Journalartikel

Jahr der Veröffentlichung: 2007

Seiten: 155-164

Zeitschrift: Physics Letters B

Bandnummer: 646

Heftnummer: 4

ISSN: 0370-2693

eISSN: 1873-2445

Open Access Status: Green

DOI Link: https://doi.org/10.1016/j.physletb.2007.01.028

Verlag: Elsevier

Abstract: 
In thermal field theory selfconsistent (Phi-derivable) approximations are used to improve (resum) propagators at the level of two-particle irreducible diagrams. At the same time vertices are treated at the perturbative level. Therefore such approximations typically violate the Ward identities connected to internal symmetries. Examples are presented how such violations can be tamed by a proper choice of representation for the fields which describe the system under consideration. These examples cover the issue of massless Goldstone bosons in the linear sigma model and the Nambu-Jona-Lasinio model and the problem of current conservation in theories with massive vector mesons. (c) 2007 Elsevier B.V. All rights reserved.

Harvard-Zitierstil: Leupold, S. (2007) Selfconsistent approximations, symmetries and choice of representation, Physics Letters B, 646(4), pp. 155-164. https://doi.org/10.1016/j.physletb.2007.01.028

APA-Zitierstil: Leupold, S. (2007). Selfconsistent approximations, symmetries and choice of representation. Physics Letters B. 646(4), 155-164. https://doi.org/10.1016/j.physletb.2007.01.028