Multifield Reheating after Modular $j$-Inflation

TL;DR

This paper investigates multifield reheating in modular $j$-inflation, providing estimates of the reheat temperature in a cosmological inflation model with weakly curved inflaton trajectories.

Contribution

It introduces a method to estimate reheating parameters in multifield inflation models with weakly curved trajectories, specifically applied to $j$-inflation.

Findings

Reheating temperature can be estimated in $j$-inflation models.

Multifield effects influence the reheating process.

Weakly curved trajectories simplify analytical estimates.

Abstract

In the inflationary framework of cosmology the initial phase of rapid expansion has to be followed by a reheating stage, which is envisioned to end in a radiation dominated big bang. Key parameters that characterize this big bang state are the temperature at the end of the reheating stage and the baryon asymmetry. For general interacting theories these parameters are difficult to obtain analytically because of the involved structure of the potential. In this paper multifield reheating is considered for interacting theories in which the inflaton trajectory is weakly curved. This scenario is realized in the model of $j$-inflation, a particular example of modular inflation, allowing an estimate of the reheat temperature.