Thermal Effective Actions

• Grant number: 12/24796-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2013
• End date: May 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Josif Frenkel
• Grantee: João Bosco de Siqueira
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

We will investigate certain physical properties of field theories at finite temperature using the background field method to obtain the effective action of static gauge fields interacting with thermal particles, in the high temperature limit. First, we intend to calculate the high temperature limit of the effective action of the static Maxwell field interacting with a QED plasma, at two loop order.We will also obtain the effective action of the static gravitational field interacting with a QED plasma, at two loop order.The methodology we are going to use for this purpose has two pillars. The first, in the context of the the background field method, lies in the identity between the pressure as a function of the external field and the effective action as a functional of the background field. The second, in the context of the finite temperature field theory, is the identity between the static Green functions and the Green functions with zero external momenta, in the high temperature limit. The validity of this identity to all orders of perturbation theory will also be investigated.