Gauge Theories at finite temperature

• Grant number: 04/10804-0
• Support Opportunities: Research Projects - Thematic Grants
• Start date: March 01, 2005
• End date: February 28, 2009
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Josif Frenkel
• Grantee: Josif Frenkel
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Pesquisadores principais: Fernando Tadeu Caldeira Brandt
• Associated research grant(s): 08/50695-7 - Ashok Kumar Das | University of Rochester - Estados Unidos, AV.EXT; 06/51748-1 - Ashok Kumar Das | University of Rochester - United States, AV.EXT; 05/52534-2 - Ashok Kumar Das | University of Rochester - Estados Unidos, AV.EXT

Abstract

Gauge theories like Quantum Electrodynamics, Quantum Chromodinamics or the Quantum theory of gravitation, are the basis for a description of the fundamental interactions between the elementary particles. In the high temperature regime, the basic structure of matter is constituted by a plasma of quarks and leptons, which interact by an exchange of gluons and fotons. The dynamics of these particles is described by field theories which are characterized by a symmetry under gauge transformations.This research project, which represents a continuation of the previous project, has the purpose of studying various relevant processes in the context of gauge theories. An aspect that we would like to investigate is related with non-commutative field theories, where the non-commutative parameter is normally characterized by a constant quantity. We intend to generalize these theories to the important case where the non-commutative parameter is a local function which depends on the coordinates. Moreover, we would like to analise the structure of Quantum Chromodynamics in the light cone gauge, where the gluons which intermediate the strong interactions have only physical degrees of freedom. We intend to determine all the residual gauge symmetries of this theory, which fix completely the structure of the gluon propagator. FinalIy, we would like to investigate the properties of the quantum field theories in a de Sitter space, which is consistent with the results of recent astronomical observations. In particular, we intend to study the vacuum structure and the properties of these theories at finite temperature. (AU)