Large field inflation and double α-attractors

Abstract

Abstract: We consider a broad class of inflationary models that arise naturally in super-gravity. They are defined in terms of a parameter α that determines the curvature and cutoff of these models. As a function of this parameter, we exhibit that the inflationary predictions generically interpolate between two attractor points. At small cutoff α, the resulting inflationary model is of plateau-type with ns = 1 − 2/N and r = 12α/N2. For α = 1, these predictions coincide with predictions of the Starobinsky model and Higgs inflation. In contrast, for large cutoff α, the theory asymptotes to quadratic inflation, with ns = 1 − 2/N, r = 8/N. Both universal predictions can be attributed to a stretching of the moduli space. For intermediate values of α, the predictions interpolate between these two critical points, thus covering the sweet spots of both Planck and BICEP2.