Radiative corrections and renormalization at finite temperature: A real-time approach.

Abstract

We analyze the one-loop radiative corrections to finite-temperature decay and scattering rates, using techniques based on the Niemi-Semenoff time-path formulation of finite-temperature field theory. Previous work is examined in the context of our general framework. We find that the finite-temperature part of the self-energy corrections cannot be absorbed into mass and wave-function renormalization counterterms and argue that finite-temperature renormalization is not a meaningful concept. We give an explicit algorithm for the calculation of the finite-temperature self-energy corrections and discuss applications in cosmology and astrophysics.