Unifying inflationary and reheating solution

TL;DR

This paper introduces a unified analytical solution for the evolution of the Universe during inflation and reheating, bridging the gap between extreme regimes and improving cosmological predictions.

Contribution

A novel, model-independent parametrized analytical solution that accurately describes the Universe's evolution across inflation and reheating phases.

Findings

Provides a near-accurate unified description of cosmic evolution.

Enhances the precision of cosmological observational predictions.

Potentially improves constraints on inflationary models.

Abstract

The conventional background solution for the evolution of a single canonical inflaton field performs admirably in extreme scenarios such as the slow-roll phase (where the slow-roll parameter is much less than one) and the deep reheating era (where the Hubble parameter is much smaller than the effective mass of the potential and the field oscillates around the minimum of the potential), but fails to accurately depict the dynamics of the Universe around the end of inflation and the initial oscillatory phases. This article proposes a single, unified, model-independent, parametrized analytical solution for such models that bridges the gap between these two extremes, providing a near-accurate comprehensive description of the evolution of the Universe. This novel strategy has the potential to substantially enhance both quantitative and qualitative cosmological observational predictions, and, as a consequence, can further constrain the inflationary models more effectively using future observations.