Parametric amplification versus collisions: An illustrative application

Abstract

We investigate the time dependence of the quantum statistical model with $\lambda {\varphi }^4/4!$ self-interaction and consider the resulting induced particle number density. For a special example in which the classical approximation exhibits parametric resonance, the effects of the back reaction and especially of collisions, treated in a perturbative way, are analysed.

Comments: LaTeX, 9 pages, 7 figures