Summary: arXiv:hep­ph/0212268
v1
18
Dec
2002 TRANSPORT COEFFICIENTS AND QUANTUM FIELDS 
GERT AARTS AND JOSE M. MARTINEZ RESCO
Department of Physics, The Ohio State University
174 West 18th Avenue, Columbus, OH 43210, USA
Various aspects of transport coeÆcients in quantum eld theory are reviewed. We
describe recent progress in the calculation of transport coeÆcients in hot gauge
theories using Kubo formulas, paying attention to the fulllment of Ward iden-
tities. We comment on why the color conductivity in hot QCD is much simpler
to compute than the electrical conductivity. The nonperturbative extraction of
transport coeÆcients from lattice QCD calculations is brie y discussed.
1. Introduction
Transport coeÆcients characterize the response of a system in thermal equi-
librium to a weak perturbation associated with a conserved current. Exam-
ples are the shear and bulk viscosities, electrical conductivity and diusion
constants. Transport coeÆcients can be relevant in various physical sce-
narios: in the formation and diusion of large-scale magnetic elds 1 , in

Source: Aarts, Gert - Department of Physics, University of Wales Swansea

Collections: Physics