Emergent Universe with particle production

TL;DR

This paper explores emergent universe solutions within Einstein's equations incorporating matter creation, demonstrating conditions under which a universe can emerge smoothly without a big bang, and analyzing its thermodynamic properties.

Contribution

It introduces new emergent universe solutions with matter production, including cases with constant creation rate and more general scenarios, expanding cosmological models.

Findings

Emergent universe solutions exist with specific matter creation rates.

The thermodynamic behavior of these solutions is characterized.

Emergent scenarios are possible with standard cosmological equations of state.

Abstract

The possibility of an emergent universe solution to Einstein's field equations allowing for an irreversible creation of matter at the expense of the gravitational field is shown. With the universe being chosen as spatially flat FRW spacetime together with equation of state proposed in [17], the solution exists when the ratio of the phenomenological matter creation rate to the number density times the Hubble parameter is a number $\beta$ of the order of unity and independent of time. The thermodynamic behaviour is also determined for this solution. Interestingly, we also find that an emergent universe scenario is present with usual equation of state in cosmology when the matter creation rate is chosen to be a constant. More general class of emergent universe solutions are also discussed.