Conformal anomaly around the sudden singularity

Abstract

Quantum effects due to particle creation on a classical sudden singularity have been investigated in a previous work. The conclusion was that quantum effects do not lead to the avoidance nor the modification of the sudden future singularity. In this paper, we investigate quantum corrections coming from conformal anomaly near the sudden future singularity. We conclude that when the equation of state is chosen to be $p=-\rho-A\rho^\alpha$, the conformal anomaly can transform the sudden singularity in the singularity of type III for any $\alpha> 1/2$ and in the singularity of the type I (the big rip) or the big crunch for $1/2<\alpha<3/2$.