Bianchi type III models with anisotropic dark energy
Articles > Article · 2009
Authors: Oezguer Akarsu, Can KILINÇ
GENERAL RELATIVITY AND GRAVITATION, Journal Indexed in SCI Expanded, International, 2009, vol 42, pp 763-775
DOI: 10.1007/s10714-009-0878-7
Summary
The general form of the anisotropy parameter of the expansion for Bianchi type-III metric is obtained in the presence of a single diagonal imperfect fluid with a dynamically anisotropic equation of state parameter and a dynamical energy density in general relativity. A special law is assumed for the anisotropy of the fluid which reduces the anisotropy parameter of the expansion to a simple form (Delta proportional to H-2V-2, where Delta is the anisotropy parameter, H is the mean Hubble parameter and V is the volume of the universe). The exact solutions of the Einstein field equations, under the assumption on the anisotropy of the fluid, are obtained for exponential and power-law volumetric expansions. The isotropy of the fluid, space and expansion are examined. It is observed that the universe can approach to isotropy monotonically even in the presence of an anisotropic fluid. The anisotropy of the fluid also isotropizes at later times for accelerating models and evolves into the well-known cosmological constant in the model for exponential volumetric expansion.