Instantons
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Instantons in curved spaces / Instantons em espaços curvos
In this work we study instanton solutions of the Yang-Mills theory in Schwarzschild and Reissner-Nordstrom spaces with gauge group SU(2).Instantons are solutions to the classical field equations of Yang-Mills theory defined in a space with Riemannian (positive de finite)metric with finite action. We begin with a review of the geometric setting of Yang-Mills
Publicado em: 2010
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2. Is the chiral phase transition induced by a metal-insulator transition?
We investigate the QCD Dirac operator with gauge configurations given by a liquid of instantons in the region of temperatures about the chiral phase transition. Both the quenched and unquenched cases are examined in detail. We present evidence of a localization transition in the low lying modes of the Dirac operator around the same temperature as the chiral
Brazilian Journal of Physics. Publicado em: 2007-03
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3. Noncommutative solitons and instantons
I review different approaches to the construction of vortex and instanton solutions in noncommutative field theories.
Brazilian Journal of Physics. Publicado em: 2004-12
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4. Topological charge screening and pseudoscalar glueballs
Topological charge screening in the QCD vacuum is found to provide crucial nonperturbative contributions to the short-distance expansion of the pseudoscalar (0-+) glueball correlator. The screening contributions enter the Wilson coefficients and are an indispensable complement to the direct instanton contributions. They restore consistency with the anomalous
Brazilian Journal of Physics. Publicado em: 2004-09
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5. QCD glueball sum rules revisited
We discuss several key problems of conventional QCD glueball sum rules in the spin-0 channels and show how they are overcome by nonperturbative Wilson coefficients. The nonperturbative contributions originate from direct instantons and, in the pseudoscalar channel, additionally from topological charge screening. The treatment of the direct-instanton sector i
Brazilian Journal of Physics. Publicado em: 2004-03
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6. Teorias de Gauge e algebras de Clifford
Nesta dissertação apresentamos uma descrição do formalismo matemático das teorias de gauge introduzindo os conceitos de grupos e álgebras de Lie, fibrados principais, conexões e curvatura. Em seguida introduzimos as álgebras de Clifford e os spinors, tais conceitos são utilizados no capítulo final onde apresenta-se algllmas de suas aplicações em
Publicado em: 2002
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7. Analise hipercomplexa : estudo detalhado de casos particulares, interpretação e aplicações
A dissertação consiste essencialmente do estudo de casos particulares de Análise de Clifford. Inicialmente revisamos a Análise Quaterniônica de Fueter comparando com abordagens alternativas e, neste contexto, pesquisamos uma aplicação das correspondentes relações de dispersão em fenomenologia de partículas elementares. Empregando a mesma sistemát
Publicado em: 1998
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8. A geometria e os instantons da teoria de Yang &Mills SU(2)
Classical Yang &Mills Theory is presented from a geometrical viewpoint. Many arguments leading to the "physical reality" of Yang &Mills potentials are given. Further, we specialize to SU(2) Lie group theory over Euclidean space-time. Instantons of this theory are defined and a way to compute them is shown. It is also given an introduction to Homotopy theory,
Publicado em: 1997
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9. Fundamentos matematicos das teorias de calibre
The purpose of this dissertation is to revisit, from the point of view of some modern mathematical methods, the mathematical foundation of gauge theories. We study in detail the theories of fiber bundles and of conections on fiber bundles. We formulate the gauge theories in the language of principal fiber bundles, finding the Klein-Gordon equation and the Kl
Publicado em: 1992
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10. Resultados sobre a geometria dos fibrados
A tese é composta essencialmente de quatro resultados sobre a geometria dos fibrados que são: Capítulo I. As métricas de Kaluza-Klein são métricas naturais de espaços totais fibrados. Tais métricas são definidas a partir de conexões. No caso de fibrados principais onde o grupo estrutural é SO(3), S9 ou S1 e a variedade da base admite métrica com
Publicado em: 1992
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11. Deformations of instantons
A study is made of the self-dual Yang-Mills fields in Euclidean 4-space. For SU(2) gauge theory it is rigorously shown that the solutions depend on 8k - 3 parameters, where k is the Pontrijagin index.
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12. Solutions to Yang—Mills equations that are not self-dual
The Yang—Mills functional for connections on principle SU(2) bundles over S4 is studied. Critical points of the functional satisfy a system of second-order partial differential equations, the Yang—Mills equations. If, in particular, the critical point is a minimum, it satisfies a first-order system, the self-dual or anti-self-dual equations. Here, we exh