Violation of non-Gaussianity consistency relation in a single-field inflationary model

Abstract

In this paper we present a simple, toy model of single-field inflation in which the standard non-Gaussianity consistency condition is violated. In this model the curvature perturbations on super-horizon scales are not conserved and the decaying modes of perturbations are not negligible in the non-attractor phase. As a result a large local non-Gaussianity can be obtained in the squeezed limit which violates the standard non-Gaussianity consistency condition for the single-field models.