Wet dark fluid with linearly varying deceleration parameter and type-V future singularity of the Bianchi type-I universe

Abstract

This work deals with the study of the dynamics of a spatially homogeneous and anisotropic Bianchi type-I universe filled with two minimally interacting isotropic fluids: cold dark matter and wet dark fluid components. To obtain an exact solution of the Einstein’s field equations, we have used the assumption of linearly varying deceleration parameter. Under suitable conditions, it is observed that the solution describes effectively the current acceleration and indicates occurrence of a type-V future singularity in the late time evolution of the universe. As the solution shows that the universe has a finite lifetime and passes through a significant time when energy densities of both the dark components are nearly comparable, so considering the coincidence parameter r to be a free parameter and $\frac{1}{r_{0}} < r< r_{0}$ , where r 0 is any fixed ratio, we have calculated the important fraction f of total life time of the universe when it passes through the coincidental stage before the singularity. We have also discussed the consistencies of our results with the recent cosmological observational data.