COSMOLOGICAL EVOLUTION OF MODIFIED CHAPLYGIN GAS INTERACTING WITH BAROTROPIC BACKGROUND FLUID
Abstract
Based on the observation that the equation of state parameter ω can cross the phantom dividing ω = -1 and has a 99% probability of being ω < -1, we introduce an interaction between the modified Chaplygin gas and the barotropic background fluid. By studying the dynamical evolution of the MCG model with interaction and the statefinder diagnostic in autonomous system, we find that the MCG vacuum-energy-dominated phase is the only stable attractor, the universe evolves from the matter-dominated phase to the MCG vacuum-energy-dominated phase, and the effect of the transfer strength parameter c is evident. In addition, we have plotted the evolution trajectories of the interacting CG, GCG and MCG models with barotropic background fluid in the statefinder parameter (s - r)-plane to illustrate the discriminations among these scenarios.
