9,259 research outputs found

    Generalized q-deformed Correlation Functions as Spectral Functions of Hyperbolic Geometry

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    We analyse the role of vertex operator algebra and 2d amplitudes from the point of view of the representation theory of infinite dimensional Lie algebras, MacMahon and Ruelle functions. A p-dimensional MacMahon function is the generating function of p-dimensional partitions of integers. These functions can be represented as amplitudes of a two-dimensional c=1 CFT. In this paper we show that p-dimensional MacMahon functions can be rewritten in terms of Ruelle spectral functions, whose spectrum is encoded in the Patterson-Selberg function of three dimensional hyperbolic geometry.Comment: 12 pages, no figure

    On the dimensional dependence of duality groups for massive p-forms

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    We study the soldering formalism in the context of abelian p-form theories. We develop further the fusion process of massless antisymmetric tensors of different ranks into a massive p-form and establish its duality properties. To illustrate the formalism we consider two situations. First the soldering mass generation mechanism is compared with the Higgs and Julia-Toulouse mechanisms for mass generation due to condensation of electric and magnetic topological defects. We show that the soldering mechanism interpolates between them for even dimensional spacetimes, in this way confirming the Higgs/Julia-Toulouse duality proposed by Quevedo and Trugenberger \cite{QT} a few years ago. Next, soldering is applied to the study of duality group classification of the massive forms. We show a dichotomy controlled by the parity of the operator defining the symplectic structure of the theory and find their explicit actions.Comment: Reference [8] has been properly place

    On duality of the noncommutative extension of the Maxwell-Chern-Simons model

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    We study issues of duality in 3D field theory models over a canonical noncommutative spacetime and obtain the noncommutative extension of the Self-Dual model induced by the Seiberg-Witten map. We apply the dual projection technique to uncover some properties of the noncommutative Maxwell-Chern-Simons theory up to first-order in the noncommutative parameter. A duality between this theory and a model similar to the ordinary self-dual model is estabilished. The correspondence of the basic fields is obtained and the equivalence of algebras and equations of motion are directly verified. We also comment on previous results in this subject.Comment: Revtex, 9 pages, accepted for publication PL

    Turbulence driven particle transport in Texas Helimak

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    We analyze the turbulence driven particle transport in Texas Helimak (K. W. Gentle and Huang He, Plasma Sci. and Technology, 10, 284 (2008)), a toroidal plasma device with one-dimensional equilibrium with magnetic curvature and shear. Alterations on the radial electric field, through an external voltage bias, change spectral plasma characteristics inducing a dominant frequency for negative bias values and a broad band frequency spectrum for positive bias values. For negative biased plasma discharges, the transport is high where the waves propagate with phase velocities near the plasma flow velocity, an indication that the transport is strongly affected by a wave particle resonant interaction. On the other hand, for positive bias the plasma has a reversed shear flow and we observe that the transport is almost zero in the shearless radial region, an evidence of a transport barrier in this region.Comment: 8 pages, 11 figure

    Contributions from Dilatonic Strings to the Flat Behaviour of the Rotational Curves in Galaxies

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    We analyse the flat behaviour of the rotational curves in some galaxies in the framework of a dilatonic, current-carrying string. We determine the expression of the tangential velocity of test objects following a stable circular equatorial orbit in this spacetime.Comment: This version to be published in the Int. Journal of Modern Phys.

    Introducing the Portuguese sustainability assessment tool for urban areas: SBTool PT – Urban Planning

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    ISBN 978-99957-0-935-8Given the accelerated urbanization process throughout the twentieth century, many of todayâ s cities reflect a fast and disordered growth, which influences directly the demand for natural resources. For an indispensable change in the current urban infrastructure management models, it is necessary to quantify the sustainability level of actual practices and proposals. In this context, based on widespread methods, SBTool_PT Urban Planning represents an adaptation of the SBTool international method to the Portuguese context. This tool assesses the sustainability level of the practices promoted in urban projects with no size restrictions and is applicable to new urban development and/or urban renovation. The process is conducted by a rigorous analysis of requisites specifically developed to stimulate improvements on energy consumption, management of potable water, solid waste, urban soil and territory and air quality. Aiming at a full introduction of the tool, this article contextualizes its development and characterizes its assessment methodology. Additional application to a case study shows how the assessment of a proposed project is performed. It is intended to demonstrate in which way sustainability assessment methodologies allow the promotion of innovation and urban sustainability through the environmental preservation and the improvement of the quality of life in urban areas

    Quantum Effects in the Spacetime of a Magnetic Flux Cosmic String

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    In this work we compute the vacuum expectation values of the energy-momentum tensor and the average value of a massive, charged scalar field in the presence of a magnetic flux cosmic string for both zero- and finite-temperature cases.Comment: To appear in the Int. Journal of Modern Phys. A (special issue). Proceedings of the Second International Londrina Winter School on Mathematical Methods in Physics, Londrina, Brazil, August 200
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