Realistic Equations of State for the Primeval Universe

TL;DR

This paper develops realistic equations of state for the early universe that incorporate interactions, leading to an inflationary phase capable of resolving flatness and horizon problems without an initial singularity.

Contribution

It introduces new equations of state for the primeval universe that naturally produce inflation and avoid initial singularities under certain conditions.

Findings

The equations generate an inflationary regime before nucleosynthesis.

The model solves flatness and horizon problems.

It explains the universe's expansion without initial singularity.

Abstract

Early universe equations of state including realistic interactions between constituents are built up. Under certain reasonable assumptions, these equations are able to generate an inflationary regime prior to the nucleosynthesis period. The resulting accelerated expansion is intense enough to solve the flatness and horizon problems. In the cases of curvature parameter \kappa equal to 0 or +1, the model is able to avoid the initial singularity and offers a natural explanation for why the universe is in expansion.