Renormalization and gauge symmetry for 2PI effective actions

Abstract

We explore a method to recover symmetry identities in the 2PI formalism. It is based on non-perturbative approximations to the 1PI effective action. We discuss renormalization questions raised by this technique.

Comments: 5 pages, 3 figures. To appear in the conference proceedings of Strong Electroweak Matter 2004 (SEWM04), Helsinki, Finland. 16-19 Jun 2004