Title: Spherically Symmetric Solutions of Massive Gravity and the Goldstone Picture.

Abstract: I will discuss static spherically symmetric solutions in "massive gravity", appropriate e.g. to describe the metric outside of a star. In particular, after having introduced these theories, I will study how the so called "decoupling limit" introduced by Arkani-Hamed, Georgi and Schwartz can be applied in the context of spherically symmetric systems. I will explain how the decoupling limit simplifies the system while focusing on the most important non-linearities, and also how this limit allows us to find a simple parametrization of all the various massive gravity models. I will then concentrate my attention on two specific models and show that in these cases, regular solutions can be found, which tend towards linear massive gravity at infinity, and whose scaling at small distances corresponds to zero modes of the non-linearities appearing in the decoupling limit; I will also specify which of these solutions corresponds to a viable solution inside the source. Finally, I will use this spherically symmetric framework to discuss to what extent the decoupling limit encodes all the physics of the full (non-decoupled) system.