Preheating with Non-Standard Kinetic Term

TL;DR

This paper investigates reheating after inflation in theories with non-standard kinetic terms, demonstrating that the Hill-Whittaker equation governs parametric resonance, which can be more unstable than the Mathieu equation, potentially leading to efficient narrow resonance preheating.

Contribution

It introduces the Hill-Whittaker equation as the key to understanding parametric resonance in non-canonical kinetic theories, highlighting its increased instability over traditional models.

Findings

Hill-Whittaker equation describes resonance in these theories

Narrow resonance preheating can be efficient with non-standard kinetic terms

Resonance instability is greater than in Mathieu equation models

Abstract

We consider reheating after inflation in theories with a non-standard kinetic term. We show that the equation that exhibits parametric resonance is the Hill-Whittaker equation, which is a particular case of the more general Hill equation. This equation is in general more unstable than the Mathieu equation, such that narrow resonance preheating may be efficient in theories with a non-canonical kinetic term.