Gravity and Dark Energy

Accelerated expansion as manifestation of gravity: when Dark Energy belongs to the left

We study geometrical dark energy models of geometrical nature, and thus a manifestation of the underlying gravitational theory.Then we introduce a novel class of modified gravity theories based on the anticurvature tensor (the inverse of the ricci tensor), and assess their capability as source of dark energy.Finally, we discuss a type of drift effects which we predicted in the contest of strong gravitational lensing, which could be employed both to study the effective equation of state of the universe and to constrain violations of the equivalence principle.