Study of Some Parameters of Modified Chaplygin Gas in Galileon Gravity Theory from Observational Perspective

TL;DR

This paper investigates a modified Chaplygin gas model within Galileon gravity, fitting it to various observational data sets to confirm its consistency with current cosmic acceleration.

Contribution

It introduces a cosmological model combining Modified Chaplygin Gas with Galileon gravity and constrains its parameters using multiple observational data sets.

Findings

Model aligns with observed cosmic acceleration

Parameter bounds obtained from OHD, BAO, CMB, and supernova data

Model agrees with Union 2 supernovae data

Abstract

We have assumed the FRW model of the universe in Galileon gravity, which is filled with dark matter and Modified Chaplygin gas (MCG) type dark energy. We present the Hubble parameter in terms of some unknown parameters and observational parameters with the redshift $z$. Some cosmological parameters are reconstructed and plots are generated to study the nature of the model and its viability. It is seen that the model is perfectly consistent with the present cosmic acceleration. From \textit{observed Hubble data (OHD) set or Stern data set} of 12 points, we have obtained the bounds of the arbitrary parameters ($A,B$) & ($A,C$) by minimizing the $\chi^{2}$ test. Next due to joint analysis of \textit{Stern+BAO} and \textit{Stern+BAO+CMB} observations, we have also obtained the best fit values and the bounds of the parameters ($A,B$) & ($A,C$) by fixing some other parameters. The best-fit values and bounds of the parameters are obtained with 66%, 90% and 99% confidence levels for \textit{Stern, Stern+BAO and Stern+BAO+CMB} joint analysis. Next we have also taken type Ia supernovae data set (union 2 data set with 557 data points). The distance modulus $\mu(z)$ against redshift $z$ for our theoretical MCG model in Galileon gravity have been tested for the best fit values of the parameters and the observed \textit{SNe Ia union 2 data} sample and from this, we have concluded that our model is in agreement with the union 2 sample data.