Reheating formulas in Quintessential Inflation via Gravitational Particle Production

TL;DR

This paper calculates reheating temperatures in Quintessential Inflation models considering gravitational particle production, decay timing, and constraints from gravitational wave overproduction, providing insights into early universe thermal history.

Contribution

It introduces a detailed analysis of reheating via gravitational particle production during phase transitions, including decay timing and gravitational wave constraints, which is a novel approach.

Findings

Reheating temperatures depend on decay timing during or after kination.

Constraints from gravitational wave overproduction limit the reheating temperature.

The study offers new bounds on early universe thermal processes.

Abstract

We calculate the reheating temperature in scenarios where heavy particles are gravitationally produced during a phase transition. We explore two distinct situations: the decay of these particles both during and after the kination phase. Subsequently, we determine the respective reheating temperatures. Finally, we constrain these temperatures based on considerations related to the overproduction of Gravitational Waves during the phase transition from the end of inflation to the onset of kination.