1207.3723 (Mikhail S. Volkov)

Exact self-accelerating cosmologies in the ghost-free massive gravity --
the detailed derivation    [PDF]

Mikhail S. Volkov

We present the detailed derivation of the recently announced in arXiv:1205.5713 most general cosmological solution with homogeneous and isotropic metric in the dRGT ghost-free massive gravity theory. We use the standard parametrization of the theory in terms of the matrix square root, and then show how the same results are recovered within the tetrad formalism. The solution obtained includes the matter source, it exists for generic values of the theory parameters, and it describes a universe that can be spatially open, closed, or flat, and that shows the late time acceleration due to the effective cosmological term mimicked by the graviton mass. The Stueckelberg fields are inhomogeneous, which could generate inhomogeneous perturbations of the homogeneous and isotropic background, although this effect should be suppressed by the smallness of the graviton mass.

View original: http://arxiv.org/abs/1207.3723