Goldstone's Theorem and Hamiltonian of Multi-galileon Modified Gravity
  The galileon model was recently proposed to locally describe a class of
modified gravity theories, including the braneworld DGP model. We discuss
spontaneous symmetry breaking of the self-accelerating branch in a
multi-galileon theory with internal global symmetries. We show a modified
version of Goldstone's theorem is applicable to the symmetry breaking pattern
and discuss its implications. We also derive the Hamiltonian of a general
multi-galileon theory and discuss its implications.
