Binary mixture of anisotropic dark energy and perfect fluid in Kantowski-Sach universe
Department of Mathematics, Sant Gadge Baba Amravati University, 444602, Amravati, India
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Revised: 1 October 2011
Accepted: 4 October 2011
Published online: 7 November 2011
The Kantowski-Sachs cosmological models with binary mixture of perfect fluid and anisotropic dark energy have been studied. In order to obtain a unique solution, it is assumed that the energy conservation equation of the perfect fluid (PF) and dark energy (DE) vanishes separately together with a special law for the mean Hubble parameter which yields a constant value of the deceleration parameter. To have a general description of an anisotropic dark-energy component, a phenomenological parameterization of dark energy in terms of its equation of state (EoS) ω (de) and two skewness parameters (γ, δ) have been introduced. It has been found out that the anisotropic distribution of dark energy leads to the present accelerated expansion of the universe. A cosmological scenario with the deceleration parameter having the desired property of signature flip has been developed. The geometrical and physical parameters of the models are studied. The analysis of the models reveals that the present acceleration, isotropy of the universe turn out to be natural consequences of dark energy.
© Società Italiana di Fisica and Springer, 2011