82 research outputs found

    A Testbed About Priority-Based Dynamic Connection Profiles in QoS Wireless Multimedia Networks

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    The ever-growing demand of high-quality broadband connectivity in mobile scenarios, as well as the Digital Divide discrimination, are boosting the development of more and more efficient wireless technologies. Despite their adaptability and relative small installation costs, wireless networks still lack a full bandwidth availability and are also subject to interference problems. In context of a Metropolitan Area Network serving a large number of users, a bandwidth increase can turn out to be neither feasible nor justified. In consequence, and in order to meet the needs of multimedia applications, bandwidth optimization techniques were designed and developed, such as Traffic Shaping, Policy-Based Traffic Management and Quality of Service (QoS). In this paper, QoS protocols are adopted and, in particular, priority-based dynamic profiles in a QoS wireless multimedia network. This technique allows to asssign different priorities to distinct applications, so as to rearrange service quality in a dynamic way and guarantee the desired performance to a given data flow

    Wigner Oscillators, Twisted Hopf Algebras and Second Quantization

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    By correctly identifying the role of central extension in the centrally extended Heisenberg algebra h, we show that it is indeed possible to construct a Hopf algebraic structure on the corresponding enveloping algebra U(h) and eventually deform it through Drinfeld twist. This Hopf algebraic structure and its deformed version U^F(h) are shown to be induced from a more fundamental Hopf algebra obtained from the Schroedinger field/oscillator algebra and its deformed version, provided that the fields/oscillators are regarded as odd-elements of the super-algebra osp(1|2n). We also discuss the possible implications in the context of quantum statistics.Comment: 23 page

    Lie-Algebraic Characterization of 2D (Super-)Integrable Models

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    It is pointed out that affine Lie algebras appear to be the natural mathematical structure underlying the notion of integrability for two-dimensional systems. Their role in the construction and classification of 2D integrable systems is discussed. The super- symmetric case will be particularly enphasized. The fundamental examples will be outlined.Comment: 6 pages, LaTex, Talk given at the conference in memory of D.V. Volkov, Kharkhov, January 1997. To appear in the proceeding

    Inequivalent Z2nZ_2^n-graded brackets, nn-bit parastatistics and statistical transmutations of supersymmetric quantum mechanics

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    Given an associative ring of Z2nZ_2^n-graded operators, the number of inequivalent brackets of Lie-type which are compatible with the grading and satisfy graded Jacobi identities is bn=n+n/2+1b_n= n+\lfloor n/2\rfloor+1. This follows from the Rittenberg-Wyler and Scheunert analysis of "color" Lie (super)algebras which is revisited here in terms of Boolean logic gates. The inequivalent brackets, recovered from Z2n×Z2nZ2Z_2^n\times Z_2^n\rightarrow Z_2 mappings, are defined by consistent sets of commutators/anticommutators describing particles accommodated into an nn-bit parastatistics (ordinary bosons/fermions correspond to 11 bit). Depending on the given graded Lie (super)algebra, its graded sectors can fall into different classes of equivalence expressing different types of (para)bosons and/or (para)fermions. As a first application we construct Z22Z_2^2 and Z23 Z_2^3-graded quantum Hamiltonians which respectively admit b2=4b_2=4 and b3=5b_3=5 inequivalent multiparticle quantizations (the inequivalent parastatistics are discriminated by measuring the eigenvalues of certain observables in some given states). As a main physical application we prove that the NN-extended, 1D1D supersymmetric and superconformal quantum mechanics, for N=1,2,4,8N=1,2,4,8, are respectively described by sN=2,6,10,14s_{N}=2,6,10,14 alternative formulations based on the inequivalent graded Lie (super)algebras. These numbers correspond to all possible "statistical transmutations" of a given set of supercharges which, for N=1,2,4,8{N}=1,2,4,8, are accommodated into a Z2nZ_2^n-grading with n=1,2,3,4n=1,2,3,4 (the identification is N=2n1N= 2^{n-1}). In the simplest N=2{N}=2 setting (the 22-particle sector of the de DFF deformed oscillator with sl(21)sl(2|1) spectrum-generating superalgebra), the Z22Z_2^2-graded parastatistics imply a degeneration of the energy levels which cannot be reproduced by ordinary bosons/fermions statistics.Comment: 57 pages, 16 figure

    An Unfolded Quantization for Twisted Hopf Algebras

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    In this talk I discuss a recently developed "Unfolded Quantization Framework". It allows to introduce a Hamiltonian Second Quantization based on a Hopf algebra endowed with a coproduct satisfying, for the Hamiltonian, the physical requirement of being a primitive element. The scheme can be applied to theories deformed via a Drinfeld twist. I discuss in particular two cases: the abelian twist deformation of a rotationally invariant nonrelativistic Quantum Mechanics (the twist induces a standard noncommutativity) and the Jordanian twist of the harmonic oscillator. In the latter case the twist induces a Snyder non-commutativity for the space-coordinates, with a pseudo-Hermitian deformed Hamiltonian. The "Unfolded Quantization Framework" unambiguously fixes the non-additive effective interactions in the multi-particle sector of the deformed quantum theory. The statistics of the particles is preserved even in the presence of a deformation.Comment: 9 pages. Talk given at QTS7 (7th Int. Conf. on Quantum Theory and Symmetries, Prague, August 2011

    Division Algebras and Extended N=2,4,8 SuperKdVs

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    The first example of an N=8 supersymmetric extension of the KdV equation is here explicitly constructed. It involves 8 bosonic and 8 fermionic fields. It corresponds to the unique N=8 solution based on a generalized hamiltonian dynamics with (generalized) Poisson brackets given by the Non-associative N=8 Superconformal Algebra. The complete list of inequivalent classes of parametric-dependent N=3 and N=4 superKdVs obtained from the ``Non-associative N=8 SCA" is also furnished. Furthermore, a fundamental domain characterizing the class of inequivalent N=4 superKdVs based on the "minimal N=4 SCA" is given.Comment: 14 pages, LaTe
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