Bianchi type-VIo Universe with wet dark fluid

Raghavendra Chaubey

doi:10.4236/ns.2011.310107

Abstract

The Bianchi type- VIo universe filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the universe has been used. It is modeled on the equation of state p=γ(ρ-ρ﹡) which can describe a liquid, for example water. The exact solutions to the corresponding field equations are obtained in quadrature form. The solution for constant deceleration parameter have been studied in detail for power-law and exponential forms both. The case γ=0, γ=1, and γ=1/3 have been also analysed.

Highlights

The nature of the dark energy component of the universe [1,2,3] remains one of the deepest mysteries of cosmology
We use Wet Dark Fluid (WDF) as a model for dark energy. This model is in the spirit of the generalized Chaplygin gas (GCG) [19], where a physically motivated equation of state is offered with properties relevant for the dark energy problem
From Eq.2.23 and taking into account that the pressure and the energy density obeying an equation of state of type pWDF = f WDF, we conclude that WDF and pWDF, the right hand side of the Eq.2.19 is a function of V only

Summary

INTRODUCTION

The nature of the dark energy component of the universe [1,2,3] remains one of the deepest mysteries of cosmology. We use Wet Dark Fluid (WDF) as a model for dark energy. This model is in the spirit of the generalized Chaplygin gas (GCG) [19], where a physically motivated equation of state is offered with properties relevant for the dark energy problem. One of the virtues of this model is that the square of the sound speed, cs , which depends on p , can be positive (as opposed to the case of phantom energy, say), while still giving rise to cosmic acceleration in the current epoch. In this paper we study the Bianchi type-VIo universe with matter term with dark energy treated as a Dark Fluid satisfying the equation of state (1.1). The models with constant deceleration parameter have been studied in detail

BASIC EQUATION

SOME PARTICULAR CASES

MODELS WITH CONSTANT DECELERATION PARAMETER

CONCLUSIONS