New Cosmological Solutions in Massive Gravity

Abstract In this talk, we have presented new and simple cosmological solutions with flat, open, and closed spatial geometries, recently found by the present authors. The metric and the Stuckelberg fields are given explicitly, showing nontrivial configurations of the Stuckelberg in the usual Friedmann-Lemaitre-Robertson-Walker coordinates. The solutions exhibit self-acceleration, while being free from ghost instabilities. Our solutions can be extended to include inhomogeneous dust collapse represented by the Lemaitre-Tolman-Bondi metric as well. Thus, our results can be used not only to describe homogeneous and isotropic cosmology but also to study gravitational collapse in massive gravity.