Bianchi Type I model of universe with customized scale factors

TL;DR

This paper investigates an anisotropic Bianchi Type I universe model with customized scale factors, comparing its evolution and anisotropy levels to the standard $\\Lambda$CDM model using observational data.

Contribution

It introduces a modified Bianchi Type I model with tailored scale factors to analyze anisotropy evolution and compare it with standard cosmology and observational data.

Findings

Significant anisotropy in the early universe.

Anisotropy diminishes and becomes negligible at recent times.

Model aligns with $\\Lambda$CDM at low redshifts.

Abstract

According to standard cosmology, the universe is homogeneous and isotropic at large scales. However, some anisotropies can be observed at the local scale in the universe through various ways. Here we have studied the Bianchi type I model with customizing the scale factors to understand the anisotropic nature of the universe. We have considered two cases with slight modifications of scale factors in different directions in the generalized Bianchi Type I metric equation, and compared the results with the $\Lambda$CDM model and also with available cosmological observational data. Through this study, we also want to predict the possible degree of anisotropy present in the early universe and its evolution to current time by calculating the value of density parameter for anisotropy ($\Omega_{\sigma}$) for both low and high redshift (z) along with the possible relative anisotropy that exist among different directions. It is found that there was a significant amount of anisotropy in the early universe and the anisotropic nature of the universe vanishes at the near past and the present epochs. Thus at near past and present stages of the universe there is no effective distinction between this anisotropic model and the standard $\Lambda$CDM model.