# Numerical study of inflationary preheating with arbitrary power-law potential and a realization of curvaton mechanism

## TL;DR

This paper develops a numerical simulation to study inflationary preheating with arbitrary power-law potentials, demonstrating how entropy field fluctuations can dominate curvature perturbations, thus realizing a curvaton-like mechanism.

## Contribution

It introduces a numerical method for analyzing preheating in models with power-law inflaton potentials and demonstrates a curvaton mechanism via entropy fluctuations during preheating.

## Key findings

- Numerical analysis of preheating with arbitrary power-law potentials.
- Entropy field fluctuations can dominate curvature perturbations.
- Validates the approach with axion-monodromy inflation model.

## Abstract

During inflationary preheating, the energy stored in the inflaton field is rapidly converted into excitations of other entropy fields. This stage is characterized by exponential particle production due to parametric resonance and is notoriously difficult to analyze using analytic methods. We develop a detailed numerical simulation to investigate inflationary preheating when the potential of the inflaton is a power-law function with arbitrary power index. To achieve a successful graceful exit from a primordial inflationary phase to a smooth, oscillatory phase during preheating, we assume the inflaton potential reduces to a quadratic function in the infrared regime, which may be regarded as a mass term at low energy scales. With this simplification, our numerical method may be applied to unconventional chaotic inflation models. To demonstrate its validity, we numerically analyze the preheating stage of axion-monodromy inflation which is inspired by string theory. By performing perturbation analyses, our result shows that the power spectrum of primordial curvature perturbation can be dominated by fluctuations of entropy field rather than those of inflaton, which can be regarded as a particular realization of the curvaton mechanism through a preheating process.