Nonperturbative renormalization for 2PI effective action techniques

Journal Article · Thu Dec 15 04:00:00 EST 2005 · Annals of Physics (New York)

DOI:https://doi.org/10.1016/j.aop.2005.06.001· OSTI ID:20766971

Berges, J ^[1]; Borsanyi, Sz ^[1]; Reinosa, U ^[2]; Serreau, J ^[3]

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1. Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)
2. Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany) and Institut fuer Theoretische Physik, Technische Universitaet Wien Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria)
3. Astro-Particule et Cosmologie, 11, place Marcelin Berthelot, 75231 Paris Cedex 05 (France) and Laboratoire de Physique Theorique, Bat. 210, Univ. Paris-Sud 11, 91405 Orsay Cedex (France)

Nonperturbative approximation schemes based on two-particle irreducible (2PI) effective actions provide an important means for our current understanding of (non-)equilibrium quantum field theory. A remarkable property is their renormalizability, since these approximations involve selective summations to infinite perturbative orders. In this paper, we show how to renormalize all n-point functions of the theory, which are given by derivatives of the 2PI-resummed effective action {gamma} [{phi}] for scalar fields {phi}. This provides a complete description in terms of the generating functional for renormalized proper vertices, which extends previous prescriptions in the literature on the renormalization for 2PI effective actions. The importance of the 2PI-resummed generating functional for proper vertices stems from the fact that the latter respect all symmetry properties of the theory and, in particular, Goldstone's theorem in the phase with spontaneous symmetry breaking. This is important in view of the application of these techniques to gauge theories, where Ward identities play a crucial role.

• OSTI ID: 20766971
• Journal Information: Annals of Physics (New York), Journal Name: Annals of Physics (New York) Journal Issue: 2 Vol. 320; ISSN 0003-4916; ISSN APNYA6
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACTION INTEGRAL
APPROXIMATIONS
GAUGE INVARIANCE
QUANTUM FIELD THEORY
RENORMALIZATION
SCALAR FIELDS
SYMMETRY
SYMMETRY BREAKING
WARD IDENTITY