Out-of-equilibrium dynamics for N-component scalar quantum fields

by A. PATKOS (Eötvös University, Budapest)

Thursday 25 Nov 1999, 14:00 → 16:00 Europe/Zurich

TH Auditorium (CERN)

Effective equations are derived for the real time dynamics of low frequency modes of the N-component scalar fields in interaction with nearly thermalised high frequency components. The statistics of the latter is determined in the low-frequency background self-consistently. Two dynamical problems will be investigated with help of these effective equations: (I) Propagation of small amplitude on-shell waves through the broken symmetry medium. Special attention is payed to the dynamical manifestation of the Goldstone effect in the linear response function. (II) Relaxation of the order parameter to its equilibrium value, after a sudden change of sign in the external 'magnetic' field occurs. Here, in principle, no assumption is made on the smallness of the deviation from equilibrium of the quenched system.