220 research outputs found

    F-structures and integral points on semiabelian varieties over finite fields

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    Motivated by the problem of determining the structure of integral points on subvarieties of semiabelian varieties defined over finite fields, we prove a quantifier elimination result for certain modules over finite simple extensions of the integers given together with predicates for orbits of the distinguished generator of the ring.Comment: 33 pages, correction made to authors' informatio

    An ADM 3+1 formulation for Smooth Lattice General Relativity

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    A new hybrid scheme for numerical relativity will be presented. The scheme will employ a 3-dimensional spacelike lattice to record the 3-metric while using the standard 3+1 ADM equations to evolve the lattice. Each time step will involve three basic steps. First, the coordinate quantities such as the Riemann and extrinsic curvatures are extracted from the lattice. Second, the 3+1 ADM equations are used to evolve the coordinate data, and finally, the coordinate data is used to update the scalar data on the lattice (such as the leg lengths). The scheme will be presented only for the case of vacuum spacetime though there is no reason why it could not be extended to non-vacuum spacetimes. The scheme allows any choice for the lapse function and shift vectors. An example for the Kasner T3T^3 cosmology will be presented and it will be shown that the method has, for this simple example, zero discretisation error.Comment: 18 pages, plain TeX, 5 epsf figues, gzipped ps file also available at http://newton.maths.monash.edu.au:8000/preprints/3+1-slgr.ps.g

    1 Finite-State Automata: Characterization Finite-State Acceptors

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    Definition (Non-deterministic finite-state acceptor (NFA)) A non-deterministic finite-state acceptor A is a 5-tuple (Q, Σ, q0, F, δ) where Q is a finite set of states Σ is the alphabet q0 ∈ Q is the start state F ⊆ Q is a set of final states δ: Q × Σ ∪ {ɛ} → 2 Q, the transition function Nondeterminism refers to the fact that a NFA has the power to be in several states at once. A transition may be labeled with ɛ. Nina Seemann (IMS) Formal Models in NLP: Finite-State Automata May 15, 2012 5Finite-State Acceptor

    On Heavy-Quark Free Energies, Entropies, Polyakov Loop, and AdS/QCD

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    In this paper we explore some of the features of a heavy quark-antiquark pair at finite temperature using a five-dimensional framework nowadays known as AdS/QCD. We shall show that the resulting behavior is consistent with our qualitative expectations of thermal gauge theory. Some of the results are in good agreement with the lattice data that provides additional evidence for the validity of the proposed model.Comment: 15 pages, 10 figures; v2: comments added, misprints correcte

    Bures and Statistical Distance for Squeezed Thermal States

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    We compute the Bures distance between two thermal squeezed states and deduce the Statistical Distance metric. By computing the curvature of this metric we can identify regions of parameter space most sensitive to changes in these parameters and thus lead to optimum detection statistics.Comment: 15 pages, 1 figure (not included - obtain from Author) To appear in Journal of Physics

    The critical exponents of the two-dimensional Ising spin glass revisited: Exact Ground State Calculations and Monte Carlo Simulations

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    The critical exponents for T→0T\to0 of the two-dimensional Ising spin glass model with Gaussian couplings are determined with the help of exact ground states for system sizes up to L=50L=50 and by a Monte Carlo study of a pseudo-ferromagnetic order parameter. We obtain: for the stiffness exponent y(=θ)=−0.281±0.002y(=\theta)=-0.281\pm0.002, for the magnetic exponent δ=1.48±0.01\delta=1.48 \pm 0.01 and for the chaos exponent ζ=1.05±0.05\zeta=1.05\pm0.05. From Monte Carlo simulations we get the thermal exponent ν=3.6±0.2\nu=3.6\pm0.2. The scaling prediction y=−1/νy=-1/\nu is fulfilled within the error bars, whereas there is a disagreement with the relation y=1−δy=1-\delta.Comment: 8 pages RevTeX, 7 eps-figures include

    Algebraic topological analysis of time-sequence of digital images

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    This paper introduces an algebraic framework for a topological analysis of time-varying 2D digital binary–valued images, each of them defined as 2D arrays of pixels. Our answer is based on an algebraic-topological coding, called AT–model, for a nD (n=2,3) digital binary-valued image I consisting simply in taking I together with an algebraic object depending on it. Considering AT–models for all the 2D digital images in a time sequence, it is possible to get an AT–model for the 3D digital image consisting in concatenating the successive 2D digital images in the sequence. If the frames are represented in a quadtree format, a similar positive result can be derived
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