Little Rip, Pseudo Rip and bounce cosmology with generalized equation of state in non-standard backgrounds

TL;DR

This paper explores various future universe scenarios like Little rip, Pseudo rip, and bounce cosmology within non-standard backgrounds, analyzing how exotic gravity theories influence cosmic evolution.

Contribution

It introduces a generalized equation of state in viscous fluids to study these cosmologies in Chern-Simons and RS-II Braneworld models, highlighting significant differences from standard gravity.

Findings

Distinct behaviors of rip and bounce scenarios in non-standard backgrounds

Influence of exotic gravity on universe's late-time evolution

Differences compared to standard general relativistic cosmology

Abstract

The discovery of universe's late-time acceleration and dark energy has overseen a great deal of research into cosmological singularities and particularly future singularities. Perhaps the most extreme of such singlarities is the big rip, which has propelled a lot of work into ways of moderating it or seeking out alternatives to it and two such alternatives to the big rip are the Little rip and Pseudo rip. Another possibility to consider the far future of the universe is through bounce cosmologies, which presents its own interesting ideas. So in this work we investigate the Little rip, Pseudo rip and Bounce cosmology in non-standard cosmological backgrounds with a generalized equation of state in the presence of a viscous fluid. In particular we discuss about Chern-Simons cosmology and the RS-II Braneworld and discuss how the exotic and non-conventional nature of gravity in such cosmologies affect universal evolution in these scenarios. We find out that there are very significant differences in the behaviour of such cosmic scenarios in these universes in comparison to how they appear in the simple general relativistic universe.