Now showing items 241-260 of 319

    • Completely bounded mappings and simplicial complex structure in the primitive ideal space of a C*-algebra 

      TIMONEY, RICHARD (American Mathematical Society, 2009)
      We consider the natural contraction from the central Haagerup tensor product of a C*-algebra A with itself to the space of completely bounded maps CB(A) on A and investigate those A where there exists an inverse map ...
    • Positive solutions for nonlinear singular boundary value problems on the half line 

      TIMONEY, RICHARD (Hikari Ltd, 2007)
      We discuss the existence of positive solutions for singular second order boundary value problems x'' = ?f(t, x, x'), ax(0) ? bx'(0) = k ? 0, x'(?) = 0, where f may be singular at x = 0 and x' = 0 and can change sign. ...
    • Finding community structures in networks by playing pass-the-parcel. 

      HOUGHTON, CONOR JAMES (2008)
      Many data sets can be represented by undirected networks. Often, an interesting and important feature of these networks is the existence of communities; groups of nodes whose interconnectivity is higher than the average ...
    • Studying spike trains using a van Rossum metric with a synapse-like filter 

      HOUGHTON, CONOR JAMES (2009)
      Spike trains are unreliable. For example, in the primary sensory areas, spike patterns and precise spike times will vary between responses to the same stimulus. Nonetheless, information about sensory inputs is communicated ...
    • Water waves and Integrability 

      IVANOV, ROSSEN (Royal Society, 2007)
      The Euler?s equations describe the motion of inviscid fluid. In the case of shallow water, when a perturbative asymtotic expansion of the Euler?s equations is taken (to a certain order of smallness of the scale parameters), ...
    • Krylov subspaces from bilinear representations of nonlinear systems 

      IVANOV, ROSSEN (Emerald, 2007)
      For efficient simulation of state-of-the-art dynamical systems as arise in all aspects of engineering, the development of reduced-order models is of paramount importance. While linear reduction techniques have received ...
    • Generalised Fourier transform for the Camassa-Holm hierarchy 

      IVANOV, ROSSEN (Institute of Physics, 2007)
      The squared eigenfunctions of the spectral problem associated to the Camassa-Holm equation represent a complete basis of functions, which helps to describe the Inverse Scattering Transform for the Camassa-Holm hierarchy ...
    • High performance scientific computing using FPGAS with IEEE floating point and logarithmic arithmetic for lattice QCD 

      PEARDON, MICHAEL JAMES (IEEE, 2006)
      The recent development of large FPGAs along with the availability of a variety of floating point cores have made it possible to implement high-performance matrix and vector kernel operations on FPGAs. In this paper we seek ...
    • Mesons at high temperature in Nf = 2 QCD 

      PEARDON, MICHAEL JAMES; SKULLERUD, JONIVAR (American Physical Society, 2006)
      We report first results for spectral functions of charmonium in 2-flavour QCD. The spectral functions are determined from vector and pseudoscalar correlators on a dynamical, anisotropic lattice. J/ and c are found ...
    • Glueball spectrum and matrix elements on anisotropic lattices 

      PEARDON, MICHAEL JAMES (American Physical Society, 2006)
      The glueball-to-vacuum matrix elements of local gluonic operators in scalar, tensor, and pseudoscalar channels are investigated numerically on several anisotropic lattices with the spatial lattice spacing ranging from ...
    • Charmonium spectral functions in Nf=2 QCD 

      PEARDON, MICHAEL JAMES; SKULLERUD, JONIVAR (Proceedings of Science, 2005)
      We report on a study of charmonium at high temperature in 2-flavour QCD. This is the first such study with dynamical fermions. Using an improved anisotropic lattice action, spectral functions are extracted from correlators ...
    • Glueball matrix elements on anisotropic lattices 

      PEARDON, MICHAEL JAMES (Elsevier, 2004)
      The glueball-to-vacuum matrix elements of local gluonic operators in scalar, tensor, and pseudoscalar channels are investigated numerically on several anisotropic lattices with the spatial lattice spacing in the range ...
    • Excitations of the torelon 

      PEARDON, MICHAEL JAMES (Elsevier, 2004)
      The excitations of gluonic flux tube in a periodic lattice are examined. Monte Carlo simulations from an anisotropic lattice are presented and the comparison with effective string models is discussed.
    • Analytic smearing of SU(3) link variables in lattice QCD 

      PEARDON, MICHAEL JAMES (American Physical Society, 2004)
      An analytic method of smearing link variables in lattice QCD is proposed and tested. The differentiability of the smearing scheme with respect to the link variables permits the use of modern Monte Carlo updating methods ...
    • Progress in lattice algorithms 

      PEARDON, MICHAEL JAMES (Elsevier, 2002)
      The development of Monte Carlo algorithms for generating gauge field configurations with dynamical fermions and methods for extracting the most information from ensembles are summarised.
    • Dynamical fermion simulations of QCD on anisotropic lattices 

      PEARDON, MICHAEL JAMES (Elsevier, 2004)
      Simulations of QCD with two flavours of improved Wilson quarks on an anisotropic lattice are discussed. Methods for improving the performance of the Hybrid Monte Carlo (HMC) algorithm in these studies are described.
    • Multiple molecular dynamics time-scales in Hybrid Monte Carlo fermion simulations 

      PEARDON, MICHAEL JAMES; SEXTON, JAMES CHRISTOPHER (Elsevier, 2003)
      A scheme for separating the high- and low-frequency molecular dynamics modes in Hybrid Monte Carlo (HMC) simulations of gauge theories with dynamical fermions is presented. The algorithm is tested in the Schwinger model ...
    • Measuring the aspect ratio renormalization of anisotropic-lattice gluons 

      PEARDON, MICHAEL JAMES (American Physical Society, 2001)
      Using tadpole-improved actions we investigate the consistency between different methods of measuring the aspect ratio renormalization of anisotropic-lattice gluons for bare aspect ratios x054,6,10 and inverse lattice spacing ...
    • In search of a scaling scalar glueball 

      PEARDON, MICHAEL JAMES (Elsevier, 1999)
      Anisotropic lattices are an efficient means of studying the glueballs of QCD, however problems arise with simulations of the lightest, scalar state. The mass is strongly dependent on the lattice spacing, even when ...
    • The glueball spectrum from novel improved actions 

      PEARDON, MICHAEL JAMES (Elsevier, 2000)
      Results for the inter-quark potential and low-lying SU(3) glueball spectrum from simulations using a new improved action are presented. The action, suitable for highly anisotropic lattices, contains a two-plaquette ...