Classical decay of inflaton

TL;DR

The first fully nonlinear calculation of inflaton decay is presented, and it is found that parametric resonance develops slower and ends at smaller values of fluctuating fields, as compared to estimates existing in literature.

Abstract

We present the first fully non-linear calculation of inflaton decay. We map inflaton decay onto an equivalent classical problem and solve the latter numerically. In the $λφ^4$ model, we find that parametric resonance develops slower and ends at smaller values of fluctuating fields, as compared to estimates existing in literature. We also observe a number of qualitatively new phenomena, including a stage of semiclassical thermalization, during which the decay of inflaton is essentially as effective as during the resonance stage.

Figures (3)

• Figure 1: Power spectrum of fluctuations at successive moments of time.
• Figure 2: Variance of the scalar field as a function of time.
• Figure 3: Time dependence of the zero-momentum mode.