  Five-dimensional theories manifesting spontaneous brane generation are
discussed in a gravitational context. Without gravity, the IR dynamics of the
brane fluctuation below the brane tension scale is described by an effective
theory for the Nambu-Goldstone modes. When gravity is properly taken into
account the long distance dynamics changes. The spontaneous breaking of local
translational invariance triggers the formation of massive representations via
the Higgs mechanism and induces the appearance of new mass scales in the IR.
These scales can in principle depend on other fundamental parameters besides
the brane tension and the Planck scale. In noncompact extra dimensions the
massive states are found to be scalar bound states. We obtain explicit
expressions for their propagator and show that their masses depend on the brane
width and are thus much heavier than expected. We present an exactly solvable
model which captures the main features of the gravitational system.
