Emergent Universe and Phantom Tachyon Model

TL;DR

This paper explores conditions under which an emergent universe scenario is possible with phantom and tachyonic fields across different spatial curvatures, analyzing stability and evolution stages.

Contribution

It demonstrates that phantom and tachyonic fields enable emergent universe scenarios for all curvature values, extending previous results limited to closed universes.

Findings

Emergent scenario possible for all k with phantom/tachyonic fields.

Statefinder parameters reveal evolution stages of the emergent universe.

Stability analysis conducted for both phantom and tachyon models.

Abstract

In this work, I have considered that the universe is filled with normal matter and phantom field (or tachyonic field). If the universe is filled with scalar field, Ellis et al have shown that emergent scenario is possible only for $k=+1$ i.e. for closed universe and here I have shown that the emergent scenario is possible for closed universe if the universe contains normal tachyonic field. But for phantom field (or tachyonic field), the negative kinetic term can generate the emergent scenario for all values of $k ~(=0,\pm 1)$. From recently developed statefinder parameters, the behaviour of different stages of the evolution of the emergent universe have been studied. The static Einstein universe and the stability analysis have been briefly discussed for both phantom and tachyon models.