Skip to content

March 2006 arXiv papers — page 33

Showing 3,2013,300 of 4,608 papers

  1. Dinesh Topwal, U. Manju, Sugata Ray, S. Raj

    Besides a drastic reduction in saturation magnetization of disordered Sr2FeMoO6 compared to highly ordered samples, magnetizations as a function of the temperature for different disordered samples may also show qualitatively different behaviors. We investigate the origin of such diversity by performing spatially resolved photoemission spectroscopy on various

  2. Hai Pang, Wu-Sheng Dai, Mi Xie

    In this paper, we show that there exists an essential difference of boundary effects between Bose and Fermi systems both for Dirichlet and Neumann boundary conditions: at low temperatures and high densities the influence of the boundary on the Bose system depends on the temperature but is independent of the density, but for the Fermi case the influence of th

  3. A. Svane, N. E. Christensen, L. Petit, Z. Szotek

    The electronic structures of substitutional rare-earth (RE) impurities in GaAs and cubic GaN are calculated. The total energy is evaluated with the self-interaction corrected local spin density approximation, by which several configurations of the open 4f shell of the rare-earth ion may be investigated. The defects are modelled by supercells of type REGa$_{n

  4. V. Yu. Trubitsin

    A 2D temperature-dependent effective potential is calculated for the interacting longitudinal and transverse $L-$phonons of $β$ zirconium in the frozen-phonon model. The effective potentials obtained for different temperatures are used for the numerical solution of a set of stochastic differential equations with a thermostat of the white-noise type. Analysis

  5. J. Okamoto, S. -I. Fujimori, T. Okane, A. Fujimori

    We have performed photoemission and soft x-ray absorption studies of pyrochlore-type Ru oxides, namely, the filling-control system Sm$_{2-x}$Ca$_x$Ru$_2$O$_7$ and the bandwidth-control system Sm$_{2-x}$Bi$_x$Ru$_2$O$_7$, which show insulator-to-metal transition with increasing Ca and Bi concentration, respectively. Core levels and the O 2$p$ valence band in

  6. M. Kohmoto, A. Sedrakyan

    We consider Bloch electrons on the honeycomb lattice under a uniform magnetic field with $2 πp/q$ flux per cell. It is shown that the problem factorizes to two triangular lattices. Treating magnetic translations as Heisenberg-Weyl group and by the use of its irreducible representation on the space of theta functions, we find a nested set of Bethe equations,

  7. Jing Xia, Peter T. Beyersdorf, Martin M. Fejer, Aharon Kapitulnik

    We describe a geometry for a Sagnac interferometer with a zero-area Sagnac loop for measuring magneto-optic Kerr effect (MOKE) at cryogenic temperatures. The apparatus is capable of measuring absolute polar Kerr rotation at 1550 nm wavelength without any modulation of the magnetic state of the sample, and is intrinsically immune to reciprocal effects such as

  8. Yong Chen

    We introduce simple prescriptions of the Yukawa potential to describe the effect of size polydispersity and macroion shielding effect in charged colloidal systems. The solid-liquid phase boundaries were presented with the Lindemann criterion based on molecular dynamics simulations. Compared with the Robbins-Kremer-Grest simulation results, a deviation of mel

  9. Latha Venkataraman, Jennifer E. Klare, Iris W. Tam, Colin Nuckolls

    We measure the conductance of amine-terminated molecules by breaking Au point contacts in a molecular solution at room temperature. We find that the variability of the observed conductance for the diamine molecule-Au junctions is much less than the variability for diisonitrile and dithiol-Au junctions. This narrow distribution enables unambiguous conductance

  10. T. Yildirim, A. B. Harris

    We present a detailed study of the magnetic structure and spin waves in the Fe jarosite compound ${\rm KFe_3(SO_4)_2(OH)_6}$ for the most general Hamiltonian involving one- and two-spin interactions which are allowed by symmetry. We compare the calculated spin-wave spectrum with the recent neutron scattering data of Matan {\it et al.} for various model Hamil

  11. Hidetoshi Nishimori, Masayuki Ohzeki

    A conjecture is given for the exact location of the multicritical point in the phase diagram of the +/- J Ising model on the triangular lattice. The result p_c=0.8358058 agrees well with a recent numerical estimate. From this value, it is possible to derive a comparable conjecture for the exact location of the multicritical point for the hexagonal lattice, p

  12. V. B. Shirokov, V. I. Torgashev, A. A. Bakirov, V. V. Lemanov

    Method of derivation of phenomenological thermodynamic potential of solid solutions is proposed in which the interaction of the order parameters of constituents is introduced through the account of elastic strain due to misfit of the lattice parameters of the end-members. The validity of the method is demonstrated for Ba(x)Sr(1-x)TiO3 system being a typical

  13. Martin Weigel, Michel J. P. Gingras

    We employ a novel algorithm using a quasi-exact embedded-cluster matching technique as minimization method within a genetic algorithm to reliably obtain numerically exact ground states of the Edwards-Anderson XY spin glass model with bimodal coupling distribution for square lattices of up to 28x28 spins. Contrary to previous conjectures, the ground state of

  14. Alexandr Malijevsky, Andres Santos

    Bounded potentials are good models to represent the effective two-body interaction in some colloidal systems, such as dilute solutions of polymer chains in good solvents. The simplest bounded potential is that of penetrable spheres, which takes a positive finite value if the two spheres are overlapped, being 0 otherwise. Even in the one-dimensional case, the

  15. Kuljit S. Virk, J. E. Sipe

    We study the dynamics of impurity bound electrons interacting with a bath of conduction band electrons in a semiconductor. Only the exchange interaction is considered. We derive master equations for the density matrices of single and two qubit systems under the usual Born and Markov approximations. The bath mediated RKKY interaction in the two qubit case ari

  16. Jonathan C. Tan, Mark R. Krumholz, Christopher F. McKee

    We argue that rich star clusters take at least several local dynamical times to form, and so are quasi-equilibrium structures during their assembly. Observations supporting this conclusion include morphologies of star-forming clumps, momentum flux of protostellar outflows from forming clusters, age spreads of stars in the Orion Nebula Cluster (ONC) and other

  17. Joshua A. Faber, Thomas W. Baumgarte, Stuart L. Shapiro, Keisuke Taniguchi

    The recent localization of some short-hard gamma ray bursts (GRBs) in galaxies with low star formation rates has lent support to the suggestion that these events result from compact object binary mergers. We discuss how new simulations in general relativity are helping to identify the central engine of short-hard GRBs. Motivated by our latest relativistic bl

  18. A. Gould, A. Udalski, D. An, D. P. Bennett

    We detect a Neptune mass-ratio (q~8e-5) planetary companion to the lens star in the extremely high-magnification (A~800) microlensing event OGLE-2005-BLG-169. If the parent is a main-sequence star, it has mass M~0.5 M_sun implying a planet mass of ~13 M_earth and projected separation of ~2.7 AU. When intensely monitored over their peak, high-magnification ev

  19. U. Heiter, K. Eriksson

    We investigate the effect of a geometric inconsistency in the calculation of synthetic spectra of giant stars. Spectra computed with model atmospheres calculated in spherical geometry while using the plane-parallel approximation for line formation calculations (s_p), as well as the fully plane-parallel case (p_p), are compared to the consistently spherical c

  20. Daniel S. Hudson, Thomas H. Reiprich, Tracy E. Clarke, Craig L. Sarazin

    We report the first X-ray detection of a proto-supermassive binary black hole at the centre of Abell 400. Using the Chandra ACIS, we are able to clearly resolve the two active galactic nuclei in 3C 75, the well known double radio source at the centre of Abell 400. Through analysis of the new Chandra observation of Abell 400 along with 4.5 GHz and 330 MHz VLA

  21. Sofia A. Cora

    We develop a model for the metal enrichment of the intracluster medium (ICM) that combines a cosmological non-radiative hydrodynamical N-Body/SPH simulation of a cluster of galaxies, and a semi-analytic model of galaxy formation. The novel feature of our hybrid model is that the chemical properties of the diffuse gas in the underlying simulation are dynamica

  22. G. Cocozza, F. R. Ferraro, A. Possenti, N. D'Amico

    We have used phase-resolved high-resolution images and low resolution spectra taken at the ESO Very Large Telescope, to study the properties of the low-mass Helium White Dwarf companion to the millisecond pulsar \psr (hereafter COM J1911$-$5958A), in the halo of the Galactic Globular Cluster NGC 6752. The radial velocity curve confirms that \com is orbiting

  23. D. A. Garcia-Hernandez, C. Abia, A. Manchado, P. Garcia-Lario

    We present high resolution optical spectroscopic observations of IRAS 09425-6040, a peculiar, extremely red, C-rich AGB star showing prominent O-rich dust features in its ISO infrared spectrum attributed to crystalline silicates. Our analysis shows that IRAS 09425-6040 is indeed a C-rich star slightly enriched in lithium (log (Li/H) + 12 ~ 0.7) with a low 12

  24. Liang Cao, Wei Zuo, Yao-Quan Chu

    In this paper, we try to detect the SZ effect in the 2MASS DWT clusters and less bound objects in order to constrain the warm-hot intergalactic medium distribution on large scales by cross-correlation analysis. The results of both observed WMAP and mock SZ effect map indicate that the hot gas distributes from inside as well as outside of the high density reg

  25. J. M. Oliveira, R. D. Jeffries, J. Th. van Loon, M. T. Rushton

    We present new K- and L'-band imaging observations for members of the young (3-5 Myr) sigma Orionis cluster, obtained with UIST at UKIRT. We determine (K-L') colour excesses with respect to the photospheres, finding evidence for warm circumstellar dust around 27 out of 83 cluster members that have masses between 0.04 Msun and 1.0 Msun. This indicates

  26. R. Maiolino, T. Nagao, A. Marconi, R. Schneider

    We summarize some recent results on the metallicity and dust properties of Active Galactic Nuclei (AGN) at high redshift (1<z<6.4). By using the spectra of more than 5000 QSOs from the SDSS we find no evidence for any metallicity evolution in the redshift range 2<z<4.5, while there is a significant luminosity-metallicity dependence. These results are confirm

  27. Masahiro Nagashima, Shu-ichiro Inutsuka, Hiroshi Koyama

    We estimate the evaporation timescale for spherical HI clouds consisting of the cold neutral medium surrounded by the warm neutral medium. We focus on clouds smaller than 1pc, which corresponds to tiny HI clouds recently discovered by Braun & Kanekar and Stanimirovi{ć} & Heiles. By performing one-dimensional spherically symmetric numerical simulations of the

  28. S. B. Popov, R. Turolla, A. Possenti

    We highlight similarities between recently discovered Rotating Radio Transients and X-ray Dim Isolated Neutron Stars. In particular, it is shown that X-ray Dim Isolated Neutron Stars have a birthrate comparable to that of Rotating Radio Transients. On the contrary, magnetars have too low a formation rate to account for the bulk of the radio transient populat

  29. D. V. Ahluwalia-Khalilova

    In astro-ph/0601489, within the framework of the Einsteinian general relativity, we made the observation that if the universe is described by a spatially flat Friedmann-Robertson-Walker (FRW) cosmology with Einsteinian cosmological constant then the resulting cosmology predicts a significant dark matter component in the universe. Furthermore, the phenomenolo

  30. F. Shi, X. Kong, F. Z. Cheng

    We present two samples of $\hii$ galaxies from the Sloan Digital Sky Survey (SDSS) spectroscopic observations data release 3. The electron temperatures($T_e$) of 225 galaxies are calculated with the photoionized $\hii$ model and $T_e$ of 3997 galaxies are calculated with an empirical method. The oxygen abundances from the $T_e$ methods of the two samples are

  31. Kevork Abazajian

    I consider constraints from observations on a cutoff scale in clustering due to free streaming of the dark matter in a warm dark matter cosmological model with a cosmological constant. The limits are derived in the framework of a sterile neutrino warm dark matter universe, but can be applied to gravitinos and other models with small scale suppression in the

  32. Eduardo Martinez

    It is shown that the Euler-Lagrange equations for a Lagrangian system on a Lie algebroid are obtained as the equations for the critical points of the action functional defined on a Banach manifold of curves. The theory of reduction and the relation with Lagrange multiplier method are also studied.

  33. Aleksandar Stojmirović, Peter Andreae, Mike Boland, Thomas William Jordan

    Protein Fragment Motif Finder (PFMFind) is a system that enables efficient discovery of relationships between short fragments of protein sequences using similarity search. It supports queries based on score matrices and PSSMs obtained through an iterative procedure similar to PSI-BLAST. PSSM construction is customisable through plugins written in Python. PFM

  34. Kayll Lake

    An explicit and complete set of constants of the motion are constructed algorithmically for Friedmann-Lemaître-Robertson-Walker (FLRW) models consisting of an arbitrary number of non-interacting species. The inheritance of constants of the motion from simpler models as more species are added is stressed. It is then argued that all FLRW models admit what amou

  35. Patrick Cote, Slawomir Piatek, Laura Ferrarese, Andres Jordan

    (Abridged) The ACS Virgo Cluster Survey is an HST program to obtain high-resolution, g and z-band images for 100 early-type members of the Virgo Cluster, spanning a range of ~460 in blue luminosity. Based on this large, homogeneous dataset, we present a sharp upward revision in the frequency of nucleation in early-type galaxies brighter than M_B ~ -15 (66 <

  36. Tamas Gal

    The mathematics of K-conserving functional differentiation, with K being the integral of some invertible function of the functional variable, is clarified. The most general form for constrained functional derivatives is derived from the requirement that two functionals that are equal over a restricted domain have equal derivatives over that domain. It is sho

  37. K. Yu. Bliokh

    We consider propagation of a paraxial beam carrying the spin angular momentum (polarization) and intrinsic orbital angular momentum (IOAM) in a smoothly inhomogeneous isotropic medium. It is shown that the presence of IOAM can dramatically enhance and rearrange the topological phenomena that previously were considered solely in connection to the polarization

  38. B. Chen, R. Kantowski, E. Baron, S. Knop

    We derive the radiative transfer equation for arbitrary stationary relativistic flows in stationary spacetimes, i.e. for steady-state transfer problems. We show how the standard characteristics method of solution developed by Mihalas and used throughout the radiative transfer community can be adapted to multi-dimensional applications with isotropic sources.

  39. Adrian Constantin, Vladimir S. Gerdjikov, Rossen I. Ivanov

    An Inverse Scattering Method is developed for the Camassa-Holm equation. As an illustration of our approach the solutions corresponding to the reflectionless potentials are explicitly constructed in terms of the scattering data. The main difference with respect to the standard Inverse Scattering Transform lies in the fact that we have a weighted spectral pro

  40. Ajay Kumar Ghosh, Peter Olsson, S. Teitel

    Resistively-shunted-junction dynamics is applied to the three dimensional uniformly frustrated XY model with randomly perturbed couplings, as a model for driven steady states in a type-II superconductor with quenched point pinning. For a disorder strength p strong enough to produce a vortex glass in equilibrium, we map the phase diagram as a function of temp

  41. Juerg Diemand, Michael Kuhlen, Piero Madau

    Earth-mass ``microhalos&#39;&#39; may be the first objects to virialize in the early universe. Their ability to survive the hierarchical clustering process as substructure in the larger halos that form subsequently has implications for dark matter detection experiments. We present a large N-body simulation of early substructure in a supersymmetric cold dark

  42. Jinwu Ye

    We construct a Ginsburg Landau (GL) theory to study the phases of liquid, solid, superfluid, especially a possible supersolid and phase transitions among these phases in a unified framework. In this GL, we put the two competing orders between the solid component and the superfluid component on the same footing. We only introduce two parameters: $ v $ which i

  43. G. V. Ustyugova, A. V. Koldoba, M. M. Romanova, R. V. E. Lovelace

    We present results of axisymmetic magnetohydrodynamic simulations of the interaction of a rapidly-rotating, magnetized star with an accretion disk. The disk is considered to have a finite viscosity and magnetic diffusivity. The main parameters of the system are the star&#39;s angular velocity and magnetic moment, and the disk&#39;s viscosity, diffusivity. We

  44. C. Y. Peng, C. D. Impey, H. -W. Rix, C. S. Kochanek

    In the present-day universe, supermassive black hole masses (MBH) appear to be strongly correlated with their galaxy&#39;s bulge luminosity, among other properties. In this study, we explore the analogous relationship between MBH, derived using the virial method, and the stellar R-band bulge luminosity (Lr) or stellar bulge mass (M*) at epochs of 1 < z < 4.5

  45. C. Montijn, W. Hundsdorfer, U. Ebert

    The evolution of negative streamers during electric breakdown of a non-attaching gas can be described by a two-fluid model for electrons and positive ions. It consists of continuity equations for the charged particles including drift, diffusion and reaction in the local electric field, coupled to the Poisson equation for the electric potential. The model gen

  46. Andrzej J. Buras, Martin Gorbahn, Ulrich Haisch, Ulrich Nierste

    We calculate the complete NNLO QCD corrections to the charm contribution of the rare decay K+ -> pi+ nu nu-bar. We encounter several new features, which were absent in lower orders. We discuss them in detail and present the results for the 2-loop matching conditions of the Wilson coefficients, the 3-loop anomalous dimensions, and the 2-loop matrix elements o

  47. Yago Ascasibar, Maxim Markevitch

    Chandra X-ray observations revealed the presence of cold fronts (sharp contact discontinuities between gas regions with different temperatures and densities) in the centers of many, if not most, relaxed clusters with cool cores. We use high-resolution simulations of idealized cluster mergers to show that they are due to sloshing of the cool gas in the centra

  48. Eric Gawiser, Pieter G. van Dokkum, Caryl Gronwall, Robin Ciardullo

    We selected 40 candidate Lyman Alpha Emitting galaxies (LAEs) at z ~=3.1 with observed frame equivalent widths >150A and inferred emission line fluxes >2.5x10^-17 ergs/cm^2/s from deep narrow-band and broad-band MUSYC images of the Extended Chandra Deep Field South. Covering 992 sq. arcmin, this is the largest ``blank field'' surveyed for LAEs at z ~3, allow

  49. P. Fraundorf

    The standing crop of correlations in metazoan communities may be assessed by an inventory of niche structures focused inward and outward from the physical boundaries of skin (self), gene-pool (family), and meme-pool (culture). We consider tracking the progression from three and four correlation layers in many animal communities, to five of six layers for the

  50. Anne V. Shepler, Sarah Witherspoon

    We develop and collect techniques for determining Hochschild cohomology of skew group algebras S(V)#G and apply our results to graded Hecke algebras. We discuss the explicit computation of certain types of invariants under centralizer subgroups, focusing on the infinite family of complex reflection groups G(r,p,n) to illustrate our ideas. Resulting formulas

  51. Peter Ebenfelt, Linda P. Rothschild

    We give some results concerning the smoothness of the image of a real-analytic submanifold in complex space under the action of a finite holomorphic mapping. For instance, if the submanifold is not contained in a proper complex subvariety, we give a necessary and sufficient condition guaranteeing that its image is smooth and the mapping is transversal to the

  52. Eric Gawiser

    The Multiwavelength Survey by Yale-Chile (MUSYC) is optimized for the study of galaxies at z=3, AGN demographics, and Galactic structure. MUSYC consists of deep optical (UBVRIz') and near-infrared (JHK) imaging of four fields on the sky covering 1.2 square degrees to AB limiting depths of U,B,V,R=26 and K=22. Our optical catalog contains 277,341 objects dete

  53. R. Rak, S. Drozdz, J. Kwapien

    The statistics of return distributions on various time scales constitutes one of the most informative characteristics of the financial dynamics. Here we present a systematic study of such characteristics for the Polish stock market index WIG20 over the period 04.01.1999 - 31.10.2005 for the time lags ranging from one minute up to one hour. This market is com

  54. Aristophanes Dimakis, Folkert Muller-Hoissen

    We consider a general framework for integrable hierarchies in Lax form and derive certain universal equations from which `functional representations&#39; of particular hierarchies (like KP, discrete KP, mKP, AKNS), i.e. formulations in terms of functional equations, are systematically and quite easily obtained. The formalism genuinely applies to hierarchies

  55. M. Dzero, M. R. Norman, I. Paul, C. Pepin

    The Kondo volume collapse describes valence transitions in f-electron metals, and is characterized by a line of first order transitions in the pressure-temperature phase plane terminated at critical end points. We analyze the quantum critical end point, when the lower end point is tuned to T=0, and determine the specific heat, thermal expansion, and compress

  56. J. K. Korbicz, M. Lewenstein

    We sketch a group-theoretical framework, based on the Heisenberg-Weyl group, encompassing both quantum and classical statistical descriptions of mechanical systems. We re-define in group-theoretical terms the kinematical arena and the state-space of the system, achieving a unified quantum-classical language and a novel version of the correspondence principle

  57. S. Perez Gaviro, Juan J. Ruiz-Lorenzo, A. Tarancon

    Using the decay of the out equilibrium spin-spin correlation function we compute the equilibrium Edward-Anderson order parameter in the three dimensional binary Ising spin glass in the spin glass phase. We have checked that the Edward-Anderson order parameter computed from out of equilibrium numerical simulations follows with good precision the critical law

  58. Michael Aizenman, Paul Jung

    We present general results for the contact process by a method which applies to all transitive graphs of bounded degree, including graphs of exponential growth. The model&#39;s infection rates are varied through a control parameter, for which two natural transition points are defined as: i. $λ_T$, the value up to which the infection dies out exponentially fa

  59. A. Libal, C. Reichhardt, C. J. Olson Reichhardt

    We demonstrate how a colloidal version of artificial ice can be realized on optical trap lattices. Using numerical simulations, we show that this system obeys the ice rules and that for strong colloid-colloid interactions, an ordered ground state appears. We show that the ice rule ordering can occur for systems with as few as twenty-four traps and that the o

  60. M. Tajmar, C. J. de Matos

    We show that non-zero masses for a spin-1 graviton (called graviphoton) leads to considerable gravitomagnetic fields around rotating mass densities, which are not observed. The solution to the problem is found by an equivalent graviphoton mass which depends on the local mass density to ensure the principle of equivalence. This solution, derived from Einstein

  61. Andreas Birkedal, Andrew Noble, Maxim Perelstein, Andrew Spray

    The introduction of T parity dramatically improves the consistency of Little Higgs models with precision electroweak data, and renders the lightest T-odd particle (LTP) stable. In the Littlest Higgs model with T parity, the LTP is typically the T-odd heavy photon, which is weakly interacting and can play the role of dark matter. We analyze the relic abundanc

  62. Quentin G. Bailey, Alan Kostelecky

    The pure-gravity sector of the minimal Standard-Model Extension is studied in the limit of Riemann spacetime. A method is developed to extract the modified Einstein field equations in the limit of small metric fluctuations about the Minkowski vacuum, while allowing for the dynamics of the 20 independent coefficients for Lorentz violation. The linearized effe

  63. Oo-Kaw Lim, Mark Saffman

    We show that non-classical intensity correlations and quadrature entanglement can be generated by frequency doubling in a resonator with two output ports. We predict twin-beam intensity correlations 6 dB below the coherent state limit, and that the product of the inference variances of the quadrature fluctuations gives an Einstein-Podolsky-Rosen (EPR) correl

  64. Wei Dai, Youjian Liu, Brian Rider

    This paper considers the quantization problem on the Grassmann manifold \mathcal{G}_{n,p}, the set of all p-dimensional planes (through the origin) in the n-dimensional Euclidean space. The chief result is a closed-form formula for the volume of a metric ball in the Grassmann manifold when the radius is sufficiently small. This volume formula holds for Grass

  65. Markus Schwarz, Ralf Hofmann, Francesco Giacosa

    We compute the one-loop polarization tensor $Π$ for the on-shell, massless mode in a thermalized SU(2) Yang-Mills theory being in its deconfining phase. Postulating that SU(2)$_{\tiny{CMB}}\stackrel{\tiny{today}}=U(1)_Y$, we discuss $Π$&#39;s effect on the low-momentum part of the black-body spectrum at temperatures $\sim 2... 4$ $T_{\tiny{CMB}}$ where $T_{\

  66. A. Silantyev

    The method of Lambda-operators developed by S. Derkachov, G. Korchemsky, A. Manashov is applied to a derivation of eigenfunctions for the open Toda chain. The Sklyanin measure is reproduced using diagram technique developed for these Lambda-operators. The properties of the Lambda-operators are studied. This approach to the open Toda chain eigenfunctions repr

  67. Massimo Mannarelli, Krishna Rajagopal, Rishi Sharma

    It is an open challenge to analyze the crystalline color superconducting phases that may arise in cold dense, but not asymptotically dense, three-flavor quark matter. At present the only approximation within which it seems possible to compare the free energies of the myriad possible crystal structures is the Ginzburg-Landau approximation. Here, we test this

  68. Paul Doukhan, Olivier Wintenberger

    The aim of this article is to refine a weak invariance principle for stationary sequences given by Doukhan & Louhichi (1999). Since our conditions are not causal our assumptions need to be stronger than the mixing and causal $θ$-weak dependence assumptions used in Dedecker & Doukhan (2003). Here, if moments of order $>2$ exist, a weak invariance principle an

  69. J. C. Martin

    This paper continues the analysis of faint high latitude B stars from Martin (2004). Here we analyze the kinematics of the stars and combine them with the abundance information from the first paper to classify each one. The sample contains 31 Population I runaways, fifteen old evolved stars (including five BHB stars, three post-HB stars, a pulsating helium d

  70. Maria Fidecaro, Hans-Juerg Gerber

    During the recent years experiments with neutral kaons have yielded remarkably sensitive results which are pertinent to such fundamental phenomena as CPT invariance (protecting causality), time-reversal invariance violation, coherence of wave functions, and entanglement of kaons in pair states. We describe the phenomenological developments and the theoretica

  71. M. Mapelli, A. Ferrara, E. Pierpaoli

    One of the possible methods to distinguish among various dark matter candidates is to study the effects of dark matter decays. We consider four different dark matter candidates (light dark matter, gravitinos, neutralinos and sterile neutrinos), for each of them deriving the decaying/annihilation rate, the influence on reionization, matter temperature and CMB

  72. Gaetano Bertoldi

    We consider double-scaling limits of multicut solutions of certain one matrix models that are related to Calabi-Yau singularities of type A and the respective topological B model via the Dijkgraaf-Vafa correspondence. These double-scaling limits naturally lead to a bosonic string with c $\leq$ 1. We argue that this non-critical string is given by the topolog

  73. A. E. Shabad, V. V. Usov

    We study the electron-positron system in a strong magnetic field using the differential Bethe-Salpeter equation in the ladder approximation. We derive the fully relativistic two-dimensional form that the four-dimensional Bethe-Salpeter equation takes in the limit of asymptotically strong constant and homogeneous magnetic field. An ultimate value for the magn

  74. Eric T. Johnson, Jeremy Goodman, Kristen Menou

    Torque fluctuations due to magnetorotational turbulence in proto-planetary disks may greatly influence the migration patterns and survival probabilities of nascent planets. Provided that the turbulence is a stationary stochastic process with finite amplitude and correlation time, the resulting diffusive migration can be described with a Fokker-Planck equatio

  75. Abhishek Agarwal

    The super Yang-Mills duals of open strings attached to maximal giant gravitons are studied in perturbation theory. It is shown that non-BPS baryonic excitations of the gauge theory can be studied within the paradigm of open quantum spin chains even beyond the leading order in perturbation theory. The open spin chain describing the two loop mixing of non-BPS

  76. Patrik O. Hoyer, Shohei Shimizu, Antti J. Kerminen

    The estimation of linear causal models (also known as structural equation models) from data is a well-known problem which has received much attention in the past. Most previous work has, however, made an explicit or implicit assumption of gaussianity, limiting the identifiability of the models. We have recently shown (Shimizu et al, 2005; Hoyer et al, 2006)

  77. Rizwan Ul Haq Ansari, P K Suresh

    We have considered phi^4 theory in higher dimensions. Using functional diagrammatic approach, we computed the one-loop correction to effective potential of the scalar field in five dimensions. It is shown that phi^4 theory can be regularised in five dimensions. Temperature dependent one-loop correction and critical temperature T_c are computed and T_c depend

  78. Pantelis S. Apostolopoulos, Nikolaos Brouzakis, Nikolaos Tetradis, Eleftheria Tzavara

    The acceleration parameter defined through the local volume expansion is negative for a pressureless, irrotational fluid with positive energy density. In the presence of inhomogeneities or anisotropies the volume expansion rate results from averaging over various directions. On the other hand, the observation of light from a certain source in the sky provide

  79. Feng-Kun Guo, Peng-Nian Shen, Huan-Ching Chiang, Rong-Gang Ping

    In terms of the heavy chiral Lagrangian and the unitarized coupled-channel scattering amplitude, interaction between the heavy meson and the light pseudoscalar meson is studied. By looking for the pole of scattering matrix on an appropriate Riemann sheet, a $DK$ bound state $D_{s0}^*$ with the mass of $2.312\pm0.041$ GeV is found. This state can be associate

  80. Knud Zabrocki, Steffen Trimper, Svetlana Tatur, Reinhard Mahnke

    We demonstrate the equivalence of a Non--Markovian evolution equation with a linear memory--coupling and a Fokker--Planck equation (FPE). In case the feedback term offers a direct and permanent coupling of the current probability density to an initial distribution, the corresponding FPE offers a non-trivial drift term depending itself on the diffusion parame

  81. Da-Guan Ke, Hong Zhang, Qin-Ye Tong

    A new complexity measure named as Lattice Complexity is presented for finite symbolic sequences. This measure is based on the symbolic dynamics of one-dimensional iterative maps and Lempel-Ziv Complexity. To make Lattice Complexity distinguishable from Lempel-Ziv Complexity, an approach called fine-graining process is also proposed. When the control paramete

  82. Joerg Freund, Dorin Comaniciu, Yannis Ioannis, Peiya Liu

    There is a compelling demand for the integration and exploitation of heterogeneous biomedical information for improved clinical practice, medical research, and personalised healthcare across the EU. The Health-e-Child project aims at developing an integrated healthcare platform for European Paediatrics, providing seamless integration of traditional and emerg

  83. Chiara Del Frate, Jose Galvez, Tamas Hauer, David Manset

    The MammoGrid project has delivered the first deployed instance of a healthgrid for clinical mammography that spans national boundaries. During the last year, the final MammoGrid prototype has undergone a series of rigorous tests undertaken by radiologists in the UK and Italy and this paper draws conclusions from those tests for the benefit of the Healthgrid

  84. Horia D. Cornean, Pierre Duclos, Benjamin Ricaud

    We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with an attractive Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum is well described by a one-dimensional effective Hamiltonian which is exactly solvable.

  85. Christiane Quesne, Volodymyr M. Tkachuk

    Two generalizations of Kempf&#39;s quadratic canonical commutation relation in one dimension are considered. The first one is the most general quadratic commutation relation. The corresponding nonzero minimal uncertainties in position and momentum are determined and the effect on the energy spectrum and eigenfunctions of the harmonic oscillator in an electri

  86. Guy Fayolle, Cyril Furtlehner

    This study deals with continuous limits of interacting one-dimensional diffusive systems, arising from stochastic distortions of discrete curves with various kinds of coding representations. These systems are essentially of a reaction-diffusion nature. In the non-reversible case, the invariant measure has generally a non Gibbs form. The corresponding steady-

  87. Yong Zeng, Ying Fu, Xiaoshuang Chen, Wei Lu

    Using an extended plane-wave-based transfer-matrix method, the photonic band structures and the corresponding transmission spectrum of a two-dimensional left-handed photonic crystal are calculated. Comparisons between the periodic structure with a single left-handed cylindric rod are made, and many interesting similarities are found. It is shown that, due to

  88. Luisa Paoluzzi, Joan Porti

    We prove that every finite group is the orientation-preserving isometry group of the complement of a hyperbolic link in the 3-sphere.

  89. Jeff Kahn, Gil Kalai

    Consider a random graph G in G(n,p) and the graph property: G contains a copy of a specific graph H. (Note: H depends on n; a motivating example: H is a Hamiltonian cycle.) Let q be the minimal value for which the expected number of copies of H&#39; in G is at least 1/2 for every subgraph H&#39; of H. Let p be the value for which the probability that G conta

  90. Y. Nakagawa, A. Nakamura, T. Saito, H. Toki

    We study the properties of the color-Coulomb string tension obtained from the instantaneous part of gluon propagators in Coulomb gauge using quenched SU(3) lattice simulation. In the confinement phase, the dependence of the color-Coulomb string tension on the QCD coupling constant is smaller than that of the Wilson loop string tension. On the other hand, in

  91. Bartosz Zielinski, Magdalena Zych

    The Margolus-Levitin lower bound on minimal time required for a state to be transformed into an orthogonal state is generalized. It is shown that for some initial states new bound is stronger than the Margolus-Levitin one.

  92. Somdeb Lahiri

    We discuss bundle auctions within the framework of an integer allocation problem. We show that for multi-unit auctions, of which bundle auctions are a special case, market equilibrium and constrained market equilibrium are equivalent concepts. This equivalence, allows us to obtain a computable necessary and sufficient condition for the existence of constrain

  93. Chuan-Hung Chen

    We study the doubly charmed baryonic B decays $B\to Ξ_{c} Λ_{c}$ and $B\to Λ^{+}_{c} Λ^{-}_{c} K$, recently observed by BELLE. We find that the unexpected large branching ratios (BRs) could be ascribed to the final state interactions (FSIs), which are dictated by $B\to DD^{+}_{s}\to Ξ_{c} Λ^{+}_{c}$ and $B\to \bar D^0 D^{0} K\to Λ^{+}_{c} Λ^{-}_{c} K$. By ut

  94. Hitoshi Murakami

    We propose a version of the volume conjecture that would relate a certain limit of the colored Jones polynomials of a knot to the volume function defined by a representation of the fundamental group of the knot complement to the special linear group of degree two over complex numbers. We also confirm the conjecture for the figure-eight knot and torus knots.

  95. A. Ghosh, P. Mitra

    The entropy of a black hole can be obtained by counting states in loop quantum gravity. The dominant term depends on the Immirzi parameter involved in the quantization and is proportional to the area of the horizon, while there is a logarithmic correction with coefficient -1/2.

  96. Grzegorz Bobinski

    We characterize the canonical algebras such that for all dimension vectors of homogeneous modules the corresponding module varieties are complete intersections (respectively, normal). We also investigate the sets of common zeros of semi-invariants of non-zero degree in important cases. In particular, we show that for sufficiently big vectors they are complet

  97. Yong Chen, Pan Zhang

    We report a new statistical general property in traveling salesman problem, that the $n$th-nearest-neighbor distribution of optimal tours verifies with very high accuracy an exponential decay as a function of the order of neighbor $n$. With defining the energy function as the deviation $λ$ from this exponential decay, which is different to the tour length $d

  98. T. A. Larsson

    A local gauge symmetry can not possibly be a mere redundancy of the description, provided that 1. charge is nonzero. 2. we also consider divergent gauge transformations, whose brackets with local transformations contain global charge operators. If these conditions hold, unitarity requires the existence of gauge anomalies. We describe the relevant multi-dimen

  99. Toshiaki Tanaka

    We present a set of necessary conditions for the existence of a biorthonormal basis composed of eigenvectors of non-Hermitian operators. As an illustration, we examine these conditions in the case of normal operators. We also provide a generalization of the conditions which is applicable to non-diagonalizable operators by considering not only eigenvectors bu

  100. Vicente Garzo

    A recent solution of the inelastic Boltzmann equation that applies for strong dissipation and takes into account non-equipartition of energy is used to derive an explicit expression for the thermal diffusion factor. This parameter provides a criterion for segregation that involves all the parameters of the granular binary mixture (composition, masses, sizes,