Gauge Invariance in 2PI Effective Actions
Abstract
The problem of maintaining gauge invariance in the 2PI formulation of QED is discussed. A modified form of the 2PI effective action is suggested in which Ward identities for external (background field) and internal (quantum field) gauge transformations are both satisfied, but in different manners. The residual gauge-fixing dependence in this modified 2PI formulation vanishes in a certain low momentum limit, which allows it to be used reliably for calculating quantities such as transport coeffcients and soft field relaxation in hot gauge theories.
Cite
@article{arxiv.hep-ph/0304279,
title = {Gauge Invariance in 2PI Effective Actions},
author = {Emil Mottola},
journal= {arXiv preprint arXiv:hep-ph/0304279},
year = {2017}
}
Comments
Talk given at Strong and Electroweak Matter 2002, Oct. 4, 2002 in Heidelberg, Germany; Five pages, uses World Scientific style file, ws-procs9x6.cls. To be published in the Proceedings of SEWM 2002 by World Scientific Publishing Co