English

Cosmological Bounce Scenario with a Novel Parametrization of Bulk Viscosity

General Relativity and Quantum Cosmology 2024-07-23 v1

Abstract

In this work, we have studied how incorporating viscous fluids leads to exact bounce cosmological solutions in general relativity (GR) framework. Specifically, we propose a novel parameterization of bulk viscosity coefficient of the form ζ=ζ0(tt0)2nH\zeta = \zeta_0 (t-t_0)^{-2n} H, where ζ0\zeta_0, nn being some positive constants and t0t_0 is the bounce epoch. We investigate how this form of bulk viscosity may assist in explaining the early universe's behaviour, with a particular focus on non-singular bounce scenario by studying the various energy conditions and other related cosmological observables and how the model parameters affect the evolution of the Universe. We demonstrate that the NEC and SEC violation occurs at the bounce point while DEC is satisfied. Finally, we carried out a stability check based on linear order perturbation to the Hubble parameter. We found that the perturbation vanishes asymptotically at later times, which indicates a stable behaviour of the bounce scenario

Keywords

Cite

@article{arxiv.2407.15178,
  title  = {Cosmological Bounce Scenario with a Novel Parametrization of Bulk Viscosity},
  author = {Rajdeep Mazumdar and Mrinnoy M. Gohain and Kalyan Bhuyan},
  journal= {arXiv preprint arXiv:2407.15178},
  year   = {2024}
}

Comments

8 figures, 2 tables, Accepted for publication in Int. J. Geom. Methods. Mod. Phys. arXiv admin note: text overlap with arXiv:2208.03171 by other authors