191 research outputs found

    Quantum Algebra of the Particle Moving on the q-Deformed Mass-Hyperboloid

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    I introduce a reality structure on the Heisenberg double of Fun_q(SL(N,C)) for q phase, which for N=2 can be interpreted as the quantum phase space of the particle on the q-deformed mass-hyperboloid. This construction is closely related to the q-deformation of the symmetric top. Finally, I conjecture that the above real form describes zero modes of certain non-compact WZNZ-models

    A Variational Formulation of Symplectic Noncommutative Mechanics

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    The standard lore in noncommutative physics is the use of first order variational description of a dynamical system to probe the space noncommutativity and its consequences in the dynamics in phase space. As the ultimate goal is to understand the inherent space noncommutativity we propose a variational principle for noncommutative dynamical systems in configuration space, based on results of our previous work [14]. We hope that this variational formulation in configuration space can be of help to elucidate the definition of some global and dynamical properties of classical and quantum noncommutative space.Comment: 17 pages, Latex. Accepted for publication in IJGMM

    Numerical Approximation of the Transport Equation: Comparison of Five Positive Definite Algorithms

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    IIASA's Regional Acidification INformation and Simulation (RAINS) model will be used to develop and assess international control strategies to reduce emissions of acidifying pollutants. These strategies will involve the expenditure of large sum of money; it is important, therefore, to assess the effect of uncertainties in the model on its results. An important component of the RAINS model is its atmospheric transport component; this paper reports the results of examining several algorithms for solution of the atmospheric transport equation. It also represents a joint effort between IIASA scientists and those in the Institute of Meteorology and Water Management in Warsaw and Central Institute for Meteorology and Geodynamics in Vienna

    Design and Implementation of a Distributed Platform for Sharing IP Flow Records

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    Experiments using real traffic traces are of key importance in many network management research fields, such as traffic characterization, intrusion detection, and accounting. Access to such traces is often restricted due to privacy issues; research institutions typically have to sign non-disclosure agreements before accessing such traces from a network operator. Having such restrictions, researchers rarely have more than one source of traffic traces on which to run and validate their experiments. Therefore, this paper develops a Distributed Platform for Sharing IP Flows (DipSIF) based on NetFlow records between multiple institutions. It is assumed that NetFlow traces collected by each participant are archived on separate storage hosts within their premises and then made available to others using a server that acts as a gateway to the storage. Due to privacy reasons the platform presented here uses a prefix-preserving, cryptography-based, and consistent anonymization algorithm in order to comply to different regulations determining the exchange of traffic traces data

    Origin of training effect of exchange bias in Co/CoO due to irreversible thermoremanent magnetization of the magnetically diluted antiferromagnet

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    The irreversible thermoremanent magnetization of a sole, magnetically diluted epitaxial antiferromagnetic Co1y_{1-y}O(100) layer is determined by the mean of its thermoremanent magnetizations at positive and negative remanence. During hysteresis-loop field cycling, thermoremanent magnetization exhibits successive reductions, consistent with the training effect (TE) of the exchange bias measured for the corresponding Co1y_{1-y}O(100)/Co bilayer. The TE of exchange bias is shown to have its microscopic origin in the TE of the irreversible thermoremanent magnetization of the magnetically diluted AFM

    A Matrix Model for \nu_{k_1k_2}=\frac{k_1+k_2}{k_1 k_2} Fractional Quantum Hall States

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    We propose a matrix model to describe a class of fractional quantum Hall (FQH) states for a system of (N_1+N_2) electrons with filling factor more general than in the Laughlin case. Our model, which is developed for FQH states with filling factor of the form \nu_{k_1k_2}=\frac{k_1+k_2}{k_1k_2} (k_1 and k_2 odd integers), has a U(N_1)\times U(N_2) gauge invariance, assumes that FQH fluids are composed of coupled branches of the Laughlin type, and uses ideas borrowed from hierarchy scenarios. Interactions are carried, amongst others, by fields in the bi-fundamentals of the gauge group. They simultaneously play the role of a regulator, exactly as does the Polychronakos field. We build the vacuum configurations for FQH states with filling factors given by the series \nu_{p_1p_2}=\frac{p_2}{p_1p_2-1}, p_1 and p_2 integers. Electrons are interpreted as a condensate of fractional D0-branes and the usual degeneracy of the fundamental state is shown to be lifted by the non-commutative geometry behaviour of the plane. The formalism is illustrated for the state at \nu={2/5}.Comment: 40 pages, 1 figure, clarifications and references adde
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