Quantum escape of sudden future singularity

TL;DR

This paper investigates finite-time future singularities, showing that quantum effects can delay or soften these singularities, potentially leading the universe to a deSitter phase before the singularity occurs, with implications for braneworld models.

Contribution

It introduces new examples of sudden future singularities and demonstrates how quantum effects can influence their development and outcome.

Findings

Quantum effects can delay or soften singularities.

Universe may reach deSitter phase before singularity.

Similar effects observed in braneworld scenarios.

Abstract

We consider finite-time, future (sudden or Big Rip type) singularities which may occur even when strong energy condition is not violated but equation of state parameter is time-dependent. Recently, example of such singularity has been presented by Barrow, we found another example of it. Taking into account back reaction of conformal quantum fields near singularity, it is shown explicitly that quantum effects may delay (or make milder) the singularity. It is argued that if the evolution to singularity is realistic, due to quantum effects the universe may end up in deSitter phase before scale factor blows up. This picture is generalized for braneworld where sudden singularity may occur on the brane with qualitatively similar conclusions.