The generalized second law and the emergent universe

TL;DR

This paper investigates the validity of the generalized second law of thermodynamics during the transition from a static universe to inflation and then to radiation domination, finding it holds under certain energy conditions.

Contribution

It analyzes the thermodynamic law's applicability during key cosmological phase transitions, highlighting conditions for its validity in emergent universe scenarios.

Findings

The generalized second law is satisfied during the transition to inflation.

The law holds if radiation does not dominate the static phase's energy.

Conditions for thermodynamic consistency in emergent universe models.

Abstract

We explore whether the generalized second law of thermodynamics is fulfilled in the transition from a generic initial Einstein static phase to the inflationary phase, with constant Hubble rate, and from the end of the latter to the conventional thermal radiation dominated era of expansion. As it turns out, the said law is satisfied provided the radiation component does not contribute largely to the total energy of the static phase.