is to allow noncritical phase matching at all wavelengths for which the wave - vector mismatch @xmath2 matches a component of the grating spectrum .
thus qpm gratings allow for efficient multiple wavelength second harmonic generation ( shg ) @xcite , which may , for example , be used for multiple - channel wavelength conversion @xcite . |
4,776 | Suppose that you have an abstract for a scientific paper: a milestone in probability theory is the _ law of the iterated logarithm _ ( lil ) , proved by khinchin and independently by kolmogorov in the 1920s , which asserts that for iid random variables @xmath0 with mean @xmath1 and variance @xmath2 @xmath3 = 1 .\ ] ] in this paper we prove that lil holds for various functionals of random graphs and hypergraphs models .
we first prove lil for the number of copies of a fixed subgraph @xmath4 .
two harder results concern the number of global objects : perfect matchings and hamiltonian cycles .
the main new ingredient in these results is a large deviation bound , which may be of independent interest . for random @xmath5-uniform hypergraphs
, we obtain the central limit theorem ( clt ) and lil for the number of hamilton cycles . .
And you have already written the first three sentences of the full article: let @xmath0 be an infinite sequence of iid random variables with mean @xmath1 and variance @xmath2 .
two key results in probability theory are the central limit theorem and the law of the iterated logarithm .
the _ central limit theorem _ ( clt ) states that for @xmath6 , one has @xmath7 where @xmath8 and @xmath9 denotes the standard gaussian distribution . the _ law of the iterated logarithm _.
Please generate the next two sentences of the article | ( lil ) , proved by khinchin @xcite and kolmogorov @xcite , asserts that @xmath10 = 1 .\ ] ] the @xmath11 term reveals a subtle correlation between the @xmath12 s , especially those with indices close to each other .
the theory of random graphs ( hypergraphs ) contains several central limit theorems , some of which are among the most well known results in the field . |
4,777 | Suppose that you have an abstract for a scientific paper: constraining the astrophysical nature of ultra - luminous x - ray ( ulx ) sources , which have x - ray luminosities exceeding 10@xmath0 erg s@xmath1 , has been elusive due to the optical faintness of any counterparts . with high spectral resolution observations in the @xmath230@xmath3 m wavelength range
we have conducted an experiment to study six ulx sources in the ngc 4485/90 galaxy pair .
we have found that five of the six ulxs , based on mid - infrared spectral diagnostics , show the characteristic higher ionization features that are found in agn .
the sixth source , ulx-1 , is consistent with being a supernova remnant .
the chief infrared spectral diagnostics used are the ratios of [ s iii]/[si ii ] _ vs _ [ ne iii]/[ne ii ] . in two instances
fits to the continuum and _ poly aromatic hydrocarbons _ ( pah ) features also indicate higher dust temperatures that are characteristic of accreting sources .
overall , however , we find the continuum is dominated by stellar processes , and the best diagnostic features are the emission lines .
high spectral resolution studies in the mid - infrared thus appear to show great promise for determining the astrophysical nature of ulxs . .
And you have already written the first three sentences of the full article: ultra - luminous x - ray sources ( ulxs ) are generally defined as extra - nuclear galactic x - ray sources with x - ray luminosities @xmath4 erg s@xmath1 , a luminosity that is seldom reached by any galactic ( milky way ) x - ray binary ( xrb ) .
if ulxs emit their x - rays isotropically , by eddington arguments , the central object could be a black hole ( bh ) with mass m @xmath5 5 m@xmath6 , and for eddington ratios of @xmath710@xmath8@xmath910@xmath1 , the implied mass of the central object is @xmath750@xmath9500 m@xmath6 .
therefore , some ulxs could be accreting intermediate - mass black holes ( imbhs , * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* ; * ? ? ? |
4,778 | Suppose that you have an abstract for a scientific paper: we present a model for explaining the fe k@xmath0 line and the continuum in the afterglow of grb 000214 . in this paper , we pose the importance to seek the physically natural environment around grb 000214 . for reproducing the observation , we need a ring - like remnant around the progenitor , like that of sn 1987a produced by the mass - loss of the progenitor and the fireball spread over all directions .
the observation of grb 000214 , in which the continuum power - law spectrum decreased faster than the line , motivated us to consider two independent systems for the line emission and the continuum spectrum . at first
, the continuum spectrum can be fitted by the afterglow emission of the fireball pointing toward the observer , which does not collide with the ring because the emission of grb and the afterglow are highly collimated to the observer by the relativistic beaming effect .
secondly , the line can be fitted by the fluorescence of the fe atoms in the ring illuminated by the x - ray afterglow .
the significance of this study is that our model may strongly constrain the grb models . @xmath1
gamma - rays : bursts x - rays : general ism : supernova remnants line : formation gamma - rays : individual ( grb 000214 ) .
And you have already written the first three sentences of the full article: there are four gamma - ray bursts ( hereafter grbs ) displaying the fe k@xmath0 emission lines in their afterglows ( @xcite,@xcite,@xcite,@xcite ) .
what are the implications of these observations ?
a fireball model @xcite , which explains the behaviors of grbs well , needs a central engine to give an initial energy input to the fireballs ..
Please generate the next two sentences of the article | what is a central engine ?
this has been a long - term mystery and a controversial problem . however , with lines in the afterglows |
4,779 | Suppose that you have an abstract for a scientific paper: in the work the data of the yakutsk complex eas array and their comparison with calculation in the case of primary nuclei of different chemical elements are presented .
the calculation by qgsjet model have been used interpreting experimental data . .
And you have already written the first three sentences of the full article: it is not possible to measure a mass composition of primary cosmic rays ( pcr ) in the energy range @xmath0 ev using the direct method .
nothing remains , but to resort to the indirect methods when for the similar estimates the measurement of different components of extensive air shower ( eas ) are used .
that can be characteristics of longitudinal or lateral development of shower in the air ..
Please generate the next two sentences of the article | and usually it is connected with the analysis of the most sensitive to the composition of shower components which differ from each other by the character of formatting and absorbing in the atmosphere , for example , of the charged particle flux ( electron , muon ) , the flux of erenkov or ionization radiation .
fig.[fig1 ] presents the eas yakutsk array experimental data and calculations by the model with the decelerated and moderate dissipation of the energy into the electromagnetic eas component : quasiscaling models ( solid line ) and qgsjet ( dashed line ) @xcite . from fig.[fig1 ] it is seen both the agreement of experimental data and calculations by qgsjet model ( proton ) in the region @xmath1 ev , and disagreement at @xmath2 ev . |
4,780 | Suppose that you have an abstract for a scientific paper: we analyze the interaction of a radiation - dominated jet and its surroundings using the equations of radiation hydrodynamics in the viscous limit . in a previous paper we considered the two - stream scenario , which treats the jet and its surroundings as distinct media interacting through radiation viscous forces . here
we present an alternative boundary layer model , known as the free - streaming jet model where a narrow stream of fluid is injected into a static medium and
present solutions where the flow is ultrarelativistic and the boundary layer is dominated by radiation .
it is shown that these jets entrain material from their surroundings and that their cores have a lower density of scatterers and a harder spectrum of photons , leading to observational consequences for lines of sight that look `` down the barrel of the jet . ''
these jetted outflow models may be applicable to the jets produced during long gamma - ray bursts and super - eddington phases of tidal disruption events . .
And you have already written the first three sentences of the full article: particles , magnetic fields , and radiation all contribute to the propulsion of relativistic jets , though the relative contribution of each is still an open matter of debate . in certain situations ,
however , the mechanism responsible for launching the jet operates simultaneously with the release of a large amount of energy in the form of radiation , making it likely that photons dominate the bulk energetics .
this scenario occurs , for example , during the super - eddington phase of jetted tidal disruption events ( tdes ) , such as _ swift _ j1644 + 57 @xcite and _ swift _ j2058 + 05 @xcite ..
Please generate the next two sentences of the article | radiation - dominated jets should also be present in the collapsar picture of long gamma - ray bursts ( grbs ; @xcite ) , where the energy released in the form of gamma - rays is ultimately derived from accretion onto a black hole , the associated accretion luminosity exceeding the eddington limit of the hole by more than ten orders of magnitude . in both of these cases ,
the propagation of the radiation - dominated jet is modulated by the presence of a radiation pressure - supported environment ; for super - eddington tdes , this environment is in the form of a highly inflated , quasi - spherical torus of fallback debris @xcite , while a `` cocoon '' of shocked jet material @xcite and the overlying stellar envelope itself @xcite serve as the confining medium for grbs . in a companion paper ( @xcite , hereafter paper i ) |
4,781 | Suppose that you have an abstract for a scientific paper: swiftj1626.6@xmath05156 is a be / x - ray binary that was in outburst from december 2005 until november 2008 .
we have examined _ rxte_/pca and hexte spectra of three long observations of this source taken early in its outburst , when the pca 220kev count rate was @xmath170counts@xmath2 , as well as several combined observations from different stages of the outburst .
the spectra are best fit with an absorbed cutoff power law with a @xmath3kev iron emission line and a gaussian optical depth absorption line at @xmath410kev .
we present strong evidence that this absorption - like feature is a cyclotron resonance scattering feature , making swiftj1626.6@xmath05156 a new candidate cyclotron line source .
the redshifted energy of @xmath410kev implies a magnetic field strength of @xmath5 g in the region of the accretion column close to the magnetic poles where the cyclotron line is produced .
analysis of phase averaged spectra spanning the duration of the outburst suggests a possible positive correlation between the fundamental cyclotron energy and source luminosity .
phase resolved spectroscopy from a long observation reveals a variable cyclotron line energy , with phase dependence similar to a variety of other pulsars , as well as the first harmonic of the fundamental cyclotron line . .
And you have already written the first three sentences of the full article: the high mass x - ray binary ( hmxb ) was discovered in outburst by the swift burst alert telescope ( bat ) on 18 december 2005 @xcite .
it was soon recognized to be an x - ray pulsar with a @xmath415s spin period @xcite and its companion was classified as a b0ve star at a distance of @xmath410kpc @xcite . shortly after the discovery , the rossi x - ray timing explorer ( _ rxte _ ) began monitoring the source and continued to do so for nearly five years .
the categorization of swiftj1626.6@xmath05156 as a be / x - ray ( bex ) binary places it in a group that comprises most of the hmxb population , so we will describe it in terms associated with that group of objects ..
Please generate the next two sentences of the article | its 220kev pca light curve is shown in figure [ fig1 ] , spanning the beginning of _ rxte _ s monitoring in 2006 january through 2009 january , when the source had returned to quiescence . 5156 , taken from heasarc s _ rxte _ mission - long data archive ( ftp://legacy.gsfc.nasa.gov/xte/data/archive/missionlongdata ) .
it shows the background subtracted 220kev count rate as recorded in ` standard2 ` mode ( 16s time resolution ) , averaged over each observation and normalized to a single pcu . |
4,782 | Suppose that you have an abstract for a scientific paper: the stability of a long cylindrical domain in a phase - separating binary fluid in an external shear flow is investigated by linear stability analysis . using the coupled cahn - hilliard and stokes equations ,
the stability eigenvalues are derived analytically for long wavelength perturbations , for arbitrary viscosity contrast between the two phases .
the shear flow is found to suppress and sometimes completely stabilize both the hydrodynamic rayleigh instability and the thermodynamic instability of the cylinder against varicose perturbations , by mixing with nonaxisymmetric perturbations .
the results are consistent with recent observations of a `` string phase '' in phase - separating fluids in shear . epsf 2 .
And you have already written the first three sentences of the full article: phase - separating binary fluids form complex patterns of domains after a quench into the two - phase region of the phase diagram .
the domain morphology is determined by a number of factors such as the volume fractions of the two phases , their viscosities , and any external forces applied to the system @xcite .
of particular interest here is the effect of an external shear flow applied to the fluid ..
Please generate the next two sentences of the article | the shear flow competes with the phase - separation process , influencing the morphology and stability of the domains . besides being a fascinating problem in nonequilibrium physics
, this question is of practical significance because the final properties of industrial materials involving binary fluids often depend on the domain morphology . at late times after a quench into an unstable state , a phase - separating binary fluid consists of domains of the two phases which coarsen with time . |
4,783 | Suppose that you have an abstract for a scientific paper: we study the vacuum polarization effects associated with a massive fermionic field in a spacetime produced by a global monopole considering a nontrivial inner structure for it . in the general case of the spherically symmetric static core with finite support we evaluate the vacuum expectation values of the energy - momentum tensor and the fermionic condensate in the region outside the core .
these quantities are presented as the sum of point - like global monopole and core - induced contributions .
the asymptotic behavior of the core - induced vacuum densities are investigated at large distances from the core , near the core and for small values of the solid angle corresponding to strong gravitational fields . as an application of general results the flower - pot model for the monopole s core
is considered and the expectation values inside the core are evaluated .
pacs number(s ) : 03.07.+k , 98.80.cq , 11.27.+d .
And you have already written the first three sentences of the full article: symmetry braking phase transitions in the early universe have several cosmological consequences and provide an important link between particle physics and cosmology .
in particular , different types of topological objects may have been formed by the vacuum phase transitions after planck time kibble , v - s .
these include domain walls , cosmic strings and monopoles ..
Please generate the next two sentences of the article | a global monopole is a spherical symmetric gravitational topological defect created by a phase transition of a system comprised by self - coupling scalar field , @xmath0 , whose original global @xmath1 symmetry is spontaneously broken to @xmath2 .
the matter fields play the role of an order parameter which outside the monopole s core acquires a non - vanishing value . the global monopole was first introduced by sokolov and starobinsky soko77 . |
4,784 | Suppose that you have an abstract for a scientific paper: we consider generalized linear transient convection - diffusion problems for differential forms on bounded domains in @xmath0 . these involve lie derivatives with respect to a prescribed smooth vector field .
we construct both new eulerian and semi - lagrangian approaches to the discretization of the lie derivatives in the context of a galerkin approximation based on discrete differential forms .
details of implementation are discussed as well as an application to the discretization of eddy current equations in moving media . .
And you have already written the first three sentences of the full article: recall the classical linear transient 2nd - order convection - diffusion problem for an unknown scalar function @xmath1 on a bounded domain @xmath2 : @xmath3{rcll } \partial_{t}u - \varepsilon \delta u + { \boldsymbol \beta}\cdot \operatorname{\bf grad } u & = & f & \text{in } \omega\;,\\ u & = & 0 & \text{on } \partial\omega\;,\\ u(0 ) & = & u_{0}\;. \end{array}\end{gathered}\ ] ] here , and in the remainder of the paper , @xmath4 stands for a smooth vector field . for @xmath5
we encounter a singularly perturbed boundary value problem , whose _ stable _ discretization has attracted immense attention in numerical analysis , see @xcite and the many references cited therein .
the boundary value problem turns out to be a member of a larger family of 2nd - order boundary value problems ( bvp ) , which can conveniently be described using the _ calculus of differential forms_. it permits us to state the generalized transient 2nd - order convection - diffusion problems as @xmath6{rcll } \ast \partial_t \omega(t ) - \varepsilon ( -1)^{l } d\ast d \omega(t ) + \ast l_{\boldsymbol \beta } \omega ( t ) & = & \varphi \quad & \text{in } \omega\subset\mathbb{r}^{n}\;,\\ \imath^{\ast}\omega & = & 0 & \text{on } \partial\omega\;,\\ \omega(0 ) & = & \omega_{0}\;. \end{array}\end{gathered}\ ] ] these are bvps for an unknown time dependent @xmath7-form @xmath8 , @xmath9 , on the domain @xmath10 ..
Please generate the next two sentences of the article | the symbol @xmath11 stands for a hodge operator mapping an @xmath7-form to an @xmath12-form , and @xmath13 denotes the exterior derivative .
dirichlet boundary conditions are imposed via the trace @xmath14 of the @xmath7-form @xmath15 . |
4,785 | Suppose that you have an abstract for a scientific paper: we study the electronic correlation effects in armchair graphene nanoribbons that have been recently proposed to be the building blocks of spin qubits .
the armchair edges give rise to peculiar quantum interferences and lead to quenched kinetic energy of the itinerant carriers at appropriate doping level .
this is a beautiful one - dimensional analogy of the landau - level formation in two dimensions except the magnetic field is not needed here . combining the techniques of effective field theory and variational wave function approach
, we found that the ground state exhibits a new type of flat - band ferromagnetism that hasnt been found before . at the end
, we address practical issues about realization of this novel magnetic state in experiments . .
And you have already written the first three sentences of the full article: graphene@xcite , composed carbon atoms arranged in a two - dimensional honeycomb lattice , is the building block for all graphitic materials from the 0d fullerenes to 1d nanotubes and also the common 3d graphite .
however , following peierls and landau s arguments , the two - dimensional lattice is unstable and can not exist at any finite temperature .
therefore , graphene is often used as a toy model and viewed as an academic material until its recent discovery in laboratory@xcite . since graphene has promising application potentials in nanoscale electronic devices , it is important to study how the band structure changes with respect to the finite transverse width and also the edge topology ..
Please generate the next two sentences of the article | in addition , we also expect the electron - electron interaction will play a crucial role for physics properties in low - energy limit .
therefore , we are motivated to investigate the ground state properties in graphene nanoribbon ( gnr ) here . with lithography techniques , |
4,786 | Suppose that you have an abstract for a scientific paper: in this paper , we report high - precision absolute distance and vibration measurements performed with frequency scanned interferometry using a pair of single - mode optical fibers .
absolute distance was determined by counting the interference fringes produced while scanning the laser frequency .
a high - finesse fabry - perot interferometer(f - p ) was used to determine frequency changes during scanning .
two multiple - distance - measurement analysis techniques were developed to improve distance precision and to extract the amplitude and frequency of vibrations . under laboratory conditions , measurement precision of @xmath0 50 nm
was achieved for absolute distances ranging from 0.1 meters to 0.7 meters by using the first multiple - distance - measurement technique .
the second analysis technique has the capability to measure vibration frequencies ranging from 0.1 hz to 100 hz with amplitude as small as a few nanometers , without a _ priori _ knowledge . .
And you have already written the first three sentences of the full article: the motivation for this project is to design a novel optical system for quasi - real time alignment of tracker detector elements used in high energy physics ( hep ) experiments .
fox - murphy _ et.al .
_ from oxford university reported their design of a frequency scanned interferometer ( fsi ) for precise alignment of the atlas inner detector @xcite ..
Please generate the next two sentences of the article | given the demonstrated need for improvements in detector performance , we plan to design an enhanced fsi system to be used for the alignment of tracker elements in the next generation of electron positron linear collider ( ilc ) detectors .
current plans for future detectors require a spatial resolution for signals from a tracker detector , such as a silicon microstrip or silicon drift detector , to be approximately 7 - 10 @xmath1@xcite . to achieve this required spatial resolution |
4,787 | Suppose that you have an abstract for a scientific paper: the vacuum oscillation solution to the solar neutrino problem predicts characteristics variations of the observable neutrinos rates , as a result of the @xmath0 dependence of the @xmath1 survival probability ( @xmath2 and @xmath3 being the neutrino pathlength and energy , respectively ) .
the @xmath3-dependence can be studied through distortions of the recoil electron spectrum in the superkamiokande experiment .
the @xmath2-dependence can be investigated through a fourier analysis of the signal in the superkamiokande and borexino experiments .
we discuss in detail the interplay among such observable variations of the signal , and show how they can help to test and constrain the vacuum oscillation solution(s ) .
the analysis includes the 374-day superkamiokande data . .
And you have already written the first three sentences of the full article: neutrino flavor oscillations @xcite with wavelength comparable to the earth - sun distance @xcite represent a solution @xcite to the deficit of solar @xmath4 s @xcite observed in the four pioneering underground experiments homestake @xcite , kamiokande @xcite , sage @xcite , and gallex @xcite , as compared to the standard solar model predictions @xcite .
the recent superkamiokande data @xcite confirm the deficit , and can be interpreted within the vacuum oscillation hypothesis as well @xcite . the planned borexino solar neutrino experiment @xcite ( in construction ) , designed to detect monochromatic @xmath5be neutrinos ( @xmath6 mev ) , is expected to test this hypothesis with unprecedented sensitivity @xcite .
an update of the current neutrino flux measurements @xcite is given in table i. figure 1 shows our vacuum oscillation fit to the data of table i , as obtained from a @xmath7 analysis ( including solar model uncertainties as in @xcite ) ..
Please generate the next two sentences of the article | we have assumed , for simplicity , two neutrino families .
it can be seen that four regions ( a , b , c , and d ) are allowed at 95% c.l . |
4,788 | Suppose that you have an abstract for a scientific paper: recently , reliable mass estimates for the central black holes in agn became feasible due to emission - line reverberation techniques . using this method as a calibrator ,
it is possible to determine black hole masses for a wide range of agn , in particular nls1s .
do nls1s have smaller black holes than ordinary seyfert 1 galaxies ?
are their black holes smaller compared to the sizes of their host galaxies ?
do they have larger @xmath0 ratios ?
do nls1s have hotter accretion disks ?
i confront these questions with accretion disk theory and with the data , showing that the above may well be the case .
# 1#2#3#4 = # 1 cm # 2 cm .3 cm galaxies : active ; quasars : general ; quasars : emission lines ; accretion disks ; black holes .
And you have already written the first three sentences of the full article: in the paradigm for the power source of an agn , the continuum luminosity and spectral temperature are related to the mass by the relation @xmath1 where @xmath2 is the average photon energy , @xmath3 cm is the radius , and @xmath4 is the bolometric luminosity .
the temperature in the part of the disk is @xmath5 where @xmath6 and @xmath7 is the in units of the ( @xmath8 being the efficiency ) , so that @xmath9 at the limit .
when the approaches the rate , the thin disk solution in the inner region is probably not valid , and it has to be replaced by a hot disk solution ( e.g. wandel & liang 1991 ) ..
Please generate the next two sentences of the article | the spectrum of a multi - is given by integrating the local spectrum over the entire disk , @xmath10 dr $ ] , where @xmath11 is the planck function and @xmath12 is the transition radius from the region to the inner optically thin region . if the disk is radially extended ( @xmath13 ) , the spectrum is almost flat ( @xmath14 ) and cuts off beyond @xmath15 , approximately @xmath16 where @xmath17 and @xmath18 are the normalization and cutoff frequency . for a kerr black hole , malkan ( 1990 )
finds @xmath19 , where @xmath20 . |
4,789 | Suppose that you have an abstract for a scientific paper: we give a combinatorial characterization of generic minimally rigid reflection frameworks .
the main new idea is to study a pair of direction networks on the same graph such that one admits faithful realizations and the other has only collapsed realizations . in terms of infinitesimal rigidity ,
realizations of the former produce a framework and the latter certifies that this framework is infinitesimally rigid .
= 1 .
And you have already written the first three sentences of the full article: [ sec : intro ] a _ reflection framework _ is a planar structure made of _ fixed - length bars _ connected by _ universal joints _ with full rotational freedom .
additionally , the bars and joints are symmetric with respect to a reflection through a fixed axis .
the allowed motions preserve the _ length _ and _ connectivity _ of the bars and _ symmetry _ with respect to some reflection ..
Please generate the next two sentences of the article | this model is very similar to that of _ cone frameworks _ that we introduced in @xcite ; the difference is that the symmetry group @xmath0 acts on the plane by reflection instead of rotation through angle @xmath1 .
when all the allowed motions are euclidean isometries , a reflection framework is _ rigid _ and otherwise it is _ flexible_. in this paper , we give a _ combinatorial _ characterization of minimally rigid , generic reflection frameworks . |
4,790 | Suppose that you have an abstract for a scientific paper: we study auto - propulsion of a interface particle , which is driven by the marangoni stress arising from a self - generated asymmetric temperature or concentration field .
we calculate separately the long - range marangoni flow @xmath0 due to the stress discontinuity at the interface and the short - range velocity field * * * * @xmath1 imposed by the no - slip condition on the particle surface ; both contributions are evaluated for a spherical floater with temperature monopole and dipole moments .
we find that the self - propulsion velocity is given by the amplitude of the source doublet which belongs to short - range contribution * * * * @xmath1 .
hydrodynamic interactions , on the other hand , are determined by the long - range marangoni flow @xmath2 ; its dipolar part results in an asymmetric advection pattern of neighbor particles , which in turn may perturb the known hexatic lattice or even favor disordered states . .
And you have already written the first three sentences of the full article: autonomous motion is an important issue in active soft matter , with possible applications ranging from energy harvesting @xcite to microfluidic transport @xcite and mixing @xcite .
recently realized microswimmers carry , as active element , heat - absorbing or catalytic parts which generate temperature or concentration gradients in the surrounding liquid . for particles dispersed in bulk phases ,
these thermodynamic forces give rise to an effective slip velocity , which in turn implies self - propulsion at a speed of the order of ten microns per second pax05,qia13 . much higher velocities can be achieved for active particles trapped at a liquid interface , where the self - generated temperature or concentration gradient induces a non - uniform interface tension and a marangoni flow . upon laser - heating one side of a centimeter - size object floating on water , oka09 observed self - propulsion at several cm / s ..
Please generate the next two sentences of the article | the mutual marangoni advection of camphor releasing gel particles results in dynamical self assembly @xcite recent theoretical studies dealt with marangoni propulsion due to a non - uniform surfactant concentration .
the resulting marangoni stress comprises a dipolar term that is proportional to the inverse distance from its source . |
4,791 | Suppose that you have an abstract for a scientific paper: we have considered the frw universe in loop quantum cosmology ( lqc ) model filled with the dark matter ( perfect fluid with negligible pressure ) and the modified chaplygin gas ( mcg ) type dark energy .
we present the hubble parameter in terms of the observable parameters @xmath0 , @xmath1 and @xmath2 with the redshift @xmath3 and the other parameters like @xmath4 , @xmath5 , @xmath6 and @xmath7 . from stern data set
( 12 points ) , we have obtained the bounds of the arbitrary parameters by minimizing the @xmath8 test .
the best - fit values of the parameters are obtained by 66% , 90% and 99% confidence levels .
next due to joint analysis with bao and cmb observations , we have also obtained the bounds of the parameters ( @xmath9 ) by fixing some other parameters @xmath7 and @xmath4 . from the best fit of distance modulus @xmath10 for our theoretical mcg model in lqc
, we concluded that our model is in agreement with the union2 sample data . .
And you have already written the first three sentences of the full article: the combinations of different observations astrophysical data continuously testing the theoretical models and the bounds of the parameters .
different observations of the sneia @xcite , large scale redshift surveys @xcite , the measurements of the cosmic microwave background ( cmb ) @xcite and wmap @xcite indicate that our universe is presently expanding with acceleration .
standard big bang cosmology with perfect fluid fails to accommodate the observational fact . in einstein s gravity ,.
Please generate the next two sentences of the article | the cosmological constant @xmath11 ( which has the equation of state @xmath12 ) is a suitable candidate which derive the acceleration , but till now there is no proof of the origin of @xmath11 .
now assume that there is some unknown matter which is responsible for this accelerating scenario which has the property that the positive energy density and sufficient negative pressure , know as dark energy @xcite . the scalar field or quintessence |
4,792 | Suppose that you have an abstract for a scientific paper: we analyze pattern - formation scenarios in the two - dimensional ( 2d ) complex ginzburg - landau ( cgl ) equation with the cubic - quintic ( cq ) nonlinearity and a cellular potential .
the equation models laser cavities with built - in gratings , which stabilize 2d patterns .
the pattern - building process is initiated by kicking a compound mode , in the form of a dipole , quadrupole , or vortex which is composed of four local peaks .
the hopping motion of the kicked mode through the cellular structure leads to the generation of various extended patterns pinned by the structure . in the ring - shaped system ,
the persisting freely moving dipole hits the stationary pattern from the opposite side , giving rise to several dynamical regimes , including periodic elastic collisions , i.e. , persistent cycles of elastic collisions between the moving and quiescent dissipative solitons , and transient regimes featuring several collisions which end up by absorption of one soliton by the other .
another noteworthy result is transformation of a strongly kicked unstable vortex into a stably moving four - peaked cluster .
pattern formation , dissipative soliton , spatial soliton , vortex , complex ginzburg - landau equation , nonlinear dynamics .
And you have already written the first three sentences of the full article: the fundamental principle behind the creation of dissipative solitons is that their stability relies upon the simultaneous balance of conservative and dissipative ingredients in the underlying system @xcite .
these are the diffraction and self - focusing nonlinearity in the conservative part of the system , and linear and nonlinear loss and gain terms in the dissipative part .
well - known physical realizations of such systems are offered by lasing @xcite and plasmonic @xcite cavities , the respective models being based on the complex ginzburg - landau ( cgl ) equations with the cubic - quintic ( cq ) set of gain and loss terms , combined with the background linear loss @xcite ..
Please generate the next two sentences of the article | this combination is well known to maintain stable localized modes @xcite .
the cgl equations constitute a generic class of dissipative pattern - formation models @xcite , which find many other applications , including bosonic condensates of quasi - particles in solid - state media @xcite , reaction - diffusion systems @xcite , and superconductivity @xcite . |
4,793 | Suppose that you have an abstract for a scientific paper: we present a new solution of the direct problem of planet transits based on transformation of double integrals to single ones . on the basis of our direct problem solution
we created the code tac - maker for rapid and interactive calculation of synthetic planet transits by numerical computations of the integrals .
the validation of our approach was made by comparison with the results of the wide - spread mandel & agol ( 2002 ) method for the cases of linear , quadratic and squared root limb - darkening laws and various combinations of model parameters .
for the first time our approach allows the use of arbitrary limb - darkening law of the host star .
this advantage together with the practically arbitrary precision of the calculations make the code a valuable tool that faces the challenges of the continuously increasing photometric precision of the ground - based and space observations .
[ firstpage ] methods : analytical methods : numerical planetary system binaries : eclipsing .
And you have already written the first three sentences of the full article: the determination of geometric parameters of extrasolar planets has an essential role in inferring their densities and hence their compositions , masses and ages .
this information leads to refinements of the models of planetary systems and yields important constraints on planet formation @xcite . during the last several years
there is a sharp rise in the detections of transiting extra - solar planets ( tep ) mainly by the wide - field photometric variability surveys : ( i ) ground - based observations as superwasp @xcite , hatnet @xcite , ogle - iii @xcite , tres @xcite , etc . ;.
Please generate the next two sentences of the article | ( ii ) space missions as _ corot _ @xcite and _ kepler _ @xcite .
the _ kepler _ mission produced a real bump of the number of exoplanet candidates , dozens of them yet confirmed ( * ? ? ? |
4,794 | Suppose that you have an abstract for a scientific paper: the wave - vector integrated dynamical spin susceptibility @xmath0 of yba@xmath1cu@xmath2o@xmath3 cuprates is considered .
@xmath4 is calculated in the superconducting state from a renormalized mean - field theory of the @xmath5@xmath6@xmath7-model , based on the slave - boson formulation . besides the well - known `` 41mev resonance '' a second , much broader peak ( ` hump ' ) appears in @xmath8 .
it is caused by particle
hole excitations across the maximum gap @xmath9 .
in contrast to the resonance , which moves to lower energies when the hole filling is reduced from optimal doping , the position of this ` hump ' at @xmath10 stays almost unchanged .
the results are in reasonable agreement with inelastic neutron - scattering experiments .
pacs numbers : 71.10.fd , 74.25.ha , 74.72.bk , 75.20.hr .
And you have already written the first three sentences of the full article: the most prominent feature in the magnetic excitation spectrum of yba@xmath1cu@xmath2o@xmath3 ( ybco ) and bi@xmath1sr@xmath1cacu@xmath1o@xmath11 ( bscco ) cuprates is the so - called `` 41mev resonance''@xcite at the antiferromagnetic ( af ) wave vector @xmath12 .
its energy @xmath13 is @xmath14mev in optimally doped samples and decreases with underdoping@xcite down to @xmath15mev .
recently the magnetic response has also been studied by averaging the neutron - scattering data over the in - plane 2d brillouin zone@xcite ..
Please generate the next two sentences of the article | the resulting local magnetic excitation spectrum @xmath16 shows the above - mentioned resonance and a second , hump - like feature at an energy @xmath17 above @xmath13 .
in contrast to @xmath13 , @xmath17 depends only weakly on the doping level . within the calculation to be presented in the following the ` hump ' |
4,795 | Suppose that you have an abstract for a scientific paper: we use numerical simulations to study a formation scenario for dwarf spheroidal galaxies in which their stellar populations are the products of the dissolution of open star clusters and stellar associations within cosmological dark matter haloes .
this paper shows that this process gives rise to objects which resemble the observed dwarf spheroidal satellites of the milky way without invoking external influences .
the presence of long - lived kinematic substructures within the stellar components of these objects affects their projected velocity dispersions .
we find that this in turn affects mass estimates based on the projected velocity dispersion profiles which may over - estimate the actual dark matter halo mass depending on the amount of substructure which is present .
our models make predictions about the detailed kinematic and photometric properties of the dsphs which can be tested using future observations .
[ firstpage ] galaxies : dwarfs galaxies : star clusters methods : n - body simulations .
And you have already written the first three sentences of the full article: dwarf spheroidal galaxies ( dsph ) galaxies are believed to be the most dark matter ( dm ) dominated stellar systems known .
they have low stellar content and are poor in , or entirely devoid of , gas .
they are widely thought of as the smallest cosmological structures containing dm in the universe @xcite and are regarded as key objects in the formation of larger galaxies . according to the @xmath0-cdm cosmological model , complex structures are formed hierarchically @xcite in the potential wells of dm haloes , having density distributions following a navarro , frenk & white ( nfw ) profile @xcite . the dsph galaxies would be formed first in small haloes , and then become involved in the mechanisms of forming larger , complex objects ..
Please generate the next two sentences of the article | the dsph galaxies are characterized by absolute magnitudes in the range @xmath1
m@xmath2 @xmath3 @xcite . |
4,796 | Suppose that you have an abstract for a scientific paper: we present the results of a radial velocity ( rv ) survey of 46 subdwarf b ( sdb ) and 23 helium - rich subdwarf o ( he - sdo ) stars .
we detected 18 ( 39% ) new sdb binary systems , but only one ( 4% ) he - sdo binary .
orbital parameters of nine sdb and sdo binaries , derived from follow - up spectroscopy , are presented .
our results are compared with evolutionary scenarios and previous observational investigations . .
And you have already written the first three sentences of the full article: in the standard picture ( e.g. ) subdwarf b ( sdb ) stars are core helium burning stars on the extended horizontal branch ( ehb ) .
they consist of a he core with a mass of @xmath00.48@xmath1 , the canonical mass for a he core flash on the first red giant branch ( rgb ) , and a thin , inert hydrogen shell .
evolutionary models of ehb stars calculated by and adopted an enhanced mass loss on the rgb , however , without specifying a particular mechanism ..
Please generate the next two sentences of the article | recent radial velocity ( rv ) surveys revealed that a large fraction of all sdb stars resides in close binaries (; ; ) .
@xcite ( @xcite , @xcite ) performed a theoretical investigation of possible close binary channels for the formation of sdbs : stable roche lobe overflow , common envelope ejection , and merging of two he core white dwarf ( wds ) . |
4,797 | Suppose that you have an abstract for a scientific paper: we consider the spectral neumann problem for the laplace operator in an acoustic waveguide @xmath0 obtained from a straight unit strip by a low box - shaped perturbation of size @xmath1 where @xmath2 is a small parameter .
we prove the existence of the length parameter @xmath3 with any @xmath4 such that the waveguide @xmath5 supports a trapped mode with an eigenvalue @xmath6 embedded into the continuous spectrum .
this eigenvalue is unique in the segment @xmath7 $ ] and is absent in the case @xmath8 the detection of this embedded eigenvalue is based on a criterion for trapped modes involving an artificial object , the augmented scattering matrix .
the main technical difficulty is caused by corner points of the perturbed wall @xmath9 and we discuss available generalizations for other piecewise smooth boundaries .
keywords : acoustic waveguide , neumann problem , embedded eigenvalues , continuous spectrum , box - shaped perturbation , asymptotics msc : 35p05 , 47a75 , 49r50 , 78a50 . .
And you have already written the first three sentences of the full article: in the union @xmath0 , fig . [ f1 ] , b and a , of the unit straight strip@xmath10 and a rectangle of length @xmath11 and a small width @xmath12@xmath13 \right\ } , \label{0}\ ] ] we consider the spectral neumann problem@xmath14 [ ptb ] newcaduna.epsc:/users/desktop/documents/google drive / articoli / articoli - in - preparazione / cardonedurantenazarov1/graphics / newcaduna__1.pdf where @xmath15 is the laplace operator , @xmath16 @xmath17 is the spectral parameter and @xmath18 is the directional derivative , @xmath19 stands for the unit outward normal defined everywhere at the boundary @xmath20 except for corner points , i.e. vertices of the rectangle ( [ 0 ] ) .
since a solution of the problem ( [ 1 ] ) , ( [ 2 ] ) may get singularities at these points , the problem ought to be reformulated as the integral identity @xcite@xmath21 where @xmath22 is the natural scalar product in the lebesgue space @xmath23 and @xmath24 stands for the sobolev space .
the symmetric bilinear form on the left - hand side of ( [ 3 ] ) is closed and positive in @xmath24 so that problem ( [ 1 ] ) , ( [ 2 ] ) is associated ( * ? ? ?.
Please generate the next two sentences of the article | * ch 10 ) with a positive self - adjoint operator @xmath25 in @xmath26 whose spectrum @xmath27 is continuous and covers the closed positive semi - axis @xmath28 the domain @xmath29 of @xmath30 of course , belongs to @xmath31 but is bigger than @xmath32 due to singularities of solutions at the corner points , see , e.g. , ( * ? ? ?
the point spectrum @xmath33 of @xmath25 can be non - empty and the main goal of our paper is to single out a particular value of the length parameter @xmath34 such that the operator @xmath25 wins an eigenvalue @xmath35 embedded into the continuous spectrum . |
4,798 | Suppose that you have an abstract for a scientific paper: starting from delay equations that model field retardation effects , we study the origin of runaway modes that appear in the solutions of the classical equations of motion involving the radiation reaction force . when retardation effects are small , we argue that the physically significant solutions belong to the so - called _ slow manifold _ of the system and we identify this invariant manifold with the attractor in the state space of the delay equation .
we demonstrate via an example that when retardation effects are no longer small , the motion could exhibit _ bifurcation _ phenomena that are not contained in the local equations of motion . .
And you have already written the first three sentences of the full article: in the treatment of the motion of _ extended _ bodies in classical field theory , the derivation of radiation reaction forces is based upon certain expansions of the retarded field potentials in powers of the retardation @xcite .
the resulting local equations of motion involve derivatives of the acceleration and generally suffer from the existence of unphysical runaway solutions . under certain model circumstances ,
we trace the origin of these problems to the expansion of the functions of the retarded arguments resulting in the replacement of the original nonlocal delay equations of motion by local higher - derivative equations that exhibit runaway solutions . in this general context.
Please generate the next two sentences of the article | , the properties of the delay equations that appear in classical field theory were first studied by l. bel @xcite .
although our approach is rather general , for the sake of concreteness we discuss physical situations involving only the gravitational interaction . |
4,799 | Suppose that you have an abstract for a scientific paper: in this work we study wave packet dynamics and @xmath0 , an oscillatory quantum motion , of heavy holes in iii - v semiconductor quantum wells in presence of a quantizing magnetic field .
it is revealed that a gaussian wave - packet describing a heavy hole diffuses asymmetrically along the circular orbit while performing cyclotron motion .
the wave packet splits into two peaks with unequal amplitudes after a certain time depending on spin - orbit coupling constant .
this unequal splitting of the wave packet is attributed to the cubic rashba interaction for heavy holes .
the difference in the peak amplitudes disappears with time . at a certain time
the two peaks diffuse almost along the entire cyclotron orbit . then tail and head of the diffused wave packet interfere and as a result a completely randomized pattern of the wave packet
is observed .
the diffusion rate of the wave packet increases with increase of the spin - orbit interaction strength .
also strong spin - orbit coupling expedite the splitting and the randomization of the wave packet .
we also study the @xmath0 in various physical observables such as position , charge current and spin angular momentum of the heavy hole .
the @xmath0 oscillations are very much sensitive to the initial wave vector of the gaussian wave packet and the strength of the rashba spin - orbit coupling . .
And you have already written the first three sentences of the full article: spin dependent transport phenomena in low - dimensional semiconductor structures have been of a lot of interest to the scientific community in recent years due to the potential applications in the highly emerging field of spintronics.@xcite intense research in this field was initiated after the proposal of spin field effect transistor by datta and das @xcite .
the principal aim of this field is to produce pure spin current and its manipulation on semiconductor nanostructure devices .
one important tool for generating pure spin current is the well known spin hall effect ( she ) ..
Please generate the next two sentences of the article | @xcite in she spin - orbit interaction ( soi ) leads to a generation of spin current from an external electric voltage . for the happening of she , the charge carriers are either electrons in the conduction band or holes in the valence band in a iii - v semiconductor such as gaas
many @xmath1-doped semiconductors such as gaas , insb , si etc show four - fold degeneracy in their valence band around the @xmath2 point . |
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