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Suppose that you have an abstract for a scientific paper: we report the first simultaneous zjhk spectroscopy on the archetypical seyfert 2 galaxy ngc 1068 covering the wavelength region 0.9 to 2.4@xmath0 m . the slit , aligned in the ns direction and centred in the optical nucleus , maps a region 300 pc in radius at sub - arcsec resolution , with a spectral resolving power of 360 km s@xmath1 . this configuration allow us to study the physical properties of the nuclear gas including that of the north side of the ionization cone , map the strong excess of continuum emission in the k - band and attributed to dust and study the variations , both in flux and profile , in the emission lines . our results show that ( 1 ) mid- to low - ionization emission lines are splitted into two components , whose relative strengths vary with the position along the slit and seem to be correlated with the jet . ( 2 ) the coronal lines are single - peaked and are detected only in the central few hundred of parsecs from the nucleus . ( 3 ) the absorption lines indicate the presence of intermediate age stellar population , which might be a signicant contributor to the continuum in the nir spectra . ( 4 ) through some simple photoionization models we find photoionization as the main mechanism powering the emitting gas . ( 5 ) calculations using stellar features point to a mass concentration inside the 100 - 200 pc of about 10@xmath2 . [ firstpage ] galaxies : active - galaxies : individual ( ngc 1068 ) - galaxies : seyfert - infrared : galaxies . And you have already written the first three sentences of the full article: near - ir spectroscopy has been playing a unique role in our understanding of the agn phenomenon for several reasons . first , it includes a wealth of emission lines and stellar absorption features not observed in the optical , which are useful for studying the physical properties of the emission gas and to determine the age and metallicity of the nuclear stellar population as , for instance , the strong co bandheads in the h and k bands ( e.g. , schreiber 1998 ; origlia , moorwood , & oliva 1993 ) . second , extinction by dust is attenuated by a factor of ten relative to that of the optical , allowing to probe depths unreachable at shorter wavelengths .. Please generate the next two sentences of the article

third , it is a transition region , where the continuum from the central source no longer dominates while the thermal continuum produced by dust and stars becomes important . in the last years , the interest for observation in this interval has increased , and thanks to the availability of cross - dispersed ( xd ) spectrographs , it is possible to study the whole 0.8 - 2.4@xmath0 m region in a single observation , avoiding the aperture and seeing effects that usually affects @xmath3 spectroscopy done in long - slit single band observations . with the above in mind , here we present the first spatially resolved xd spectroscopy covering the interval 0.8 - 2.4@xmath0 m made for ngc1068 .

Suppose that you have an abstract for a scientific paper: we study toral s parrondo games with @xmath0 players and one - dimensional spatial dependence as modified by xie et al . specifically , we use computer graphics to sketch the parrondo and anti - parrondo regions for @xmath1 . our work was motivated by a recent paper of li et al . , who applied a state space reduction method to this model , reducing the number of states from @xmath2 to @xmath3 . we show that their reduced markov chains are inconsistent with the model of xie et al . _ key words and phrases _ : markov chain , equivalence class , lumpability , dihedral group , parrondo s paradox , cooperative parrondo games . . And you have already written the first three sentences of the full article: the parrondo effect refers to a reversal in direction of some system parameter when two similar dynamics are combined . it was first described by j. m. r. parrondo in 1996 in the context of games of chance : he showed that there exist two losing games that can be combined to win . the games were originally intended as a pedagogical model of the flashing brownian ratchet .. Please generate the next two sentences of the article

early work focussed on capital - dependent ( harmer and abbott @xcite ) and history - dependent ( parrondo , harmer , and abbott @xcite ) games for a single player . multi - player games were introduced by toral @xcite , including games with spatial dependence and games with redistribution of wealth .

Suppose that you have an abstract for a scientific paper: a large arcade flare of 2 march 1993 has been investigated using x - ray observations recorded by the _ yohkoh _ and goes satellites and the _ compton gamma ray observatory_. we analyzed quasi - periodicity of the hard - x - ray ( hxr ) pulses in the flare impulsive phase and found close similarity between the quasi - periodic sequence of the pulses with that observed in another large arcade flare of 2 november 1991 . this similarity helped to explain the strong hxr pulses which were recorded at the end of the impulsive phase , as due to an inflow of dense plasma ( coming from the chromospheric evaporation ) into the acceleration volume inside the cusp . in hxr images a high flaring loop was seen with a triangular cusp structure at the top , where the electrons were efficiently accelerated . the sequence of hxr images allowed us to investigate complicated changes in the precipitation of the accelerated electrons toward the flare footpoints . we have shown that all these impulsive - phase observations can be easily explained in terms of the model of electron acceleration in oscillating magnetic traps located within the cusp structure . some soft - x - ray ( sxr ) images were available for the late decay phase . they show a long arcade of sxr loops . important information about the evolution of the flare during the slow decay phase is contained in the time variation of the temperature , @xmath0 , and emission measure , em@xmath1 . this information is the following : i ) weak heating occurs during the slow decay phase and it slowly decreases ; ii ) the decrease in the heating determines slow and smooth decrease in em ; iii ) the coupling between the heating and the amount of the hot plasma makes the flare evolve along a sequence of quasi - steady states during the slow decay phase ( qss evolution ) . . And you have already written the first three sentences of the full article: quasi - periodic variations were observed in the hard x - ray ( hxr ) emission of many flares (; see also the review of and references therein ) . in our previous papers ( ( paper i ) , @xcite ( paper ii ) ) we investigated quasi - periodic oscillations in flares with periods @xmath2 s , but in paper i we have found three flares with periods @xmath3 s. they turned out to be large arcade flares . investigation of the quasi - periodic oscillations in such large flares is very important , since their large sizes allow us to investigate the structure of the oscillation volume more comprehensively . unfortunately , appropriate observations of the x - ray oscillations in such large flares are very rare . in paper. Please generate the next two sentences of the article

iii @xcite we investigated such a large arcade flare of 2 november 1991 . its hxr light curve is shown in figure [ fig1]a .

Suppose that you have an abstract for a scientific paper: hexagonal boron nitride ( @xmath0-bn ) and graphite are structurally similar but with very different properties . their combination in graphene - based devices is now of intense research focus , and it becomes particularly important to evaluate the role played by crystalline defects on their properties . in this paper , the cathodoluminescence ( cl ) properties of hexagonal boron nitride crystallites are reported and compared to those of nanosheets mechanically exfoliated from them . first the link between the presence of structural defects and the recombination intensity of trapped excitons , the so - called @xmath1 series , is confirmed . low defective @xmath0-bn regions are further evidenced by cl spectral mapping ( hyperspectral imaging ) , allowing us to observe new features in the near - band - edge region , tentatively attributed to phonon replica of exciton recombinations . second the @xmath0-bn thickness was reduced down to six atomic layers , using mechanical exfoliation , as evidenced by atomic force microscopy . even at these low thicknesses , the luminescence remains intense and exciton recombination energies are not strongly modified with respect to the bulk , as expected from theoretical calculations indicating extremely compact excitons in @xmath0-bn . . And you have already written the first three sentences of the full article: hexagonal boron nitride ( @xmath0-bn ) has the same honeycomb lattice as graphite with two atoms per unit cell and similar lattice parameters . due to this similarity , boron nitride materials have attracted a growing interest in line with the development of low - dimensional carbon - related materials . similarly to carbon , bn materials can be synthesized either as nanotubes ( one - dimensional ( 1d ) form ) @xcite or as monolayers and/or multilayers ( two - dimensional ( 2d ) form).@xcite in the following we focus on this latter form . 2d layers of carbon , namely graphene sheets , display extraordinary electronic properties which open unanticipated routes for a new generation of electronic devices .. Please generate the next two sentences of the article

however , the electron mobility of supported graphene typically falls short of that of suspended graphene , due to detrimental effects of substrate disorder and adsorbents . @xcite facing this problem , @xmath0-bn layers are of particular interest as support or capping layers of graphene .

Suppose that you have an abstract for a scientific paper: published mid infrared spectra of transiting planets hd 209458b and hd 189733b , obtained during secondary eclipse by the infrared spectrograph ( irs ) aboard the _ spitzer space telescope _ , are predominantly featureless . in particular these flux ratio spectra do not exhibit an expected feature arising from water vapor absorption short - ward of @xmath0 . here we suggest that , in the absence of flux variability , the spectral data for hd 189733b are inconsistent with @xmath1m - photometry obtained with _ spitzer _ s infrared array camera ( irac ) , perhaps an indication of problems with the challenging reduction of the irs spectra . the irac point , along with previously published secondary eclipse photometry for hd 189733b , are in good agreement with a one - dimensional model of hd 189733b that clearly shows absorption due to water vapor in the emergent spectrum . we are not able to draw firm conclusions regarding the irs data for hd 209458b , but spectra predicted by 1d and 3d atmosphere models fit the data adequately , without adjustment of the water abundance or reliance on cloud opacity . we argue that the generally good agreement between model spectra and irs spectra of brown dwarfs with atmospheric temperatures similar to these highly irradiated planets lends confidence in the modeling procedure . . And you have already written the first three sentences of the full article: since the detection of the first extrasolar giant planet ( egp ) , 51 peg b @xcite , considerable effort has gone into both observing and modeling properties of the atmospheres of the close - in `` hot jupiter '' planets . spitzer space telescope _ now provides us a unique probe into the mid - infrared emission from these exotic atmospheres . in this letter we examine mid infrared spectra of transiting planets hd 209458b and hd 189733b , which were recently observed with _ spitzer _ s infrared spectrograph ( irs ) by @xcite and @xcite , respectively .. Please generate the next two sentences of the article

the spectra were obtained from @xmath27.5 to 14@xmath3 m around the time of secondary eclipse . the most prominent conclusion of these works is that strong absorption arising from h@xmath4o , expected short - ward of 10@xmath3 m , was not seen for either planet .

Suppose that you have an abstract for a scientific paper: we present a @xmath0 ( 100 pc ) resolution @xmath1co ( 32 ) map of the nearby intermediate stage interacting galaxy pair ngc 4038/9 ( the antennae galaxies ) obtained with the submillimeter array . we find that half the co ( 32 ) emission originates in the overlap region where most of the tidally induced star formation had been previously found in shorter wavelength images , with the rest being centered on each of the nuclei . the gross distribution is consistent with lower resolution single dish images , but we show for the first time the detailed distribution of the warm and dense molecular gas across this galaxy pair at resolutions comparable to the size of a typical giant molecular complex . while we find that 58% ( 33/57 ) of the spatially resolved giant molecular associations ( gmas ; a few @xmath2 100 pc ) are located in the overlap region , only @xmath3 spatially coincides with the optically detected star clusters , suggesting that the bulk of the co ( 32 ) emission traces the regions with very recent or near future star formation activity . the spatial distribution of the co ( 32)/co ( 10 ) integrated brightness temperature ratios mainly range between 0.3 and 0.8 , which suggests that on average the co ( 32 ) line in the antennae is not completely thermalized and similar to the average values of nearby spirals . a higher ratio is seen in both nuclei and the southern complexes in the overlap region . higher radiation field associated with intense star formation can account for the nucleus of ngc 4038 and the overlap region , but the nuclear region of ngc 4039 show relatively little star formation or agn activities and can not be easily explained . we show kinematical evidence that the high line ratio in ngc 4039 is possibly caused by gas inflow into the counter - rotating central disk . . And you have already written the first three sentences of the full article: gravitational interaction between galaxies is now considered to be one of the primary mechanisms of galaxy evolution . major mergers , composed of two or more galaxies with comparable masses , are widely believed to provide a way to form elliptical and spheroidal galaxies @xcite . furthermore , galaxy interaction is known to increase star formation activities as seen in the increasing fraction of tidally distorted morphologies in ultraluminous infrared galaxies ( ulirgs : l@xmath4 l@xmath5 , sfr @xmath6 m@xmath5 yr@xmath7 ; * ? ? ?. Please generate the next two sentences of the article

in addition , the number of merging galaxies appears to increase at high redshifts ( e.g. * ? ? ? * ) . the obvious first step in characterizing this process and the response of the cold gas and its relation to merger induced starburst activity is to observe nearby merging galaxies .

Suppose that you have an abstract for a scientific paper: the asteroseismology of red giant stars has continued to yield surprises since the onset of high - precision photometry from space - based observations . an exciting new theoretical result shows that the previously observed suppression of dipole oscillation modes in red giants can be used to detect strong magnetic fields in the stellar cores . a fundamental facet of the theory is that nearly all the mode energy leaking into the core is trapped by the magnetic greenhouse effect . this results in clear predictions for how the mode visibility changes as a star evolves up the red giant branch , and how that depends on stellar mass , spherical degree , and mode lifetime . here , we investigate the validity of these predictions with a focus on the visibility of different spherical degrees . we find that mode suppression weakens for higher degree modes with an average reduction in the quadrupole mode visibility of up to 49% for the least evolved stars in our sample , and no detectable suppression of octupole modes , in agreement with the theoretical predictions . we furthermore find evidence for the influence of increasing mode lifetimes on the measured visibilities along the red giant branch , in agreement with previous independent observations . these results support the theory that strong internal magnetic fields are responsible for the observed suppression of non - radial modes in red giants . we also find preliminary evidence that stars with suppressed dipole modes on average have slightly lower metallicity than normal stars . stars : fundamental parameters stars : oscillations stars : interiors stars : magnetic field . And you have already written the first three sentences of the full article: the asteroseismology of red giant stars has become a highlight of the corot and _ kepler _ space missions ( for general reviews see e.g. * ? ? ? * ; * ? ? ? one feature that has made these stars interesting , is the presence of non - radial oscillation modes that reveal properties of the stellar cores .. Please generate the next two sentences of the article

the non - radial modes have a mixed nature , behaving like acoustic ( or p ) modes in the envelope with pressure acting as the restoring force , and as gravity ( or g ) modes in the core region with buoyancy being the restoring force ( e.g. * ? ? ? the p- and g - mode cavities are separated by an evanescent zone , which the waves can tunnel through from either side .

Suppose that you have an abstract for a scientific paper: in our recent paper , we have obtained a model solution to the problem of radiation - inefficient accretion flows ( riafs ) in a global magnetic field ( so called , resistive riaf model ) , which is asymptotically exact in outer regions of such flows forming accretion disks . when extrapolated inwardly , the model predicts a local enhancement of the vertical poynting flux within a small radius that may be regarded as the disk inner - edge . this fact has been interpreted as the origin of power source for the astrophysical jets observationally well - known to be ejected from this type of accretion disks . since the accuracy of the solution may become rather poor in such inner regions , however , the ground of this assertion may not seem to be so firm . in the present paper , we develop a sophisticated discussion for the appearance of jet - driving circumstances , based on a much more firm ground by deriving a global solution in the same situation . although the new solution still has an approximate nature , it becomes exact in the limits not only of large radius but also of small radius . the analytic results clarify that the electrodynamic power is gathered by the poynting flux , from outer main - disk region to feed the innermost part of an accretion disk . the injected power largely exceeds the local supply of work by the fluid motion . . And you have already written the first three sentences of the full article: the series of states of accretion disks called the radiatively inefficient accretion flows ( riaf ) forms an optically - thin , under - luminous ( usually radiating at a small fraction of the eddigton luminosity of each central object ) branch in the accretion - rate vs. surface - density diagram . another separate branch exists in a more optically - thick ( i.e. , large surface - density ) domain and continues from the standard - disk series to the slim - disk series , via a thermally unstable part , as the accretion rate increases ( e.g. , @xcite ) . specifically for the riaf theories , a more detailed description can be found , e.g. , in @xcite . the main efforts to take the effects of ordered magnetic fields into account in the accretion disk theories may be divided into two classes . in one class ,. Please generate the next two sentences of the article

the presence in the disk of only a toroidal field with even polarity ( i.e. , the polarity is the same on both upper and lower sides of the equatorial plane ) is taken seriously . the resulting magnetic pressure is added to gas pressure to support the disk against the vertical component of gravity .

Suppose that you have an abstract for a scientific paper: this paper presents a new achievable rate - distortion region for the general l channel multiple descriptions problem . a well known general region for this problem is due to venkataramani , kramer and goyal ( vkg ) @xcite . their encoding scheme is an extension of the el - gamal - cover ( ec ) and zhang - berger ( zb ) coding schemes to the l channel case and includes a combinatorial number of refinement codebooks , one for each subset of the descriptions . as in zb , the scheme also allows for a single common codeword to be shared by all descriptions . this paper proposes a novel encoding technique involving ` combinatorial message sharing ' ( cms ) , where every subset of the descriptions may share a distinct common message . this introduces a combinatorial number of shared codebooks along with the refinement codebooks of @xcite . these shared codebooks provide a more flexible framework to trade - off redundancy across the messages for resilience to descriptions loss . we derive an achievable rate - distortion region for the proposed technique , and show that it subsumes the vkg region for general sources and distortion measures . we further show that cms provides a strict improvement of the achievable region for any source and distortion measures for which some 2-description subset is such that zb achieves points outside the ec region . we then show a more surprising result : cms outperforms vkg for a general class of sources and distortion measures , including scenarios where the zb and ec regions coincide for all 2-description subsets . in particular , we show that cms strictly improves on vkg , for the @xmath0channel quadratic gaussian md problem , for all @xmath1 , despite the fact that the ec region is complete for the corresponding 2-descriptions problem . consequently , the ` correlated quantization ' scheme ( an extreme special case of vkg ) , that has been proven to be optimal for several cross - sections of the @xmath0channel quadratic gaussian md problem , is strictly.... And you have already written the first three sentences of the full article: the multiple descriptions ( md ) problem was proposed in the late seventies and has been studied extensively since , yielding a series of advances , ranging from the derivation of asymptotic bounds @xcite to practical approaches for multiple descriptions quantizer design @xcite . it was originally viewed as a method to cope with channel failures , where multiple source descriptions are generated and sent over different paths . the encoder generates @xmath2 descriptions for transmission over @xmath2 available channels .. Please generate the next two sentences of the article

it is assumed that the decoder receives a subset of the descriptions perfectly and the remaining are lost , as shown in fig . [ fig : basic_md ] .

Suppose that you have an abstract for a scientific paper: we show that a droplet of a bose - einstein condensate can be dynamically stabilized in free space by rapid oscillations of interatomic interactions between attractive and repulsive through , e.g. , the feshbach resonance . energy dissipation , which is present in realistic situations , is found to play a crucial role to suppress dynamical instabilities inherent in nonlinear nonequilibrium systems . . And you have already written the first three sentences of the full article: matter - wave bright solitons stable solitary waves whose density is greater than the background one have recently been realized in a quasi one - dimensional ( 1d ) bose - einstein condensate ( bec ) @xcite . in 1d , the quantum kinetic pressure counterbalances an attractive interatomic interaction , allowing a stable bright soliton to be formed . however , in 2d or higher dimensions , bright solitons are always unstable against collapse or expansion as long as the attractive interaction is constant in time @xcite .. Please generate the next two sentences of the article

it has been demonstrated by abdullaev _ et al . _

Suppose that you have an abstract for a scientific paper: in this paper we study the coarsening dynamics of a spinor condensate quenched into an easy - axis ferromagnetic phase by a sudden change in the quadratic zeeman energy . we show that applying a spin rotation prior to changing the zeeman energy accelerates the development of local order and reduces heating . we examine the longitudinal spin ordering and the superfluid ordering of the system and show that the respective order parameter correlation functions exhibit dynamic scaling in the late time dynamics . our results also demonstrate that these two types of order grow at different rates , i.e. with different dynamic critical exponents . the spin domain area distribution is calculated and is shown to have power law scaling behavior expected from percolation theory . . And you have already written the first three sentences of the full article: a spinor bose - einstein condensate is a system that possesses both superfluid and magnetic order @xcite . experiments are able to explore transitions between phases of different magnetic order by controlling the quadratic zeeman energy ( @xmath0 ) that shifts the magnetic sublevels @xcite . such a system presents a rich playground for studies of non - equilibrium phenomena , including defect formation related to the rate that the phase transition is crossed @xcite , through to the late - time coarsening dynamics describing how the small domains produced by the quench anneal towards the equilibrium state @xcite .. Please generate the next two sentences of the article

studies have largely focused on the spin properties of the system , leaving the superfluid dynamics unexplored . we note that in binary condensates , which can be regarded as a pseudo spin-@xmath1 system , there has been work on both spin coarsening @xcite and aspects of the superfluid behavior ( e.g. analyzed via kinetic energy spectra @xcite ) .

Suppose that you have an abstract for a scientific paper: monte carlo simulations are used to investigate the tricritical point properties of a 2d spin fluid . measurements of the scaling operator distributions are employed in conjunction with a finite - size scaling analysis to locate the tricritical point and determine the directions of the relevant scaling fields and their associated tricritical exponents . the scaling operator distributions and exponents are shown to match quantitatively those of the 2d blume - capel model , confirming that both models belong to the same universality class . mean - field calculations of the tricritical point properties are also compared with the simulation measurements . epsf pacs numbers 64.60fr , 64.70.fx , 05.70.jk . And you have already written the first three sentences of the full article: for tricritical phenomena , the highest dimension in which non - classical behaviour can be observed is @xmath0 @xcite . consequently , 2d tricritical phenomena has been the subject of a large number of previous investigations , employing a wide variety of techniques , including series expansions @xcite , mean - field theory @xcite , renormalisation group ( rg ) @xcite , transfer matrix @xcite , monte carlo simulations @xcite and monte carlo rg methods @xcite . to date , however , this interest has focused almost exclusively on lattice - based spin models such as the blume - capel model or the spin-@xmath1 next - nearest - neighbour ising model . in this paper. Please generate the next two sentences of the article

, we report the first detailed simulation study of 2d tricritical behaviour in an off - lattice spin fluid model . the model we consider is a simplified representation for a liquid of two - state molecules , and has been the subject of a number of previous studies in both its classical and quantum regimes @xcite . in the present work , however , we shall consider only the classical limit , for which the configurational energy is given by : @xmath2 with @xmath3 and where @xmath4 is chosen to be a hard disk potential with diameter @xmath5 . the distance - dependent spin coupling parameter @xmath6 is assigned a square well form : @xmath7 the phase diagram of this model is expected to correspond to the situation depicted schematically in figure [ fig : pdschem ] . for high temperatures , there exists a line of ising critical points ( the so - called ` critical line ' ) separating a ferromagnetic fluid phase from a paramagnetic fluid phase .

Suppose that you have an abstract for a scientific paper: a graph is pseudo - outerplanar if each of its blocks has an embedding in the plane so that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another . in this paper , the total coloring conjecture is completely confirmed for pseudo - outerplanar graphs . in particular , it is proved that the total chromatic number of every pseudo - outerplanar graph with maximum degree @xmath0 is @xmath1 . + keywords : pseudo - outerplanar graph , total coloring , maximum degree . . And you have already written the first three sentences of the full article: a total coloring of a graph @xmath2 is an assignment of colors to the vertices and edges of @xmath2 such that every pair of adjacent / incident elements receive different colors . a @xmath3-total coloring of a graph @xmath2 is a total coloring of @xmath2 from a set of @xmath3 colors . the minimum positive integer @xmath3 for which @xmath2 has a @xmath3-total coloring , denoted by @xmath4 , is called the total chromatic number of @xmath2 .. Please generate the next two sentences of the article

it is easy to see that @xmath5 for any graph @xmath2 by looking at the color of a vertex with maximum degree and its incident edges . the next step is to look for a brooks - typed or vizing - typed upper bound on the total chromatic number in terms of maximum degree .

Suppose that you have an abstract for a scientific paper: we report an experimental study of miniband magnetoconduction in semiconducting inas / gasb superlattices . for samples with miniband widths below the longitudinal optical phonon energy we identify a new superlattice magnetophonon resonance ( slmpr ) caused by resonant scattering of electrons across the mini - brillouin zone . this new resonant feature arises directly from the superlattice dispersion and total magnetic quantisation ( energetic decoupling ) of the superlattice landau level minibands . semiconductor superlattices ( sl s ) comprise alternating layers of two or more semiconductor materials , leading to the formation of continuous energy bands in the growth direction called minibands . the reduced brillouin zone and energy band width of the sl allows measurements that probe parameter spaces which are inaccessible in bulk semiconductors . total quantisation of the superlattice energy scheme can be achieved by the application of a large magnetic field which suppresses inter - landau level miniband ( llmb ) scattering and allows the realisation of a quasi 1-dimensional or quantum box sl ( qbsl ) regime . this has led to strong interest in the sl magnetoresistance and transport characteristics @xcite . the sl miniband structure can be engineered such that in the qbsl regime optical phonon scattering is limited@xcite by using narrow minigap and miniband widths , leaving only weak acoustic - phonon processes to dissipate the electron energy . in this report we investigate magnetotransport properties of inas / gasb superlattices in the miniband transport regime . in a previous publication@xcite we investigated hot - electron magnetophonon resonance caused by the lo phonon mediated hopping between landau wannier - stark states at low temperatures . in this report we study longitudinal magnetophonon resonances caused by the resonant emission / absorption of longitudinal optical ( lo ) phonons in the miniband transport regime for a range of sl structures at high tempertures . through.... And you have already written the first three sentences of the full article: the bloch frequency ( @xmath0 ) of a biased sl is given by @xmath1 where @xmath2 is the applied electric field and @xmath3 is the superlattice period . superlattice transport at low temperatures is characterised by two regimes . at low electric fields where @xmath4 , where @xmath5 is the sl miniband width , miniband transport through extended sl states dominates . in the simple esaki - tsu miniband transport model@xcite electron drift velocity ( @xmath6 ) is described by a scattered bloch oscillator in 1-dimension , @xmath7 , where electron mobility @xmath8 , @xmath9 and @xmath10 is the scattering time .. Please generate the next two sentences of the article

the main mechanisms which contribute to @xmath10 are phonon scattering , impact ionisation and interface roughness scattering . at high electric fields however @xmath11 causing the miniband to split into localised wannier - stark - ladder ( wsl ) states@xcite and consequently miniband transport is no longer the dominant process . despite the critical role of energy relaxation processes in superlattices the magnetophonon effect@xcite has only received a small amount of attention .

Suppose that you have an abstract for a scientific paper: we calculate the production of massive kaluza - klein(kk ) modes via nucleon - nucleon gravi - bremsstrahlung in the early universe . overproduction of these states would result in early matter domination and therefore a low age for the universe so it is possible to place constraints on the number and size of large extra dimensions . the constraints are stronger than those from sn1987a - for 2 large extra dimensions and @xmath0170 mev , we show the fundamental scale must be larger than 1,000 tev . . And you have already written the first three sentences of the full article: over the past few years various authors have considered the possibility of large extra dimensions as a solution to the discrepancy between the @xmath1 tev scale of standard model physics and the apparent mass scale associated with gravitational interactions @xmath2gev@xmath3 . in these models , the standard model particles are confined to a 3 + 1 dimensional brane whilst gravity is free to inhabit all 3 + 1+n dimensions . the expression for the observed value of g in four dimensions is given by @xmath4 @xmath5 and so it is possible to obtain arbitrarily small values of the higher dimensional fundamental scale @xmath6 provided the radii @xmath7 of the higher dimensions are large enough .. Please generate the next two sentences of the article

factorisable higher dimensions ( for example higher dimensions compactified on @xmath8 or @xmath9 ) have associated with them an infinite tower of massive kk states which can be produced during high energy scattering of standard model particles on the brane , a phenomenon which may be investigated at the lhc @xmath10 . the possibility of this kk mode generation has already led to strong constraints on the size and number of higher dimensions from astro - particle physics .

Suppose that you have an abstract for a scientific paper: chandra images show symmetric , 8 kpc long , arm - like features in the x - ray halo surrounding ngc 4636 . the leading edges of these features are sharp and are accompanied by temperature increases of @xmath0% . these properties , along with their scale and symmetry , suggest that the arm - like structures are produced by nuclear outburst driven shocks . we interpret these observations as part of a cycle in which cooling gas originally fueled a nuclear outburst about @xmath1 years ago leading to shocks that reheat the cooling gas , thus preventing the accumulation of significant amounts of cooled gas in the galaxy center and temporarily starving the central agn . . And you have already written the first three sentences of the full article: ngc 4636 is one of the nearest and , at @xmath22@xmath3 , one of the most x - ray luminous `` normal '' ellipticals . ngc 4636 lies in the outskirts of the virgo cluster , 10 or 2.6 mpc on the sky to the south of m87 , for a distance to ngc 4636 of 15 mpc ( tonry et al . 2001 ) . as found for most luminous , slowly rotating ellipticals , the optical surface brightness of ngc 4636 flattens in the inner regions .. Please generate the next two sentences of the article

the central region , as seen in short exposures and with hst , has low eccentricity and is classed as an e0 . however , as noted by sandage ( 1961 ) , at low surface brightness the galaxy is flattened ( e4 ) .

Suppose that you have an abstract for a scientific paper: hybrid meson energies are calculated in the static quark limit with the dynamical quark model ( dqm ) . in the dqm , transverse gluons are represented as effective constituents with a dynamically generated mass . hybrid masses are determined within the tamm - dancoff approximation for the resulting relativistic salpeter equation . although the general features of the adiabatic potential surfaces correspond with lattice data , the results disagree on level orderings . similar problems appear to exist in all constituent glue models of hybrids . we conclude that constituent gluons do not accurately represent soft gluonic degrees of freedom . the steps necessary to correct this deficiency are discussed . . And you have already written the first three sentences of the full article: a decade of experimental signals@xcite for qcd hybrids ( in particular with @xmath0 ) has culminated in the claimed observation of three such states at brookhaven@xcite in the last year . the question of the nature of qcd hybrids has thus become topical . furthermore , lattice gauge calculations are now at the point of accurately determining light hybrid masses . in view of these developments. Please generate the next two sentences of the article

, it is of interest to compare models of strong ( low energy ) qcd with lattice data to determine their viability and to explicate and guide current experimental efforts . it is often stated that a hybrid is a hadron consisting of valence quarks and glue .

Suppose that you have an abstract for a scientific paper: we show that the null melvin map applied to a rotational isometry of global anti - de sitter space produces a spacetime with properties analogous to both the gdel and schrdinger geometries . the isometry group of this gdel - schrdinger spacetime is appropriate to provide a holographic dual for the same non - relativistic conformal theory as the ordinary schrdinger geometry , but defined on a sphere . this spacetime also possesses closed timelike curves outside a certain critical radius . we show that a holographic preferred screen for an observer at the origin sits at an interior radius , suggesting that a holographic dual description would only require the chronologically consistent region . additionally , giant graviton probe branes experience repulson - type instabilities in the acausal region , suggesting a condensation of branes will modify the pathological part of the geometry to remove the closed timelike curves . colo - hep-566 0.5 in charles max brown@xmath0 and oliver dewolfe@xmath1 0.4 in _ @xmath2 department of mathematics and physics + kentucky state university + carver hall 131 , 400 e. main st . + frankfort , ky 40601 , usa _ 0.2 in _ @xmath1 department of physics + university of colorado + 390 ucb + boulder , co 80309 , usa _ 0.5 in . And you have already written the first three sentences of the full article: geometries in general relativity can possess various pathological features , and it is of interest how string theory , as a quantum mechanical theory of gravity , might or might not remove these pathologies . curvature singularities are the most well - known problematic features , but another interesting class is closed timelike curves ( ctcs ) , which apparently enable time travel and render the usual notions of causal time evolution untenable . hawking conjectured that no geometry initially free of closed timelike curves would develop them , the so - called chronology protection conjecture @xcite ; but whether a quantum theory of gravity might remove closed timelike curves that are already classically present is another question . in a separate development , there has been considerable interest in using the ads / cft correspondence to build models of condensed matter physics ( for reviews , see @xcite ) .. Please generate the next two sentences of the article

the schrdinger spacetime , formulated in @xcite and embedded in string theory in @xcite , is of interest due to its isometry group matching the non - relativistic conformal symmetry @xcite of certain ultracold gases at unitarity , although a number of issues with the application of the geometry remain ( for a recent discussion of some aspects , see for example @xcite ) . the schrdinger spacetime may be generated from the poincar patch of anti - de sitter space ( ads ) through the so - called

Suppose that you have an abstract for a scientific paper: we have investigated the gas content of a sample of several hundred agn host galaxies at z@xmath01 and compared it with a sample of inactive galaxies , matched in bins of stellar mass and redshift . gas masses have been inferred from the dust masses , obtained by stacked herschel far - ir and sub - mm data in the goods and cosmos fields , under reasonable assumptions and metallicity scaling relations for the dust - to - gas ratio . we find that agns are on average hosted in galaxies much more gas rich than inactive galaxies . in the vast majority of stellar mass bins , the average gas content of agn hosts is higher than in inactive galaxies . the difference is up to a factor of ten higher in low stellar mass galaxies , with a significance of 6.5@xmath1 . in almost half of the agn sample the gas content is three times higher than in the control sample of inactive galaxies . our result strongly suggests that the probability of having an agn activated is simply driven by the amount of gas in the host galaxy ; this can be explained in simple terms of statistical probability of having a gas cloud falling into the gravitational potential of the black hole . the increased probability of an agn being hosted by a star - forming galaxy , identified by previous works , may be a consequence of the relationship between gas content and agn activity , found in this paper , combined with the schmidt - kennicutt law for star formation . [ firstpage ] methods : data analysis galaxies : active galaxies : ism . And you have already written the first three sentences of the full article: during the past decades several studies have revealed a connection between the mass of black holes hosted in galactic nuclei and the properties of their host galaxies ( e.g. * ? ? ? * ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

moreover , the redshift evolution of the cosmic star formation rate ( sfr ) and smbh accretion rate density are very similar @xcite . this co - evolution " has led various authors to investigate a possible connection between the presence of active galactic nuclei ( agn , which traces the smbh growth ) and the star formation properties of galaxies . a correlation was indeed observed between star formation and nuclear activity in numerous works at high agn luminosities ( e.g * ? ? ?

Suppose that you have an abstract for a scientific paper: since the unifying strasbourg - eso catalogue of galactic planetary nebulae + ( secgpn ) a large number of new discoveries have been made thanks to improved surveys and discovery techniques . the increasingly heterogeneous published population of galactic pne , that we have determined totals @xmath0 2850 pne , is becoming more difficult to study on the whole without a centralised repository . we introduce a consolidated and interactive online database with object classifications that reflect the latest multi - wavelength data and the most recent results . the extensible database , hosted by the centre de donnees astronomique de strasbourg ( cds ) , will contain a wealth of observed data for large , well - defined samples of pne including coordinates , multi - wavelength images , spectroscopy , line intensities , radial velocities and central star information . it is anticipated that the database will be publicly released early 2012 . . And you have already written the first three sentences of the full article: the database was meticulously constructed by visually inspecting images of purported pne ( sourced from major catalogues , simbad and other literature sources ) in the supercosmos halpha survey ( shs , parker et al . 2005 ) , the int photometric halpha survey ( iphas , drew et al . 2005 ) and the supercosmos sky surveys ( sss , hambly et al .. Please generate the next two sentences of the article

2001 ) . during this process both pne and obvious non - pne ( e.g. galaxies , photographic flaws , hii regions , duplicates , etc . ) were added to the database .

Suppose that you have an abstract for a scientific paper: we consider data transmission through a time - selective , correlated ( first - order markov ) rayleigh fading channel subject to an average power constraint . the channel is estimated at the receiver with a pilot signal , and the estimate is fed back to the transmitter . the estimate is used for coherent demodulation , and to adapt the data and pilot powers . we explicitly determine the optimal pilot and data power control policies in a continuous - time limit where the channel state evolves as an ornstein - uhlenbeck diffusion process , and is estimated by a kalman filter at the receiver . the optimal pilot policy switches between zero and the maximum ( peak - constrained ) value ( `` bang - bang '' control ) , and approximates the optimal discrete - time policy at low signal - to - noise ratios ( equivalently , large bandwidths ) . the switching boundary is defined in terms of the system state ( estimated channel mean and associated error variance ) , and can be explicitly computed . under the optimal policy , the transmitter conserves power by decreasing the training power when the channel is faded , thereby increasing the data rate . numerical results show a significant increase in achievable rate due to the adaptive training scheme with feedback , relative to constant ( non - adaptive ) training , which does not require feedback . the gain is more pronounced at relatively low snrs and with fast fading . results are further verified through monte carlo simulations . limited - rate feedback , gauss - markov channel , channel estimation , adaptive training , wideband channel , diffusion approximation , free boundary problems , bang - bang control , variational inequalities . . And you have already written the first three sentences of the full article: the achievable rate for a time - selective fading channel depends on what channel state information ( csi ) is available at the receiver and transmitter . namely , csi at the receiver can increase the rate by allowing coherent detection , and csi at the transmitter allows adaptive rate and power control ( e.g. , see ( * ? ? ? 6 ) ) . obtaining csi at the receiver and/or transmitter requires overhead in the form of a pilot signal and feedback .. Please generate the next two sentences of the article

we consider a correlated time - selective flat rayleigh fading channel , which is unknown at both the receiver and transmitter . the transmitter divides its power between a pilot , used to estimate the channel at the receiver , and the data .

Suppose that you have an abstract for a scientific paper: we investigate the feasibility of reconstructing the radial intensity profile of extended stellar sources by inverting their microlensed light curves . using a simple , linear , limb darkening law as an illustration , we show that the intensity profile can be accurately determined , at least over the outer part of the stellar disc , with realistic light curve sampling and photometric errors . the principal requirement is that the impact parameter of the lens be less than or equal to the stellar radius . thus , the analysis of microlensing events provides a powerful method for testing stellar atmosphere models . gravitational lensing , stars : atmospheres . And you have already written the first three sentences of the full article: in recent years a number of authors have investigated the microlensing of extended stellar sources . ( hereafter snw95 ) have shown that the light curves of extended sources can exhibit a significant chromatic dependence , essentially because limb darkening renders the effective radius of the star a function of wavelength . thus , in addition to improving constraints on the lens parameters , modelling the microlensing of extended sources provides a powerful tool for gravitational imaging stellar surfaces . in this contribution. Please generate the next two sentences of the article

we describe how microlensing light curves of extended sources may be used as a test of stellar atmosphere models . we generate artificial light curves , assuming a particular model atmosphere , and use the backus - gilbert numerical inversion method to estimate the radial stellar intensity profile from the observed light curves .

Suppose that you have an abstract for a scientific paper: we give an explicit and simple construction of the incidence graph for the integral cohomology of _ real _ grassmann manifold @xmath0 in terms of the young diagrams filled with the letter @xmath1 in checkered pattern . it turns out that there are two types of graphs , one for the trivial coefficients and other for the twisted coefficients , and they compute the homology groups of the orientable and non - orientable cases of @xmath0 via the poincar - verdier duality . we also give an explicit formula of the poincar polynomial for @xmath0 and show that the poincar polynomial is also related to the number of points on @xmath0 over a finite field @xmath2 with @xmath1 being a power of prime which is also used in the young diagrams . partially supported by nsf grant dms-1108813 . ] . And you have already written the first three sentences of the full article: the grassmann manifolds ( sometimes , referred to as simply the grassmannian ) which parametrize vector subspaces of fixed dimensions of a given vector space are fundamental objects , and appear in many areas of mathematics . their study dates back to plcker who , in the 19th century , considered the case of vector subspaces of dimension @xmath3 of a space of dimension @xmath4 . in this note we study the integral cohomology of _ real _ grassmann manifolds .. Please generate the next two sentences of the article

the cohomology of _ complex _ grassmann manifolds is well - known but the real case poses additional challenges . we give an explicit description of the betti numbers and the incidence graph which leads to the integral cohomology .

Suppose that you have an abstract for a scientific paper: the long - standing problem of dramatic structure change near @xmath0 in ge isotopes is investigated by means of large - scale shell model calculation . the analysis of simulated calculations suggests a possible understanding of the problem in terms of rapid increase in the @xmath1 proton and neutron occupation . the observed variation in excitation of the second @xmath2 state in @xmath3ge appears to correlate closely with the @xmath1 occupations induced by strong proton - neutron interactions . the enhancement of the @xmath1 occupancies is probably due to correlations in the @xmath4 shell . , , , @xmath3ge , structure change , @xmath5 , second @xmath2 energy , shell model 27.50.+e , 23.20.lv , 21.10.re , 21.60.cs . And you have already written the first three sentences of the full article: experimental information on nuclei far from stability constitutes a challenging test for the applicability of nuclear models and serves as a guidance for improvement of the models . radioactive ion beam facility plays a vital role in gathering such information . in a recent experiment at the oak ridge hribf , padilla - rodal _ et al . _ measured @xmath6 in @xmath7ge @xcite , which provides a complete view of @xmath8 data extended to the neutron - rich region , reaching the major shell closure at @xmath9 .. Please generate the next two sentences of the article

it was also demonstrated @xcite that the observed @xmath5 values in @xmath7ge can be reproduced by using a shell model with the model space @xmath10 for both protons and neutrons . hence this work showed that the structure change in the exotic mass region could be microscopically studied by means of large - scale shell model calculation , which has become available only recently .

Suppose that you have an abstract for a scientific paper: we present the results of colour - selection of candidate high redshift ( 2.6 @xmath0 z @xmath0 3.9 ) galaxies within the hubble deep field based on the ly - break at 912 . we find 8 such objects in the region , giving a comoving number density comparable to that of nearby bright galaxies ( for a flat q@xmath1=0.5 , h@xmath1=100 kms@xmath2mpc@xmath2 universe ) . we provide basic data on the properties of these objects , and show that despite their absolute magnitude being significantly brighter than l@xmath3 ( typically m@xmath4 = -22 ) , they are generally smaller than nearby galaxies . furthermore , visual inspection of their images shows that they are all highly disturbed systems , with multiple nuclei , tails and plumes , suggesting that they are undergoing merging processes similar to most nearby starburst galaxies . theoretical models suggest that galaxies form by accumulation of numerous subcomponents , and we suggest that we are seeing this process underway in these objects . it is thus possible that the epoch of galaxy formation might have been discovered . galaxies : formation - galaxies : primeval - galaxies : interactions - galaxies : starburst . And you have already written the first three sentences of the full article: the discovery of very high redshift and primeval galaxies has been a ` holy - grail ' for cosmologists for many years @xcite . amongst numerous approaches to finding forming galaxies and understanding their subsequent evolution , faint imaging surveys , for both number counts @xcite and to find individual interesting objects selected by various colour criteria ( e.g. multicolour searches for high redshift quasars ) are well established techniques @xcite . among the more interesting results to emerge from these studies has been the discovery , at blue wavelengths , of many more galaxies than standard ` no evolution ' models predict the so called ` faint blue excess ' @xcite . however , various spectroscopic ( glazebrook et al . , lilly et al . ) and hst - based morphological studies ( driver et al . , glazebrook et al . ) have shown this excess population to reside at only intermediate redshifts ( @xmath5 ) , and to consist of dwarf late - type spiral / irregular galaxies which undergo substantial luminosity and colour evolution between @xmath6 and the present time .. Please generate the next two sentences of the article

on the other hand , these same studies have shown the redder early - type ( e / s0abc ) population to have undergone little if any evolution in this period . the formation epoch of these galaxies , therefore , must lie at considerably greater redshift , even if the nature of the faint blue excess has now been determined .

Suppose that you have an abstract for a scientific paper: we discuss the phenomenon of spontaneous self compactification in a model colloidal system , proposed in a recent work on dna mediated self assembly . we focus on the effect of thermal fluctuations on the stability of membrane - like self assembled phase with in - plane square order . surprisingly , the fluctuations are shown to enhance the stability of this quasi2d phase with respect to transition to alternative 3d structures . * pacs numbers : 64.70.kb , 64.70.nd * . And you have already written the first three sentences of the full article: effects of physical dimensionality on crystallization are among the most important problems in condensed matter physics . as was established by landau and pierls @xcite , the long - range crystalline order in 2d is universally destroyed by thermal fluctuations . the problem has been revisited in 1970s by kosterlitz and thouless @xcite-@xcite , who have shown that crystals do exist in 2d , within a new topological definition . nevertheless , their melting temperature is believed to be always lower than in 3d systems ( assuming the same interparticle potential ) .. Please generate the next two sentences of the article

one of the manifestations of this effect is the phenomenon of surface melting : a microscopic liquid layer normally appear at the interface of a crystalline solid well below its bulk melting temperature . in this paper , we describe a remarkable example in which the thermal fluctuation _ stabilize _ a 2d crystalline solid , embedded in 3d physical space , with respect to transition to an alternative 3d structure . the model system discussed below has been introduced in the recent work by one of us @xcite , in order to describe dna assisted self

Suppose that you have an abstract for a scientific paper: we study the non - equilibrium relaxation kinetics of interacting magnetic flux lines in disordered type - ii superconductors at low temperatures and low magnetic fields by means of a three - dimensional elastic line model and monte carlo simulations . investigating the vortex density and height autocorrelation functions as well as the flux line mean - square displacement , we observe the emergence of glassy dynamics , caused by the competing effects of vortex pinning due to point defects and long - range repulsive interactions between the flux lines . our systematic numerical study allows us to carefully disentangle the associated different relaxation mechanisms , and to assess their relative impact on the kinetics of dilute vortex matter at low temperatures . . And you have already written the first three sentences of the full article: in this paper , we report an investigation of the non - equilibrium relaxation kinetics in the vortex glass phase of layered disordered type - ii superconductors . since struik s original investigations,@xcite many glassy systems have been found to exhibit physical aging phenomena , which have attracted considerable interest during the past decades.@xcite recently , it has been realized that glass - like relaxation and aging can in fact be found in many other systems.@xcite glassy materials feature extremely long relaxation times which facilitates the investigation of aging phenomena in real as well as in numerical experiments . our definition of physical aging here entails two fundamental properties : first , we require relaxation towards equilibrium to be very slow , typically characterized by a power law decay , observable in a large accessible time window @xmath0 ; here @xmath1 denotes an appropriate short microscopic time scale , whereas @xmath2 is the much larger equilibration time for the macroscopic system under consideration . second , a non - equilibrium initial state is prepared such that the kinetics is rendered non - stationary ; thus , time - translation invariance is broken , and two - time response and correlation functions depend on both times @xmath3 and @xmath4 independently , not just on the elapsed time difference @xmath5 . in this context , @xmath3 is often referred to as waiting time , and @xmath6 as observation time .. Please generate the next two sentences of the article

in addition , in the limit @xmath7 many aging systems are characterized by the emergence of dynamical scaling behavior.@xcite the physics of interacting vortex lines in disordered type - ii superconductors is remarkably complex and has been a major research focus in condensed matter physics in the past two decades . it has been established that the temperature vs. magnetic - field phase diagram displays a variety of distinct phases.@xcite a thorough understanding of the equilibrium and transport properties of vortex matter is clearly required to render these materials amenable to optimization with respect to dissipative losses , especially in ( desirable ) high - field applications .

Suppose that you have an abstract for a scientific paper: we study the relationship between the local density of states ( ldos ) and the conductance variation @xmath0 in scanning - gate - microscopy experiments on mesoscopic structures as a charged tip scans above the sample surface . we present an analytical model showing that in the linear - response regime the conductance shift @xmath0 is proportional to the hilbert transform of the ldos and hence a generalized kramers - kronig relation holds between ldos and @xmath0 . we analyze the physical conditions for the validity of this relationship both for one - dimensional and two - dimensional systems when several channels contribute to the transport . we focus on realistic aharonov - bohm rings including a random distribution of impurities and analyze the ldos-@xmath0 correspondence by means of exact numerical simulations , when localized states or semi - classical orbits characterize the wavefunction of the system . . And you have already written the first three sentences of the full article: scanning probe microscopy ( spm ) is nowadays an essential technique to measure local electronic properties of mesoscopic structures . scanning tunnel microscopy ( stm ) , consisting in probing the sample surface with a metallic tip , is the most popular among all spm techniques . stm experiments have first enabled the detection of standing wave pattern in confined surface electron systems such as quantum corrals.@xcite the physical interpretation of such images is immediate since they derive from direct tunneling between the surface electrons and the tip .. Please generate the next two sentences of the article

hence , stm images represent the density of states of the system at a given position of the scanning probe.@xcite later on , another spm technique , named scanning gate microscopy ( sgm ) , has been introduced in order to obtain similar information for structures buried under an insulating layer . this technique consists in scanning a biased tip over the sample surface .

Suppose that you have an abstract for a scientific paper: kepler-22b is the first transiting planet to have been detected in the habitable - zone of its host star . at 2.4@xmath0 , kepler-22b is too large to be considered an earth - analog , but should the planet host a moon large enough to maintain an atmosphere , then the kepler-22 system may yet possess a telluric world . aside from being within the habitable - zone , the target is attractive due to the availability of previously measured precise radial velocities and low intrinsic photometric noise , which has also enabled asteroseismology studies of the star . for these reasons , kepler-22b was selected as a target - of - opportunity by the `` hunt for exomoons with kepler '' ( hek ) project . in this work , we conduct a photodynamical search for an exomoon around kepler-22b leveraging the transits , radial velocities and asteroseismology plus several new tools developed by the hek project to improve exomoon searches . we find no evidence for an exomoon around the planet and exclude moons of mass @xmath1@xmath2 to 95% confidence . by signal injection and blind retrieval , we demonstrate that an earth - like moon is easily detected for this planet even when the time - correlated noise of the data set is taken into account . we provide updated parameters for the planet kepler-22b including a revised mass of @xmath3@xmath2 to 95% confidence and an eccentricity of @xmath4 by exploiting single - body asterodensity profiling ( sap ) . finally , we show that kepler-22b has a @xmath5% probability of being within the empirical habitable - zone but a @xmath6% probability of being within the conservative habitable - zone . . And you have already written the first three sentences of the full article: kepler-22b is a recently validated extrasolar planet detected by the _ kepler mission _ via the transit technique ( @xcite , b12 hereafter ) . orbiting a star with 75% of solar luminosity once every 290days , kepler-22b receives an insolation just 10 - 15% greater than that received by the earth and thus was claimed to be the first transiting planet discovered to orbit within the so - called habitable - zone of its parent sun ( b12 ) . although habitable - zone exoplanets have been detected by radial velocity surveys @xcite , kepler-22b is a fascinating object thanks to the plethora of follow - up opportunities afforded by transiting planets @xcite .. Please generate the next two sentences of the article

this excitement is evident in the preceding astronomical literature with speculation about the planet s habitability @xcite , a presently undetected exomoon s habitability @xcite and considerable efforts to redefine the so - called habitable - zone ( e.g. @xcite ) . despite the excitement generated by the pioneering discovery of kepler-22b by b12 , the planet can not be considered `` earth - like '' given its radius of 2.4@xmath0 .

Suppose that you have an abstract for a scientific paper: we investigate the finite frequency noise of a quantum point contact at filling factor @xmath0 using a weakly coupled resonant lc circuit as a detector . we show how one could spectroscopically address the fractional charged excitations inspecting separately their charge and scaling dimensions . we thus compare the behaviour of the pfaffian and the anti - pfaffian non - abelian edge states models in order to give possible experimental signatures to identify the appropriate model for this fractional quantum hall states . finally we investigate how the temperature of the lc resonant circuit can be used in order to enhance the sensibility of the measurement scheme . . And you have already written the first three sentences of the full article: among the extremely remarkable properties of the fractional quantum hall ( fqh ) effect @xcite a major role is played by the emergence of anyonic excitations carrying fractional charge and statistics @xcite . in particular , quasiparticle ( qp ) excitations for states belonging to the laughlin @xcite and jain sequence @xcite are predicted to have abelian exchange statistics . more intriguingly , some of the proposed models for the filling factor @xmath0 @xcite predict the emergence of excitations with charge @xmath1 , and multiples , with possible non - abelian properties @xcite . these predictions paved the way to possible applications of non - abelian anyons in fault - tolerant topological quantum computation ( see @xcite and references therein ) .. Please generate the next two sentences of the article

unfortunately , as far as we know , a direct confirmation of fractional statistics is still lacking even if different proposal are reported in the literature @xcite . so far , evidence of the fractional statistics is indirect , essentially based on the evidence of the existence of fractional charges @xcite .

Suppose that you have an abstract for a scientific paper: we analyze the temperature dependence of the entropy of the spin-1/2 heisenberg model on the three - dimensional simple - cubic lattice , for both the case of antiferromagnetic and ferromagnetic nearest neighbor exchange interactions . using optimized extended ensemble quantum monte carlo simulations , we extract the entropy at the critical temperature for magnetic order from a finite - size scaling analysis . for the antiferromagnetic case , the critical entropy density equals @xmath0 , whereas for the ferromagnet , a larger value of @xmath1 is obtained . we compare our simulation results to estimates put forward recently in studies assessing means of realizing the antiferromagnetic nel state in ultra - cold fermion gases in optical lattices . . And you have already written the first three sentences of the full article: ultra - cold atom gases provide a unique opportunity to study basic models of strongly interacting many - body systems in a highly controlled experimental framework @xcite . after the pioneering realization of the superfluid - to - mott insulator transition of ultra - cold bosonic atoms @xcite , recently different groups reported the realization of a mott - insulating state also for ultra - cold @xmath2k fermionic atoms on three - dimensional simple - cubic lattices @xcite . a next major step would be the realization and identification of a low - temperature antiferromagnetically ordered nel state in such systems .. Please generate the next two sentences of the article

in fact , various recent studies explored the prospects of realizing the antiferromagnetic nel state in an ultra - cold gas of fermionic atoms confined to an optical lattice @xcite . a quantity that is important in assessing the relevant temperature scale is the upper bound on the entropy allowed in order to transfer the atoms into the antiferromagnetically ordered state . for a three - dimensional fermionic hubbard model on a simple - cubic lattice at half - filling , estimates of the entropy @xmath3 as a function of temperature , as well as the ratio @xmath4 between the onsite repulsion @xmath5 and the hopping amplitude @xmath6 , were obtained within a single - site dynamical mean - field theory ( dmft ) approach @xcite . as reported in ref .

Suppose that you have an abstract for a scientific paper: we investigate the dynamics of peeling of an adhesive tape subjected to a constant pull speed . we derive the equations of motion for the angular speed of the roller tape , the peel angle and the pull force used in earlier investigations using a lagrangian . due to the constraint between the pull force , peel angle and the peel force , it falls into the category of differential - algebraic equations requiring an appropriate algorithm for its numerical solution . using such a scheme , we show that stick - slip jumps emerge in a purely dynamical manner . our detailed numerical study shows that these set of equations exhibit rich dynamics hitherto not reported . in particular , our analysis shows that inertia has considerable influence on the nature of the dynamics . following studies in the portevin - le chatelier effect , we suggest a phenomenological peel force function which includes the influence of the pull speed . this reproduces the decreasing nature of the rupture force with the pull speed observed in experiments . this rich dynamics is made transparent by using a set of approximations valid in different regimes of the parameter space . the approximate solutions capture major features of the exact numerical solutions and also produce reasonably accurate values for the various quantities of interest . . And you have already written the first three sentences of the full article: peeling is a kind of fracture that has been studied experimentally in the context of adhesion and is a technologically important subject . experimental studies on peeling of an adhesive tape mounted on a cylindrical roll are usually in constant pull speed condition @xcite . more recently , constant load experiments have also been reported @xcite .. Please generate the next two sentences of the article

early studies by bikermann @xcite , kaeble @xcite have attempted to explain the results by considering the system as a fully elastic object . this is clearly inadequate as it ignores the viscoelastic nature of the glue at the contact surface and therefore can not capture many important features of the dynamics .

Suppose that you have an abstract for a scientific paper: this paper considers the problem of simultaneously communicating two messages , a high - security message and a low - security message , to a legitimate receiver , referred to as the security embedding problem . an information - theoretic formulation of the problem is presented . a coding scheme that combines rate splitting , superposition coding , nested binning and channel prefixing is considered and is shown to achieve the secrecy capacity region of the channel in several scenarios . specifying these results to both scalar and independent parallel gaussian channels ( under an average individual per - subchannel power constraint ) , it is shown that the high - security message can be embedded into the low - security message at full rate ( as if the low - security message does not exist ) without incurring any loss on the overall rate of communication ( as if both messages are low - security messages ) . extensions to the wiretap channel ii setting of ozarow and wyner are also considered , where it is shown that perfect " security embedding can be achieved by an encoder that uses a two - level coset code . . And you have already written the first three sentences of the full article: physical layer security has been a very active area of research in information theory . see @xcite and @xcite for overviews of recent progress in this field . a basic model of physical layer security is a wiretap / broadcast channel @xcite with two receivers , a legitimate receiver and an eavesdropper .. Please generate the next two sentences of the article

both the legitimate receiver and the eavesdropper channels are assumed to be _ known _ at the transmitter . by exploring the ( statistical ) difference between the legitimate receiver channel and the eavesdropper channel , one may design coding schemes that can deliver a message reliably to the legitimate receiver while keeping it asymptotically perfectly secret from the eavesdropper . while assuming the transmitter s knowledge of the legitimate receiver channel might be reasonable ( particularly when a feedback link is available ) , assuming that the transmitter knows the eavesdropper channel is _ unrealistic _ in most scenarios . this is mainly because the eavesdropper is an _

Suppose that you have an abstract for a scientific paper: an optical spectropolarimetric study has shown that the detectability of polarised broad h@xmath0 in seyfert 2 galaxies is correlated to the iras @xmath1 flux ratio where only those seyfert 2s with warm " iras colours show polarised broad line emission . it was suggested that those seyfert 2s with cool " iras colours have highly inclined tori which obscure the broad line scattering screen . i present here hard x - ray observations inconsistent with this picture showing that the derived column densities of warm and cool seyfert 2 galaxies are statistically the same . i classify the bright galaxy sample to produce a non - seyfert comparison . the analysis of the properties of these galaxies with the seyfert 2s suggest that the iras @xmath1 flux ratio is consistent with implying the relative strength of galactic to seyfert emission . i show that this new picture can account for the absence of polarised broad h@xmath0 in the cool seyfert 2s . # 1 2_2h@xmath2 2_h_2@xmath3 # 1.#2 # 1#2 # 1.#2 # 1#2 # 1.#2 # 1#2 # 1h#2m#3s # 1^h#2^m#3^s # 1d#2m#3s # 1#2#3 # 1h#2m#3.#4s ( ra ) # 1^h#2^m#3#4 # 1d#2m#3.#4s ( dec ) # 1#2#3#4 # 1.#2 # 1^m -0.55em.0.22em#2 = = = = = = = = # 1 # 1 # 1 # 1 @mathgroup@group @mathgroup@normal@groupeurmn @mathgroup@bold@groupeurbn @mathgroup@group @mathgroup@normal@groupmsamn @mathgroup@bold@groupmsamn = `` 019 = ' ' 016 = `` 040 = ' ' 336 = " 33e = = = = = = = = # 1 # 1 # 1 # 1 = = = = = = = = [ firstpage ] polarization - galaxies : active - infrared : galaxies - galaxies : seyfert . And you have already written the first three sentences of the full article: the unified model for seyfert galaxies proposes that all types of seyfert galaxy are fundamentally the same , however , the presence of an optically thick structure obscures the broad line region ( blr ) in many systems . in this paper it is assumed that , in the majority of seyfert 2s , this structure is a dusty molecular torus " although other galactic structures ( e.g. dust lanes / starbursts , see malkan , gorjian and tam , 1998 ) can perform the same role . in this scenario the classification of a seyfert 1 or seyfert 2 galaxy ( seyfert 1broad permitted lines , seyfert 2narrow permitted lines ) depends on the inclination of the torus to the line of sight ( antonucci , 1993 ) .. Please generate the next two sentences of the article

probably the most convincing evidence for this model comes from optical spectropolarimetry . using this technique , the scattered emission from the blr of many seyfert 2s is revealed in the form of broad lines in the polarised flux ( e.g. antonucci and miller , 1985 , young et al , 1996 , heisler , lumsden and bailey , 1997 ) . in this unified picture

Suppose that you have an abstract for a scientific paper: in this paper we introduce an algebraic form of the dispersion relation for a non ideal inhomogeneous dusty plasma in order to improve drastically the calculation of the drift instability growth rate . this method makes use of the multipole approximation of the z dispersion function , previously published , and valid for the entire range . a careful analysis of the solutions spectra of this kind of polynomial equation permits us to calculate easily the growth rate of the drift instability for the ion - dust and dust acoustic mode . the value of the parallel to magnetic field wavelength for which the instability reaches the maximal value is carefully localized and discussed . the unstable dust - ion and dust acoustic mode are discriminated and analyzed in function of the density gradient , te / ti - ratio , and dust grain radius . . And you have already written the first three sentences of the full article: plasma inhomogeneities across the magnetic field in the presence of finite - size charged grains causes a wide class of instabilities of an inhomogeneous dusty plasma called gradient instabilities . such instabilities can be studied in the approximation on magnetic field where we have parallel straight field lines in order to simplify our treatment . we look for instabilities in the very low frequency regime where a new spectrum instabilities and waves appear , induced by the dust collective dynamics : dust - acoustic - waves ( daws ) , dust - ion - acoustic - waves ( diaws ) , etc .. Please generate the next two sentences of the article

the frequency of daws are around 10 hz as determined in the laboratory and lower in astrophysical plasmas [ 1,2 ] . in the case that grains are in the micron range we expect a non - ideal behavior due to the fact that the particulate are highly charged and intermolecular forces could play certainly an important role . in order to discuss this problem we compare the ideal properties with the simple hard - core model and in a next work we will use a better model by means of of the square - well model and the pad rational approximant to the equation of state [ 3 ] for hard - sphere gas , that in our knowledge is more realistic as the simple application of the van der waals equation of state [ 4 ] . in this paper

Suppose that you have an abstract for a scientific paper: when evaluating the efficacy of social programs and medical treatments using randomized experiments , the estimated overall average causal effect alone is often of limited value and the researchers must investigate when the treatments do and do not work . indeed , the estimation of treatment effect heterogeneity plays an essential role in ( 1 ) selecting the most effective treatment from a large number of available treatments , ( 2 ) ascertaining subpopulations for which a treatment is effective or harmful , ( 3 ) designing individualized optimal treatment regimes , ( 4 ) testing for the existence or lack of heterogeneous treatment effects , and ( 5 ) generalizing causal effect estimates obtained from an experimental sample to a target population . in this paper , we formulate the estimation of heterogeneous treatment effects as a variable selection problem . we propose a method that adapts the support vector machine classifier by placing separate sparsity constraints over the pre - treatment parameters and causal heterogeneity parameters of interest . the proposed method is motivated by and applied to two well - known randomized evaluation studies in the social sciences . our method selects the most effective voter mobilization strategies from a large number of alternative strategies , and it also identifies the characteristics of workers who greatly benefit from ( or are negatively affected by ) a job training program . in our simulation studies , we find that the proposed method often outperforms some commonly used alternatives . . And you have already written the first three sentences of the full article: while the average treatment effect can be easily estimated without bias in randomized experiments , treatment effect heterogeneity plays an essential role in evaluating the efficacy of social programs and medical treatments . we define treatment effect heterogeneity as the degree to which different treatments have differential causal effects on each unit . for example , ascertaining subpopulations for which a treatment is most beneficial ( or harmful ) is an important goal of many clinical trials . however , the most commonly used method , subgroup analysis , is often inappropriate and remains one of the most debated practices in the medical research community [ e.g. , @xcite ] .. Please generate the next two sentences of the article

estimation of treatment effect heterogeneity is also important when ( 1 ) selecting the most effective treatment among a large number of available treatments , ( 2 ) designing optimal treatment regimes for each individual or a group of individuals [ e.g. , @xcite ] , ( 3 ) testing the existence or lack of heterogeneous treatment effects [ e.g. , @xcite ] , and ( 4 ) generalizing causal effect estimates obtained from an experimental sample to a target population [ e.g. , @xcite ] . in all of these cases , the researchers must infer how treatment effects vary across individual units and/or how causal effects differ across various treatments . two well - known randomized evaluation studies in the social sciences serve as the motivating applications of this paper .

Suppose that you have an abstract for a scientific paper: three epochs of high resolution spectra of the star show that it is a short period ( @xmath03.4 day ) spectroscopic binary of two nearly identical stars . surprisingly , the two stars , though differing in effective temperature by only @xmath0250 k and having a mass ratio of 0.91 , show very different li line equivalent widths . a li 6707 line is only detected from the primary star , and it is weak . this star is therefore likely to be older than 1 gyr . if so , the large amount of hot circumbinary dust must be from a very large and recent , but very late evolutionarily , collision of planetesimals . . And you have already written the first three sentences of the full article: debris disks older than @xmath010 myr containing dust at temperatures @xmath1100 k are extremely rare @xcite . when warm dust does appear , it is likely to be from a stochastic event , perhaps akin to our own solar system s `` late heavy bombardment , '' at about 600 myr after formation . late episodes of dust production may signal the presence of a planetary system undergoing architectural reconfiguration @xcite .. Please generate the next two sentences of the article

bd+20 307 is one of the few examples of a non - young star with hot debris @xcite . it has a ring of dust at @xmath00.5 au @xcite . in order to understand the implications of the large amount of close - in dust ,

Suppose that you have an abstract for a scientific paper: we study quasinormal modes of black holes in lovelock gravity . we formulate the wkb method adapted to lovelock gravity for the calculation of quasinormal frequencies ( qnfs ) . as a demonstration , we calculate various qnfs of lovelock black holes in seven and eight dimensions . we find that the qnfs show remarkable features depending on the coefficients of the lovelock terms , the species of perturbations , and spacetime dimensions . in the case of the scalar field , when we increase the coefficient of the third order lovelock term , the real part of qnfs increases , but the decay rate becomes small irrespective of the mass of the black hole . for small black holes , the decay rate ceases to depend on the gauss - bonnet term . in the case of tensor type perturbations of the metric field , the tendency of the real part of qnfs is opposite to that of the scalar field . the qnfs of vector type perturbations of the metric show no particular behavior . the behavior of qnfs of the scalar type perturbations of the metric field is similar to the vector type . however , available data are rather sparse , which indicates that the wkb method is not applicable to many models for this sector . . And you have already written the first three sentences of the full article: according to the large extra - dimension scenario , there exists a chance for higher dimensional black holes to be created at the lhc @xcite . hence , the higher dimensional black holes have been intensively investigated . it should be noted that the einstein theory of gravity is not the most general one in higher dimensions . in four dimensions ,. Please generate the next two sentences of the article

the einstein gravity can be deduced by assuming the general coordinate covariance and the absence of higher derivative terms larger than the second order in the lagrangian . in higher dimensions , however , the same assumptions lead to lovelock theory of gravity @xcite . in addition to this mathematical motivation , we have a physical motivation to consider lovelock gravity .

Suppose that you have an abstract for a scientific paper: an algorithm for computing eigenvalues and eigenfunctions of the angular spheroidal wave equation , based on a known but scarcely used method , is developed . by requiring the regularity of the wave function , represented by its series expansion , the eigenvalues appear as the zeros of a one variable function easily computable . the iterative extended newton method is suggested as especially suitable for determining those zeros . the computation of the eigenfunctions is then immediate . the usefulness of the method , applicable also in the case of complex values of the prolateness " parameter , is illustrated by comparing its results with those of procedures used by other authors . msc [ 2010 ] 33e10 ( primary ) 33f05 , 34l16 , 65d20 ( secondary ) pacs 02.30.hq 02.30.gp 03.65.ge . And you have already written the first three sentences of the full article: the usefulness of spheroidal functions in many branches of physics , like quantum mechanics , general relativity , signal processing , etc . , is well known and it does not need to be stressed . due to that usefulness , the description of the spheroidal equation and of the main properties of its solutions deserves a chapter in handbooks of special functions like that by abramowitz and stegun ( * ? ? ? 21 ) , the best known one , or the _ nist digital library of mathematical functions _. Please generate the next two sentences of the article

30 ) , the most recent one . a review of the procedures used in the past century for obtaining the eigenvalues and eigenfunctions of the spheroidal wave equation can be found in a paper by li _ @xcite , where also an algorithm , implemented with the software package ` mathematica ` , is provided . in the present century , articles dealing with the solutions of the angular spheroidal wave equation have continued appearing . without aiming to be exhaustive ,

Suppose that you have an abstract for a scientific paper: the addition of metals to any gas can significantly alter its evolution by increasing the rate of radiative cooling . in star - forming environments , enhanced cooling can potentially lead to fragmentation and the formation of low - mass stars , where metal - free gas - clouds have been shown not to fragment . adding metal cooling to numerical simulations has traditionally required a choice between speed and accuracy . we introduce a method that uses the sophisticated chemical network of the photoionization software , cloudy , to include radiative cooling from a complete set of metals up to atomic number 30 ( zn ) that can be used with large - scale three - dimensional hydrodynamic simulations . our method is valid over an extremely large temperature range ( 10 k @xmath0 t @xmath0 10@xmath1 k ) , up to hydrogen number densities of 10@xmath2 @xmath3 . at this density , a sphere of 1 m@xmath4 has a radius of roughly 40 au . we implement our method in the adaptive mesh refinement ( amr ) hydrodynamic / n - body code , enzo . using cooling rates generated with this method , we study the physical conditions that led to the transition from population iii to population ii star formation . while c , o , fe , and si have been previously shown to make the strongest contribution to the cooling in low - metallicity gas , we find that up to 40% of the metal cooling comes from fine - structure emission by s , when solar abundance patterns are present . at metallicities , z @xmath5 10@xmath6 z@xmath4 , regions of density and temperature exist where gas is both thermally unstable and has a cooling time less than its dynamical time . we identify these doubly unstable regions as the most inducive to fragmentation . at high redshifts , the cosmic microwave background inhibits efficient cooling at low temperatures and , thus , reduces the size of the doubly unstable regions , making fragmentation more difficult . [ firstpage ] stars : formation methods : numerical . And you have already written the first three sentences of the full article: the first luminous objects in the universe formed from primordial gas , comprised solely of h and he , with only trace amounts of d an li . the relatively simple chemistry of metal - free gas , combined with tighly constrained cosmological parameters @xcite , has allowed the formation of the first stars to be simulated with extremely high precision , from the hierarchical growth of their host dark matter halos through to the point where the dense proto - stellar cores becomes optically thick @xcite . with the deaths of these stars came the creation of the first heavy elements . core - collapse and pair - instability supernovae created metals in copious amounts @xcite and ejected them into the igm @xcite . the presence of metals alters the dynamics of collapsing gas - clouds by increasing the number of available atomic and molecular transitions , allowing the gas to lose its internal energy more quickly than in case of no metals @xcite .. Please generate the next two sentences of the article

the introduction of metals adds a new level of complexity to the problem of simulating the formation and evolution of cosmic structure . @xcite identified a minimal set of 21 chemical reactions necessary for accurately following the non - equilibrium evolution of a gas consisting solely of species of h and he , including h@xmath7

Suppose that you have an abstract for a scientific paper: we consider a pairwise interacting quantum 3-body system in 3-dimensional space with finite masses and the interaction term @xmath0 , where all pair potentials are assumed to be nonpositive . the pair interaction of the particles @xmath1 is tuned to make them have a zero energy resonance and no negative energy bound states . the coupling constant @xmath2 is allowed to take the values for which the particle pairs @xmath3 and @xmath4 have no bound states with negative energy . let @xmath5 denote the critical value of the coupling constant such that @xmath6 for @xmath7 , where @xmath8 is the ground state energy of the 3-body system . we prove the theorem , which states that near @xmath5 one has @xmath9^{-1}+$]h.t . , where @xmath10 is a constant and h.t . stands for `` higher terms '' . this behavior of the ground state energy is universal ( up to the value of the constant @xmath10 ) , meaning that it is independent of the form of pair interactions . [ 1]#1 [ 1]#1 . And you have already written the first three sentences of the full article: universality plays an important role in physics . the interest to it is inspired by the striking similarity in behavior near the critical point among systems that are otherwise quite different in nature . for example , various substances , which exhibit liquid - gas phase transition , near the critical point obey the universal law @xmath11 . here. Please generate the next two sentences of the article

@xmath12 denote the density of gas and critical density respectively , @xmath13 are temperature and critical temperature , @xmath14 is a constant and @xmath15 is the so - called critical exponent @xcite . amazingly , the value of @xmath16 is the same for many substances , which are completely different on the atomic level . similar law with the same value of the critical exponent holds true for magnetization in ferromagnets as a function of temperature .

Suppose that you have an abstract for a scientific paper: the electric polarizability of the nucleon is calculated in the soliton approach to the nambu jona - lasinio model . we analyze the leading-@xmath0 contributions , as well as the effects of rotational @xmath1 corrections and @xmath2-@xmath3 mass splitting . our model prediction is substantially reduced compared to other soliton calculations , and is closer to the experimental value . # 10= 0=0 1= 1=1 0>1 # 1 / # 1 . And you have already written the first three sentences of the full article: electromagnetic polarizabilities are fundamental properties of hadrons which are manifest in various processes involving two photons @xcite . recent measurements @xcite of the electric , @xmath4 , and magnetic , @xmath5 , polarizabilities of the nucleon narrowed considerably experimental uncertainties in these observables , and were accompanied by a number of theoretical studies . attempts to describe @xmath4 and @xmath5 were made in various approaches , ranging from chiral perturbation theory @xcite and dispersion relations @xcite to chiral soliton models @xcite .. Please generate the next two sentences of the article

earlier calculations of @xmath4 and @xmath5 are reviewed in ref . @xcite . in this paper

Suppose that you have an abstract for a scientific paper: we perform finite - temperature dynamical simulations of the arrest of a rotating bose - einstein condensate by a fixed trap anisotropy , using a hamiltonian classical - field method . we consider a quasi - two - dimensional condensate containing a single vortex in equilibrium with a rotating thermal cloud . introducing an elliptical deformation of the trapping potential leads to the loss of angular momentum from the system . we identify the condensate and the complementary thermal component of the nonequilibrium field , and compare the evolution of their angular momenta and angular velocities . by varying the trap anisotropy we alter the relative efficiencies of the vortex - cloud and cloud - trap coupling . for strong trap anisotropies the angular momentum of the thermal cloud may be entirely depleted before the vortex begins to decay . for weak trap anisotropies , the thermal cloud exhibits a long - lived steady state in which it rotates at an intermediate angular velocity . . And you have already written the first three sentences of the full article: since the first experimental realizations @xcite of dilute - gas bose - einstein condensates , there has been much interest in the properties of quantum vortices in such systems , and the effect of thermal atoms on their dynamics and stability . the description of the dynamics of vortices in the presence of thermal excitations provides a challenging test for dynamical theories of cold bosonic gases , and promises new insights into the role of thermal excitations in the dynamics of vortices in systems less amenable to such _ ab initio _ descriptions @xcite .. Please generate the next two sentences of the article

the stability of a vortex state in a dilute condensate was first investigated theoretically by rokhsar @xcite , who showed that a vortex is subject to decay in the presence of a nonrotating thermal cloud , providing a physical interpretation of a negative - energy excitation of the vortex previously found by dodd _ fedichev and shlyapnikov @xcite then put forward an analytic theory of the dynamics of vortex decay in the presence of a nonrotating thermal cloud , based on a two - fluid model of superfluidity .

Suppose that you have an abstract for a scientific paper: we present the first full fir spectrum of centaurus a ( ngc 5128 ) from 43 - 196.7 @xmath0 m . the data was obtained with the iso long wavelength spectrometer ( lws ) . we conclude that the fir emission in a 70 beam centred on the nucleus is dominated by star formation rather than agn activity . the flux in the far - infrared lines is @xmath1 1 % of the total fir : the line flux is @xmath1 0.4 % fir and the line is @xmath1 0.2 % , with the remainder arising from , and lines . these are typical values for starburst galaxies . the ratio of the / line intensities from the hii regions in the dust lane corresponds to an effective temperature , t@xmath2 @xmath1 @xmath3 k , implying that the tip of the main sequence is headed by o8.5 stars and that the starburst is @xmath1 6 @xmath4 years old . this suggests that the galaxy underwent either a recent merger or a merger which triggered a series of bursts . the n / o abundance ratio is consistent with the range of @xmath1 0.2 - 0.3 found for galactic hii regions . we estimate that @xmath5 5 % of the observed arises in the cold neutral medium ( cnm ) and that @xmath1 10 % arises in the warm ionized medium ( wim ) . the main contributors to the emission are the pdrs , which are located throughout the dust lane and in regions beyond where the bulk of the molecular material lies . on scales of @xmath1 1 kpc the average physical properties of the pdrs are modelled with a gas density , n @xmath1 @xmath6 @xmath7 , an incident far - uv field , g @xmath1 @xmath8 times the local galactic field , and a gas temperature of @xmath1 250 k. 0h_0 . And you have already written the first three sentences of the full article: centaurus a ( ngc 5128 ) is the nearest ( d = 3.5 mpc ; 1 @xmath117 pc , hui et al . 1993 ) example of a giant elliptical galaxy associated with a powerful radio source . the large - scale radio morphology consists of twin radio lobes separated by @xmath1 5 degrees on the sky . the compact ( @xmath1 milliarcsecond ) radio nucleus is variable and has a strong jet extending @xmath1 4 arcminutes towards the northeast lobe .. Please generate the next two sentences of the article

the spectacular optical appearance is that of a giant elliptical galaxy that appears enveloped in a nearly edge on , warped dust lane . there is also a series of faint optical shells . the stellar population in the dominant elliptical structure is old , whilst that of the twisted dust lane is young , sporadically punctuated by hii regions , dust and gas ( graham 1979 ) .

Suppose that you have an abstract for a scientific paper: we prove that the zarisky closure of the monodromy group of the polynomial @xmath0 is the symplectic group @xmath1 . this shows that some previous results about this monodromy representation are wrong . . And you have already written the first three sentences of the full article: the study of a germ of a vector fields in @xmath2 with two pairs of non - resonant imaginary eigenvalues reduces to the study of the special perturbations @xmath3 of the integrable quadratic foliation @xmath4 with first integral @xmath5 , e.g. ( * ? ? ? * , section 4.6 ) . equivalently , we may consider the following generalized lotka - volterra system associated to ( [ lv ] ) @xmath6\\ y ' = & y[x - p(1-x - y ) ] \end{aligned}\ ] ] and the perturbed foliation ( [ lvp ] ) is associated then to @xmath7\\ y ' = & y[x - p(1-x - y ) + \varepsilon_1 + \varepsilon_2 x^2 ] .. Please generate the next two sentences of the article

\end{aligned}\ ] ] the limit cycles of the perturbed system correspond to the zeros of the displacement map @xmath8 where @xmath9 is a continuous family of ovals ( closed orbits ) of the non - perturbed system ( [ glv ] ) . the unicity of the limit cycle of ( [ lvp]),([glvp ] ) was shown first by ( * ? ? ?

Suppose that you have an abstract for a scientific paper: the impact of reduced dimensionality on the magnetic properties of the tetragonal * l1@xmath0 * copt alloy is investigated from ab - initio considering several kinds of surface defects . by exploring the dependence of the magnetocrystalline anisotropy energy ( mae ) on the thickness of copt thin films , we demonstrate the crucial role of the chemical nature of the surface . for instance , pt - terminated thin films exhibit huge maes which can be 1000% larger than those of co - terminated films . besides the perfect thin films , we scrutinize the effect of defective surfaces such as stacking faults or anti - sites on the surface layers . both types of defects reduce considerably the mae with respect to the one obtained for pt - terminated thin films . a detailed analysis of the electronic structure of the thin films is provided with a careful comparison to the copt bulk case . the behavior of the maes is then related to the location of the different virtual bound states utilizing second order perturbation theory . . And you have already written the first three sentences of the full article: the magnetocrystalline anisotropy energy ( mae ) is at the heart of magnetic properties of materials . it is of crucial importance from the fundamental or technological point of views since it provides an energy scale for the stability of magnetic domains where for example magnetic information is stored . when the mae is large and favors an out - of - plane orientation of the magnetic moments , perpendicular magnetic recording or magneto - optical recording is possible ( see e.g. refs@xcite ) . copt binary bulk alloy in the * l1@xmath0 * structure ( see fig.[cell_bulk ] ) is by now a classical example of a material exhibiting a large perpendicular mae , around 1 mev @xcite .. Please generate the next two sentences of the article

there has been a tremendous number of studies related to the magnetic properties of this alloy in its bulk phase , as nanoparticles or in nanostructures combining co and pt ( see e.g. refs . @xcite ) . * alloy .

Suppose that you have an abstract for a scientific paper: quantum parallelism is the main feature of quantum computation . in 1985 d. deutsch showed that a single quantum computation may be sufficient to state whether a two valued function of a two valued variable is constant or not . though the generalized problem with unconstrained domain and range size admits no deterministic quantum solution , a fully probabilistic quantum algorithm is presented in which quantum parallelism is harnessed to achieve a quicker exploration of the domain with respect to the classical `` sampling '' strategy . . And you have already written the first three sentences of the full article: a quantum computer is a quantum system whose time evolution can be thought of as a computation , much in the same way as we think of the time evolution of a pocket calculator to be a computation . for our pourposes it will suffice to model the quantum system as a `` black box '' and focus our attention on two discrete observables out of a complete set , which we shall call the input and output register . following the standard notation @xcite , we shall indicate the computation of a function @xmath0 as @xmath1 the first ket describing the state of the input register and the second the state of the output register . kets are labelled according to the elements of @xmath2 and @xmath3 they represent .. Please generate the next two sentences of the article

one of the most powerful features of quantum computation is _ quantum parallelism_. the superposition principle of quantum mechanics allows us to prepare the computer in a coherent superposition of a set @xmath4 of input states . after a single run , all of the corresponding outputs @xmath5 appear in the final state , according to the time evolution @xmath6 unfortunately , this is no `` pay one , take n '' .

Suppose that you have an abstract for a scientific paper: the lowest - lying states of lih have been widely used to develop and calibrate many different methods in quantum mechanics . in this paper we show that the electron - transfer processes occurring in these two states are a difficult test for chemical bonding descriptors and can be used to assess new bonding descriptors on its ability to recognize the harpoon mechanism . to this aim , we study the bond formation mechanism in a series of diatomic molecules . in all studied electron - reorganization mechanisms , the maximal electron - transfer variation point along the bond formation path occurs when about half electron has been transferred from one atom to another . if the process takes places through a harpoon mechanism , this point of the reaction path coincides with the avoided crossing . the electron sharing indices and one - dimensional plots of the electron localization function and the laplacian of the electron density along the molecular axis can be used to monitor the bond formation in diatomics and provide a distinction between the harpoon mechanism and a regular electron - reorganization process . this paper is dedicated to andreas savin on the occasion of his @xmath0 birthday . ] . And you have already written the first three sentences of the full article: the formation of molecules through the _ harpoon mechanism _ @xcite occurs from the interaction of two fragments , one with a low ionization potential ( ip ) and another that has a large electron affinity ( ea ) . the reactants approach each other and , at a certain distance , an electron from the fragment with low ip _ harpoons _ the fragment with large ea , giving rise to a rapid electron - transfer process that is triggered by the coulomb attraction exerted by the two fragments .. Please generate the next two sentences of the article

the interplay between the energy exchange due to the harpoon process and the coulomb attraction determines the distance at which the electron transfer takes place . the harpoon mechanism was proposed by michael polanyi to explain the unusually large cross sections observed in the formation of alkali halides .

Suppose that you have an abstract for a scientific paper: polyakov loop eigenvalues and their @xmath0-dependence are studied in 2 and 4 dimensional su(n ) ym theory . the connected correlation function of the single eigenvalue distributions of two separated polyakov loops in 2d ym is calculated and is found to have a structure differing from the one of corresponding hermitian random matrix ensembles . no large @xmath0 non - analyticities are found for two point functions in the confining regime . suggestions are made for situations in which large-@xmath0 phase transitions involving polyakov loops might occur . . And you have already written the first three sentences of the full article: this work is concerned with @xmath1 ym theory ( qcdn ) in 4d . qcdn admits a large @xmath0 expansion @xcite . lattice work has shown that there is confinement at finite and infinite @xmath0 @xcite . then , qcdn at @xmath2 ( qcd@xmath3 ) is similar to the starting point of the topological expansion ( te ) @xcite . in te one constructs iteratively an s - matrix from a set of postulated basic general properties .. Please generate the next two sentences of the article

another starting point for the te is provided by string theory . in both cases one starts from a system consisting of an infinite set of stable particles interacting weakly at linear order . upon iteration

Suppose that you have an abstract for a scientific paper: from our radio observations of the magnetic field strength and large - scale pattern of spiral galaxies of different hubble types and star formation rates ( sfr ) we conclude that though a high sfr in the disk increases the total magnetic field strength in the disk and the halo the sfr does not change the global field configuration nor influence the global scale heights of the radio emission . the similar scale heights indicate that the total magnetic field regulates the galactic wind velocities . the galactic wind itself may be essential for an effective dynamo action . . And you have already written the first three sentences of the full article: observations of a sample of three late - type galaxies with low surface - brightness and the radio - weak edge - on galaxy ngc 5907 ( all with a low sfr ) revealed that they all have an unusually high thermal fraction and weak total and regular magnetic fields ( chyy et al . 2007 , dumke et al . however , these objects still follow the total radio - fir correlation , extending it to the lowest values measured so far .. Please generate the next two sentences of the article

hence , these galaxies have a lower fraction of synchrotron emission than galaxies with higher sfr . it is known that the thermal intensity is proportional to the sfr .

Suppose that you have an abstract for a scientific paper: a graph is called _ ricci - flat _ if its ricci - curvatures vanish on all edges . here we use the definition of ricci - cruvature on graphs given in [ lin - lu - yau , tohoku math . , 2011 ] , which is a variation of [ ollivier , j. funct . math . , 2009 ] . in this paper , we classified all ricci - flat connected graphs with girth at least five : they are the infinite path , cycle @xmath0 ( @xmath1 ) , the dodecahedral graph , the petersen graph , and the half - dodecahedral graph . we also construct many ricci - flat graphs with girth @xmath2 or @xmath3 by using the root systems of simple lie algebras . . And you have already written the first three sentences of the full article: the ricci curvature plays a very important role in geometric analysis on riemannian manifolds . ricci - flat manifolds are riemannian maniflods with ricci curvature vanishes . in physics , they represent vacuum solutions to the analogues of einstein s equations for riemannian manifolds of any dimension , with vanishing cosmological constant . the important class of ricci - flat manifolds is calabi - yau manifolds .. Please generate the next two sentences of the article

this follows from yau s proof of the calabi conjecture , which implies that a compact @xmath4 manifold with a vanishing first real chern class has a @xmath4 metric in the same class with vanishing ricci curvature . they are many works to find the calabi - yau manifolds .

Suppose that you have an abstract for a scientific paper: we study a class of generalized riesz products connected to the spectral type of some class of rank one flows on @xmath0 . applying a central limit theorem of kac , we exhibit a large class of singular generalized riesz products on the bohr compactification of @xmath0 . moreover , we discuss the problem of the flat polynomials in this setting . + @xmath1dedicated to professors jean - paul thouvenot and bernard host . + ( 2010 ) primary : 42a05 , 42a55 ; secondary : 11l03 , 42a61 . + generalized riesz products , almost periodic functions , bohr compactification , mean value , besicovitch space , kac central limit theorem , kakutani criterion . + . And you have already written the first three sentences of the full article: we stress that the main purpose of this paper is to extend and complete the study of the notion of generalized riesz product associated to the rank one flows on @xmath0 formulated in the same manner as peyrire in @xcite . the authors in @xcite mentioned that peyrire extended the notion of riesz product to the real line using a class of kernel functions . furthermore , it is noted by peyrire in his pioneer paper @xcite that an alternative extension of the classical riesz products can be done using the bohr compactification of @xmath0 .. Please generate the next two sentences of the article

indeed , it is usual that the extension of some notions from the periodic setting to the almost periodic deals with the bohr compactification @xmath2 of @xmath0 ( or more generally , the bohr compactification of local abelian groups ) . the bohr compactification plays in the almost periodic case the same role played by the torus @xmath3 in the periodic case as the domain of the fast scale variables .

Suppose that you have an abstract for a scientific paper: inverse compton ( ic ) scattering is one of two viable mechanisms that can produce the prompt non - thermal soft gamma - ray emission in gamma - ray bursts . ic requires low energy seed photons and a population of relativistic electrons that upscatter them . the same electrons will upscatter the gamma - ray photons to even higher energies in the tev range . using the current upper limits on the prompt optical emission we show that under general conservative assumption the ic mechanism suffers from an energy crisis " . namely , ic will over - produce a very high energy component that would carry much more energy than the observed prompt gamma - rays , or alternatively it will require a low energy seed that is more energetic than the prompt @xmath0-rays . our analysis is general and it makes no assumptions on the specific mechanism that produces the relativistic electrons population . gamma rays : bursts@xmath1ism : jets and outflows radiation mechanisms : nonthermal . And you have already written the first three sentences of the full article: the mechanism that produces the prompt gamma - ray emission in gamma ray burst ( grbs ) is still uncertain . the non - thermal character of the spectrum points out towards inverse compton ( ic ) and synchrotron as the two natural candidates . the latter become , somehow , the standard " process but the former remained always a serious alternative ( * ? ? ? * ; * ? ? ? * ; * ? ? ? * ; * ? ? ? * ; * ? ? ? * ; * ? ? ? * ; * ? ? ? * ; * ? ? ? * and others ) .. Please generate the next two sentences of the article

the observations of numerous bursts with low energy spectral slopes that are inconsistent with synchrotron @xcite provided additional motivation to consider ic . recently @xcite have shown further inconsistency with the overall synchrotron model and suggested that synchrotron self - compton ( ssc ) can resolve some of these problems .

Suppose that you have an abstract for a scientific paper: we have observed the hco@xmath0 @xmath1 line toward 17 starless cores selected from the list of ward - thompson et al . ( 1994 ) . six of these cores have line asymmetries indicative of collapse . the excess of blue - skewed profiles over red - skewed profiles is at least as large as that found in samples of class 0 and early class i sources . the observed line profiles have the same narrow linewidths and small peak temperatures predicted for young sources in evolutionary models , but the blue / red ratios , like those of older sources , are higher than models predict . the infall signature also occurs over large scales , suggesting that these cores have overall inward motions . we have divided these starless cores into two groups based on the continuum photometry of ward - thompson et al . and our hco@xmath0 data . we find stronger hco@xmath0 emission among the cores detected in the submillimeter and all the blue - skewed line profiles are in this group , supporting the suggestion of ward - thompson et al . that these are the pre - protostellar cores . = 2 ed at min . , . And you have already written the first three sentences of the full article: for years , the protostellar collapse stage had been an impenetrable mystery , until walker et al . ( 1986 ) observed line profiles indicative of collapse in iras 16293 - 2422 . menten et al .. Please generate the next two sentences of the article

( 1987 ) disputed this interpretation and claimed that the asymmetric line profiles of walker et al . were caused by rotation , but zhou ( 1995 ) later modeled iras 16293 - 2422 as collapse with rotation . zhou et al . ( 1993 ) observed b335 , a slowly rotating source , and modeled its blue - peaked profiles as inside - out collapse ( shu 1977 ) .

Suppose that you have an abstract for a scientific paper: in this paper we prove a nekhoroshev type theorem for perturbations of hamiltonians describing a particle subject to the force due to a central potential . precisely , we prove that under an explicit condition on the potential , the hamiltonian of the central motion is quasi - convex . thus , when it is perturbed , two actions ( the modulus of the total angular momentum and the action of the reduced radial system ) are approximately conserved for times which are exponentially long with the inverse of the perturbation parameter . . And you have already written the first three sentences of the full article: in this paper we study the applicability of nekhoroshev s theorem @xcite ( see also @xcite ) to the central motion . the main point is that nekhoroshev s theorem applies to perturbations of integrable systems whose hamiltonian is a _ steep _ function of the actions . even if such a property is known to be generic , it is very difficult ( and not at all explicit ) to verify it .. Please generate the next two sentences of the article

here we prove that , under an explicit condition on the potential ( see eq . ) , the hamiltonian of the central motion is a quasi - convex function of the actions and thus it is steep , so that nekhoroshev s theorem applies . actually , the form of nekhoroshev s theorem used here is not the original one , but that for degenerate systems proved by fass in @xcite .

Suppose that you have an abstract for a scientific paper: in this article we obtain some positive results about the existence of a common nontrivial invariant subspace for @xmath0-tuples of not necessarily commuting operators on banach spaces with a schauder basis . the concept of joint quasinilpotence plays a basic role . our results complement recent work by kosiek @xcite and ptak @xcite . [ ssection ] [ ssection ] . And you have already written the first three sentences of the full article: let @xmath1 be a continuous linear operator defined on a separable banach space @xmath2 . let us say that @xmath1 is cyclic if @xmath3 such that @xmath4 is dense in @xmath2 . on the other hand , we said that @xmath1 is locally quasinilpotent at @xmath3 if @xmath5 the notion of local quasinilpotence was introduced in @xcite to obtain nontrivial invariant subspaces for positive operators .. Please generate the next two sentences of the article

positive results about @xmath0-tuples of operators with a nontrivial common invariant subspace have been obtained in @xcite . in this article , we extend the results of abramovich _ et al _ @xcite to the case of not - necessarily commuting @xmath0-tuples of continuous linear operators . to extend these results

Suppose that you have an abstract for a scientific paper: in this review , we describe our surveys of low column density ( ) absorbers ( @xmath0 @xmath1 ) , which show that the warm photoionized igm contains @xmath230% of all baryons at @xmath3 . this fraction is consistent with cosmological hydrodynamical simulations , which also predict that an additional 2040% of the baryons reside in much hotter 10@xmath4 k gas , the warm - hot igm ( whim ) . the observed line density of absorbers , @xmath5 for @xmath6 2 , is dominated by low- systems that exhibit slower redshift evolution than those with @xmath7 2 . hst / fuse surveys of o vi absorbers , together with recent detections of o vii with _ chandra _ and _ xmm / newton _ , suggest that anywhere from 2070% ( with large errors ) of the baryons could reside in the whim , for an assumed abundance o / h @xmath8 10% solar . we also review the relationship between the various types of absorbers and galaxies . at the highest column densities , @xmath9 @xmath1 , the damped ( dla ) systems are often identified with gas - rich disks of galaxies over a large range in luminosities ( 0.031 @xmath10 ) and morphologies . lyman - limit systems ( @xmath11 @xmath1 ) appear to be associated with bound bright ( @xmath12 0.10.3 @xmath10 ) galaxy halos . the absorbers with @xmath13 @xmath1 are associated with filaments of large - scale structure in the galaxy distribution , although some may arise in unbound winds from dwarf galaxies . our discovery that @xmath14% of low-@xmath15 absorbers reside in galaxy voids suggests that a substantial fraction of baryons may be entirely unrelated to galaxies . in the future , hst can play a crucial role in a precise accounting of the local baryons and the distribution of heavy elements in the igm . these studies will be especially effective if nasa finds a way to install the _ cosmic origins spectrograph _ ( cos ) on _ hubble _ , allowing an order - of - magnitude improvement in throughput and a comparable increase in our ability to study the igm . . And you have already written the first three sentences of the full article: in its first year , the _ hubble space telescope _ ( hst ) discovered that a majority of all baryons in the current universe are not in galaxies , but instead remain in the intergalactic medium ( igm ) . in subsequent years , the uv spectrographs aboard hst and the _ far ultraviolet spectroscopic explorer _ ( fuse ) have continued these investigations of the multiphase igm , using sensitive uv tracers of diffuse gas : the lyman series of h i ( at 1215.67 , at 1025.72 , etc ) and the o vi doublet ( 1031.926 , 1037.617 ) . these hst and fuse studies have led to a preliminary `` baryon census '' of the `` warm '' ( photoionized ) and `` warm - hot '' ( collisionally ionized ) igm . with spectrographs aboard the _ chandra _ and _ xmm / newton _ x - ray telescopes , astronomers are beginning to search for even more highly ionized gas through resonance absorption lines of o vii , o viii , n vii , and ne ix . unlike virtually all other astronomical objects. Please generate the next two sentences of the article

, the ly@xmath16 absorption systems were first discovered at great distances ( @xmath17 ) owing to their cosmological redshifts and the near - uv atmospheric cutoff . only with the advent of hst have nearby examples been found .

Suppose that you have an abstract for a scientific paper: a detailed theoretical interpretation of the josephson interference experiment between sr@xmath0ruo@xmath1 and pb reported by kidwingira _ et al _ @xcite is given . assuming chiral p - wave pairing symmetry a ginzburg - landau theory is derived in order to investigate the structure of domain walls between chiral domains . it turns out that anisotropy effects of the fermi surface and the orientation of the domain walls are essential for their internal structure . introducing a simple model for a josephson junction the effect of domain walls intersecting the interface between sr@xmath0ruo@xmath1 and pb is discussed . it is shown that characteristic deviations of the fraunhofer interference pattern for the critical josephson current as a function of the magnetic field occurs in qualitative agreement with the experimental finding . moreover the model is able also to account for peculiar hysteresis effects observed in the experiment . . And you have already written the first three sentences of the full article: the aim to identify the symmetry of the superconducting phase in sr@xmath0ruo@xmath1 has stimulated numerous experiments since more than a decade @xcite . most of them provide strong evidence that the pairing state has the so - called chiral @xmath2-wave symmetry . this state is the analog of the a - phase of superfluid @xmath3he , which is a spin triplet state breaking time reversal symmetry with an angular moment along the fourfold @xmath4-axis of the tetragonal crystal lattice of sr@xmath0ruo@xmath1 .. Please generate the next two sentences of the article

the full gap function is a @xmath5-matrix in spin space , @xmath6 , and can be represented by the @xmath7-vector in the case of spin - triplet pairing : @xmath8 with @xmath9 as the gap magnitude . squid interferometer experiments probing the internal phase structure of the cooper pairs are consistent with odd - parity ( @xmath2-wave ) pairing @xcite .

Suppose that you have an abstract for a scientific paper: the `` business elite '' constitutes a small but strikingly influential subset of the population , oftentimes affecting important societal outcomes such as the consolidation of political power @xcite , the adoption of corporate governance practices , and the stability of national economies more broadly . research has shown that this exclusive community often resembles a densely structured network , where elites exchange privileged access to capital , market information , and political clout in an attempt to preserve their economic interests and maintain the status quo @xcite . while there is general awareness that connections among the business elite arise because `` elites attend the same schools , belong to the same clubs , and in general are in the same place at the same time '' , surprisingly little is known about the network dynamics that emerge within these formative settings . here we analyze a unique dataset of all mba students at a top 5 mba program . students were randomly assigned to their first classes ; friendship among students prior to coming into the program was rare ; and the network data email transmissions among students were collected for the year 2006 when students almost entirely used the school s email server to communicate , thereby providing an excellent proxy for their networks . after matching students on all available characteristics ( e.g. , age , grade scores , industry experience , etc . ) i.e. creating `` twin pairs '' we find that the distinguishing characteristics between students who do well in job placement and those who do not is their network . further , we find that the network differences between the successful and unsuccessful students develops within the first month of class and persists thereafter , suggesting a network imprinting that is persistent . finally , we find that these effects are pronounced for students who are at the extreme ends of the distribution on other measures of success students with the best expected job placement do.... And you have already written the first three sentences of the full article: we collected and analyzed more than 4.5 million time - stamped emails from students at a globally top - ranked mba program , focusing specifically on the relationship between students evolving communication networks and their subsequent career outcomes . this data is available in the form of email logs recorded and stored by the university , along with registrar data on each student before and during their matriculation in the program . included in the dataset is a record of each email sent by an mba student between fall 2006 and spring 2008 .. Please generate the next two sentences of the article

the record includes the date and time at which the email was sent and received and the ( anonymous ) numeric ids of the sender and receiver of the message . academic records ( gmat scores , grades , extra - curricular activities , prior work experience and job titles ) , and demographic data ( age , race and nationality ) , were merged with the network data to connect email transmissions with personal characteristics .

Suppose that you have an abstract for a scientific paper: we describe an expansion of legendre polynomials , analogous to the taylor expansion , to approximate arbitrary functions . we show that the polynomial coefficients in legendre expansion , thus , the whole series , converge to zero much more rapidly compared to the taylor expansion of the same order . furthermore , using numerical analysis with sixth - order polynomial expansion , we demonstrate that the legendre polynomial approximation yields an error at least an order of magnitude smaller than the analogous taylor series approximation . this strongly suggests that legendre expansions , instead of taylor expansions , should be used when global accuracy is important . numerical approximation , least squares , legendre polynomial 41a10 , 65d15 . And you have already written the first three sentences of the full article: the question whether and how a given function can be expressed approximately by polynomials are of great importance in theory as well as in practice . for example , by definition , an explicit , finite formula is unavailable for transcendental functions , and instead , an appropriate polynomial approximation is chosen to replace the function . because polynomials , particularly the ones of low order , are easy to manipulate , this approach provides computational speed with minimal penalty in accuracy . a natural candidate for polynomial approximation is a truncated taylor expansion , typically at the midpoint of the interval where the approximation is most accurate . taylor s theorem and the weierstrass approximation theorem @xcite asserts the possibility of local approximation of an arbitrary function @xmath0. Please generate the next two sentences of the article

. moreover , the approximation accuracy improves as the degree of the polynomial increases . however , this improvement comes at the expense of complexity and computational speed .

Suppose that you have an abstract for a scientific paper: this paper reports conduction mechanism in a - over a wide range of temperature ( 238k to 338k ) and frequency ( 5hz to 100khz ) . the d.c . conductivity measured as a function of temperature shows semiconducting behaviour with activation energy @xmath0e= 0.42 ev . thermally induced changes in the electrical and dielectric properties of a - have been examined . the a.c . conductivity in the material has been explained using modified cbh model . the band conduction and single polaron hopping is dominant above room temperature . however , in the lower temperature range the bipolaron hopping dominates . * keywords . * chalcogenides glasses ; amorphous semiconductors ; a.c . conductivity ; electrical properties . + * pac nos 72 - 20 ; 71 - 55 * . And you have already written the first three sentences of the full article: during the last few years amorphous semiconductors have been used in the manufacture of solar cells , batteries and phototransistors as well as in some steps of technological processing of very large scale integration ( vlsi ) microelectronics circuits @xcite . thermally induced structural and electrical effects are known to be important in inducing the memory phenomenon in semiconducting chalcogenide glasses @xcite-@xcite . alzewel et al . , @xcite have studied the electrical conductivity of powdered antimony chalcogenides .. Please generate the next two sentences of the article

antimony alloys have recieved great attention in the past due to semiconductivity of sb concentration . it was reported by mott and devis @xcite that the effect of sb in se is even greater than in te in promoting crystallisation .

Suppose that you have an abstract for a scientific paper: prompted by intriguing events observed in certain particle - physics searches for rare events , we study light and acoustic emission simultaneously in some inorganic scintillators subject to mechanical stress . we observe mechanoluminescence in , and , in various mechanical configurations at room temperature and ambient pressure . we analyze the temporal and amplitude correlations between the light emission and the acoustic emission during fracture . a novel application of the precise energy calibration of provided by radioactive sources allows us to deduce that the fraction of elastic energy converted to light is at least @xmath0 . rare - event searches in particle physics , like those looking for particle dark matter @xcite , employ draconian measures to reduce all forms of background that could hide their signal . the main background is usually of radioactive nature , however other forms are possible . for instance , the first , calorimetric phase of the cresst experiment measured phonons in sapphire crystals cooled to around @xmath1 to detect particle interactions @xcite . initially , thermal contraction of the holders caused fractures in the crystals , limiting sensitivity of the experiment by three orders of magnitude in rate above the radioactive background until the problem was identified @xcite . certain more recent experiments use a coupled measurement of phonons and scintillation to determine the nature of the interacting particles and reject the radioactive background @xcite . however , mechanoluminescence , i.e. the emission of light by a solid subject to mechanical stress , occurs in many materials @xcite , including plastic scintillators @xcite . in addition , correlated acoustic emission ( ae ) and visible - photon emission have been observed during mechanical deformation of colored alkali halides @xcite . other types of emission , including electrons @xcite , positive ions @xcite , and x - rays @xcite , have also been studied in various materials under.... And you have already written the first three sentences of the full article: this work has been funded in canada by nserc ( grant sapin 386432 ) , cfi - lof and orf - sif ( project 24536 ) , and by the france - canada research fund ( project `` listening to scintillating fractures '' ) . prof . c. dujardin of lyon , france , kindly provided access to his equipment to measure x - ray emission spectra . we thank m. chapellier for stimulating discussion , and a. b. mcdonald for comments on our manuscript .. Please generate the next two sentences of the article

32ifxundefined [ 1 ] ifx#1 ifnum [ 1 ] # 1firstoftwo secondoftwo ifx [ 1 ] # 1firstoftwo secondoftwo `` `` # 1''''@noop [ 0]secondoftwosanitize@url [ 0 ] + 12$12 & 12#1212_12%12@startlink[1]@endlink[0]@bib@innerbibempty http://arxiv.org/abs/1101.5205 [ ( ) ] , link:\doibase 10.1016/s0927 - 6505(02)00111 - 1 [ * * , ( ) ] link:\doibase 10.1016/j.physleta.2006.03.059 [ * * , ( ) ] arxiv : hep - ex/0011064 [ * * , ( ) ] , link:\doibase 10.1140/epjc / s10052 - 012 - 1971 - 8 [ * * , ( ) ] @noop * * , ( ) link:\doibase 10.1016/s0022 - 2313(00)00230 - 1 [ * * , ( ) ] link:\doibase 10.1088/0022 - 3727/17/1/016 [ * * , ( ) ] link:\doibase 10.1063/1.339650 [ * * , ( ) ] link:\doibase 10.1007/bf00555916 [ * * , ( ) ] link:\doibase 10.1038/nature07378 [ * * , ( ) ] http://arxiv.org/abs/astro-ph/0106200 [ ( ) ] , http://repository.dl.itc.u-tokyo.ac.jp/dspace/handle/2261/12045 [ * * , ( ) ] link:\doibase 10.1103/physrevlett.79.3202 [ * * , ( ) ] link:\doibase 10.1007/s10704 - 006 - 0051 - 1 [ * * , ( ) ] @noop _ _ , ed . ( , ) @noop _ _ , ed .

Suppose that you have an abstract for a scientific paper: the kinetic theory of fermi liquid is applied to finite nuclei . the nuclear collective dynamics is treated in terms of the observable variables : particle density , current density , pressure etc . the relaxation processes and the development of instabilities in nuclear fermi - liquid drop are strongly influenced by the fermi - surface distortion effects . . And you have already written the first three sentences of the full article: dynamics and dissipative properties of nuclear fermi liquid depend in many aspects on the dynamic distortion of the fermi surface in the momentum space . it is well - known that taking into account this distortion allows the description of a new class of phenomena , most famous of which are giant multipole resonances . furthermore , scattering of particles from the distorted fermi surface leads to relaxation of collective motion and gives rise to fluid viscosity @xcite .. Please generate the next two sentences of the article

we point out that the development of instability in nuclear processes like binary fission or multifragmentation in hi - reactions also depends on dynamic effects such as the dynamic fermi - surface distortion . a convenient way to introduce the fermi - liquid effects into the nuclear many body problem is to start from the kinetic equation for the phase space distribution function @xmath0 . the kinetic equation can then be transformed identically to a set ( infinite ) of equations for the moments of @xmath0 in @xmath1-space , namely , local single - particle density @xmath2 , the velocity field @xmath3 , the pressure tensor @xmath4 , etc . , see @xcite .

Suppose that you have an abstract for a scientific paper: we study the influence of off - resonant two photon transitions on high precision measurements with atom interferometers based on stimulated raman transitions . these resonances induce a two photon light shift on the resonant raman condition . the impact of this effect is investigated in two highly sensitive experiments : a gravimeter and a gyroscope - accelerometer . we show that it can lead to significant systematic phase shifts , which have to be taken into account in order to achieve best performances in term of accuracy and stability . . And you have already written the first three sentences of the full article: in the field of atom interferometry , the improving sensitivity of inertial sensors @xcite is paving the way for many new applications in geophysics , navigation and tests of fundamental physics . most of these experiments are based on raman transitions @xcite to realize beamsplitters and mirrors , which manipulate the atomic wave - packets . among others , this technique has the advantage of an internal state labelling of the exit ports of the interferometer @xcite , enable an efficient detection methods . moreover , the atoms spend most of the time in free fall , with very small and calculable interactions with the environment .. Please generate the next two sentences of the article

the inertial forces are then determined by the relative displacement of the atomic sample with respect to the equiphases of the laser beams , which realise a very accurate and stable ruler . this makes this technique suitable for high precision measurements , as required for instance for inertial sensors and for the determination of fundamental constants @xcite . a limit to the accuracy and

Suppose that you have an abstract for a scientific paper: estimating the time lag between two hydrogeologic time series ( e.g. precipitation and water levels in an aquifer ) is of significance for a hydrogeologist - modeler . in this paper , we present a method to quantify such lags by adapting the visibility graph algorithm , which converts time series into a mathematical graph . we present simulation results to assess the performance of the method . we also illustrate the utility of our approach using a real world hydrogeologic dataset . time series , visibility graph algorithm , hydrogeology , aquifer water level , precipitation . And you have already written the first three sentences of the full article: in the field of hydrogeology , many interesting concepts are related to finding the lag between two time series . for example , it is often hypothesized that for a seepage lake there is a significant time lag between net precipitation ( precipitation minus water loss through evaporation and runoff ) and the water levels over time , while such a lag for a drainage lake is often nonexistent or insignificant . seepage lakes are hydraulically isolated from surface water features and primarily fed by groundwater and direct precipitation .. Please generate the next two sentences of the article

drainage lakes are typically connected to a network of streams and rivers ( wisconsin department of natural resources , 2009 ) . another example , which is our motivating example , is the relationship between precipitation and water levels of a shallow well in an unconfined aquifer versus water levels in a relatively deeper well in a semi - confined aquifer .

Suppose that you have an abstract for a scientific paper: we analyze the steady - state entanglement between bose - einstein condensate trapped inside an optical cavity with a moving end mirror ( nanomechanical resonator ) driven by a single mode laser . the quantized laser field mediates the interaction between the bose - einstein condensate and nanomechanical resonator . in particular , we study the influence of temperature on the entanglement of the coupled system , and note that the steady - state entanglement is fragile with respect to temperature . . And you have already written the first three sentences of the full article: optical nano - mechanical systems that couple optical degree of freedom to the mechanical motion of a cantilever have been subject of increasing investigation @xcite . in these optomechanical systems coupling is obtained via radiation pressure inside a cavity @xcite , or via quantum dots @xcite or ions @xcite . recently , it is made possible to couple mechanical resonators with the ensembles of atoms , where , the interaction is mediated by the field inside the cavity which couples the mechanical resonators to the internal degrees of freedom of the atoms @xcite , or to motional degrees of the freedom of the atoms @xcite causing effects , ( _ e.g _ , cooling of the mechanical resonator via bath of atoms @xcite ) . in quantum meteorology. Please generate the next two sentences of the article

, various targets , such as , measurement of displacement with larger accuracy @xcite and the detection of gravitational waves @xcite are set as milestone achievements . engineering entanglement in nano - mechanical systems is useful in quantum technologies @xcite .

Suppose that you have an abstract for a scientific paper: for a general class of percolation models with long - range correlations on @xmath0 , @xmath1 , introduced in @xcite , we establish regularity conditions of barlow @xcite that mesoscopic subballs of all large enough balls in the unique infinite percolation cluster have regular volume growth and satisfy a weak poincar inequality . as immediate corollaries , we deduce quenched heat kernel bounds , parabolic harnack inequality , and finiteness of the dimension of harmonic functions with at most polynomial growth . heat kernel bounds and the quenched invariance principle of @xcite allow to extend various other known results about bernoulli percolation by mimicking their proofs , for instance , the local central limit theorem of @xcite or the result of @xcite that the dimension of at most linear harmonic functions on the infinite cluster is @xmath2 . in terms of specific models , all these results are new for random interlacements at every level in any dimension @xmath3 , as well as for the vacant set of random interlacements @xcite and the level sets of the gaussian free field @xcite in the regime of the so - called local uniqueness ( which is believed to coincide with the whole supercritical regime for these models ) . . And you have already written the first three sentences of the full article: delmotte @xcite proved that the transition density of the simple random walk on a graph satisfies gaussian bounds and the parabolic harnack inequality holds if all the balls have regular volume growth and satisfy a poincar inequality . barlow @xcite relaxed these conditions by imposing them only on all _ large enough _ balls , and showed that they imply large time gaussian bounds and the elliptic harnack inequality for large enough balls . later , barlow and hambly @xcite proved that the parabolic harnack inequality also follows from barlow s conditions .. Please generate the next two sentences of the article

barlow @xcite verified these conditions for the supercritical cluster of bernoulli percolation on @xmath0 , which lead to the almost sure gaussian heat kernel bounds and parabolic harnack inequality . by using stationarity and heat kernel bounds , the quenched invariance principle was proved in @xcite , which lead to many further results about supercritical bernoulli percolation , including the local central limit theorem @xcite and the fact that the dimension of harmonic functions of at most linear growth is @xmath2 @xcite .

Suppose that you have an abstract for a scientific paper: we analyze coherence effects during the splitting of a quasi one - dimensional condensate into two spatially separated ones and their subsequent merging into a single condensate . our analysis takes into account finite - temperature effects , where phase fluctuations play an important role . we show that , at zero - temperature , the two split condensates can be merged into a single one with a negligible phase difference . by increasing temperature to a finite value below the critical point for condensation ( @xmath0 ) , i.e. , @xmath1 , a considerable enhancement of phase and density fluctuations appears during the process of splitting and merging . our results show that if the process of splitting and merging is sufficiently adiabatic , the whole process is quite insensitive to phase fluctuations and even at high temperatures , a single condensate can be produced . . And you have already written the first three sentences of the full article: the experimental exploration of bose - einstein condensates ( becs ) in many different systems such as alkali metal gases @xcite , hydrogen @xcite , meta - stable helium @xcite , and molecules @xcite has led to a surge of interest in manipulating ultracold atomic samples under very different circumstances . one of the initial motivations for such development was and is the prospect of creating a continuous and coherent atomic beam @xcite , which is the atomic analogy of the optical laser beam @xcite . among the major challenges in achieving a continuous atom laser is how to overcome the difficulty due to the restrictive cooling conditions for continuously condensing the atomic gas .. Please generate the next two sentences of the article

spatial separation of the evaporative cooling from the destructive laser cooling may play a role in alleviating these challenges @xcite . recently , a continuous bec source was achieved by periodically replenishing a reservoir with condensates @xcite . there , optical tweezers were used to transport sodium condensates from where they were created to the reservoir .

Suppose that you have an abstract for a scientific paper: we consider the non - local quantum transport properties of a graphene superconducting spin - valve . it is shown that one may create a spin - switch effect between perfect elastic co - tunneling ( ct ) and perfect crossed andreev - reflection ( car ) for all bias voltages in the low - energy regime by reversing the magnetization direction in one of the ferromagnetic layers . this opportunity arises due the possibility of tuning the local fermi - level in graphene to values equivalent to a weak , magnetic exchange splitting , thus reducing the fermi surface for minority spins to a single point and rendering graphene to be half - metallic . such an effect is not attainable in a conventional metallic spin - valve setup , where the contributions from ct and car tend to cancel each other and noise - measurements are necessary to distinguish these processes . . And you have already written the first three sentences of the full article: quantum entanglement @xcite describes a scenario where the quantum states of two objects separated in space are strongly correlated . these correlations can be exploited in emerging technologies such as quantum computing , should one be able to spatially separate the entangled objects without destroying the correlations . in a broader context , quantum entanglement could prove to be of practical importance in the fields of spintronics @xcite and information cryptography @xcite . it also holds a considerable interest from a purely fundamental physics point of view , prompting some of the more philosophically inclined discussions related to quantum theory and causality .. Please generate the next two sentences of the article

superconductors have been proposed as natural sources for entangled electrons @xcite , as cooper pairs consist of two electrons that are both spin and momentum - entangled . the cooper pair can be spatially deformed by means of the crossed andreev reflection ( car ) process in superconducting heterostructures . in this scenario ,

Suppose that you have an abstract for a scientific paper: we propose boundary conditions for the diffusion equation that maintain the initial mean and the total mass of a discrete data sample in the density estimation process . a complete study of this framework with numerical experiments using the finite element method is presented for the one dimensional diffusion equation , some possible applications of this results are presented as well . we also comment on a similar methodology for the two - dimensional diffusion equation for future applications in two - dimensional domains . . And you have already written the first three sentences of the full article: estimating a density function using a set of initial data points in order to find probability information is a very significant tool in statistics@xcite . the method of kernel density estimation ( kde)@xcite is now standard in many analysis and applications . furthermore , this idea has been applied in multiple fields ( archaeology @xcite , economy @xcite , etc ) . the author of this article is particularly interested in constructing perception of security ( pos ) hotspots using ( kde ) methods to analyze real data registered by security experts in bogot @xcite .. Please generate the next two sentences of the article

nowadays a wide variety of methods are available to find density functions ( kde ) @xcite,@xcite . the method of kde via difussion is of particular interest for this document ; a recent article @xcite develops a systematic method for ( kde ) using the diffusion equation , also they propose a more general equation to solve some biases for data estimation .

Suppose that you have an abstract for a scientific paper: we calculate the semi - leptonic decays of @xmath0 and @xmath1 baryons which involve transitions of a heavy quark to a light quark . in a previous work we used data on the cabibbo favoured non - leptonic decays of charmed baryons @xmath2 and @xmath3 to obtain information on the form factors in the @xmath4 transition . this form factor information is used to study the semi - leptonic decay @xmath5 . using su(3 ) symmetry and hqet it is shown how a knowledge of form factors in @xmath5 can be applied to @xmath6 decay and used to measure @xmath7 . plus 1pt @=12 -0.5 in 0.0 in 0.0 in 8.5 in 6.5 in -.375 in = 0 uh-511 - 825 - 95 + april 1995 * semi - leptonic decays of @xmath8 and @xmath9 baryons involving heavy to light transitions and the determination of @xmath10 + * + .5 in .1 in .25 in . And you have already written the first three sentences of the full article: recently there has been a measurement of the form factors in the semi - leptonic decay @xmath11 @xcite , where a fit to the data was done using the model of krner and kramer @xcite . the model , constructed within the framework of hqet , treats both the charm quark and the strange quark as heavy and considers @xmath12 expansion keeping @xmath13 . even though the model has only one input parameter , use of @xmath12 expansion is questionable and the omission of @xmath14 corrections is also not justified . for a heavy to light transition , for example of the type @xmath15 ,. Please generate the next two sentences of the article

the use of hqet in the limit @xmath16 allows one to express all the form factors in terms of only two form factors @xcite . semileptonic decays of @xmath17 have been studied in this limit @xcite . in ref .

Suppose that you have an abstract for a scientific paper: this paper is devoted to the special case of the restricted circular three - body problem , when the two primaries are of equal mass , while the third body of negligible mass performs oscillations along a straight line perpendicular to the plane of the primaries ( so called periodic vertical motions ) . the main goal of the paper is to study the stability of these periodic motions in the linear approximation . a special attention is given to the alternation of stability and instability within the family of periodic vertical motions , whenever their amplitude is varied in a continuous monotone manner . . And you have already written the first three sentences of the full article: the term sitnikov problem " appeared originally in the context of studies of oscillatory solutions in the restricted three body problem . these studies were initiated by sitnikov @xcite ; they stimulated the application of symbolic dynamics in celestial mechanics @xcite . we recall that sitnikov considered the case when two primaries have equal masses and rotate around their barycenter @xmath0 , while the infinitesimal third body moves along a straight line normal to the plane defined by the motion of the primaries and passing through @xmath0 ( usually the motions of the third body perpendicularly to the plane of the primaries are called vertical " ; below we will follow this tradition ) .. Please generate the next two sentences of the article

sitnikov concentrated his attention on phenomena taking place when the primaries move in elliptic orbits . more bibliography on `` elliptic '' sitnikov problem can be found , for example , in @xcite .

Suppose that you have an abstract for a scientific paper: in this study , we performed monte carlo simulations of the @xmath0-potts model on quasiperiodic decagonal lattices ( qdl ) to assess the critical behavior of these systems . using the single histogram technique in conjunction with the finite - size scaling analysis , we estimate the infinite lattice critical temperatures and the leading critical exponents for @xmath1 and @xmath2 states . our estimates for the critical exponents on qdl are in good agreement with the exact values on 2d periodic lattices , supporting the claim that both the @xmath1 and @xmath2 potts model on quasiperiodic lattices belong to the same universality class as those on 2d periodic lattices . . And you have already written the first three sentences of the full article: electron diffraction patterns exhibiting octagonal , decagonal , dodecagonal , and icosahedral point symmetry are found in various alloys . the most well - known pattern is the icosahedral phase in @xmath3-@xmath4 alloys , which is observed when these materials are cooled at a rapid rate such that their constituent atoms do not have adequate time to form a crystal lattice . these structures are referred to as quasicrystals @xcite . in principle , quasicrystals are characterized as atomic structures that present long - range quasiperiodic translational and long - range orientational order .. Please generate the next two sentences of the article

they can exhibit rotational symmetries otherwise forbidden to crystals . in the last decade , quasicrystals have attracted significant attention , mostly because of their stronger magnetic properties and enhanced elasticity at higher temperatures , compared with the traditional crystals . a most intriguing research topic about quasicrystals is to determine whether its intrinsic complicated structure can result in a change of the universality class compared with its counterpart periodic structure . to this end , potts model @xcite offers a simple and feasible way to study quasicrystals from this perspective , as it contains both first- and second - order phase transitions . however , given the lack of periodicity of these quasiperiodic lattices , only numerical approaches can be performed .

Suppose that you have an abstract for a scientific paper: the spectral statistics of the circular billiard with a point - scatterer is investigated . in the semiclassical limit , the spectrum is demonstrated to be composed of two uncorrelated level sequences . the first corresponds to states for which the scatterer is located in the classically forbidden region and its energy levels are not affected by the scatterer in the semiclassical limit while the second sequence contains the levels which are affected by the point - scatterer . the nearest neighbor spacing distribution which results from the superposition of these sequences is calculated analytically within some approximation and good agreement with the distribution that was computed numerically is found . classical dynamics may be illuminating for the understanding of the corresponding quantum mechanical systems . one of the most studied aspects of the relation between classical and quantum mechanics is the connection between the spectral statistics of the quantum system and the dynamical properties of its classical counterpart . classically integrable systems typically exhibit poisson - like spectral statistics @xcite while classically chaotic systems exhibit spectral statistics of random matrix ensembles @xcite . the spectral statistics of integrable and chaotic systems are universal , that is , they do not depend on specific details of the system but rather on the type of motion and its symmetries . there are systems which are intermediate between integrable and chaotic ones and their spectral properties are not known to be universal . such systems are of experimental relevance . the spectral statistics of mixed systems , for which the phase space is composed of both integrable and chaotic regions , were studied by berry and robnik @xcite . the spectrum can be viewed as a superposition of uncorrelated level sequences , corresponding to the various regions , which are either chaotic or integrable . the nearest neighbor spacing distribution ( nnsd ) of such a superposition of.... And you have already written the first three sentences of the full article: 99 bohigas o 1991 _ random matrix theories and chaotic dynamics _ , in giannoni m j , voros a and zinn - justin j ( eds ) , _ proceedings of the 1989 les houches summer school on chaos and quantum physics _ , pages 88 - 199 . ( amsterdam : elsevier ) .. Please generate the next two sentences of the article

Suppose that you have an abstract for a scientific paper: the history and current status of the cross - disciplinary fields of astrostatistics and astroinformatics are reviewed . astronomers need a wide range of statistical methods for both data reduction and science analysis . with the proliferation of high - throughput telescopes , efficient large scale computational methods are also becoming essential . however , astronomers receive only weak training in these fields during their formal education . interest in the fields is rapidly growing with conferences organized by scholarly societies , textbooks and tutorial workshops , and research studies pushing the frontiers of methodology . r , the premier language of statistical computing , can provide an important software environment for the incorporation of advanced statistical and computational methodology into the astronomical community . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ * an aphorism * _ _ . + the scientist collects data in order to understand natural phenomena . + the statistician helps the scientist acquire understanding from the data . + the computer scientist helps the scientist perform the needed calculations ( * ) . + the individual proficient at all these tasks is a data scientist + _ ( * ) help needed only for big data _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . And you have already written the first three sentences of the full article: astronomers combine telescopic observations of cosmic populations in the effort to understand astrophysical conditions and processes throughout the universe . telescopes at all wavebands of light @xmath0 and recently telescopes for neutrinos and gravitational waves @xmath0 are pointed at a myriad targets to characterize properties of planets , stars , the milky way galaxy , other galaxies , material between the stars and galaxies , and the universe as a whole . in an increasing proportion of studies , a dataset of considerable size is collected .. Please generate the next two sentences of the article

this might be zero - dimensional photometry , one - dimensional spectra or time series , two - dimensional images , three - dimensional hyperspectral or video images . the targets may be a single cosmic target , a small sample of targets sharing common properties , or a large heterogeneous sample of targets .

Suppose that you have an abstract for a scientific paper: we have undertaken a study of diluted magnetic semiconductors @xmath0 and @xmath1 with @xmath2 , using the all electron linearized augmented plane wave method ( lapw ) for different configurations of mn as well as cr . we study four possible configurations of the impurity in the wurtzite gan structure to predict energetically most favorable structure within the 32 atom supercell and conclude that the near - neighbor configuration has the lowest energy . we have also analyzed the ferro - magnetic as well as anti - ferromagnetic configurations of the impurity atoms . the density of states as well as bandstructure indicate half metallic state for all the systems . @xmath3 has also been estimated for the above systems . introduction gallium nitride is one of the most promising materials among the diluted magnetic semiconductor ( dms ) material for application in spintronics . by doping transition metal ( tm ) atoms , mn or cr , local magnetic moment are introduced in semiconductor which mediate ferromagnetically . ( ga , cr)n based dms was predicted to show high @xmath3 @xcite for high enough concentration of cr and further hashimoto _ et al . _ @xcite observed that ( ga , cr)n based dms grown by ecr molecular beam epitaxy showed @xmath3 above @xmath4k . cr@xmath5-implanted gan , studied by photoluminescence and superconducting quantum interference device ( squid ) reveal that the implanted cr@xmath5 incorporates substitutionally at ga site and the ferromagnetic order is retained upto @xmath6k @xcite . takeuch _ et al . _ @xcite . have reported a systematic study of changes in the occupied and unoccupied n - partial density of states ( dos ) and confirm the wurtzite n @xmath7 dos and substitutional doping of cr into ga sites using sxes and xas . recently , ferromagnetism above @xmath8k was reported in cr - gan thin films @xcite . theoretically it was predicted that the ferromagnetic ( fm ) interaction in ( ga , mn)n may be retained upto room temperature @xcite . the initial.... And you have already written the first three sentences of the full article: 20 p. blaha , k. schwarz , g. k. h. madsen , d. kvasnicka and j. luitz , _ an augmented plane wave plus local orbitals program for calculating crystal properties _ , vienna univ . of technology , austria ( 2001 ) isbn 3 - 950131 - 1 - 2. Please generate the next two sentences of the article

Suppose that you have an abstract for a scientific paper: the possibility to use functionals of occupation numbers and natural orbitals for interacting fermions is discussed as an alternative to multi - reference energy density functional method . an illustration based on the two - level lipkin model is discussed . address = ganil , cea and in2p3 , bote postale 5027 , 14076 caen cedex , france . And you have already written the first three sentences of the full article: the nuclear many - body problem of @xmath0 interacting nucleons can be solved exactly only in very specific cases or for very small particle numbers . this is due to the large number of degrees of freedom involved in such a complex system . let us for instance consider particles interacting through n hamiltonian written as @xmath1 then the exact ground state energy can be written as @xmath2 where @xmath3 , @xmath4 , ... denote the one- , two- , ... body density matrices that contain all the information on the one- , two- ... body degrees of freedom respectively .. Please generate the next two sentences of the article

a natural way to reduce the complexity of this problem is to assume that at a given level , the @xmath5body ( and higher - order ) density matrices becomes a functional of the lower - order ones . this is what is done for instance in the hartree - fock ( hf ) approximation where all @xmath6-body density matrices ( with @xmath7 ) become a functional of @xmath8 .

Suppose that you have an abstract for a scientific paper: we compare two approaches to the study of galois module structures : on the one hand factor equivalence , a technique that has been used by frhlich and others to investigate the galois module structure of rings of integers of number fields and of their unit groups , and on the other hand regulator constants , a set of invariants attached to integral group representations by dokchitser and dokchitser , and used by the author , among others , to study galois module structures . we show that the two approaches are in fact closely related , and interpret results arising from these two approaches in terms of each other . we then use this comparison to derive a factorisability result on higher @xmath0-groups of rings of integers , which is a direct analogue of a theorem of de smit on @xmath1-units . . And you have already written the first three sentences of the full article: let @xmath2 be a finite group . factor equivalence of finitely generated @xmath3-free @xmath4$]-modules is an equivalence relation that is a weakening of local isomorphism . it has been used e.g. in @xcite among many other works to derive restrictions on the galois module structure of rings of integers of number fields and of their units in terms of other arithmetic invariants .. Please generate the next two sentences of the article

more recently , a set of rational numbers has been attached to any finitely generated @xmath4$]-module , called regulator constants @xcite , with the property that if two modules are locally isomorphic , then they have the same regulator constants . these invariants have been used in @xcite and in @xcite to investigate the galois module structure of integral units of number fields , of higher @xmath0-groups of rings of integers , and of mordell - weil groups of elliptic curves over number fields .

Suppose that you have an abstract for a scientific paper: for eleven examples of one - dimensional quantum mechanics with shape - invariant potentials , the darboux - crum transformations in terms of multiple _ pseudo virtual state wavefunctions _ are shown to be equivalent to krein - adler transformations deleting multiple eigenstates with _ shifted parameters_. these are based upon infinitely many polynomial wronskian identities of classical orthogonal polynomials , _ i.e. _ the hermite , laguerre and jacobi polynomials , which constitute the main part of the eigenfunctions of various quantum mechanical systems with shape - invariant potentials . yukawa institute kyoto + dpsu-12 - 3 + yitp-12 - 85 + * krein - adler transformations for shape - invariant potentials and pseudo virtual states + + * * satoru odake@xmath0 and ryu sasaki@xmath1 * @xmath2 department of physics , shinshu university , + matsumoto 390 - 8621 , japan + @xmath1 yukawa institute for theoretical physics , + kyoto university , kyoto 606 - 8502 , japan + e - mail : ryu@yukawa.kyoto-u.ac.jp . And you have already written the first three sentences of the full article: the virtual state wavefunctions are essential for the construction of the multi - indexed laguerre and jacobi polynomials @xcite . they are polynomial type solutions of one - dimensional schrdinger equations for shape - invariant potentials @xcite . they are characterised as having negative energies ( the groundstate has zero energy ) , no zeros in the physical domain and that they and their reciprocals are square non - integrable . by dropping the condition of no zeros and the reciprocals. Please generate the next two sentences of the article

are required to be square - integrable at both boundaries , _ pseudo virtual state wavefunctions _ are obtained . in most cases , the virtual and pseudo virtual state wavefunctions are obtained from the eigenfunctions by twisting the parameter(s ) based on the discrete symmetries of the hamiltonian @xcite .

Suppose that you have an abstract for a scientific paper: high spatial resolution observations of the @xmath0co(10 ) , hcn(10 ) , hco@xmath1(10 ) , and @xmath2co(10 ) molecular lines toward the luminous infrared merger ngc 6240 have been performed using the nobeyama millimeter array and the rainbow interferometer . all of the observed molecular emission lines are concentrated in the region between the double nuclei of the galaxy . however , the distributions of both hcn and hco@xmath1 emissions are more compact compared with that of @xmath0co , and they are not coincident with the star - forming regions . the hcn/@xmath0co line intensity ratio is 0.25 ; this suggests that most of the molecular gas between the double nuclei is dense . a comparison of the observed high hcn/@xmath2co intensity ratio , 5.9 , with large velocity gradient calculations suggests that the molecular gas is dense [ @xmath3 @xmath4 and warm ( @xmath550 k ) . the observed structure in ngc 6240 may be explained by time evolution of the molecular gas and star formation , which was induced by an almost head - on collision or very close encounter of the two galactic nuclei accompanied with the dense gas and star - forming regions . . And you have already written the first three sentences of the full article: luminous infrared galaxies ( lirgs ) and ultra - luminous infrared galaxies ( ulirgs ) are known to be huge molecular gas reservoirs [ @xmath6 ] . the results of @xmath0co(10 ) and ( 21 ) observations reveal that this molecular gas is usually concentrated at the center of the galaxies ( e.g. @xcite ) , and in general it forms a compact ( radius @xmath7 kpc ) rotating disk or ring ( e.g. , @xcite ) . the molecular gas within the disk or ring often shows large turbulent motions , and the molecular line profiles exhibit large velocity widths of up to 1000 km s@xmath8 .. Please generate the next two sentences of the article

the physical properties , namely the density and the temperature , of the molecular gas in lirgs / ulirgs are still being studied . single - dish hcn(10 ) observations ( @xcite ; @xcite , ) revealed that most of their molecular gas is supposed to be dense [ @xmath9 cm @xmath10 .

Suppose that you have an abstract for a scientific paper: = 0.6 cm * abstract * we study the absorption probability and hawking radiation spectra of a phantom scalar field in the kerr black hole spacetime . we find that the presence of the negative kinetic energy terms modifies the standard results in the greybody factor , super - radiance and hawking radiation . comparing with the usual scalar particle , the phantom scalar emission is enhanced in the black hole spacetime . = 0.8 cm . And you have already written the first three sentences of the full article: our universe is assumed to be filled with dark energy because it can explain the accelerated expansion of the universe , which is strongly supported by many cosmological observations@xcite . dark energy is an exotic energy component with negative pressure and constitutes about @xmath0 of present total cosmic energy . the leading interpretation of such a dark energy is the cosmological constant with an equation of state @xmath1 ( for a classic review see @xcite , for a recent nice review see @xcite , and for a recent discussion see @xcite ) .. Please generate the next two sentences of the article

the energy density of this dark energy is associated with quantum vacuum @xcite . although this explanation is consistent with observational data , it is plagued with the so - called coincidence problem namely , why are the vacuum and matter energy densities of precisely the same order today ? " .

Suppose that you have an abstract for a scientific paper: we consider a family of birational transformations of two variables , depending on one parameter , for which simple rational expressions with integer coefficients , for the exact expression of the dynamical zeta function , have been conjectured . together with an equality between the ( asymptotic of the ) arnold complexity and the ( exponential of the ) topological entropy . this identification takes place for the birational mapping seen as a mapping bearing on two complex variables ( acting in a complex projective space ) . we revisit this identification between these two quite `` universal complexities '' by considering now the mapping as a mapping bearing on two _ real _ variables . the definitions of the two previous `` topological '' complexities ( arnold complexity and topological entropy ) are modified according to this real - variables point of view . most of the `` universality '' is lost . however , the results presented here are , again , in agreement with an identification between the ( asymptotic of some ) `` real arnold complexity '' and the ( exponential of some ) `` real topological entropy '' . a detailed analysis of this `` real arnold complexity '' as a function of the parameter of this family of birational transformations of two variables is given . one can also slightly modify the definition of the dynamical zeta function , introducing a `` real dynamical zeta function '' associated with the counting of the real cycles only . similarly one can also introduce some `` real arnold complexity '' generating functions . we show that several of these two `` real '' generating functions seem to have the same singularities . furthermore we actually conjecture several simple rational expressions for them , yielding again algebraic values for the ( exponential of the ) `` real topological entropy '' . in particular , when the parameter of our family of birational transformations becomes large , we obtain two interesting compatible non trivial rational expressions . these.... And you have already written the first three sentences of the full article: the purpose of this paper is to sketch a classification of birational transformations based on various notions of `` complexity '' . in previous papers @xcite an analysis , based on the examination of the successive ( bi)rational expressions corresponding to the iteration of some given birational mappings , has been performed . when one considers the degree @xmath0 of the numerators ( or denominators ) of the corresponding successive rational expressions for the @xmath1-th iterate , the growth of this degree is ( generically ) exponential with @xmath1 : @xmath2 .. Please generate the next two sentences of the article

@xmath3 has been called the `` growth complexity '' @xcite and it is closely related to the arnold complexity @xcite . a semi - numerical analysis , enabling to compute these growth complexities @xmath4 for these birational transformations , has been introduced in @xcite . it has been seen , on particular sets of birational transformations @xcite , that these `` growth complexities '' correspond to a remarkable spectrum of _ algebraic _ values @xcite .

Suppose that you have an abstract for a scientific paper: given a covering of the plane by closed unit discs @xmath0 and two points @xmath1 and @xmath2 in the region doubly covered by @xmath0 , what is the length of the shortest path connecting them that stays within the doubly covered region ? this is a problem of g. fejes - tth and he conjectured that if the distance between @xmath1 and @xmath2 is @xmath3 , then the length of this path is at most @xmath4 . in this paper we give a bound of @xmath5 . . And you have already written the first three sentences of the full article: let @xmath0 be a locally finite covering of the plane @xmath6 by closed unit discs . the doubly covered region of @xmath6 by @xmath0 consists of the sets of points @xmath7 that are contained in at least two elements of @xmath0 . a few years ago gabor fejes - tth posed the following question : if @xmath8 are two points at distance @xmath3 apart and contained in the doubly covered region of @xmath6 , what is the length of the shortest path @xmath9 joining @xmath1 and @xmath2 that is completely contained in the doubly covered region ? in a sense , this is the dual of a problem by laszlo fejes tth about the length of a path avoiding a packing of discs @xcite .. Please generate the next two sentences of the article

gabor fejes - tth conjectured that when the centres of the circles in @xmath0 form a unit square lattice , the length of @xmath9 is maximal . for any two points @xmath1 and @xmath2 in this example , @xmath10

Suppose that you have an abstract for a scientific paper: the prisoner s dilemma , a 2-person game in which the players can either cooperate or defect , is a common paradigm for studying the evolution of cooperation . in real situations cooperation is almost never all or nothing . this observation is the motivation for the continuous prisoner s dilemma , in which individuals exhibit variable degrees of cooperation . it is known that in the presence of spatial structure , when individuals `` play against '' ( i.e. interact with ) their neighbours , and `` compare to '' ( `` learn from '' ) them , cooperative investments can evolve to considerable levels . here we examine the effect of increasing the neighbourhood size : we find that the mean - field limit of no cooperation is reached for a critical neighbourhood size of about five neighbours on each side in a moore neighbourhood , which does not depend on the size of the spatial lattice . we also find the related result that in a network of players , the critical average degree ( number of neighbours ) of nodes for which defection is the final state does not depend on network size , but only on the network topology . this critical average degree is considerably ( about ten times ) higher for clustered ( social ) networks , than for distributed random networks . this result strengthens the argument that clustering is the mechanism which makes the development and maintenance of the cooperation possible . in the lattice topology , it is observed that when the neighbourhood sizes for `` interacting '' and `` learning '' differ by more than 0.5 , cooperation is not sustainable , even for neighbourhood sizes that are below the mean - field limit of defection . we also study the evolution of neighbourhood sizes , as well as investment level . here we observe that the series of the interaction and learning neighbourhoods converge , and a final cooperative state with considerable levels of average investment is achieved . prisoner s dilemma , continuous , spatial , lattice , network . And you have already written the first three sentences of the full article: the origin of cooperation is a fundamental problem in evolutionary biology . cooperation is essential in the functioning of almost every known biological system ( hamilton ( 1964a ) , hamilton ( 1964b ) , trivers ( 1971 ) , dugatkin ( 1997 ) ) . for example , according to eigen & schuster ( 1979 ) , michod ( 1983 ) , and maynard smith & szathmry ( 1995 ) , early replicating molecules may have cooperated to form larger entities which could encode more information .. Please generate the next two sentences of the article

also , the transition from free - living single - cell protists to multicellular organisms seems to have depended on cooperation ( maynard smith & szathmry ( 1995 ) , buss ( 1987 ) ) . it is however , difficult to explain why individuals should cooperate . in the traditional prisoner s dilemma model of cooperation

Suppose that you have an abstract for a scientific paper: properties of hypernuclei @xmath0h and @xmath1he are studied in a two - channel approach with explicit treatment of coupling of channels @xmath2 and @xmath3 . diagonal @xmath4 and coupling @xmath5 interactions are derived within @xmath6-matrix procedure from nijmegen meson - exchange models . bond energy @xmath7 in @xmath0he exceeds significantly that in @xmath0h due to the channel coupling . diagonal @xmath8 attraction amplifies the effect , which is sensitive also to @xmath9-core interaction . the difference of the @xmath10 values can be an unambiguous signature of the @xmath5 coupling in @xmath4 hypernuclei . however , improved knowledge of the hyperon - nucleus potentials is needed for quantitative extraction of the coupling strength from future data on the @xmath4 hypernuclear binding energies . . And you have already written the first three sentences of the full article: mixing of different baryonic states in nuclear systems remains a topic rather exciting but being far from sophisticated understanding . a long time ago , it was speculated that a nucleus is not generally a pure nucleonic system . due to @xmath11 and @xmath12 transitions , a nuclear wave function incorporates some admixture of states with one ( or even more ) @xmath13 baryon(s ) @xcite . strictly speaking , also heavier baryons should be taken into account .. Please generate the next two sentences of the article

admixtures of @xmath14 states in @xmath15 hypernuclei probably are more important for hypernuclear dynamics . the @xmath16 mass difference ( 80 mev ) is rather less than the @xmath17 difference ( 300 mev ) .

Suppose that you have an abstract for a scientific paper: we present an embedding approach for semiconductors and insulators based on orbital rotations in the space of occupied kohn - sham orbitals . we have implemented our approach in the popular vasp software package . we demonstrate its power for defect structures in silicon and polaron formation in titania , two challenging cases for conventional kohn - sham density functional theory . . And you have already written the first three sentences of the full article: ab - initio electronic structure theory for bulk materials has experienced tremendous advances in many areas such as density functional theory @xcite , improved post - dft @xcite and , e.g. , van der waals functionals,@xcite as well as highly accurate quantum chemical @xcite and monte - carlo approaches@xcite . however , many problems are still out of reach of an advanced theoretical description due to their size : the accurate description of , for example , defect structures requires both a highly accurate treatment of the local defect region , as well as the treatment of a large number of atoms of the environment@xcite . it is often challenging for a single method to meet both requirements .. Please generate the next two sentences of the article

embedding is therefore a suitable strategy to evercome this hurdle . its underlying idea is to treat the local structure or , more generally , the subsystem of interest by a high - level method while treating the environment with the help of a numerically less demanding lower level method . consistently combining different electronic structure methods within the same calculation

Suppose that you have an abstract for a scientific paper: we show several examples were the tensor interaction of the lowest order g matrix in a nucleus is too strong . the examples include the quadrupole moment of @xmath0li , the isosplitting of the lowest 0@xmath1 states in @xmath2o , the near vanishing gamow - teller matrix element in the weak decay of the j=0 t=1 state of @xmath3o to the j=1 t=0 ground state of @xmath3n , and the magnitude of the deformation of @xmath4c . it would appear that we could get better results by decreasing the tensor interaction strength by about a factor of two . we then examine the simple estimates of gerry brown concerning second order tensor effects . we note that for the triplet even channel the combination of first and second order tensor does indeed yield an effective weaker tensor interaction and helps to get better agreement with experiment . . And you have already written the first three sentences of the full article: in order to study the effects of the tensor and spin orbit interactions in nuclei we use a simple interaction v = v@xmath5 + x v@xmath6 + y v@xmath7 where c @xmath8 central , s.o . @xmath8 spin - orbit and t @xmath8 tensor . for x=1 , y=1 we select v so as to be close to a realistic g matrix like bonn a. we can turn the spin orbit interaction off ( on ) by setting x=0 ( x=1 ) . likewise we can turn the tensor interaction off ( on ) by setting y=0(1 ) . this allows us to study behaviors as a function of x and/or of y. this interaction @xcite is a modification and correction of a previous interaction @xcite .. Please generate the next two sentences of the article

this change does not affect calculations purely in the p shell but there are some changes when core excitations are included . to avoid confusion we call the current interaction v(2005 ) and the previous one v(1991),i.e after the year of publication .

Suppose that you have an abstract for a scientific paper: we have searched for time modulation of the electron capture decay probability of @xmath0pm in an attempt to confirm a recent claim from a group at the gesellschaft fr schwerionenforschung ( gsi ) . we produced @xmath0pm via the @xmath1sn(@xmath2na , 5n)@xmath0pm reaction at the berkeley 88-inch cyclotron with a bombardment time short compared to the reported modulation period . isotope selection by the berkeley gas - filled separator is followed by implantation and a long period of monitoring the @xmath0nd k@xmath3 x - rays from the daughter . the decay time spectrum of the x - rays is well - described by a simple exponential and the measured half - life of 40.68(53 ) seconds is consistent with the accepted value . we observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by litvinov _ et al . _ ( phys . lett . b 664 ( 2008 ) 162 ) . a literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in @xmath0eu electron - capture decay . a reanalysis of the published data shows no oscillatory behavior . a recent paper reported observation of an oscillating decay rate of the isotopes @xmath4pr and @xmath0pm when electron capture decays were measured using highly charged ions with a schottky mass spectroscopy technique @xcite . the authors concluded that the decay activity oscillated in time with a period of about 7 seconds and a relative amplitude of 20% for both isotopes , and attributed the oscillating behavior to interference between neutrino mass eigenstates in the two - body kinematics for electron capture decay of the hydrogen - like ions . if confirmed , this effect is surprising and might offer a new avenue for studying neutrino mixing . references @xcite suggest quantitative explanations for the observations of ref . @xcite in terms of two - species neutrino mixing . other authors argue strongly in refs . @xcite that associating the claimed decay.... And you have already written the first three sentences of the full article: we appreciate the assistance of the technical staff and operators at the 88-inch cyclotron . this work was supported by the director , office of science , office of nuclear physics , u.s . department of energy under contract no .. Please generate the next two sentences of the article

de - ac02 - 05ch11231f . part of this work was performed under the auspices of the u.s .

Suppose that you have an abstract for a scientific paper: we present high - precision photometry of five consecutive transits of wasp-18 , an extrasolar planetary system with one of the shortest orbital periods known . through the use of telescope defocussing we achieve a photometric precision of 0.470.83 mmag per observation over complete transit events . the data are analysed using the jktebop code and three different sets of stellar evolutionary models . we find the mass and radius of the planet to be @xmath0@xmath1 and @xmath2@xmath3 ( statistical and systematic errors ) respectively . the systematic errors in the orbital separation and the stellar and planetary masses , arising from the use of theoretical predictions , are of a similar size to the statistical errors and set a limit on our understanding of the wasp-18 system . we point out that seven of the nine known massive transiting planets ( @xmath4@xmath1 ) have eccentric orbits , whereas significant orbital eccentricity has been detected for only four of the 46 less massive planets . this may indicate that there are two different populations of transiting planets , but could also be explained by observational biases . further radial velocity observations of low - mass planets will make it possible to choose between these two scenarios . . And you have already written the first three sentences of the full article: the recent discovery of the transiting extrasolar planetary system wasp-18 ( * ? ? ? * hereafter h09 ) lights the way towards understanding the tidal interactions between giant planets and their parent stars . wasp-18b is one of the shortest - period ( @xmath5d ) and most massive ( @xmath6@xmath1 ) extrasolar planets known .. Please generate the next two sentences of the article

these properties make it an unparallelled indicator of the tidal dissipation parameters @xcite for the star and the planet @xcite . a value similar to that observed for solar system bodies ( @xmath7@xmath8 ; @xcite ) would cause the orbital period of wasp-18 to decrease at a sufficient rate for the effect to be observable within ten years ( h09 ) . in this work we present high - precision follow - up photometry of wasp-18 , obtained using telescope - defocussing techniques @xcite which give a scatter of only 0.47 to 0.83 mmag per observation .

Suppose that you have an abstract for a scientific paper: based on the first - principles calculations , we recover the silent topological nature of cd@xmath0as@xmath1 , a well known semiconductor with high carrier mobility . we find that it is a symmetry - protected topological semimetal with a single pair of three - dimensional ( 3d ) dirac points in the bulk and non - trivial fermi arcs on the surfaces . it can be driven into a topological insulator and a weyl semi - metal state by symmetry breaking , or into a quantum spin hall insulator with gap more than 100mev by reducing dimensionality . we propose that the 3d dirac cones in the bulk of cd@xmath0as@xmath1 can support sizable linear quantum magnetoresistance even up to room temperature . . And you have already written the first three sentences of the full article: weyl semimetal is a new topological state of three - dimensional ( 3d ) quantum matters @xcite , different from the 3d topological insulators ( ti ) @xcite . it can be characterized by weyl nodes ( at fermi level ) in the bulk and fermi arcs on the surfaces @xcite . around the weyl nodes , the low energy physics is given as 3d two - component weyl fermions @xcite , @xmath2 ( where @xmath3 is pauli matrix and @xmath4 is crystal moment ) , which carries chirality , left- or right - handed defined by the sign of velocity @xmath5 .. Please generate the next two sentences of the article

weyl nodes are stable topological objects as long as @xmath4 is well defined , and can be viewed as effective magnetic monopoles in the 3d momentum space @xcite . to get weyl semimetal , either time - reversal ( tr ) or inversion symmetry needs to be broken @xcite . otherwise , there will be double degeneracy for all @xmath4 . in the case with both tr and inversion symmetries ,

Suppose that you have an abstract for a scientific paper: we construct the first example of a `` one - cusped '' hyperbolic 3-orbifold for which we see the true shape of the space of hyperbolic dehn fillings . . And you have already written the first three sentences of the full article: the hyperbolic dehn filling theory was established by w. thurston in his original note @xcite . besides the general theory , he extensively analyzed the space of dehn fillings of the figure eight knot complement in terms of the decomposition by two ideal tetrahedra . the analysis leaded us to extremely fascinated research activities on dehn fillings in the last 25 years .. Please generate the next two sentences of the article

one of unsolved problems in his analysis was to determine the global shape of the dehn filling space . since then , there have been many deep researches such as @xcite discussing this problem in fact , however it is still mysterious .

Suppose that you have an abstract for a scientific paper: in the present work , we examine the combined effects of cubic and quintic terms of the long range type in the dynamics of a double well potential . employing a two - mode approximation , we systematically develop two cubic - quintic ordinary differential equations and assess the contributions of the long - range interactions in each of the relevant prefactors , gauging how to simplify the ensuing dynamical system . finally , we obtain a reduced canonical description for the conjugate variables of relative population imbalance and relative phase between the two wells and proceed to a dynamical systems analysis of the resulting pair of ordinary differential equations . while in the case of cubic and quintic interactions of the same kind ( e.g. both attractive or both repulsive ) , only a symmetry breaking bifurcation can be identified , a remarkable effect that emerges e.g. in the setting of repulsive cubic but attractive quintic interactions is a `` symmetry restoring '' bifurcation . namely , in addition to the supercritical pitchfork that leads to a spontaneous symmetry breaking of the anti - symmetric state , there is a subcritical pitchfork that eventually reunites the asymmetric daughter branch with the anti - symmetric parent one . the relevant bifurcations , the stability of the branches and their dynamical implications are examined both in the reduced ( ode ) and in the full ( pde ) setting . the model is argued to be of physical relevance , especially so in the context of optical thermal media . . And you have already written the first three sentences of the full article: in the study of both atomic and optical physics problems , often analyzed in the realm of nonlinear schrdinger ( nls ) type equations @xcite , the study of double well potentials has a prominent position . such potentials can be straightforwardly realized in atomic bose - einstein condensates ( becs ) through the combination of a parabolic ( harmonic ) trap with a periodic potential . their experimental realization and subsequent study in becs with self - repulsive nonlinearity has led to numerous interesting observations including tunneling and josephson oscillations for small numbers of atoms in the condensate , and macroscopic quantum self - trapped states for large atom number @xcite and symmetry - breaking dynamical instabilities @xcite .. Please generate the next two sentences of the article

these experimental developments have been accompanied by a larger array of theoretical studies on issues such as finite - mode reductions and symmetry - breaking bifurcations @xcite , quantum effects @xcite , and nonlinear variants of the potentials @xcite . similar features have also emerged in nonlinear optical settings including the formation of asymmetric states in dual - core fibers @xcite , self - guided laser beams in kerr media @xcite , and optically - induced dual - core waveguiding structures in photorefractive crystals @xcite . on the other hand ,

Suppose that you have an abstract for a scientific paper: by employing a recently introduced optimization algorithm we explicitely design optimally synchronizable ( unweighted ) networks for any given scale - free degree distribution . we explore how the optimization process affects degree - degree correlations and observe a generic tendency towards disassortativity . still , we show that there is not a one - to - one correspondence between synchronizability and disassortativity . on the other hand , we study the nature of optimally un - synchronizable networks , that is , networks whose topology minimizes the range of stability of the synchronous state . the resulting `` pessimal networks '' turn out to have a highly assortative string - like structure . we also derive a rigorous lower bound for the laplacian eigenvalue ratio controlling synchronizability , which helps understanding the impact of degree correlations on network synchronizability . _ keywords _ : article preparation , iop journals . And you have already written the first three sentences of the full article: synchronizability is one of the currently leading problems in the fast - growing field of complex networks @xcite . a number of studies have been devoted to scrutinize which network topologies are more prone to sustain a stable globally - synchronized state of generic oscillators defined at each of its nodes @xcite . this question is of broad interest since many complex systems in fields ranging from physics , biology , computer science , or physiology , can be seen as networks of coupled oscillators , whose functionality depends crucially on the network ability to maintain a synchronous oscillation pattern .. Please generate the next two sentences of the article

in addition , it has been shown that networks with good synchronizability are also `` good '' for ( i ) fast random walk spreading and therefore for efficient communication @xcite , ( ii ) searchability in the presence of congestion @xcite , ( iii ) robustness in the absence of privileged hubs @xcite , ( iv ) performance of neural networks @xcite , ( v ) generating consensus in social networks , etc . another related and important problem that has received a lot of attention , but that we will not study here , is the dynamics _ towards _ synchronized states ( see for example @xcite ) . in general terms

Suppose that you have an abstract for a scientific paper: it has been some time since interval - valued linear regression was investigated . in this paper , we focus on linear regression for interval - valued data within the framework of random sets . the model we propose generalizes a series of existing models . we establish important properties of the model in the space of compact convex subsets of @xmath0 , analogous to those for the classical linear regression . furthermore , we carry out theoretical investigations into the least squares estimation that is widely used in the literature . a simulation study is presented that supports our theorems . finally , an application to a climate data set is provided to demonstrate the applicability of our model . . And you have already written the first three sentences of the full article: linear regression for interval - valued data has been attracting increasing interests among researchers . see @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , for a partial list of references . however , issues such as interpretability and computational feasibility still remain .. Please generate the next two sentences of the article

especially , a commonly accepted mathematical foundation is largely underdeveloped , compared to its demand of applications . by proposing our new model , we continue to build up the theoretical framework that deeply understands the existing models and facilitates future developments . in the statistics literature ,

Suppose that you have an abstract for a scientific paper: we report the recent results from the computer simulations of a fermion - gauge - scalar model with dynamical chiral - symmetry breaking and chiral transition induced by the scalar field . this model might be considered to be a possible alternative to the higgs mechanism of mass generation . a new scheme is developed for detecting the chiral transition . our results show with higher precision than the earlier works that the chiral transition line joins the higgs phase transition line , separating the higgs and nambu ( chiral - symmetry breaking ) phases . the end point of the higgs transition with divergent correlation lengths is therefore suitable for an investigation of the continuum limit . . And you have already written the first three sentences of the full article: some strongly coupled lattice fermion - gauge models with a charged scalar field , which break chiral symmetry dynamically , might be considered to be a possible alternative to the higgs mechanism for mass generation , as discussed in @xcite . let us concentrate on a prototype with @xmath0 gauge group , a scalar of fixed modulus and one staggered fermion ( corresponding to 4 flavors ) , where both the scalar and fermion have charge one . the action has been described in @xcite with three bare parameters @xmath1 .. Please generate the next two sentences of the article

the dynamical mass generation is meaningful only in the chiral limit @xmath2 . we consider here the phase transition line * net * between two phases @xcite : \(1 ) dynamical mass generation ( nambu ) phase , below the * net * line , where chiral symmetry is spontaneously broken ( @xmath3 ) due to the strong gauge fluctuations so that the fermion mass @xmath4 is dynamically generated ; \(2 ) higgs phase , above the * nets * line , where the higgs mechanism is operative , but @xmath5 .

Suppose that you have an abstract for a scientific paper: a new `` dynamical mean - field theory '' based approach for the _ kondo lattice model _ with quantum spins is introduced . the inspection of exactly solvable limiting cases and several known approximation methods , namely the _ second - order perturbation theory _ , the _ self - consistent cpa _ and finally a _ moment - conserving decoupling _ of the equations of motion help in evaluating the new approach . this comprehensive investigation gives some certainty to our results : whereas our method is somewhat limited in the investigation of the @xmath0-model , the results for @xmath1 reveal important aspects of the physics of the model : the energetically lowest states are not completely spin - polarized . a band splitting , which occurs already for relatively low interaction strengths , can be related to distinct elementary excitations , namely magnon emission ( absorption ) and the formation of magnetic polarons . we demonstrate the properties of the ferromagnetic kondo lattice model in terms of spectral densities and quasiparticle densities of states . . And you have already written the first three sentences of the full article: the kondo model and its periodic extension , the kondo lattice model ( klm ) , which describe spin - exchange interaction between a localized spin or a system of localized spins , respectively , and a band of itinerant electrons , has been subject of intense theoretical studies in the past @xcite . this model has been applied to a variety of different problems in solid - state physics using both a ferromagnetic and antiferromagnetic coupling constant @xmath2 . the model with @xmath0 is the one originally known as _ kondo lattice model _ or simply _ kondo model _ in its non - periodic form with a single impurity spin in the system .. Please generate the next two sentences of the article

it was used by kondo to explain the unusual temperature behavior of the resistivity of magnetic impurities in non - magnetic hosts @xcite . the negative spin - exchange interaction can be derived from the hybridization of a correlated `` atomic '' level with a conduction band , the situation described by the anderson model @xcite . in the limit of a low - lying half - filled atomic level and strong correlations ,

Suppose that you have an abstract for a scientific paper: can we learn about new physics with astronomical and astro - particle data ? understanding how this is possible is key to unraveling one of the most pressing mysteries at the interface of cosmology and particle physics : the fundamental nature of dark matter . i will discuss some of the recent puzzling findings in cosmic - ray electron - positron data and in gamma - ray observations that might be related to dark matter . i will argue that recent cosmic - ray data , most notably from the pamela and fermi satellites , indicate that previously unaccounted - for powerful sources in the galaxy inject high - energy electrons and positrons . interestingly , this new source class might be related to new fundamental particle physics , and specifically to pair - annihilation or decay of galactic dark matter . this exciting scenario is directly constrained by fermi gamma - ray observations , which also inform us on astrophysical source counterparts that could also be responsible for the high - energy electron - positron excess . observations of gamma - ray emission from the central regions of the galaxy as well as claims on a gamma - ray line at around 130 gev also recently triggered a wide - spread interest : i will address the question of whether we are really observing signals from dark matter annihilation , how to test this hypothesis , and which astrophysical mechanisms constitute the relevant background . . And you have already written the first three sentences of the full article: the standard picture for galaxies such as our own milky way is one where the visible matter is embedded in a halo of _ dark matter _ of as of yet unknown particle nature . many theoretically well - motivated particle theories beyond the standard model predict the existence of particles that could be the dark matter . in many of these theories , such particles can pair - annihilate , producing , as a result , standard model particles that can be detected . these detectable final states include antimatter particles , high - energy neutrinos , gamma rays , electrons and positrons ( @xmath0 ) , and secondary products of @xmath0 energy losses , such as radiation at x - ray frequencies from inverse compton and at radio frequencies from synchrotron .. Please generate the next two sentences of the article

collectively , the search for a signature from dark matter looking at its annihilation products is known as _ indirect detection_. the key question for a particle physicist is : can we do fundamental physics with indirect dark matter detection ? specifically

Suppose that you have an abstract for a scientific paper: the index of a seaweed lie algebra can be computed from its associated meander graph . we examine this graph in several ways with a goal of determining families of frobenius ( index zero ) seaweed algebras . our analysis gives two new families of frobenius seaweed algebras as well as elementary proofs of known families of such lie algebras . * 2000 msc : * 17b05 , 17b08 . And you have already written the first three sentences of the full article: let @xmath0 be a lie algebra over a field of characteristic zero . for any functional @xmath1 there is an associated skew bilinear form @xmath2 on @xmath0 defined by @xmath3)$ ] for @xmath4 . the index of @xmath0 is defined to be @xmath5 the lie algebra @xmath0 is _ frobenius _ if @xmath6 ; equivalently , if there is a functional @xmath1 such that @xmath7 is non - degenerate .. Please generate the next two sentences of the article

frobenius lie algebras were first studied by ooms in @xcite where he proved that the universal enveloping algebra @xmath8 is primitive ( i.e. admits a faithful simple module ) provided that @xmath0 is frobenius and that the converse holds when @xmath9 is algebraic . the relevance of frobenius lie algebras to deformation and quantum group theory stems from their relation to the classical yang - baxter equation ( cybe ) .

Suppose that you have an abstract for a scientific paper: we present results of ultrasonic measurements on a single crystal of the distorted diamond - chain compound azurite cu@xmath0(co@xmath0)@xmath1(oh)@xmath1 . pronounced elastic anomalies are observed in the temperature dependence of the longitudinal elastic mode @xmath2 which can be assigned to the relevant magnetic interactions in the system and their couplings to the lattice degrees of freedom . from a quantitative analysis of the magnetic contribution to @xmath2 the magneto - elastic coupling @xmath3 = @xmath4/@xmath5 can be determined , where @xmath6 is the intra - dimer coupling constant and @xmath7 the strain along the intra - chain @xmath8 axis . we find an exceptionally large coupling constant of @xmath93650 @xmath10 150)k highlighting an extraordinarily strong sensitivity of @xmath6 against changes of the @xmath8-axis lattice parameter . these results are complemented by measurements of the hydrostatic pressure dependence of @xmath6 by means of thermal expansion and magnetic susceptibility measurements performed both at ambient and finite hydrostatic pressure . we propose that a structural peculiarity of this compound , in which cu@xmath1o@xmath11 dimer units are incorporated in an unusually stretched manner , is responsible for the anomalously large magneto - elastic coupling . . And you have already written the first three sentences of the full article: low - dimensional quantum - spin systems have attracted continuous attention due to the wealth of unusual magnetic properties that result from the interplay of low dimensionalty , competing interactions and strong quantum fluctuations . among these systems , the diamond chain has been of particular interest , where triangular arrangements of spin @xmath12 = 1/2 entities with exchange coupling constants @xmath13 , @xmath6 and @xmath14 , are connected to form chains . @xcite in recent years , great interest has surrounded the discovery of azurite , cu@xmath0(co@xmath0)@xmath1(oh)@xmath1 , @xcite as a model system of a cu@xmath15(@xmath12 = 1/2)-based distorted diamond chain with _ @xmath13 @xmath16 @xmath6 @xmath16 @xmath14_.@xcite the observation of a plateau at 1/3 of the saturation magnetization @xcite is consistent with a description of azurite in terms of an alternating dimer - monomer model @xcite . two characteristic temperatures ( energies ) have been derived from peaks in the magnetic susceptibility @xmath17(@xmath18 ) .. Please generate the next two sentences of the article

@xcite whereas the peak at @xmath19 25k , has been assigned to the dominant intra - dimer coupling @xmath20 , the one at @xmath21 5k has been linked to a monomer - monomer coupling along the chain @xmath8 axis.@xcite there have been conflicting results , however , as for the appropriate microscopic description of the relevant magnetic couplings of azurite.@xcite very recently , jeschke _ et al . _ @xcite succeeded in deriving an effective microscopic model capable of providing a consistent picture of most available experimental data for not too low temperatures , i.e. , distinctly above the transition into long - range antiferromagnetic order at @xmath22 = 1.86k @xcite . according to this work ,

Suppose that you have an abstract for a scientific paper: we study propagation of tm- and te - polarized light in two - dimensional arrays of silver nanorods of various diameters in a gelatin background . we calculate the transmittance , reflectance and absorption of arranged and disordered nanorod arrays and compare the exact numerical results with the predictions of the maxwell - garnett effective - medium theory . we show that interactions between nanorods , multipole contributions and formations of photonic gaps affect strongly the transmittance spectra that can not be accounted for in terms of the conventional effective - medium theory . we also demonstrate and explain the degradation of the transmittance in arrays with randomly located rods as well as weak influence of their fluctuating diameter . for tm modes we outline the importance of skin - effect , which causes the full reflection of the incoming light . we then illustrate the possibility of using periodic arrays of nanorods as high - quality polarizers . . And you have already written the first three sentences of the full article: resonance properties of nanoparticles have been observed for centuries thanks to beautiful colors of gold- and silver - patterned stained glasses . over the last decade nanopatterned materials have attracted even increased attention due to their unique electronic and optical characteristics . novadays , they are considered as promising candidates for wide variety of applications in subwavelength waveguiding @xcite , enhanced raman scattering spectroscopy 2005_prb_bachelier , non - linear optics @xcite , photovoltaics @xcite and biological / medical sensing 2004_natbio_alivisatos and many others . a characteristic size of metallic nanoparticles @xmath0 is about an order of magnitude smaller than the wavelength of incoming light @xmath1 , which can excite collective oscillations of electron density inside the particle , - plasmons . the plasmon excitation results in an enhanced extinction ( extinction = absorption + scattering ) as well as an increased intensity of the electromagnetic field near the particle @xcite .. Please generate the next two sentences of the article

the important issue that makes nanoparticles so attractive for sensing applications is the effect of the geometry and size of nanoparticles and surrounding environment on a position of the plasmonic resonance 1995_book_kreibig , 2005_os_khlebtsov , 2005_jpcb_lee , 2003_jpcb_kelly . for example , the presence of antibodies in cells affected by cancer modifies the environment for the gold nanoparticles placed on a tissue and results in a shift of extinction peak that can be easily imaged by conventional microscopy @xcite .