Interacting Chaplygin gas revisited

Abstract

The implications of considering interaction between Chaplygin gas and a barotropic fluid with constant equation of state have been explored. The unique feature of this work is that assuming an interaction Q ∝ Hρ d , analytic expressions for the energy density and pressure have been derived in terms of the Hypergeometric 2F1 function. It is worthwhile to mention that an interacting Chaplygin gas model was considered in 2006 by Zhang and Zhu, nevertheless, analytic solutions for the continuity equations could not be determined assuming an interaction proportional to H times the sum of the energy densities of Chaplygin gas and dust. Our model can successfully explain the transition from the early decelerating phase to the present phase of cosmic acceleration. Arbitrary choice of the free parameters of our model through trial and error show at recent observational data strongly favors wm = 0 and wm = − case. Interestingly, the present model also incorporates the transition of dark energy into the phantom domain, however, future deceleration is forbidden.

An extended analysis for a generalized Chaplygin gas model

“…But, the CG models are under strong observational pressure from CMB anisotropies [15,16]. This has led to the study of several interacting CG models in the literature [17,18]. It is worthwhile to mention here that Kamenshchik et al [13] also introduced a single-fluid model of a generalized Chaplygin gas (GCG) with a modified equation of state p = − A ρ α where A > 0 and α is a real number, and it reduces to CG when α = 1.…”

Dynamical system analysis of logotropic dark fluid with a power law in the rest-mass energy density

“…This was the first instance of assuming a single dark fluid to reproduce the entire evolutionary history of the Universe and also to explain the present accelerating phase. Nevertheless, the Chaplygin gas model does not fit the observations well [6,7] which is why several generalizations of the Chaplygin gas have been considered in the literature [8][9][10][11][12][13][14][15][16]. Among them, the modified Chaplygin gas (MCG) and the generalized Chaplygin gas (GCG) have been widely discussed in the literature although they have also failed to be accepted as promising candidates when observations were taken into account [11].…”