  We use the power-counting formalism of effective field theory to study the
size of loop corrections in theories of slow-roll inflation, with the aim of
more precisely identifying the limits of validity of the usual classical
inflationary treatments. We keep our analysis as general as possible in order
to systematically identify the most important corrections to the classical
inflaton dynamics. Although most slow-roll models lie within the semiclassical
domain, we find the consistency of the Higgs-Inflaton scenario to be more
delicate due to the proximity between the Hubble scale during inflation and the
upper bound allowed by unitarity on the new-physics scale associated with the
breakdown of the semiclassical approximation within the effective theory.
Similar remarks apply to curvature-squared inflationary models.
