Parametric resonance in dissipative field dynamics

the effects of bosonic trilinear interactions are investigated in the process of resonant particle production. we study a generic model of three fields with trilinear couplings. in this model a scalar field φ can excite a heavy bosonic field χ which then decays into a light bosonic field σ. we study the consequences of dissipation and stochastic noise terms in the field equations of motion that result from a calculation in nonequlibrium quantum field theory and determine the effects of these terms for the phenomenon of parametric resonance, which can occur e.g. during preheating after inflation.