Observable Signatures of Inflaton Decays
  We numerically compute features in the power-spectrum that originate from the
decay of fields during inflation. Using a simple, phenomenological, multi-field
setup, we increase the number of fields from a few to thousands. Whenever a
field decays, its associated potential energy is transferred into radiation,
causing a jump in the equation of state parameter and mode mixing at the
perturbed level. We observe discrete steps in the power-spectrum if the number
of fields is low, in agreement with analytic arguments in the literature. These
features become increasingly smeared out once many fields decay within a given
Hubble time. In this regime we confirm the validity of the analytic approach to
staggered inflation, which is based on a coarse-graining procedure. Our
numerical approach bridges the aforementioned analytic treatments, and can be
used in more complicated scenarios.
