Eur. Phys. J. Plus (2016) 131: 415
https://doi.org/10.1140/epjp/i2016-16415-9

Regular Article

Similarity dark energy models in Bianchi type-I space-time

¹ King Abdul Aziz University, Faculty of Science, Department of Mathematics, PO Box 80203, 21589, Jeddah, Saudi Arabia
² Mathematics Department, Faculty of Science, Al-Azhar University, Nasr city, 11884, Cairo, Egypt
³ Department of Physics, United College of Engineering & Research, 201306, Greater Noida, India

^* e-mail: abanilyadav@yahoo.co.in

Received: 7 March 2016
Accepted: 7 November 2016
Published online: 29 November 2016

Abstract

We investigate some new similarity inhomogeneous solutions of anisotropic dark energy and perfect fluid in Bianchi type-I space-time. Three different equation-of-state (EoS) parameters along the spatial directions are introduced to quantify the deviation of pressure from isotropy. We consider the case when the dark energy is minimally coupled to the perfect fluid as well as the direct interaction with it. The Lie symmetry generators that leave the equation invariant are identified and we generate an optimal system of one-dimensional sub-algebras. Each element of the optimal system is used to reduce the partial differential equation to an ordinary differential equation which is further analyzed. We solve the Einstein field equations, described by a system of non-linear partial differential equations (NLPDEs), by using the Lie point symmetry analysis method. The geometrical and kinematic features of the models and the behavior of the anisotropy of dark energy are examined in detail.