Eddington-Born-Infeld action for dark matter and dark energy

We argue that Einstein gravity coupled to a Born-Infeld theory provides an attractive candidate to represent dark matter and dark energy. For cosmological models, the Born-Infeld field has an equation of state which interpolates between matter, p=0 (small times), and a cosmological constant p=-rho (large times). On galactic scales, the Born-Infeld theory predicts asymptotically flat rotation curves.