Cosmological perturbations for an inflaton field coupled to radiation

TL;DR

This paper numerically solves the Boltzmann equation for an inflaton field coupled to radiation, analyzing cosmological perturbations during slow-roll with stochastic sources, relevant for warm inflation models.

Contribution

It provides a numerical approach to the evolution of inflaton-radiation systems, including stochastic effects, extending warm inflation perturbation analysis.

Findings

Recovered known perturbation expressions for warm inflation.

Demonstrated the impact of stochastic sources on perturbation evolution.

Validated the numerical solution within the slow-roll regime.

Abstract

Within the framework of the interacting fluid formalism, we provide the numerical solution to the Boltzmann equation describing the evolution of an inflaton field coupled to radiation. We study the behavior of the system during the slow-roll regime, in the case in which an additional stochastic source term is included in the set of equations, and we recover the expression for the cosmological perturbations previously obtained in the Warm inflation scenarios.