Variable Equation of State for Generalized Dark Energy Model

Abstract

We present a model for the present accelerating Universe and focus on the different important physical variables involved in the model under the phenomenological assumption $Λ\propto H^2$ with a prescription for equation of state parameter in the form $ω(t)=ω_0+\frac{ω_1τ}{t^2}$, where $ω_0$ and $ω_1$ are two constants and $τ$ is a parameter having dimension of time $t^2$. General expressions for the density parameter $Ω$ and deceleration parameter $q$ are obtained which under specific bound reproduce some of the previous results. We explore physical features of these parameters which (i) provide the scenario of complete evolution of the cosmos with $ω(t)$ and (ii) agree mostly with the observational status of the present phase of the accelerating Universe.

6 Latex pages, 3 figures