# Curvaton: Perturbations and reheating

## TL;DR

This paper explores how the curvaton mechanism can address key issues in inflationary models, such as tensor-to-scalar ratio, spectral tilt, and reheating, by analyzing chaotic and runaway potentials in light of Planck data.

## Contribution

It demonstrates the applicability of the curvaton scenario to both chaotic and runaway inflation models, providing constraints on model parameters and reheating temperature.

## Key findings

- Curvaton can resolve tensor-to-scalar ratio and spectral tilt issues.
- Constraints on curvaton decay epoch and field value from non-Gaussianity.
- Reheating temperature estimates consistent with nucleosynthesis constraints.

## Abstract

We study chaotic and runaway potential inflationary models in the curvaton scenario. In particular, we address the issue of large tensor-to-scalar ratio and red-tilted spectrum in chaotic models and reheating in runaway model in the light of latest Planck results. We show that curvaton can easily circumvent these problems and is well applicable to both type of models. For chaotic models, the observable non-Gaussianity put strong constraints on the decay epoch of curvaton as well as on its field value around the horizon exit. Besides, it can also explain the observed red-tilt in the spectrum as a consequence of its negative mass-squared value. As for the runaway inflationary models, curvaton by sudden decay into the background radiation provides an efficient reheating mechanism, whereas the inflaton rolls down from its potential and enters into the kinetic regime. To this effect, we consider the generalized exponential potential and obtain the allowed parametric space for model parameters. From the estimates on inflaton parameters, we constrained the curvaton mass and then the reheating temperature. We constrained the latter for both dominating and sub-dominating case and show that it agrees with the nucleosynthesis constraint.