Variable Equation of State for Generalized Dark Energy Model

TL;DR

This paper proposes a variable equation of state for dark energy within a cosmological model, deriving expressions for key parameters that align with observations of the accelerating universe.

Contribution

It introduces a new phenomenological model with a time-dependent equation of state parameter and derives general expressions for cosmic parameters.

Findings

Derived expressions for density and deceleration parameters.

Model aligns with current observational data.

Provides a complete evolution scenario of the cosmos.

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 $\Lambda \propto H^2$ with a prescription for equation of state parameter in the form $\omega(t)=\omega_0+\frac{\omega_1\tau}{t^2}$, where $\omega_0$ and $\omega_1$ are two constants and $\tau$ is a parameter having dimension of time $t^2$. General expressions for the density parameter $\Omega$ 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 $\omega(t)$ and (ii) agree mostly with the observational status of the present phase of the accelerating Universe.