Astronomical bounds on future big freeze singularity

Understand

Recently it was found that dark energy in the form of phantom generalized Chaplygin gas may lead to a new form of the cosmic doomsday, the big freeze singularity.

• Like the big rip singularity, the big freeze singularity would also take place at a finite future cosmic time, but unlike the big rip singularity it happens for a finite scale factor.Our goal is to test if a universe filled with phantom generalized Chaplygin gas can conform to the data of astronomical observations.
• We shall see that if the universe is only filled with generalized phantom Chaplygin gas with equation of state $p=-c^2s^2/\rho^{\alpha}$ with $\alpha<-1$, then such a model cannot be matched to the data of astronomical observations.
• To construct matched models one actually need to add dark matter.