Resonance enhancement of particle production during reheating

We found a consistent equation of reheating after inflation which shows tha t for small quantum fluctuations the frequencies of resonance are slighted different from the standard ones. Quantum interference is taken into accoun t and we found that at large fluctuations the process mimics very well the usual parametric resonance, but proceeds in a different dynamical way. The analysis is made in a toy quantum mechanical model and we discuss further i ts extension to quantum field theory.