Observation constraints on scalar field cosmological model in Anisotropic universe

TL;DR

This paper constrains a scalar field dark energy model in an anisotropic universe using observational data, providing parameter estimates and analyzing the universe's dynamical properties and evolution.

Contribution

It presents the first detailed constraint of a scalar field cosmological model within an anisotropic Bianchi type-I universe using recent observational data.

Findings

Best-fit Hubble constant H0 = 71.54±0.28

Redshift transition at zt ≈ 0.6964

Current deceleration parameter q0 ≈ -0.6964

Abstract

In this study, we have explored a scalar field cosmological model in the axially symmetric Bianchi type-I universe. In this study, our aim is to constrain the scalar field dark energy model in an anisotropic background. For this purpose, the explicit solution of the developed field equations for the model is determined and analysed. Constraints on the cosmological model parameters are established utilizing Markov Chain Monte Carlo (MCMC) analysis and using the latest observational data sets of OHD, BAO, and Pantheon. For the combined dataset (OHD, BAO, and Pantheon), the best-fit values of Hubble and density parameters are estimated as $ H_{0} = 71.54\pm 0.28$, $\Omega_{m0}=0.2622\pm0.0021$ $\Omega_{\phi0} = 0.7331\pm0.0046$, and $\Omega_{\sigma 0} = 0.000162\pm0.000063$. The model shows a flipping nature and redshift transition occurs at $z_{t} = 0.6964^{+0.0136}_{-0.0006}$, and the present value of decelerated parameter is computed to be $q_{0} = -0.6964\pm0.028$ for the combined dataset. We have explored characteristics like the universe's age, particle horizon, deceleration parameter, and jerk parameter. The dynamical properties such as energy density $\rho_{\phi}$, scalar field pressure $p_{\phi}$, and equation of state parameter $\omega_{\phi}$ are analyzed and presented. We have also described the behavior of the scalar potential $V(\phi)$ and scalar fields. Furthermore, the authors also described the behavior of energy conditions in scalar-tensor cosmology. The scenario of the present accelerated expansion of the universe is described by the contribution of the scalar field.