Cosmological Applications of Massive Gravity

Abstract

Models of modified gravity in the infrared are especially appealing for their late-time cosmology. We review different models before focusing on the cosmology of massive gravity. We start by information derived from its decoupling limit where a self-acceleration solution can be found but suffers from strong coupling issues in the vector modes. This feature is carried through for most FRW self-accelerating solutions in the full theory. We emphasize the role played by inhomogeneous solutions which reduce to a self-accelerating FRW solution on distances comparable to our current Universe but are inhomogeneous at larger distances. We also give an overview of cosmological solutions in extensions of massive gravity such as bi-gravity and quasi-dilaton massive gravity.