Preheating with Fractional Powers

TL;DR

This paper investigates preheating dynamics in models with fractional power inflaton potentials, demonstrating that parametric resonance occurs despite anharmonic oscillations, with the Floquet exponent explicitly calculated.

Contribution

It provides the first detailed analysis of parametric resonance in fractional power inflaton models, including the calculation of the Floquet exponent.

Findings

Parametric resonance occurs despite anharmonic inflaton oscillations.

The Floquet exponent for instability is explicitly derived.

Preheating dynamics are characterized in fractional power potential models.

Abstract

We consider preheating in models in which the potential for the inflaton is given by a fractional power, as is the case in axion monodromy inflation. We assume a standard coupling between the inflaton field and a scalar matter field. We find that in spite of the fact that the oscillation of the inflaton about the field value which minimizes the potential is anharmonic, there is nevertheless a parametric resonance instability, and we determine the Floquet exponent which describes this instability as a function of the parameters of the inflaton potential.