A case study of small field inflationary dynamics in the Einstein–Gauss–Bonnet framework in the light of GW170817

Abstract

We study two of the most theoretically promising models of inflation, namely Natural inflation and Mutated Hilltop inflation, in the Einstein-Gauss Bonnet(EGB) gravity framework. In this work, we try to explore these models keeping observations from GW170817 on the speed of gravitational wave to be equal to the speed of light. This has direct implications on the non-minimal coupling to the Gauss–Bonnet invariant in the action. Thus, the effective potential gets new features. We have not only analysed the inflationary dynamics, but also the reheating dynamics and finally the corresponding energy spectrum of the gravitational wave.