Growth of Perturbations using LambertW Equation of State

Abstract

Recently, a novel equation of state (EoS) parameter for dark energy has been introduced which deals with a special mathematical function, known as the LambertW function. In this paper, we study the effect on the growth of perturbations for the LambertW dark energy model. We perform the analysis for two different approaches. In the first case we consider the universe to be filled with two different fluid components, namely, the baryonic matter component and the LambertW dark energy component, while in the second case we consider that there is a single fluid component in the universe whose equation of state parameter is described by the LambertW function. We then compare the growth rates of LambertW model with that for a standard model as well as the CPL model. Our results indicate that the presence of LambertW dynamical dark energy sector changes the growth rate and affects the matter fluctuations in the universe to a great extent.