Renormalization of the inflationary perturbations revisited
  In this work we clarify aspects of renormalization on curved backgrounds
focussing on the potential ramifications on the amplitude of inflationary
perturbations. We provide an alternate view of the often used adiabatic
prescription by deriving a correspondence between the adiabatic subtraction
terms and traditional renormalization. Specifically, we show how adiabatic
subtraction can be expressed as a set of counter terms that are introduced by
redefining the bare parameters of the action. Our representation of adiabatic
subtraction then allows us to easily find other renormalization prescriptions
differing only in the finite parts of the counter terms. As our main result, we
present for quadratic inflation how one may consistently express the
renormalization of the spectrum of perturbations from inflation as a
redefinition of the bare cosmological constant and Planck mass such that the
observable predictions coincide with the unrenormalized result.
