  The physical properties of our universe at energy scales above the expansion
rate during inflation can affect predictions for the ratio between the
amplitudes of the primordial scalar and tensor fluctuations. In particular, we
study here the effects of a breakdown of a locally Lorentz invariant
description of nature at tiny space-time intervals. In some instances, these
effects shift the amplitudes by a constant amount, altering the standard
relation between this ratio and the slow-roll parameters. More generally,
"trans-Planckian" effects introduce a modulation in the primordial power
spectra which grows at shorter scales, making the value of the ratio sensitive
to the scale at which it is defined. We also present a model where symmetries
are broken at horizon scales during inflation. In this case, the power at large
scales today could then be suppressed, relative to that at smaller scales.
