Constraining Modified Chaplygin gas parameters

Abstract

We investigate the evolution of a FRW model fuelled by a modified Chaplygin gas with an equation of state $p=A\rho -\frac{B}{{\rho }^{\alpha }}$. An attempt is made here to constrain the free parameters of MCG model through the wellknown contour plot technique using observational data. The permissible range of values of the pair of free parameters are determined to study the viability of cosmological models \emph{vis-a-vis} observational results. Aside from allowing the desirable feature of \emph{flip} of the sign of deceleration parameter we also find that the transition from the decelerating to the accelerating phase occurs at relatively low value of redshift in accordance with the observational prediction that the acceleration is a recent phenomenon. It is found that the effective acoustic speed may become imaginary depending upon the initial conditions signalling that perturbations associated with instability sets in resulting in structure formation. As one considers more negative values of $A$ the \emph{flip} in sign is delayed resulting the density parameter to change fast. Again it is found from the contour plot that compatibility with observational results is admitted with a value of $A$ which is very near to zero or a small negative number.

15 pages, 9 figures

References in corpus (8)

• Dynamics of dark energy
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• String Cosmology: A Review
• Constraints on modified Chaplygin gas from recent observations and a comparison of its status with other models
• Cosmological constraints on a decomposed Chaplygin gas
• Phantom field dynamics in loop quantum cosmology
• Ruling out the Modified Chaplygin Gas Cosmologies
• Single-field inflation à la generalized Chaplygin gas

Cited by in corpus (4)

• Higher order corrections of the extended Chaplygin gas cosmology with varying $G$ and $\Lambda$
• Thermodynamics of the Variable Modified Chaplygin gas
• Thermodynamics of Modified Chaplygin-Jacobi Gas and Modified Chaplygin-Abel Gas: Stability Analysis and Observational Constraints
• Emergent Universe Scenario in the Modified Chaplygin gas : Towards an Exact Solution and Observational Constraints