arXiv.org > hep-th > arXiv:1406.5192
Inflation from Broken
Scale Invariance
Csaba Csaki, Nemanja Kaloper, Javi Serra, John Terning
(Submitted on 19 Jun 2014)
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.