GInflationary hubble parameter from the gravitational wave spectrum in the general slow-roll approximation

Abstract

We derive first and second order general slow-roll inverse formulae giving the Hubble parameter H in terms of the gravitational wave spectrum. We also derive improved forward general slow-roll formulae giving the gravitational wave spectrum in terms of the Hubble parameter H. Moreover, the general slow-roll consistency condition relating the scalar and tensor spectra is obtained.