English

Phase Space Analysis for Anisotropic Universe with Nonlinear Bulk Viscosity

General Relativity and Quantum Cosmology 2019-05-29 v1

Abstract

In this paper, we discuss the phase space analysis of locally rotationally symmetric Bianchi type I universe model by taking a noninteracting mixture of dust like and viscous radiation like fluid whose viscous pressure satisfies a nonlinear version of the Israel-Stewart transport equation. An autonomous system of equations is established by defining normalized dimensionless variables. In order to investigate the stability of the system, we evaluate corresponding critical points for different values of the parameters. We also compute the power-law scale factor whose behavior indicates different phases of the universe model. It is found that our analysis does not provide a complete immune from fine-tuning because the exponentially expanding solution occurs only for a a particular range of parameters. We conclude that stable solutions exist in the presence of nonlinear model for bulk viscosity with different choices of the constant parameter mm for anisotropic universe.

Keywords

Cite

@article{arxiv.1905.09468,
  title  = {Phase Space Analysis for Anisotropic Universe with Nonlinear Bulk Viscosity},
  author = {M. Sharif and Saadia Mumtaz},
  journal= {arXiv preprint arXiv:1905.09468},
  year   = {2019}
}

Comments

13 pages, 6 figures. arXiv admin note: text overlap with arXiv:1702.04716

R2 v1 2026-06-23T09:18:57.572Z