Quantum field thermalization in expanding backgrounds
arXiv:0806.3158 · doi:10.1088/1126-6708/2008/11/037
Abstract
The 2PI effective action formalism for quantum fields out of equilibrium is set up in an expanding (Friedmann-Robertson-Walker) background. We write down and solve the evolution equations for a phi^4 model at NLO in a coupling expansion. We comment on issues of renormalization, lattice discretization and the range of applicability of the approach. A number of example calculations are presented, including thermalization and (p)reheating. Generalizations to more complicated systems and applications are discussed.
27 pages, 11 figures. Some modifications and clarifications in presentation. Minor errors and some typos fixed. Conclusions unchanged. Published version