On the Covariant Galileon and a consistent self-accelerating Universe
  In this paper we show that the flat space Galilean theories with up to three
scalars in the equation of motion (the quartic Galileons) are recovered in the
decoupling limit of certain scalar theories non-minimally coupled to gravity,
the so-called "Slotheonic" theories. These theories are also invariant under
the generalized Galilean shifts in curved spacetime. While Galilean
self-(derivative)couplings are not explicit in the action, they appear after
integrating out gravity. We then argue that Galilean supersymmetric theories
may only be found in the context of supergravity. Finally, we discuss on the
possibility that Slotheonic theories are the effective four dimensional
theories of consistent DGP-like models with self-accelerating cosmological
solutions. Moreover, we show that the quartic and cubic Galileon in consistent
DGP models cannot be decoupled.
