Skip to content

October 2008 arXiv papers — page 37

Showing 3,6013,700 of 5,765 papers

  1. Emmanuel Olaiya

    We present results of B -> vector-vector (VV) and B -> vector-axial vector (VA) decays B0 -> phi X (X = phi, rho+ or rho0), B+ -> phi K(*)+, B0 -> K*K*, B0 -> rho+b_1- and B+ -> K*0a_1+. The largest dataset used for these results is based on 465 * 10^6 Y(4S) -> BB decays, collected with the BABAR detector at the PEP-II B meson factory located at the Stanford

  2. Alexandre Eremenko, Sebastian van Strien

    Let f be a rational function such that the multipliers of all repelling periodic points are real. We prove that the Julia set of such a function belongs to a circle. Combining this with a result of Fatou we conclude that whenever J(f) belongs to a smooth curve, it also belongs to a circle. Then we discuss rational functions whose Julia sets belong to a circl

  3. G. Vujanovic, J. Ruppert, C. Gale

    We calculate the spectral density of the phi meson in a hot bath of nucleons and pions using a general formalism relating self-energy to the forward scattering amplitude (FSA). In order to describe the low energy FSA, we use experimental data along with a background term. For the high energy FSA, a Regge parameterization is employed. We verify the resulting

  4. Natalya Gorobey, Alexander Lukyanenko

    A quantum version of the action principle is formulated in terms of real parameters of a wave functional. The classical limit of the quantum action of a harmonic oscillator is obtained.

  5. Suleyman Er, Dhirendra Tiwari, Gilles A. de Wijs, Geert Brocks

    Magnesium dihydride ($\mgh$) stores 7.7 weight % hydrogen, but it suffers from a high thermodynamic stability and slow (de)hydrogenation kinetics. Alloying Mg with lightweight transition metals (TM = Sc, Ti, V, Cr) aims at improving the thermodynamic and kinetic properties. We study the structure and stability of Mg$_x$TM$_{1-x}$H$_2$ compounds, $x=[0$-1], b

  6. K. D. Elworthy, Y. LeJan, Xue-Mei Li

    Geometry arising from two diffusion operators (smooth semi-elliptic, second order differential operators) on different spaces but intertwined by a smooth map is described. Particular cases arise from Riemannian submersions when the operators are Laplace-Beltrami operators, from equivariant operators on the total space of a principal bundle, and for the opera

  7. A. Denbleyker, Daping Du, Yuzhi Liu, Y. Meurice

    We compare MC calculations of the density of states in SU(2) pure gauge theory with the weak and strong coupling expansions. Surprisingly, the range of validity of the two approximations overlap significantly, however the large order behavior of both expansions appear to be similar to the corresponding expansions of the plaquette. We discuss the implications

  8. Karen Yeats

    Dyson-Schwinger equations are integral equations in quantum field theory that describe the Green functions of a theory and mirror the recursive decomposition of Feynman diagrams into subdiagrams. Taken as recursive equations, the Dyson-Schwinger equations describe perturbative quantum field theory. However, they also contain non-perturbative information. Usi

  9. A. Moretti, G. Piotto, C. Arcidiacono, A. P. Milone

    Deep photometry of crowded fields, such as Galactic Globular Clusters, is severely limited by the actual resolution of ground-based telescopes. On the other hand, the Hubble Space Telescope does not provide the near-infrared (NIR) filters needed to allow large color baselines. In this work we aim at demonstrating how ground based observations can reach the r

  10. William Y. C. Chen, Robert L. Tang, Larry X. W. Wang, Arthur L. B. Yang

    We prove a conjecture of Liu and Wang on the q-log-convexity of the polynomial sequence $\{\sum_{k=0}^n{n\choose k}^2q^k\}_{n\geq 0}$. By using Pieri's rule and the Jacobi-Trudi identity for Schur functions, we obtain an expansion of a sum of products of elementary symmetric functions in terms of Schur functions with nonnegative coefficients. Then the pr

  11. Juan León, Carlos Sabín

    We analyze entanglement generation between a pair of neutral two level atoms that are initially excited in a common electromagnetic vacuum. The nonlocal correlations that appear due to the interaction with the field can become entanglement when the field state is known. We distinguish two different situations: in the first, the field remains in the vacuum st

  12. M. Mignoli, G. Zamorani, M. Scodeggio, A. Cimatti

    Aims. We investigate the relationships between three main optical galaxy observables (spectral properties, colours, and morphology), exploiting the data set provided by the COSMOS/zCOSMOS survey. The purpose of this paper is to define a simple galaxy classification cube, using a carefully selected sample of around 1000 galaxies. Methods. Using medium resolut

  13. A. Udalski

    We describe two new OGLE-III real time data analysis systems: XROM and RCOM. The XROM system has been designed to provide continuous real time photometric monitoring of the optical counterparts of X-ray sources while RCOM system provides real time photometry of R Coronae Borealis variable stars located in the OGLE-III fields. Both systems can be used for tri

  14. E. Matar, E. Congiu, F. Dulieu, A. Momeni

    Aims. The mobility of H atoms on the surface of interstellar dust grains at low temperature is still a matter of debate. In dense clouds, the hydrogenation of adsorbed species (i.e., CO), as well as the subsequent deuteration of the accreted molecules depend on the mobility of H atoms on water ice. Astrochemical models widely assume that H atoms are mobile o

  15. Y. Y. Kovalev, A. P. Lobanov, A. B. Pushkarev

    The apparent position of the origin (core) of extragalactic radio jets shifts with the observing frequency, owing to synchrotron self-absorption and external absorption. One of the largest core shifts was detected by us in the quasar 0850+581 between 2 and 8 GHz. We have followed this up recently by a dedicated VLBA experiment at 5, 8, 15, 24, and 43 GHz. Fi

  16. Tabetha S. Boyajian, Harold A. McAlister, Justin R. Cantrell, Douglas R. Gies

    We present angular diameters of the Hyades giants, gamma, delta^1, epsilon, and theta^1 Tau from interferometric measurements with the CHARA Array. Our errors in the limb-darkened angular diameters for these stars are all less than 2%, and in combination with additional observable quantities, we determine the effective temperatures, linear radii and absolute

  17. Aleksandra Andić

    High-frequency waves (5 mHz to 20mHz) have previously been suggested as a source of energy accounting partial heating of the quiet solar atmosphere. The dynamics of previously detected high-frequency waves is analysed here. Image sequences are taken using the German Vacuum Tower Telescope (VTT), Observatorio del Teide, Izana, Tenerife, with a Fabry-Perot spe

  18. W. G. Nowak

    This article is concerned with estimations from below for the remainder term in Weyl's law for the spectral counting function of certain rational (2l+1)-dimensional Heisenberg manifolds. Concentrating on the case of odd l, it continues the work done in part I which dealt with even l.

  19. Michal Godlinski

    A PhD thesis written under supervision of Pawel Nurowski and defended at the Faculty of Physics of the University of Warsaw. We adress the problems of local equivalence and geometry of third order ODEs modulo contact, point and fibre-preserving transformations of variables. Several new and already known geometries are described in a uniform manner by the Car

  20. Arti Dua, R. Adhikari

    Recent experiments using fluorescence spectroscopy have been able to probe the dynamics of conformational fluctuations in proteins. The fluctuations are Gaussian but do not decay exponentially, and are therefore, non-Markovian. We present a theory where non-Markovian fluctuation dynamics emerges naturally from the superposition of the Markovian fluctuations

  21. G. Rozenblum, N. Shirokov

    For a real non-signdefinite function $B(z)$, $z\in \C$, we investigate the dimension of the space of entire analytical functions square integrable with weight $e^{\pm 2F}$, where the function $F(z)=F(x_1,x_2)$ satisfies the Poisson equation $\D F=B$. The answer is known for the function $B$ with constant sign. We discuss some classes of non-signdefinite posi

  22. M. Aurière, R. Konstantinova-Antova, P. Petit, C. Charbonnel

    We observe the slowly-rotating, active, single giant, EK Eri, to study and infer the nature of its magnetic field directly. We used the spectropolarimeter NARVAL at the Telescope Bernard Lyot, Pic du Midi Observatory, and the Least Square Deconvolution method to create high signal-to-noise ratio Stokes V profiles. We fitted the Stokes V profiles with a model

  23. Bogdan Nicolae, Gabriel Antoniu, Luc Bougé

    This paper addresses the problem of efficiently storing and accessing massive data blocks in a large-scale distributed environment, while providing efficient fine-grain access to data subsets. This issue is crucial in the context of applications in the field of databases, data mining and multimedia. We propose a data sharing service based on distributed, RAM

  24. Bogdan Nicolae, Gabriel Antoniu, Luc Bougé

    We consider the problem of efficiently managing massive data in a large-scale distributed environment. We consider data strings of size in the order of Terabytes, shared and accessed by concurrent clients. On each individual access, a segment of a string, of the order of Megabytes, is read or modified. Our goal is to provide the clients with efficient fine-g

  25. S. Zayzoune, M. Mazroui, Y. Boughaleb, A. Kara

    Langevin simulations provide an effective way to study collective effects of Brownian particles immersed in a two-dimensional periodic potential. In this paper, we concentrate essentially on the behaviour of the tracer (DTr) and bulk (DB) diffusion coefficients as function of friction. Our simulations show that in the high friction limit, the two physical qu

  26. A. Bonafede, G. Giovannini, L. Feretti, F. Govoni

    The aim of the present work is to study the radio properties of double relics in Abell 1240 and Abell 2345 in the framework of double relic formation models. We present new Very Large Array observations at 20 and 90 cm for these two clusters. We performed spectral index and polarization analysis and compared our results with expectations from theoretical mod

  27. Duncan Forgan

    The search for extraterrestrial intelligence (SETI) has been heavily influenced by solutions to the Drake Equation, which returns an integer value for the number of communicating civilisations resident in the Milky Way, and by the Fermi Paradox, glibly stated as: "If they are there, where are they?". Both rely on using average values of key parameter

  28. A. E. Egorov, K. A. Postnov

    Impact of supernova explosion on the neutron star magnetosphere in a massive binary system is considered. The supernova shock striking the NS magnetosphere filled with plasma can lead to the formation of a magnetospheric tail with significant magnetic energy. The magnetic field reconnection in the current sheet formed can convert the magnetic energy stored i

  29. C. E. Neal-Sturgess

    It is the purpose of this short paper to show that the well known Griffiths theory of brittle fracture can be re-interpreted as a simple case of a modified Hamiltonian, and corresponds to a stationary action solution using the Euler-Lagrange equations. In this derivation it is still necessary to employ the equivalence with Irwins stress intensity factor appr

  30. S. Dürr, N. Syassen, D. M. Bauer, M. Lettner

    Strongly correlated states in many-body systems are traditionally created using elastic interparticle interactions. Here we show that inelastic interactions between particles can also drive a system into the strongly correlated regime. This is shown by an experimental realization of a specific strongly correlated system, namely a one-dimensional molecular To

  31. Yu. B. Gaididei, C. Gorria, P. L. Christiansen, M. P. Soerensen

    The role of thermal fluctuations on the conformational dynamics of a single closed filament is studied. It is shown that, due to the interaction between charges and bending degrees of freedom, initially circular aggregates may undergo transformation to polygonal shape. The transition occurs both in the case of hardening and softening charge-bending interacti

  32. Cristian Pisano

    It is shown that the previously noted extreme perturbative instability of the longitudinal structure function F_L(x,Q^2) in the small Bjorken-$x$ region, is a mere artefact of the commonly utilized `standard' gluon distributions. In particular it is demonstrated that using the appropriate -- dynamically generated -- parton distributions at NLO and NNLO,

  33. Norbert Straumann

    In this written version of a pre-dinner-speech at the workshop "The Nature of Gravity" at ISSI I illustrate Pauli's science primarily with material that has not formally been published by him, but was communicated in detailed letters to eminent colleagues and friends.

  34. M. Zobov, for DAFNE Collaboration Team

    The Phi-factory DAFNE was upgraded in the second half of 2007 in order to implement a recently proposed scheme of crab waist collisions aimed at substantial luminosity increase. Commissioning of the modified collider started in November 2007. In this paper we briefly describe the crab waist collision concept and discuss in detail the DAFNE hardware upgrade a

  35. Tobias Koch, Amos Lapidoth

    The capacity of discrete-time, noncoherent, multipath fading channels is considered. It is shown that if the variances of the path gains decay faster than exponentially, then capacity is unbounded in the transmit power.

  36. Alexander M. Kasprzyk, Maximilian Kreuzer, Benjamin Nill

    Toric log del Pezzo surfaces correspond to convex lattice polygons containing the origin in their interior and having only primitive vertices. An upper bound on the volume and on the number of boundary lattice points of these polygons is derived in terms of the index l. Techniques for classifying these polygons are also described: a direct classification for

  37. E. Massaro, P. Giommi, C. Leto, P. Marchegiani

    We present a new catalogue of blazars based on multi-frequency surveys and on an extensive review of the literature. Blazars are classified as BL Lacertae objects, as flat spectrum radio quasars or as blazars of uncertain/transitional type. Each object is identified by a root name, coded as BZB, BZQ and BZU for these three subclasses respectively, and by its

  38. Michael Blank

    We introduce and study a deterministic lattice model describing the motion of an infinite system of oppositely charged particles under the action of a constant electric field. As an application this model represents a traffic flow of cars moving in opposite directions along a narrow road. Our main results concern the Fundamental diagram of the system describ

  39. J. R. Pelaez, R. Garcia-Martin, R. Kaminski, F. J. Yndurain

    This talk is dedicated to the memory of Paco Yndurain, the original speaker in the conference. After a short account of his scientific career, we briefly review our ongoing collaboration to determine precisely the $ππ$ scattering amplitude including the most recent data by means of Forward Dispersion Relations and Roy Equations. A remarkable improvement in p

  40. P. Soleri, S. Heinz, R. Fender, R. Wijnands

    We present the results of the analysis of two Chandra observations of Circinus X-1 performed in 2007, for a total exposure time of ~50 ks. The source was observed with the High Resolution Camera during a long X-ray low-flux state of the source. Cir X-1 is an accreting neutron-star binary system that exhibits ultra-relativistic arcsec-scale radio jets and an

  41. N. N. Achasov, G. N. Shestakov

    The high-statistics Belle data on the γγ\toπ^+π^- and γγ\toπ^0π^0 reactions have been jointly analyzed. The main dynamical mechanisms of these reactions for energies below 1.5 GeV have been revealed. It has been shown that the direct coupling constants of the σ(600) and f_0(980) resonances with a γγpair are small and that the σ(600)\toγγand f_0(980)\toγγdeca

  42. Tom Coates

    In this paper we analyze four examples of birational transformations between local Calabi-Yau 3-folds: two crepant resolutions, a crepant partial resolution, and a flop. We study the effect of these transformations on genus-zero Gromov-Witten invariants, proving the Coates-Corti-Iritani-Tseng/Ruan form of the Crepant Resolution Conjecture in each case. Our r

  43. Yousef Sobouti

    Whenever and wherever one talks of dark matter, one does so when and where there is a luminous matter and a dynamical issue to be settled. We promote this observation to the status of an axiom and assume that there is a dark companion to every luminous matter and there are orders to this companionship. To pursue the proposition in a formal and quantitative m

  44. I. Chikina, S. Nazin, V. Shikin

    Details of the dynamic behaviour of different charged clusters in liquids are discussed. Their associated mass is considered which possesses a number of interesting features in a normal viscous liquid.

  45. Franco Carillo, Detlef Born, Vittorio Pellegrini, Francesco Tafuri

    Transport properties of high quality Nb/semiconductor/Nb long Josephson junctions based on metamorphic In_0.75Ga_0.25As epitaxial layers are reported. Different junction geometries and fabrication procedures are presented that allow a systematic comparison with quasiclassical theory predictions. The impact of junction transparency is highlighted and a proced

  46. I. Shapiro

    We prove results that, for a certain class of non-compact Calabi-Yau threefolds, relate the Frobenius action on their $p$-adic cohomology to the Frobenius action on the $p$-adic cohomology of the corresponding curves. In the appendix, we describe our interpretation of the Griffiths-Dwork method.

  47. Ram Brustein, A. J. M. Medved

    Near the horizon of a black brane in Anti-de Sitter (AdS) space and near the AdS boundary, the long-wavelength fluctuations of the metric exhibit hydrodynamic behaviour. The gauge-gravity duality then relates the boundary hydrodynamics for generalized gravity to that of gauge theories with large finite values of 't Hooft coupling. We discuss, for this fr

  48. P V Landshoff

    I review the formalism for gauge-field perturbation theory in noncovariant gauges, particularly the temporal axial gauge. I show that, even at zero temperature, there are complications and it is not known whether a formalism exists for handling these that is correct for all calculations. For thermal field theory in the imaginary time formalism, there are dif

  49. Victor Chulaevsky, Yuri Suhov

    We establish the phenomenon of Anderson localisation for a quantum two-particle system on a d-dimensional lattice with short-range interaction and in presence of an IID external potential with sufficiently regular marginal distribution.

  50. A. Giuliani, F. D'Ammando, S. Vercellone, V. Vittorini

    Context. We report the detection by the AGILE satellite of an intense gamma-ray flare from the gamma-ray source 3EG J1255-0549, associated to the Flat Spectrum Radio Quasar 3C 279, during the AGILE pointings towards the Virgo Region on 2007 July 9-13. Aims. The simultaneous optical, X-ray and gamma-ray covering allows us to study the spectral energy distribu

  51. Pablo Roig

    We present our study of the hadronization structure of both vector and axial-vector currents leading to decays of the tau into two kaons and a pion. The cornerstones of our framework are the large-N_C limit of QCD, the chiral structure exhibited at low energies and the proper asymptotic behaviour, ruled by QCD, that is demanded to the associated form factors

  52. Sam Elliott

    Building on techniques used in the case of the disc, we use a variety of methods to develop formulae for the adjoints of composition operators on Hardy spaces of the upper half-plane. In doing so, we prove a slight extension of a known necessary condition for the boundedness of such operators, and use it to provide a complete classification of the bounded co

  53. Maxim Krikun, Anatoly Yambartsev

    Ising model without external field on an infinite Lorentzian triangulation sampled from the uniform distribution is considered. We prove uniqueness of the Gibbs measure in the high temperature region and coexistence of at least two Gibbs measures at low temperature. The proofs are based on the disagreement percolation method and on a variant of Peierls metho

  54. Andreas Thom

    In this note we give an example of a group which is locally embeddable into finite groups (in particular it is initially subamenable, sofic and hence hyperlinear) but does not have Kirchberg's factorization property. This group provides also an example of a sofic Kazhdan group which is not residually finite, answering a question of Elek and Szabo. We als

  55. Miao Zhang, H. Y. Jia, L. F. Wei

    For certain {\it specific} (or {\it"magic"}) Lamb-Dicke (LD) parameters, Monroe {\it et al} showed [Phys. Rev. {\bf A 55}, R2489 (1997)] that a two-qubit quantum operation, between the external and internal degrees of freedom of a single trapped ion, could be implemented by applying a single carrier laser pulse. Here, we further show that, such a two

  56. R. E. Angulo, C. G. Lacey, C. M. Baugh, C. S Frenk

    We use the Millennium Simulation, a large, high resolution N-body simulation of the evolution of structure in a LambdaCDM cosmology, to study the properties and fate of substructures within a large sample of dark matter haloes. We find that the subhalo mass function departs significantly from a power law at the high mass end. We also find that the radial and

  57. C. Marini, C. Mirri, G. Profeta, S. Lupi

    We measured the Raman and the Infrared phonon spectrum of SmFeAsO polycrystalline samples. We also performed Density Functional Theory calculations within the pseudopotential approximation to obtain the structural and dynamical lattice properties of both the SmFeAsO and the prototype LaFeAsO compounds. The measured Raman and Infrared phonon frequencies are w

  58. Valentin Polishchuk, Jukka Suomela

    We present a local algorithm (constant-time distributed algorithm) for finding a 3-approximate vertex cover in bounded-degree graphs. The algorithm is deterministic, and no auxiliary information besides port numbering is required.

  59. Dominik C. Hezel, Sara S. Russell, Aidan J. Ross, Anton T. Kearsley

    Modal abundances of Ca,Al-rich inclusions (CAIs) are poorly known and reported data scatter across large ranges. We combine reported CAI modal abundances and our own set, and present a complete list of CAI modal abundances in carbonaceous chondrites. This includes (in area%): CV: 2.98, CM: 1.21, Acfer 094: 1.12, CO: 0.99, CK/CV (Ningqiang & DaG 055): 0.77, C

  60. Andreas Aste

    A condensed introduction to the basic concepts of causal perturbation theory is given. Causal perturbation theory is a mathematically rigorous approach to renormalization theory, which makes it possible to put the theoretical setup of perturbative quantum field theory on a sound mathematical basis by avoiding infinities from the outset. It goes back to a sem

  61. I. Gavignaud, L. Wisotzki, A. Bongiorno, S. Paltani

    We use one of the deepest spectroscopic samples of broad line active galactic nuclei (AGN) currently available, extracted from the VIMOS VLT Deep Survey (VVDS), to compute MgII and CIV virial masses estimate of 120 super-massive black holes in the redshift range 1.0<z<1.9 and 2.6<z<4.3. We find that the mass-luminosity relation shows considerably enhanced di

  62. W. Potzel

    Recoilless resonant capture of monoenergetic electron antineutrinos (Moessbauer antineutrinos) emitted in bound-state beta-decay in the system 3H - 3He is discussed. The recoilfree fraction including a possible phonon excitation due to local lattice expansion and contraction at the time of the nuclear transition, homogeneous and inhomogeneous line broadening

  63. Hao-jie Xu, Qun Wang

    We derive an Abelian-like Ward identity in color superconducting phase and calculate vertex corrections to the color superconducting gap. Making use of the Ward identity, we show that subleading order contributions to the gap from vertices are absent for gapped excitations.

  64. M. Faber, A. N. Ivanov, P. Kienle, E. L. Kryshen

    We calculate the decay rates lambda_(beta^-_c) and lambda_(beta^-_b) of the continuum- and bound-state beta^- decays for bare 205Hg80+ and 207Tl81+ ions. For the ratio of the decay rates R_(b/c) = lambda_(beta^-_b)/lambda_(beta^-_c) we obtain the values R_(b/c) = 0.161 and R_(b/c) = 0.190 for bare 205Hg80+ and 207Tl81+ ions, respectively. The theoretical val

  65. J. Schnack, R. Schnalle

    Frustration of magnetic systems which is caused by competing interactions is the driving force of several unusual phenomena such as plateaus and jumps of the magnetization curve as well as of unusual energy spectra with for instance many singlet levels below the first triplet state. The antiferromagnetic cuboctahedron can serve as a paradigmatic example of c

  66. Neri Merhav

    We examine the classical joint source--channel coding problem from the viewpoint of statistical physics and demonstrate that in the random coding regime, the posterior probability distribution of the source given the channel output is dominated by source sequences, which exhibit a behavior that is highly parallel to that of thermal equilibrium between two sy

  67. Franz X. Bronold, H. Fehske

    This chapter presents, from a quantum-mechanical point of view, a tutorial discussion of elementary collision processes in the bulk of a gas discharge. Instead of merely listing kitchen-made cross section formulae and unrelated cross section data, emphasis has been given on an unified description of elementary processes based on general principles of quantum

  68. M. L. Martin-Manjon, M. Molla, A. I. Diaz, R. Terlevich

    We have computed a series of realistic and self-consistent models that reproduce the properties of HII galaxies. The emitted spectrum of HII galaxies is reproduced by means of the photoionization code CLOUDY, using as ionizing spectrum the spectral energy distribution of the modelled HII galaxy, calculated using new and updated stellar population synthesis m

  69. Ivan Panin, Serge Yagunov

    Using Dold--Puppe category approach to the duality in topology, we prove general duality theorem for the category of motives. As one of the applications of this general result we obtain, in particular, a generalization of Friedlander--Voevodsky&#39;s duality to the case of arbitrary base field characteristic.

  70. Joseph Kiskis, Rajamani Narayanan

    We numerically compute the string tension in the large N limit of three dimensional Yang-Mills theory using Wilson loops. Space-time Wilson loops are formed using smeared space-like links and unsmeared time-like links. We use partial reduction and both unfolded and folded Wilson loops in the analysis.

  71. Charles H. Conley

    Fix a manifold M, and let V be an infinite dimensional Lie algebra of vector fields on M. Assume that V contains a finite dimensional semisimple maximal subalgebra A, the projective or conformal subalgebra. A projective or conformal quantization of a V-module of differential operators on M is a decomposition into irreducible A-modules. We survey recent resul

  72. Tatyana Fadeyeva, Alexander Rubass, Bogdan Sokolenko, Alexander Volyar

    We consider theoretically and experimentally the precession of the optical vortex in a singular beam propagating nearly perpendicular to the crystal optical axis, the beam and the crystal axis rotating with different angular velocities. The precession is a result of different scales along the major axes in a uniaxial crystal. Also we analyze the properties o

  73. Kresimir Josic, Eric Shea-Brown, Brent Doiron, Jaime de la Rocha

    The magnitude of correlations between stimulus-driven responses of pairs of neurons can itself be stimulus-dependent. We examine how this dependence impacts the information carried by neural populations about the stimuli that drive them. Stimulus-dependent changes in correlations can both carry information directly and modulate the information separately car

  74. K. Nishijima, Y. Sakamoto, J. Kushida, K. Saito

    We have observed the high-frequency-peaked BL Lacertae object PKS2155-304 in 2004, 2005 and 2006 with the CANGAROO-III imaging atmospheric Cherenkov telescope, and have detected a signal above 660 GeV at the 4.8/sigma level during the 2006 outburst period. Intranight flux variability on time scale of half an hour is observed. From this variability time scale

  75. H. Kamada, W. Gloeckle, H. Witala, J. Golak

    The phase equivalent relativistic NN potential, which is related by a nonlinear equation to the original nonrelativistic potential, is used to construct the mass operator (rest Hamiltonian) of the 3-nucleon system. Employing the CD Bonn NN potential, the solution of the relativistic 3N Faddeev equation for $^3$H shows slightly less binding energy than the co

  76. Namiko Mitarai, Ian B. Dodd, Michael T. Crooks, Kim Sneppen

    Noise in the expression of a gene produces fluctuations in the concentration of the gene product. These fluctuations can interfere with optimal function or can be exploited to generate beneficial diversity between cells; gene expression noise is therefore expected to be subject to evolutionary pressure. Shifts between modes of high and low rates of transcrip

  77. Guangyue Han, Brian Marcus

    We derive an asymptotic formula for entropy rate of a hidden Markov chain around a &#34;weak Black Hole&#34;. We also discuss applications of the asymptotic formula to the asymptotic behaviors of certain channels.

  78. Medini Padmanabhan, T. Gokmen, M. Shayegan

    Measurements on a two-dimensional electron system confined to an AlAs quantum well reveal that for a given electron density the valley susceptibility, defined as the change in valley population difference per unit strain, is enhanced as the system makes a transition from partial to full spin polarization. This observation is reminiscent of earlier studies in

  79. Ryan B. Patterson

    This note summarizes a presentation of the same title given at XXVIII Physics in Collision 2008. We review recent results from short-baseline neutrino experiments, including MiniBooNE, CHORUS, and K2K, and we look ahead to expected upcoming results from several collaborations.

  80. B. N. Barlow, B. H. Dunlap, R. Rosen, J. C. Clemens

    We have discovered periodic variations in the light curves of two hot DQ stars from the Sloan Digital Sky Survey, SDSS J220029.08-074121.5 and SDSS J234843.30-094245.3. These are the second and third variables detected among the hot DQs and confirm the existence of a new class of variable white dwarf stars. The amplitudes of the variations are one half as la

  81. M. Tegel, S. Johansson, V. Weiss, I. Schellenberg

    The new quaternary iron arsenide-fluoride SrFeAsF with the tetragonal ZrCuSiAs-type structure was synthesized and the crystal structure was determined by X-ray powder diffraction (P4/nmm, a = 399.30(1), c = 895.46(1) pm). SrFeAsF undergoes a structural and magnetic phase transition at 175 K, accompanied by strong anomalies in the specific heat, electrical re

  82. Rajesh Singh, Pankaj Chauhan, Nirmala Sawan, Florentin Smarandache

    This study proposes improved chain-ratio type estimator for estimating population mean using some known values of population parameter(s) of the second auxiliary character. The proposed estimators have been compared with two-phase ratio estimator and some other chain type estimators. The performances of the proposed estimators have been supposed with a numer

  83. Pedro F. dos Santos, Paulo Lima-Filho

    We develop an integral version of Deligne cohomology for smooth proper real varieties. For this purpose the role played by singular cohomology in the complex case has to be replaced by ordinary bigraded G-equivariant cohomology, where G=Gal(C/R). This is the G-equivariant counterpart of singular cohomology. We establish the basic properties of the theory and

  84. Wen-shan Duan, Cang-long Wang, Xue-ren Hong, Jian-min Chen

    A two-dimensional Frenkel-Kontorova model is set up. Its application to the tribology is considered. The materials and the commensurability between two layers strongly affect the static friction force. It is found that the static friction force is larger between two layer of same materials than that for different materials. For two-dimensional case the avera

  85. M. V. Garzelli

    The overlapping stage of heavy-ion reactions can be simulated by dynamical microscopical models, such as those built on the basis of the Molecular Dynamics (MD) approaches, allowing to study the fragment formation process. The present performances of the Quantum MD (QMD) code developed at the University of Milano are discussed, showing results concerning fra

  86. Pedro Miguel Moreira, Luís Paulo Reis, António Augusto de Sousa

    In this paper we demonstrate the use of intelligent optimization methodologies on the visualization optimization of virtual / simulated environments. The problem of automatic selection of an optimized set of views, which better describes an on-going simulation over a virtual environment is addressed in the context of the RoboCup Rescue Simulation domain. A g

  87. Sebastian Zwicknagl

    Let g be a Lie bialgebra and let V be a finite-dimensional g-module. We study deformations of the symmetric algebra of V which are equivariant with respect to an action of the quantized enveloping algebra of g. In particular we investigate such quantizations obtained from the quantization of certain Lie bialgebra structures on the semidirect product of g and

  88. K. M. Seemann, S. Gopalakrishnan, R. J. Behm, H. Rauscher

    This paper has been withdrawn by first author KM Seemann.

  89. Gary R. Goldstein, Simonetta Liuti, Saeed Ahmad

    Exclusive pi0 electroproduction from nucleons can be related to transversity, the tensor charge, and other quantities related to transversity. This process isolates C-parity odd and chiral odd combinations of t-channel exchange quantum numbers. In a hadronic picture the meson production amplitudes for intermediate energy and Q are determined by C-odd Regge e

  90. Geir T. Helleloid, Fernando Rodriguez Villegas

    Let $\Gamma$ be a quiver on n vertices $v_1, v_2, ..., v_n$ with $g_{ij}$ edges between $v_i$ and $v_j$, and let $\alpha \in \N^n$. Hua gave a formula for $A_{\Gamma}(\alpha, q)$, the number of isomorphism classes of absolutely indecomposable representations of $\Gamma$ over the finite field $\F_q$ with dimension vector $\alpha$. Kac showed that $A_{\Gamma}(

  91. Heping Gao, Meera Sitharam

    We define and study exact, efficient representations of realization spaces of a natural class of underconstrained 2D Euclidean Distance Constraint Systems(EDCS) or Frameworks based on 1-dof Henneberg-I graphs. Each representation corresponds to a choice of parameters and yields a different parametrized configuration space. Our notion of efficiency is based o

  92. Yacine Chitour, Mario Sigalotti

    We consider control systems of the type $\dot x = A x +α(t)bu$, where $u\in\R$, $(A,b)$ is a controllable pair and $α$ is an unknown time-varying signal with values in $[0,1]$ satisfying a persistent excitation condition i.e., $\int_t^{t+T}\al(s)ds\geq μ$ for every $t\geq 0$, with $0<μ\leq T$ independent on $t$. We prove that such a system is stabilizable wi

  93. Marco Mazzucchelli

    We prove a Lagrangian analogue of the Conley conjecture: given a 1-periodic Tonelli Lagrangian with global flow on a closed configuration space, the associated Euler-Lagrange system has infinitely many periodic solutions. More precisely, we show that there exist infinitely many contractible integer periodic solutions with a priori bounded mean action and eit

  94. Philippe Droz-Vincent

    We investigate the survival of symmetries in a relativistic system of two mutually interacting bosons coupled with an external field, when this field is &#34;strongly&#34; translation invariant in some directions and additionally remains unchanged by other isometries of spacetime. Since the relativistic interactions cannot be composed additively, it is not a

  95. C. Trachternach, W. J. G. de Blok, F. Walter, E. Brinks

    We present harmonic decompositions of the velocity fields of 19 galaxies from THINGS (The \HI Nearby Galaxy Survey) which quantify the magnitude of the non-circular motions in these galaxies and yield observational estimates of the elongations of the dark matter halo potentials. Additionally, we present accurate dynamical center positions for these galaxies.

  96. J. Berian James, Matthew Colless, Geraint F. Lewis, John A. Peacock

    We study the evolution of non-linear structure as a function of scale in samples from the 2dF Galaxy Redshift Survey, constituting over 221 000 galaxies at a median redshift of z=0.11. The two flux-limited galaxy samples, located near the southern galactic pole and the galactic equator, are smoothed with Gaussian filters of width ranging from 5 to 8 Mpc/h to

  97. Yuanyou Furui Cheng

    We give an explicit form of Ingham&#39;s Theorem on primes in the short intervals, and show that there is at least one prime between every two consecutive cubes $x\sp{3}$ and $(x+1)\sp{3}$ if $\log\log x\ge 15$.

  98. Robert C. Rhoades

    We discuss the problem of the vanishing of Poincaré series. This problem is known to be related to the existence of weakly holomorphic forms with prescribed principal part. The obstruction to the existence is related to the pseudomodularity of Ramanujan&#39;s mock theta functions. We embed the space of weakly holomorphic modular forms into the larger space o

  99. Lado Samushia, Bharat Ratra

    We use the radial baryon acoustic oscillation (BAO) measurements of Gaztanaga et al. (2008) to constrain parameters of dark energy models. These constraints are comparable with constraints from other &#34;non-radial&#34; BAO data. The radial BAO data are consistent with the time-independent cosmological constant model but do not rule out time-varying dark en

  100. Yuanyou Cheng

    The Riemann hypothesis, conjectured by Bernhard Riemann in 1859, claims that the non-trivial zeros of $\zeta(s)$ lie on the line $\Re(s) =1/2$. The density hypothesis is a conjectured estimate $N(\lambda, T) =O\bigl(T\sp{2(1-\lambda) +\epsilon} \bigr)$ for any $\epsilon >0$, where $N(\lambda, T)$ is the number of zeros of $\zeta(s)$ when $\Re(s) \ge\lambda$