Modified Chaplygin Gas and Constraints on its B parameter from CDM and UDME Cosmological models

TL;DR

This paper investigates the Modified Chaplygin Gas as a dark energy candidate, constraining its parameters using cosmological data within CDM and UDME models to identify viable parameter ranges.

Contribution

It provides the first detailed constraints on the B parameter of MCG in the context of both CDM and UDME cosmological models.

Findings

Constraints on B parameter vary with alpha and A_s.

Allowed parameter ranges are identified for physically viable models.

Results help refine dark energy models using observational data.

Abstract

We study Modified Chaplygin Gas (MCG) as a candidate for dark energy and predict the values of parameters of the gas for a physically viable cosmological model. The equation of state of MCG ($p=B \rho - \frac {A}{\rho^\alpha} $) involves three parameters: $B$, $A$ and $\alpha$. The permitted values of these parameters are determined with the help of dimensionless age parameter ($H_{o}t_{o}$) and $H(z)-z$ Data. Specifically we study the allowed ranges of values of B parameter in terms of $\alpha$ and $A_{s}$ ($A_{s}$ is defined in terms of the constants in the theory). We explore the constraints of the parameters in Cold Dark Matter(CDM) model and UDME(Unified Dark Matter Energy) model respectively.