Viscous GCG(generalized Chaplygin gas) cosmology is discussed, assuming that there is bulk viscosity in the linear barotropic fluid and GCG. The dynamical analysis indicates that the phase wg = −1 + √ 3γκτg/(γ − √ 3κτγ) is a dynamical attractor and the equation of state of GCG approaches it from either wg > −1 or wg < −1 depending on the choice of its initial cosmic density parameter and the ra...

In the classical relativistic regime, the accretion of phantom energy onto a black hole reduces the mass of the black hole. In this context, we have investigated the evolution of a Schwarzschild black hole in the standard model of cosmology using the phantom-like modified variable Chaplygin gas and the viscous generalized Chaplygin gas. The corresponding expressions for accretion time scale and...

In this work gravitational collapse of a spherical cloud, consists of both dark matter and dark energy in the form of modified Chaplygin gas is studied. It is found that dark energy alone in the form of modified Chaplygin gas forms black hole. Also when both components of the fluid are present then the collapse favors the formation of black hole in cases the dark energy dominates over dark matt...

We have investigated constraints on the coupling between dark matter and the interacting Chaplygin gas. Our results indicate that the coupling constant c between these two entities can take arbitrary values, which can be either positive or negative, thus giving arbitrary freedom to the inter-conversion between Chaplygin gas and dark matter. Thus, our results indicate that the restriction 0 < c ...

We clarify the procedure for expressing the Friedmann equation in terms of directly measurable cosmological scalars constructed out of higher derivatives of the scale factor. We carry out this procedure for pure dust, Chaplygin gas and generalised Chaplygin gas energy–momentum tensors. In each case it leads to a constraint on the scalars thus giving rise to a test of General Relativity. We also...

We have investigated constraints on the coupling between dark matter and the interacting Chaplygin gas. Our results indicate that the coupling constant c between these two entities can take arbitrary values, which can be either positive or negative, thus giving arbitrary freedom to the inter-conversion between Chaplygin gas and dark matter. Thus our results indicate that the restriction 0 < c <...

Cosmologies with a Chaplygin gas have recently been explored with the objective of explaining the transition from a dust dominated epoch towards an accelerating expansion stage. We consider the hypothesis that the transition to the accelerated period involves a quantum mechanical process. Three physically admissible cases are possible. In particular, we identify a minisuperspace configuration w...

We provide a new electromagnetic mass model admitting Chaplygin gas equation of state. We investigate three specializations, the first characterized by a vanishing effective pressure, the second provided with a constant effective density and the third is described by a constant effective pressure p0. For these specializations two particular cases are discussed: (1) σe λ 2 = σ0, and (2) σe λ 2 =...

Perturbations in a Chaplygin gas, characterized by an equation of state p = −A/ρ, may acquire non-adiabatic contributions if spatial variations of the parameter A are admitted. This feature is shown to be related to a specific internal structure of the Chaplygin gas. We investigate how perturbations of this type modify the adiabatic sound speed. A reduction of the effective sound speed compared...