Reheating mechanism of Curvaton with Nonminimal Derivative Coupling to Gravity

TL;DR

This paper investigates the reheating process in a curvaton model with nonminimal derivative coupling to gravity, analyzing different evolution scenarios, particle creation rates, reheating temperatures, and the stability of curvature perturbations.

Contribution

It extends previous work by analyzing the reheating mechanism in the nonminimal derivative coupling curvaton model, including temperature estimates and perturbation behavior.

Findings

Reheating behavior varies depending on curvaton dominance after inflation.

Reheating temperatures are estimated with loose constraints compared to gravitino overproduction.

Curvature perturbation remains stable during resonance, avoiding blow-up.

Abstract

In this paper, we continue our study on the curvaton model with nonminimal derivative coupling (NDC) to Einstein gravity proposed in our previous work, focusing on the reheating mechanism. We found that according to whether the curvaton has dominated the background after the end of inflation, it will have two different behaviors of evolution, which should be the general property of curvaton with nonminimal couplings. This will cause diffferent rates of particle creation, which goes on via the parametric resonance process. The reheating temperature is estimated for both cases in which reheating completes before and after curvaton domination, and the constraints are quite loose compared to that of overproduction of gravitino. Finally we investigated the evolution of curvature perturbation during reheating. We have shown both analytically and numerically that the curvature perturbation will not blow up during the resonance process.