From the spectrum to inflation: an inverse formula for the general slow-roll spectrum

Abstract

We propose a general inverse formula for extracting inflationary parameters from the power spectrum of cosmological perturbations. Under the general slow-roll scheme, which helps to probe the properties of inflation in a model independent way, we invert the leading- order, single-field, power spectrum formula. We also give some physically interesting examples to demonstrate its wide applicability and illuminate its properties.