Constant-roll warm inflation and the $\beta$-function approach

TL;DR

This paper introduces a novel approach to constant-roll warm inflation using the $eta$-function formalism, classifying models into universality classes and analyzing their physical viability for sufficient inflation.

Contribution

It generalizes constant-roll inflation to warm inflation via the $eta$-function approach, identifying universality classes and exploring model realizability.

Findings

Models fall into three universality classes based on $eta$-functions.

Warm inflation models can be physically realized with appropriate $eta$-functions and dissipation ratios.

The approach provides a systematic way to classify and analyze warm inflation scenarios.

Abstract

We propose a new approach to constant-roll warm inflation as a generalization of constant-roll inflation. Based on the $\beta$-function formalism, it is shown that constant-roll warm inflation models with a natural end fall into universality classes defined by three different types of $\beta$-functions, under the assumption that radiation energy density is quasi-stable. Given that warm inflation is completely specified by the $\beta$-function and dissipation coefficient ratio, we investigate whether or not the inflation can physically be realized for enough number of e-foldings at the background level for some combinations of the $\beta$-functions and non-trivial dissipation coefficient ratios.