Constraining Anisotropic Cosmological Model in $f(\mathcal{R},\mathscr{L}_m)$ Gravity

TL;DR

This paper investigates anisotropic cosmological models within $f( ext{R}, ext{L}_m)$ gravity, constraining parameters using observational data and analyzing the universe's anisotropy with a specific non-linear gravity model.

Contribution

It introduces a non-linear $f( ext{R}, ext{L}_m)$ gravity model and constrains its parameters using observational data, analyzing anisotropy in a homogeneous Bianchi-I universe.

Findings

Model parameters constrained by observational data.

Anisotropy parameter measured for the proposed model.

Equation of state parameter constrained using MCMC analysis.

Abstract

The observational evidence regarding the present cosmological aspects tells us about the presence of very little anisotropy in the universe on a large scale. Here, in this paper, we attempt to study locally rotationally symmetric (LRS) homogeneous Bianchi-I spacetime with the isotropic matter distribution. This is done within the framework of $f(\mathcal{R},\mathscr{L}_m)$ gravity. Particularly, we consider a non-linear $f(\mathcal{R},\mathscr{L}_m)$ model, $f(\mathcal{R},\mathscr{L}_m)=\dfrac{1}{2}\mathcal{R}+\mathscr{L}_m^{\,{\alpha}}$. Furthermore, $\omega$, the equation of state parameter, which is vital stuff in determining the present phase of the universe is constrained. To constrain the model parameters and the equation of state parameter, we use 57 Hubble data points and 1048 Pantheon supernovae type Ia data sample. And, for our statistical analysis, we use Markoc Chain Monte Carlo (MCMC) simulation. Moreover, with the help of obtained values of parameters, we measure the anisotropy parameter for our model.