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arXiv · 2307.05576

Constraining the bulk viscous coefficients in a viscous universe with cosmological constant

Athira Sasidharan·Titus K Mathew
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Abstract

In this paper we consider dissipative effects in $\Lambda$CDM model, i.e., we consider a universe with cosmological constant having viscous matter. We assume the most general form for bulk viscous coefficient, $\zeta=\zeta_{0}+\zeta_{1}\frac{\dot{a}}{a}+\zeta_{2}\frac{\ddot{a}}{\dot{a}}$ and obtained various constrains for $\zeta$'s . We also studied the background study of the model with $\zeta=\zeta_{0}$ and $\zeta=\zeta_{1}\frac{\dot{a}}{a}$. Extracted the value of $\zeta_1$ using the Pantheon data and also obtained its thermodynamic evolution and the age.

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Athira Sasidharan, Titus K Mathew. 2023-07-10. Constraining the bulk viscous coefficients in a viscous universe with cosmological constant. https://arxiv.org/abs/2307.05576

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