Massive gravity from Dirichlet boundary conditions
  We propose an explicit non-linear realization of massive gravity, which
relies on the introduction of a spurious compact extra dimension, on which we
impose half-Newmann and half-Dirichlet boundary conditions. At the linearized
level, we recover the expected gravitational exchange amplitude between two
sources mediated by a massive Fierz-Pauli spin-2 field, while cubic
interactions in the additional helicity-0 mode give rise to the expected
Vainsthein mechanism. We also show that this framework can accommodate for a
flat four-dimensional geometry in the presence of a cosmological constant,
putting this framework on a good footing for the study of degravitation.
