Bound to bounce: A coupled scalar-tachyon model for a smooth bouncing/cyclic universe

The minimum size of the universe is nonzero for generic initial values. The smooth bounces are made possible because of the negative contribution to effective energy density by the curvature term. No ghosts are ever generated at any point in the entire evolution of the universe, with the Null, Weak, and Dominant Energy Conditions preserved even at the bounce points, contrary to many bounce models previously proposed. And the Strong Energy Condition is satisfied in periods with tachyon matter domination.