The generalized second law in the emergent universe

TL;DR

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

Contribution

It provides a detailed analysis of thermodynamic law fulfillment during key cosmological phase transitions in the emergent universe scenario.

Findings

The generalized second law is satisfied during the transition.

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

Conditions for thermodynamic consistency in emergent universe models.

Abstract

This paper studies 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 era of thermal radiation dominated expansion. As it turns out, the said law is satisfied provided the radiation component does not largely contribute to the total energy of the static phase.