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September 2009 arXiv papers — page 54

Showing 5,3015,400 of 5,691 papers

  1. A. Lazarides, O. Tieleman, C. Morais Smith

    We calculate the finite-temperature shift of the critical wavevector $Q_{c}$ of the Pokrovsky-Talapov model using a renormalization-group analysis. Separating the Hamiltonian into a part that is renormalized and one that is not, we obtain the flow equations for the stiffness and an arbitrary potential. We then specialize to the case of a cosine potential, an

  2. S. Leurini, C. Codella, L. A. Zapata, A. Belloche

    Molecular outflows from high-mass young stellar objects provide an excellent way to study the star formation process, and investigate if they are scaled-up versions of their low-mass counterparts. We selected the nearby massive star forming region IRAS 17233-3606 in order to study the kinematics and physics along the molecular outflow(s) originating from thi

  3. A. G. Ramm

    Let $\ell_j:=-\frac{d^2}{dx^2}+k^2q_j(x),$ $k=const>0, j=1,2,$ $0<c_0\leq q_j(x)\leq c_1,$ %$q\in BV([0,1])$, $q$ has finitely many discontinuity points $x_m\in [0,1],$ and is real-analytic on the intervals $[x_m,x_{m+1}]$ between these points. The set of such functions $q$ is denoted by $M.$ Only the following property of $M$ is used: if $q_j\in M$, $j=1,2,

  4. A. G. Ramm

    A method is given for creating material with a desired refraction coefficient. The method consists of embedding into a material with known refraction coefficient many small particles of size $a$. The number of particles per unit volume around any point is prescribed, the distance between neighboring particles is $O(a^{\frac{2-κ}{3}})$ as $a\to 0$, $0<κ<1$ is

  5. N. S. Hoang, A. G. Ramm

    An evolution equation, arising in the study of the Dynamical Systems Method (DSM) for solving equations with monotone operators, is studied in this paper. The evolution equation is a continuous analog of the regularized Newton method for solving ill-posed problems with monotone nonlinear operators $F$. Local and global existence of the unique solution to thi

  6. Tamara Bogdanovic, Michael Eracleous, Steinn Sigurdsson

    Detection of electromagnetic (EM) counterparts of pre-coalescence binaries has very important implications for our understanding of the evolution of these systems as well as the associated accretion physics. In addition, a combination of EM and gravitational wave signatures observed from coalescing supermassive black hole binaries (SBHBs) would provide indep

  7. D. Polishook, N. Brosch, D. Prialnik, S. Kaspi

    We present results of visible wavelengths spectroscopic measurements (0.45 to 0.72 microns) of two binary asteroids, obtained with the 1-m telescope at the Wise Observatory on January 2008. The asteroids (90) Antiope and (1509) Esclangona were observed to search for spectroscopic variations correlated with their rotation while presenting different regions of

  8. David R. Soderblom, Tanmoy Laskar, Jeff A. Valenti, John R. Stauffer

    We have measured the abundances of Fe, Si, Ni, Ti, and Na in 20 Pleiads with \teff values near solar and with low \vsini using high-resolution, high signal-to-noise echelle spectra. We have validated our procedures by also analyzing 10 field stars of a range of temperatures and metallicities that were observed by \citet{Vale05}. Our result for the Pleiades i

  9. A. G. Ramm

    It is proposed to create materials with a desired refraction coefficient in a bounded domain $D\subset \R^3$ by embedding many small balls with constant refraction coefficients into a given material. The number of small balls per unit volume around every point $x\in D$, i.e., their density distribution, is calculated, as well as the constant refraction coeff

  10. Richard Massey, Chris Stoughton, Alexie Leauthaud, Jason Rhodes

    Charge Transfer Inefficiency (CTI) due to radiation damage above the Earth&#39;s atmosphere creates spurious trailing in Hubble Space Telescope (HST) images. Radiation damage also creates unrelated warm pixels - but these happen to be perfect for measuring CTI. We model CTI in the Advanced Camera for Surveys (ACS)/Wide Field Channel (WFC) and construct a phy

  11. Sarbani Basu, William J. Chaplin, Yvonne Elsworth

    The NASA Kepler mission is designed to find planets through transits. Accurate and precise radii of the detected planets depend on knowing the radius of the host star accurately, which is difficult unless the temperature and luminosity of the star are known precisely. Kepler, however, has an asteroseismology programme that will provide seismic variables that

  12. Jeffrey S. Oishi, Mordecai-Mark Mac Low

    We investigate fluid motions near the midplane of vertically stratified accretion disks with highly resistive midplanes. In such disks, the magnetorotational instability drives turbulence in thin layers surrounding a resistive, stable dead zone. The turbulent layers in turn drive motions in the dead zone. We examine the properties of these motions using thre

  13. John J. Eldridge

    We derive a new age for the Gamma^2 Velorum binary by comparing recent observations to our set of binary models. We find that it is very unlikely the stars have not interacted, which implies that previous estimates of the age from single-star models of 3.5+/-0.4 Myrs are incorrect. We prefer an older age of 5.5+/-1 Myrs that agrees with the age of other lowe

  14. A. G. Ramm

    Boundary integral equation is derived for the problem of scattering of electromagnetic waves by 3D homogeneous body of arbitrary shape.

  15. N. Jenkins, Y. Fasano, C. Berthod, I. Maggio-Aprile

    We have used scanning tunneling spectroscopy to investigate short-length electronic correlations in three-layer Bi2Sr2Ca2Cu3O(10+d) (Bi-2223). We show that the superconducting gap and the energy Omega_dip, defined as the difference between the dip minimum and the gap, are both modulated in space following the lattice superstructure, and are locally anti-corr

  16. K. Mikelsons, E. Khatami, D. Galanakis, A. Macridin

    We study the thermodynamics of the two-dimensional Hubbard model within the dynamical cluster approximation. We use continuous time quantum Monte Carlo as a cluster solver to avoid the systematic error which complicates the calculation of the entropy and potential energy (double occupancy). We find that at a critical filling, there is a pronounced peak in th

  17. A. G. Ramm

    A 3D singular integral equation is derived for electromagnetic wave scattering by bodies of arbitrary shape. Its numerical solution by a projection method is outlined.

  18. H. Witala, W. Glockle

    In view of recent neutron-deuteron (nd) breakup data for neutron-neutron (nn) and neutron-proton (np) quasi-free-scattering (QFS) arrangements and the large discrepancy found between theoretical predictions and measured nn QFS cross sections, we analyze the sensitivity of the QFS cross sections to different partial wave components of the nucleon-nucleon (NN)

  19. Marco Delmastro

    The search strategy for the Standard Model Higgs boson at the Large Hadron Collider is reviewed, with a particular emphasis on its potential observation by the ATLAS and CMS detectors in the $γγ$, $τ^+τ^-$, $ZZ^{*}$ and $WW^{*}$ final states. The combined Higgs discovery potential of ATLAS and CMS is discussed, as well as the expected exclusion limits on the

  20. Geordie Richards

    This paper is concerned with the analysis of blow-up solutions to the elliptic-elliptic Davey-Stewartson system, which appears in the description of the evolution of surface water waves. We prove a mass concentration property for $H^{1}$-solutions, analogous to the one known for the $L^{2}$-critical nonlinear Schrödinger equation. We also prove a mass concen

  21. J. Ruostekoski, C. J. Foot, A. B. Deb

    We propose a method for measuring the temperature of fermionic atoms in an optical lattice potential from the intensity of the scattered light in the far-field diffraction pattern. We consider a single-component gas in a tightly-confined two-dimensional lattice, illuminated by far off-resonant light driving a cycling transition. Our calculations show that th

  22. NA49 Collaboration, SHINE Collaboration

    Lattice QCD calculations locate the QCD critical point at energies accessible at the CERN Super Proton Synchrotron (SPS). We present average transverse momentum and multiplicity fluctuations, as well as baryon and anti-baryon transverse mass spectra which are expected to be sensitive to effects of the critical point. The future CP search strategy of the NA61

  23. Nima Arkani-Hamed, Freddy Cachazo, Clifford Cheung

    A dual formulation of the S Matrix for N=4 SYM has recently been presented, where all leading singularities of n-particle N^{k-2}MHV amplitudes are given as an integral over the Grassmannian G(k,n), with cyclic symmetry, parity and superconformal invariance manifest. In this short note we show that the dual superconformal invariance of this object is also ma

  24. Wilfried Buchmuller, Jan Moller, Jonas Schmidt

    We discuss the stabilization of the compact dimension for a class of five-dimensional orbifold supergravity models. Supersymmetry is broken by the superpotential on a boundary. Classically, the size $L$ of the fifth dimension is undetermined, with or without supersymmetry breaking, and the effective potential is of no-scale type. The size $L$ is fixed by qua

  25. Fionn Murtagh, Pedro Contreras, Jean-Luc Starck

    By a &#34;covering&#34; we mean a Gaussian mixture model fit to observed data. Approximations of the Bayes factor can be availed of to judge model fit to the data within a given Gaussian mixture model. Between families of Gaussian mixture models, we propose the Rényi quadratic entropy as an excellent and tractable model comparison framework. We exemplify thi

  26. Martin C. Lehman, Despina Louca, Kazumasa Horigane, Anna Llobet

    We report on the first local atomic structure study via the pair density function (PDF) analysis of neutron diffraction data and show a direct correlation of local coordinates to TC in the newly discovered superconducting FeSe1-xTex. The isovalent substitution of Te for Se such as in FeSe0.5Te0.5 increases Tc by twofold in comparison to a-FeSe without changi

  27. A. Milchev, V. Rostiashvili, S. Bhattacharya, T. Vilgis

    We examine the phase transition of polymer adsorption as well as the underlying kinetics of polymer binding from dilute solutions on a structureless solid surface. The emphasis is put on the properties of regular multiblock copolymers, characterized by block size M and total length N as well as on random copolymers with quenched composition p of sticky and n

  28. Konstantinos Dimopoulos, Mindaugas Karciauskas, Jacques M. Wagstaff

    A vector curvaton model with a Maxwell kinetic term and varying kinetic function and mass during inflation is studied. It is shown that, if light until the end of inflation, the vector field can generate statistical anisotropy in the curvature perturbation spectrum and bispectrum, with the latter being predominantly anisotropic. If by the end of inflation th

  29. Juan Pablo Paz, Augusto J. Roncaglia

    We analyze the time dependence of entanglement and total correlations between a system and fractions of its environment in the course of decoherence. For the quantum Brownian motion model we show that the entanglement and total correlations have rather different dependence on the size of the environmental fraction. Redundancy manifests differently in both ty

  30. Istvan Dekany, Geza Kovacs

    We study the variable star content of the globular cluster M53 to compute the physical parameters of the constituting stars and the distance of the cluster. Covering two adjacent seasons in 2007 and 2008, new photometric data are gathered for 3048 objects in the field of M53. By using the OIS method and subsequently TFA, we search for variables in the full s

  31. Kyle E. Kinneberg, Aaron Mazel-Gee, Tia Sondjaja, Francis Edward Su

    The classical Lusternik-Schnirelman-Borsuk theorem states that if a d-sphere is covered by d+1 closed sets, then at least one of the sets must contain a pair of antipodal points. In this paper, we prove a combinatorial version of this theorem for hypercubes. It is not hard to show that for any cover of the facets of a d-cube by d sets of facets, at least one

  32. C. Allende Prieto, L. Koesterke, I. Ramirez, H. -G. Ludwig

    For late-type non-active stars, gravitational redshifts and convective blueshifts are the main source of biases in the determination of radial velocities. If ignored, these effects can introduce systematic errors of the order of ~ 0.5 km/s. We demonstrate that three-dimensional hydrodynamical simulations of solar surface convection can be used to predict the

  33. Emilie Hogan

    Non-linear recurrences which generate integers in a surprising way have been studied by many people. Typically people study recurrences that are linear in the highest order term. In this paper I consider what happens when the recurrence is not linear in the highest order term. In this case we no longer produce a unique sequence, but we sometimes have surpris

  34. Franz Saija, Santi Prestipino, Gianpietro Malescio

    We study the phase behavior of a classical system of particles interacting through a strictly convex soft-repulsive potential which, at variance with the pairwise softened repulsions considered so far in the literature, lacks a region of downward or zero curvature. Nonetheless, such interaction is characterized by two length scales, owing to the presence of

  35. D. P. Yearchuck, E. D. Yerchak, A. I. Kirilenko, V. I. Popechits

    New phenomenon is experimentally identified: ferroelectrical spin wave resonance (FE SWR), which consist in characteristic splitting of vibration (electronic-vibration) levels in optical spectra of interacting localized centers. Spectral positions of ESWR lines are determined in linear approach by quadratic dispersion law. It has been found that the values o

  36. Jingyi Fei, Jonathan E. Bronson, Jake M. Hofman, Rathi L. Srinivas

    Determining the mechanism by which transfer RNAs (tRNAs) rapidly and precisely transit through the ribosomal A, P and E sites during translation remains a major goal in the study of protein synthesis. Here, we report the real-time dynamics of the L1 stalk, a structural element of the large ribosomal subunit that is implicated in directing tRNA movements duri

  37. C. S. Stalin, P. Petitjean, R. Srianand, A. J. Fox

    We present optical spectroscopic identifications of X-ray sources in ~3 square degrees of the XMM-Large Scale Structure survey (XMM-LSS), also covered by the Canada France Hawaii Telescope Legacy Survey (CFHTLS), obtained with the AAOmega instrument at the Anglo Australian Telescope. In a flux limited sample of 829 point like sources in the optical band with

  38. Wlodek Zawadzki, Tomasz M. Rusin

    We demonstrate both classically and quantum mechanically that the Zitterbewegung (ZB, the trembling motion) of electrons in crystalline solids is nothing else, but oscillations of velocity assuring the energy conservation when the electron moves in a periodic potential. This means that the nature of electron ZB in a solid is completely different from that of

  39. Sergey Foss

    The paper contains a discussion on a number of open problems in queueing theory. Some of them are known for decades, some are more recent. They relate to stability and to rare events. There is an idea to prepare a special issue of QUESTA on open problems, and this text may be considered as a prospective contribution to that. The choice of open problems refle

  40. Laurent Baratchart, Maxim Yattselev

    For all n large enough, we show uniqueness of a critical point in best rational approximation of degree n, in the L^2-sense on the unit circle, to functions f, where f is a sum of a Cauchy transform of a complex measure \mu supported on a real interval included in (-1,1), whose Radon-Nikodym derivative with respect to the arcsine distribution on its support

  41. Z. Sun, T. Hasan, F. Torrisi, D. Popa

    Graphene is at the center of a significant research effort. Near-ballistic transport at room temperature and high mobility make it a potential material for nanoelectronics. Its electronic and mechanical properties are also ideal for micro and nanomechanical systems, thin-film transistors and transparent and conductive composites and electrodes. Here we explo

  42. Tommy Ohlsson, Thomas Schwetz, He Zhang

    We investigate non-standard neutrino interactions (NSIs) in the Zee--Babu model. The size of NSIs predicted by this model is obtained from a full scan over the parameter space, taking into account constraints from low-energy experiments such as searches for lepton flavor violation (LFV) and the requirement to obtain a viable neutrino mass matrix. The depende

  43. Yunhua Zhang, Lijing Shao, Bo-Qiang Ma

    A simple statistical model in terms of light-front kinematic variables is used to explain the nuclear EMC effect in the range $x \in [0.2,~0.7]$, which was constructed by us previously to calculate the parton distribution functions (PDFs) of the nucleon. Here, we treat the temperature $T$ as a parameter of the atomic number $A$, and get reasonable results in

  44. Edoardo Ballico, Elizabeth Gasparim, Thomas Köppe

    In a recent paper, Gallego, González and Purnaprajna showed that rational 3-ropes can be smoothed. We generalise their proof and obtain smoothability of rational $m$-ropes for $m \geq 3$.

  45. Victor de Haan

    Two optical fiber Mach-Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer with a length of 2 m optical fiber in each arm with the main direction of the arms parallel to each other. A path (length 175 mm) filled with atmospheric air is inserted in one arm. Another interfe

  46. S. H. Pravdo, Y. Tsuboi, A. Uzawa, Y. Ezoe

    We report an observation of X-ray emission from the exciting region of Cepheus A with the Chandra/ACIS instrument. What had been an unresolved X-ray source comprising the putative power sources is now resolved into at least 3 point-like sources, each with similar X-ray properties and differing radio and submillimeter properties. The sources are HW9, HW3c, an

  47. Haibo Hu, Xiaofan Wang

    The conventional wisdom is that social networks exhibit an assortative mixing pattern, whereas biological and technological networks show a disassortative mixing pattern. However, the recent research on the online social networks modifies the widespread belief, and many online social networks show a disassortative or neutral mixing feature. Especially, we fo

  48. Suzanne M. Fielding, Helen J. Wilson

    Motivated by the need for a theoretical study in a planar geometry that can easily be implemented experimentally, we study the pressure driven Poiseuille flow of a shear banding fluid. After discussing the &#34;basic states&#34; predicted by a one dimensional calculation that assumes a flat interface between the bands, we proceed to demonstrate such an inter

  49. S. N. Aristov, A. D. Polyanin

    New classes of exact solutions of the three-dimensional unsteady Navier-Stokes equations containing arbitrary functions and parameters are described. Various periodic and other solutions, which are expressed through elementary functions are obtained. The general physical interpretation and classification of solutions is given.

  50. M. Tluczykont, T. Kneiske, D. Hampf, D. Horns

    We propose to explore the so-far poorly measured cosmic ray and gamma-ray sky (accelerator sky) in the energy range from 10 TeV to 1 EeV. New physics questions might be addressed in this last remaining observation window of gamma-ray astronomy. The very high beam-energies provided by Cosmic accelerators and the air-shower detection technique naturally imply

  51. Martin Durant, Remon Cornelisse, Ron Remillard, Alan Levine

    Regular observations by the All Sky Monitor aboard the Rossi X-ray Timing Explorer satellite have yielded well-sampled light-curves with a time baseline of over ten years. We find that up to eight of the sixteen brightest persistent low mass X-ray binaries show significant, possible sinusoidal, variations with periods of order ten years. We speculate on its

  52. Pritam Ranjan, Derek R. Bingham, Angela M. Dean

    Regular factorial designs with randomization restrictions are widely used in practice. This paper provides a unified approach to the construction of such designs using randomization defining contrast subspaces for the representation of randomization restrictions. We use finite projective geometry to determine the existence of designs with the required struct

  53. Philippe Wenger, Damien Chablat

    A class of analytic planar 3-RPR manipulators is analyzed in this paper. These manipulators have congruent base and moving platforms and the moving platform is rotated of 180 deg about an axis in the plane. The forward kinematics is reduced to the solution of a 3rd-degree polynomial and a quadratic equation in sequence. The singularities are calculated and p

  54. B. Horvath, B. Lazarovits, G. Zarand

    We study equilibrium and non-equilibrium properties of a two-level quantum dot close to the singlet-triplet transition. We treat the on-site Coulomb interaction and Hund&#39;s rule coupling perturbatively within the Keldysh formalism. We compute the spectral functions and the differential conductance of the dot. For moderate interactions our perturbative app

  55. Zachary Mesyan

    Given a unital associative ring S and a subring R, we say that S is an ideal (or Dorroh) extension of R if for some ideal I of S, S = R + I, where the sum is direct. In this note we investigate the ideal structure of an arbitrary ideal extension of an arbitrary ring R. In particular, we describe the Jacobson and upper nil radicals of such a ring, in terms of

  56. Yoichi Nishiyama

    This paper generalizes a part of the theory of $Z$-estimation which has been developed mainly in the context of modern empirical processes to the case of stochastic processes, typically, semimartingales. We present a general theorem to derive the asymptotic behavior of the solution to an estimating equation $θ\leadsto Ψ_n(θ,\widehat{h}_n)=0$ with an abstract

  57. Jorgen Cherly

    In this paper we illustrate by some examples the connection between the number of solutions of polynomial equations satisfying degree conditions and the number of rank I matrices related to persymmetric matrices.

  58. Ivo Herzog

    Given an associative, not necessarily commutative, ring R with identity, a formal matrix calculus is introduced and developed for pairs of matrices over R. This calculus subsumes the theory of homogeneous systems of linear equations with coefficients in R. In the case when the ring R is a field, every pair is equivalent to a homogeneous system. Using the for

  59. Shouchuan Zhang, Jieqiong He, Guichao Wu

    To classify the finite dimensional pointed Hopf algebras with $G= {\rm McL}$ we obtain the representatives of conjugacy classes of $G$ and all character tables of centralizers of these representatives by means of software {\rm GAP}.

  60. Yoshihiro Yajima, Yasumasa Matsuda

    We formulate nonparametric and semiparametric hypothesis testing of multivariate stationary linear time series in a unified fashion and propose new test statistics based on estimators of the spectral density matrix. The limiting distributions of these test statistics under null hypotheses are always normal distributions, and they can be implemented easily fo

  61. R. J. Angeles-Canul, R. Norton, M. Opperman, C. Paribello

    We study perfect state transfer on quantum networks represented by weighted graphs. Our focus is on graphs constructed from the join and related graph operators. Some specific results we prove include: (1) The join of a weighted two-vertex graph with any regular graph has perfect state transfer. This generalizes a result of Casaccino et al. [clms09] where th

  62. Ana Hurtado, Vicente Palmer

    We give a geometric criterion which shows p-parabolicity of a class of submanifolds in a Riemannian manifold, with controlled second fundamental form, for p bigger or equal than 2.

  63. W. B. Cardoso, N. G. de Almeida, A. T. Avelar, B. Baseia

    In this brief report we present a feasible scheme to split quantum information in the realm of traveling waves. An oversimplified scheme is also proposed for the generation of a class of W states useful for perfect teleportation and superdense coding. The scheme employs only linear optical elements as beam splitters and phase shifters, in addition to photon

  64. Jordan M. Horowitz, Christopher Jarzynski

    We analyze a generic model of mesoscopic machines driven by the nonadiabatic variation of external parameters. We derive a formula for the probability current; as a consequence we obtain a no-pumping theorem for cyclic processes satisfying detailed balance and demonstrate that the rectification of current requires broken spatial symmetry.

  65. Juan Pablo Paz, Augusto J. Roncaglia

    The evolution of the entanglement between oscillators that interact with the same environment displays highly non-trivial behavior in the long time regime. When the oscillators only interact through the environment, three dynamical phases were identified and a simple phase diagram characterizing them was presented. Here we generalize those results to the cas

  66. Antonio Esteve, Vicente Palmer

    We give a set of sufficient and necessary conditions for parabolicity and hyperbolicity of a submanifold with controlled mean curvature in a Riemannian manifold with a pole and with sectional curvatures bounded from above or from below.

  67. Pere Ara, Miquel Brustenga

    In this paper we introduce a new class of $K$-algebras associated with quivers. Given any finite chain $\mathbf{K}_r: K=K_0\subseteq K_1\subseteq ... \subseteq K_r$ of fields and a chain $\mathbf{E}_r : H_0\subset H_1\subset ... \subset H_r=E^0$ of hereditary saturated subsets of the set of vertices $E^0$ of a quiver $E$, we build the mixed path algebra $P_{

  68. H. Spiesberger

    The conference &#39;Photon 2009&#39; on the structure and the interactions of the photon included sessions on photon-photon collisions and a future high-energy photon linear collider. This summary of theoretical contributions to the conference therefore has two parts. I will discuss the physics potential of photon colliders with an emphasis on the study of e

  69. S. Floerchinger

    The method of functional renormalization is applied to the theoretical investigation of ultracold quantum gases. Flow equations are derived for a Bose gas with approximately pointlike interaction, for a Fermi gas with two (hyperfine) spin components in the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) crossover and for a Fermi gas with

  70. Xiao-Qiang Xu, Li-Hua Lu, You-Quan Li

    We propose a strategy to enhance the atom-to-molecule conversion efficiency near a Feshbach resonance. Based on the mean-field approximation, we derive the fixed point solutions of the classical Hamiltonian. Rabi oscillation between the atomic and molecular states around fixed point solutions and its oscillation period are discussed. By designing a sequence

  71. János Barát, Géza Tóth

    Albertson conjectured that if a graph $G$ has chromatic number $r$ then its crossing number is at least as much as the crossing number of $K_r$. Albertson, Cranston, and Fox verified the conjecture for $r\le 12$. We prove the statement for $r\le 16$.

  72. N. N. Guan, Z. J. He, J. L. Long, X. Z. Cai

    By considering the effect of shear viscosity we have investigated the evolution of a chemically equilibrating quark-gluon plasma at finite baryon density. Based on the evolution of the system we have performed a complete calculation for the dilepton production from the following processes: $q\bar{q}{\to}l\bar{l}$, $q\bar{q}{\to}gl\bar{l}$, Compton-like scatt

  73. Peng Zhao, Guilherme Rocha, Bin Yu

    Extracting useful information from high-dimensional data is an important focus of today&#39;s statistical research and practice. Penalized loss function minimization has been shown to be effective for this task both theoretically and empirically. With the virtues of both regularization and sparsity, the $L_1$-penalized squared error minimization method Lasso

  74. Amit Verma, Anirban Pathak

    Single photon sources to be used in quantum cryptography must show higher order antibunching (HOA). HOA is reported by us in several many wave mixing processes. In the present work we have investigated the possibility of observing HOA in multiwave mixing processes in general. The generalized Hamiltonian is solved for several particular cases in Heisenberg pi

  75. Teiko Heinosaari, Alexander S. Holevo, Michael M. Wolf

    We investigate the semigroup structure of bosonic Gaussian quantum channels. Particular focus lies on the sets of channels which are divisible, idempotent or Markovian (in the sense of either belonging to one-parameter semigroups or being infinitesimal divisible). We show that the non-compactness of the set of Gaussian channels allows for remarkable differen

  76. Matan Mussel, Ran Yacoby

    We compute the 2-loop thermal partition function of Yang-Mills theory on a small 3-sphere, in the large N limit with weak 't Hooft coupling. We include N_s scalars and N_f chiral fermions in the adjoint representation of the gauge group (S)U(N), with arbitrary Yukawa and quartic scalar couplings, assuming only commutator interactions. From this computation o

  77. J. M. Paredes, J. Marti, C. H. Ishwara-Chandra, J. R. Sanchez-Sutil

    (abridged) MGRO J2019+37 is an unidentified extended source of VHE gamma-rays originally reported by the Milagro Collaboration as the brightest TeV source in the Cygnus region. Its extended emission could be powered by either a single or several sources. The GeV pulsar AGL J2020.5+3653, discovered by AGILE and associated with PSR J2021+3651, could contribute

  78. Raul Jimenez, Licia Verde

    The recent weak lensing measurement of the dark matter mass of the high-redshift galaxy cluster XMMUJ2235.3-2557 of (8.5 +- 1.7) x 10^{14} Msun at z=1.4, indicates that, if the cluster is assumed to be the result of the collapse of dark matter in a primordial gaussian field in the standard LCDM model, then its abundance should be < 0.002 clusters in the obse

  79. Noam Shental, Amnon Amir, Or Zuk

    Detection of rare variants by resequencing is important for the identification of individuals carrying disease variants. Rapid sequencing by new technologies enables low-cost resequencing of target regions, although it is still prohibitive to test more than a few individuals. In order to improve cost trade-offs, it has recently been suggested to apply poolin

  80. Alan W. McConnachie, Michael J. Irwin, Rodrigo A. Ibata, John Dubinski

    In hierarchical cosmological models, galaxies grow in mass through the continual accretion of smaller ones. The tidal disruption of these systems is expected to result in loosely bound stars surrounding the galaxy, at distances that reach $10 - 100$ times the radius of the central disk. The number, luminosity and morphology of the relics of this process prov

  81. Ying Jiang, Guo-Hong Yang

    Deconfined quantum phase transition from Néel phase to Valence bond crystal state in 2D Heisenberg model is under debate nowadays. One crucial issue is the suppression of Haldane&#39;s instanton on quantum critical point which drives the spinon deconfined. In this paper, by making use of the $ϕ$-mapping topological current theory, we reexamine the Haldane&#3

  82. Jian-Wen Xu, Hui-Rong Zhang

    There are either a near kinematic distance of 5.5 kpc or a far distance of 8.8 kpc for a Galactic supernova remnant (SNR) G32.8$-$0.1 derived by using the rotation curve of the Galaxy. Here we make sure that the remnant distance is the farther one 8.8 kpc through solving a group of equations for the shell-type remnants separately at the adiabatic-phase and t

  83. Olivier Finkel, Pierre Simonnet

    We investigate the topological complexity of non Borel recognizable tree languages with regard to the difference hierarchy of analytic sets. We show that, for each integer $n \geq 1$, there is a $D_{ω^n}({\bf Σ}^1_1)$-complete tree language L_n accepted by a (non deterministic) Muller tree automaton. On the other hand, we prove that a tree language accepted

  84. Marie Doumic Jauffret, Pedro Maia, Jorge P. Zubelli

    The aim of this work is twofold. First, we survey the techniques developed in (Perthame, Zubelli, 2007) and (Doumic, Perthame, Zubelli, 2008) to reconstruct the division (birth) rate from the cell volume distribution data in certain structured population models. Secondly, we implement such techniques on experimental cell volume distributions available in the

  85. Floris van der Tak, Holger Müller, Michael Harding, Jürgen Gauss

    We have observed the rotational ground-state (J = 1-0) transitions of DCO+, HN13C and DNC with the IRAM 30m telescope toward the dark cloud LDN 1512 which has exceptionally narrow lines permitting hyperfine splitting to be resolved in part. The measured splittings of 50-300 kHz are used to derive nuclear quadrupole and spin-rotation parameters for these spec

  86. Christian P. Robert

    Monte Carlo methods are now an essential part of the statistician&#39;s toolbox, to the point of being more familiar to graduate students than the measure theoretic notions upon which they are based! We recall in this note some of the advances made in the design of Monte Carlo techniques towards their use in Statistics, referring to Robert and Casella (2004,

  87. J. J. Omiste, R. J. Yanez, J. S. Dehesa

    The half-line one-dimensional Coulomb potential is possibly the simplest D-dimensional model with physical solutions which has been proved to be successful to describe the behaviour of Rydberg atoms in external fields and the dynamics of surface-state electrons in liquid helium, with potential applications in constructing analog quantum computers and other f

  88. Miomir S. Stankovic, Predrag M. Rajkovic, Sladjana D. Marinkovic

    Based on the fractional $q$-integral with the parametric lower limit of integration, we define fractional $q$-derivative of Riemann-Liouville and Caputo type. The properties are studied separately as well as relations between them. Also, we discuss properties of compositions of these operators.

  89. Jian-Wen Xu

    We briefly reviewed some recent progress on the studies of supernova remnants (SNRs), including the radio SNRs (the structure, polarization, spectrum etc.), observational characteristics of X-ray emission, pulsar wind nebulae (PWNe), association properties between SNR and PSR, interaction of SNR and interstellar medium (ISM), cosmos ray and the SNRs in exter

  90. Paolo Umari, Nicola Marzari

    We calculate the linear and non-linear susceptibilities of periodic longitudinal chains of hydrogen dimers with different bond-length alternations using a diffusion quantum Monte Carlo approach. These quantities are derived from the changes in electronic polarization as a function of applied finite electric field - an approach we recently introduced and made

  91. Rafał Kulik, Marc Raimondo

    We investigate function estimation in nonparametric regression models with random design and heteroscedastic correlated noise. Adaptive properties of warped wavelet nonlinear approximations are studied over a wide range of Besov scales, $f\in\mathcal{B}^s_{π,r}$, and for a variety of $L^p$ error measures. We consider error distributions with Long-Range-Depen

  92. Y. Fukui, A. Kawamura, T. Wong, M. Murai

    We compare the CO J =(1-0) and HI emission in the Large Magellanic Cloud (LMC) in three dimensions, i.e. including a velocity axis in addition to the two spatial axes, with the aim of elucidating the physical connection between giant molecular clouds (GMCs) and their surrounding HI gas. The CO J =1-0 dataset is from the second NANTEN CO survey and the HI dat

  93. Cecilia Tarantino

    We present a summary of our recent analysis update of flavour changing neutral current (FCNC) processes in the Littlest Higgs model with T-parity (LHT). The essential novelties of our update are: the removal of the logarithmic UV cutoff dependence by the inclusion of the new contribution to the Z^0-penguin diagrams identified by Goto et al. and by del Aguila

  94. V. Gichev

    The paper contains a characterization of compact groups $G\subseteq\GL(V)$, where $V$ is a finite dimensional real vector space, which have the following property \SP{}: the family of convex hulls of $G$-orbits is a semigroup with respect to the Minkowski addition. If $G$ is finite, then \SP{} holds if and only if $G$ is a Coxeter group; if $G$ is connected

  95. Jinhua Gao, Wei-Qiang Chen, Xiao-Yong Feng, X. C. Xie

    We study the transmission through single and double ferromagnetic barriers on the surface of a topological insulator. By adjusting the gate voltage and magnetization oreintation, the ferromagnetic barrier can be tuned into various transmission regions, where the wavevector-dependent tunnelings are quite different. We find that the Klein tunneling can be mani

  96. Yang Li, Hong Guo

    The dynamic behavior of the entanglement for two two-level atoms coupled to a common lossy cavity is studied. We find that the speed of disentanglement is a decreasing (increasing) function of the damping rate of the cavity for on/near (far-off) resonant couplings. The quantitative explanations for these phenomena are given, and further, it is shown that the

  97. F. Romeo, R. Citro

    A general expression of the current induced spin torque in a magnetic layered structure in the presence of external dc or ac voltages is derived in the framework of the scattering matrix approach. A detailed analysis is performed for a magnetic-nonmagnetic-magnetic trilayer connected to external leads in the presence of dc voltage bias in the ballistic regim

  98. Yong-Lu Liu, Ming-Qiu Huang

    We present the light-cone distribution amplitudes of the Xi baryons up to twist six on the basis of QCD conformal partial wave expansion to the leading order conformal spin accuracy. The nonperturbative parameters relevant to the DAs are determined in the framework of the QCD sum rule. The light-cone QCD sum rule approach is used to investigate both the elec

  99. Giovanni Montani, Riccardo Benini

    We analyse the two-dimensional MHD configurations characterising the steady state of the accretion disk on a highly magnetised neutron star. The model we describe has a local character and represents the extension of the crystalline structure outlined in Coppi (2005), dealing with a local model too, when a specific accretion rate is taken into account. We li

  100. Lotfi Chaari, Jean-Christophe Pesquet, Philippe Ciuciu, Amel Benazza-Benyahia

    To reduce scanning time and/or improve spatial/temporal resolution in some MRI applications, parallel MRI (pMRI) acquisition techniques with multiple coils acquisition have emerged since the early 1990s as powerful 3D imaging methods that allow faster acquisition of reduced Field of View (FOV) images. In these techniques, the full FOV image has to be reconst