Quantum fields out of equilibrium: beyond the leading order

by Jurgen Baacke (University of Dortmund)

Thursday 18 Mar 2004, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

Consider a specific way in which quantum fields may be "out of equilibrium": a spatially constant background field drives quantum oscillations, and these react back on the dynamics of the background field. The background field may be the famous inflaton, some Higgs field, but also a condensate "sigma" field in effective low energy approaches to hadron physics. I will review the basic Schwinger-Keldysh formalism, the leading order 1-loop or large-N dynamics, renormalization, and some basic results obtained in this order. I will then discuss resummation schemes and approximations within these schemes that have been considered recently. I will also draw some parallels to results obtained in finite temperature quantum field theory, and of course present our own recent results. Keywords: quantum back reaction, inflation, preheating, spontaneous symmetry breaking, thermalization.