Conformal anomaly around the sudden singularity

Understand

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 $1/2<\alpha<3/2$.