Anisotropic perturbations and stability of a static universe in gravity
Department of Mathematics, University of the Punjab, Quaid-e-Azam Campus, 54590, Lahore, Pakistan
* e-mail: firstname.lastname@example.org
Accepted: 27 November 2017
Published online: 18 December 2017
The aim of this paper is to analyze the stability of the Einstein universe against anisotropic homogeneous perturbations in gravity ( and T represent the Gauss-Bonnet invariant and trace of the energy-momentum tensor, respectively). The corresponding field equations are constructed for static as well as perturbed configurations in the presence of a perfect fluid. We consider two specific forms of generic function associated with zero as well as non-zero covariant divergence of the energy-momentum tensor and explore the stability regions of the Einstein universe parameterized by the equation of state parameter. It is concluded that a stable Einstein universe exists for an appropriate choice of model parameters.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2017