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arXiv · 2107.05044

The simplest parametrization of equation of state parameter in the scalar field Universe

Preeti Shrivastava·A. J. Khan·G. K. Goswami·Anil Kumar Yadav·J. K. Singh
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Abstract

In this paper, we have investigated a scalar field cosmological model of accelerating Universe with the simplest parametrization of equation of state parameter of the scalar field. We used $H(z)$ data, pantheon compilation of SN Ia data and BAO data to constrained the model parameters using $χ^{2}$ minimization technique. We obtain the present values of Hubble constant $H_{0}$ as $66.2^{+1.42}_{-1.34}$, $70.7^{+0.32}_{-0.31}$ and $67.74^{+1.24}_{-1.04}$ for $H(z)$, $H(z)$ + Pantheon and $H(z)$ + BAO respectively. Also, we have estimated the present age of the Universe in derived model $t_{0} = 14.38^{+0.63}_{-0.64}$ for joint $H(z)$ and pantheon compilation of SN Ia data which has only $0.88~σ$ tension with its empirical value obtained in Plank collaboration \cite{Ade/2016}. Moreover, the present values of the deceleration parameter $q_{0}$ come out to be $-0.55^{+0.031}_{-0.038}$, $-0.61^{+0.030}_{-0.021}$ and $-0.627^{+0.022}_{-0.025}$ by bounding the Universe in derived model with $H(z)$, $H(z)$ + Pantheon compilation of SN Ia and $H(z)$ + BAO data sets respectively. We also have performed the state-finder diagnostics to discover the nature of dark energy.

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Preeti Shrivastava, A. J. Khan, G. K. Goswami, Anil Kumar Yadav, J. K. Singh. 2021-07-11. The simplest parametrization of equation of state parameter in the scalar field Universe. https://doi.org/10.3390/galaxies11020057

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