We investigate cosmological scenarios in a universe governed by Horava-Lifshitz gravity, with or without the detailed-balance condition. In particular, we study the dark energy dynamics, the bouncing solutions and the cyclic behavior, and we perform a phase-space analysis examining the late-time cosmological evolution. Furthermore, we use observational data in order to constrain the parameters of the theory, and additionally we discuss some thermodynamic aspects of Horava-Lifshitz cosmology. Although this analysis indicates that Horava-Lifshitz cosmology can be very interesting, Horava-Lifshitz gravity itself may have crucial conceptual and theoretical problems, as a simple perturbation analysis indicates.

National Technical University of Athens