Primordial Gravitational Waves and Reheating in a New Class of Plateau-like Inflationary Potentials

TL;DR

This paper introduces a new class of plateau-like inflationary models characterized by a specific Hubble radius parametrization, analyzing their observational viability, gravitational wave signatures, and reheating implications, including low-temperature scenarios affecting dark matter.

Contribution

The paper proposes a novel inflationary potential class with unique parametrization, exploring its compatibility with observations and implications for gravitational waves and reheating processes.

Findings

Models are consistent with current observational constraints.

Primordial gravitational waves are detectable by future interferometers.

Reheating can be instantaneous or occur at very low temperatures.

Abstract

We study a new class of inflation model parametrized by the Hubble radius, such that $aH\propto \exp(-k\phi^n)$. These potentials are plateau-like, and reduce to the power-law potentials in the simplest case $n=2$. We investigate the range of model parameters that is consistent with current observational constraints on the scalar spectral index and the tensor-to-scalar ratio. The amplitude of primordial gravitational waves in these models is shown to be accessible by future laser interferometers such as DECIGO. We also demonstrate how these observables are affected by the temperature and equation of state during reheating. We find that a large subset of this model can support instantaneous reheating, as well as very low reheating temperatures of order a few MeV, giving rise to interesting consequences for dark-matter production.