The Equation of State of an Interacting Tachyon

We examine the cosmological solutions of a tachyon field non minimally coupled to gravity through an effective Born-Infeld interacting Lagrangian with a power law potential, in order to investigate its equation of state as related to tracking properties. We find exact solutions in the case of a tachyon dominated Universe and when the dominant component of the stress energy tensor is determined by some other perfect fluid.