Generalized Chaplygin gas, accelerated expansion, and dark-energy-matter unification

We consider the scenario emerging from the dynamics of a generalized Born-Infeld theory. The equation of state describing this system is given in terms of the energy density rho and pressure p by the relationship p=-A/rho(alpha), where A is a positive constant and 0<= 1. We discuss the conditions under which homogeneity arises and show that this equation of state describes the evolution of a universe evolving from a phase dominated by nonrelativistic matter to a phase dominated by a cosmological constant via an intermediate period where the effective equation of state is given by p=alpha rho.