Accelerating Universe with binary mixture of bulk viscous fluid and dark energy

TL;DR

This paper proposes a cosmological model combining bulk viscous fluid and dark energy to explain universe acceleration, constrained by recent observational data, and finds it closely aligns with the standard Lambda-CDM model.

Contribution

The paper introduces a novel accelerating universe model with a binary mixture of bulk viscous fluid and dark energy, constrained by recent observational data.

Findings

Estimated Hubble constant: ~70 km/s/Mpc

Universe age: ~13.82 billion years

Transition redshift: ~0.73

Abstract

In this paper, we have proposed a model of accelerating Universe with binary mixture of bulk viscous fluid and dark energy. and probed the model parameters: present values of Hubble's constant $H_{0}$, Equation of state paper of dark energy $\omega_{de}$ and density parameter of dark energy $(\Omega_{de})_{0}$ with recent OHD as well as joint Pantheon compilation of SN Ia data and OHD. Using cosmic chronometric technique, we obtain $H_{0} = 69.80 \pm 1.64~km~s^{-1}Mpc^{-1}$ and $70.0258 \pm 1.72~km~s^{-1}Mpc^{-1}$ by restricting our derived model with recent OHD and joint Pantheon compilation SN Ia data and OHD respectively. The age of the Universe in derived model is estimated as $t_{0} = 13.82 \pm 0.33\; Gyrs$. Also, we observe that derived model represents a model of transitioning Universe with transition redshift $z_{t} = 0.7286$. We have constrained the present value of jerk parameter as $j_{0} = 0.969 \pm 0.0075$ with joint OHD and Pantheon data. From this analysis, we observed that the model of the Universe, presented in this paper shows a marginal departure from $\Lambda$CDM model.