Inflation from Broken Scale Invariance
  We construct a model of inflation based on a low-energy effective theory of
spontaneously broken global scale invariance. This provides a shift symmetry
that protects the inflaton potential from quantum corrections. Since the
underlying scale invariance is non-compact, arbitrarily large inflaton field
displacements are readily allowed in the low-energy effective theory. A weak
breaking of scale invariance by almost marginal operators provides a
non-trivial inflaton minimum, which sets and stabilizes the final low-energy
value of the Planck scale. The underlying scale invariance ensures that the
slow-roll approximation remains valid over large inflaton displacements, and
yields a scale invariant spectrum of perturbations as required by the CMB
observations.
