A non-singular universe with vacuum energy

TL;DR

This paper proposes a non-singular cosmological model based on quantum fields at finite temperature with a cosmological constant, explaining early and present universe features without singularities.

Contribution

It introduces a novel non-singular universe model incorporating quantum field effects and vacuum energy, addressing limitations of standard cosmology.

Findings

Model explains features of early and current universe

Achieves thermal equilibrium in vacuum regime

Avoids singularities of standard cosmology

Abstract

We construct a model for the universe based on the existence of quantum fields at finite temperature in the background of Robertson-Walker spacetime in presence of a non-zero cosmological constant. We discuss the vacuum regime in the light of the results obtained through previous studies of the back-reaction of massless quantum fields in the static Einstein universe, and we argue that an adiabatic vacuum state and thermal equilibrium is achieved throughout this regime. Results shows that such a model can explain many features of the early universe as well as the present universe. The model is free from the basic problems of the standard Friedmann cosmology, and is non-singular but involves a continuous creation of energy at a rate proportional to the size of the universe, which is lower than that suggested by the steady-state cosmology.