Collective phenomena in gauge theories. II. Renormalization in finite-temperature field theory

Abstract

A procedure is given for renormalization of finite-temperature and -density Green's functions to all orders of perturbation theory. The Lagrangian counterterms are independent of temperature, density, and all mass parameters of the Lagrangian. Thus renormalization-group equations may be written for Green's functions in a medium for which the Callan-Symanzik functions depend only on the dimensionless coupling constants. By scaling the temperature and/or chemical potential in the renormalization-group equations it is shown that asymptotic freedom in non-Abelian gauge theories occurs for large temperatures (early hot universe) and for large chemical potential (high density of the medium) as well as large momenta.