Title: 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 $Q \propto H\rho_d$,
analytic expressions for the energy density and pressure have been derived in
terms of the Hypergeometric $_2\text{F}_1$ 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
$w_m=0$ and $w_m=-\frac{1}{3}$ over the $w_m=\frac{1}{3}$ case. Interestingly,
the present model also incorporates the transition of dark energy into the
phantom domain, however, future deceleration is forbidden.