New Cosmological Solutions in Massive Gravity
  We find new, simple cosmological solutions with flat, open, and closed
spatial geometries, contrary to the previous wisdom that only the open model is
allowed. The metric and the St\"{u}ckelberg fields are given explicitly,
showing nontrivial configurations of the St\"{u}ckelberg in the usual
Friedmann-Lema\^{i}tre-Robertson-Walker coordinates. The solutions exhibit
self-acceleration, while being free from ghost instabilities. Our solutions can
accommodate inhomogeneous dust collapse represented by the
Lema\^{i}tre-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.
