It seems during cosmic inflation the universe expands at an accelerated rate. This expansion is driven by the potential of the inflaton field. There's a slow role off of the inflaton potential as the universe inflates very rapidly and then the potential drops off rather sharply and the energy of the potential then goes into creating all the various kinds of particles common to the Standard Model. But this confuses me because I'm also told elsewhere (by the same person) that acceleration causes fluctuations in the quantum fields to produce particles. This occurs, for example, in the Unruh radiation. So my question is this: Does particle creation occur during the very fast inflationary expansion before the inflaton potential drops off? Or does particle creation only occur as the inflaton potential drop off sharply? It seems there should be particle creation at high inflaton potential too since there is very rapid acceleration. Thank you.