Interacting Chaplygin gas

Abstract

We investigate a kind of interacting Chaplygin gas model in which the Chaplygin gas plays the role of dark energy and interacts with cold dark matter particles. We find that there exists a stable scaling solution at late times with the Universe evolving into a phase of steady state. Furthermore, the effective equation of state of Chaplygin gas may cross the so-called phantom divide $w=-1$. The above results are derived from continuity equations, which means that they are independent of any gravity theories. Assuming standard general relativity and a spatially flat FRW metric, we also find the deceleration parameter is well consistent with current observations.