A universal attractor for inflation at strong coupling

Abstract

We introduce a novel non-minimal coupling between gravity and the inflaton sector. Remarkably, for large values of this coupling all models asymptote to a universal attractor. This behavior is independent of the original scalar potential and generalizes the attractor in the phi^4 theory with non-minimal coupling to gravity. The attractor is located in the `sweet spot' of Planck's recent results.

Comments: 5 pages, 4 figures. v2: discussion on unitarity and extra refs added, extended version of PRL paper