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

TL;DR

This paper introduces a simple single-field inflation model where the usual non-Gaussianity consistency relation is violated due to non-conservation of curvature perturbations and significant decaying modes, resulting in large local non-Gaussianity.

Contribution

It presents a toy model of single-field inflation that breaks the standard non-Gaussianity consistency condition by allowing non-conservation of curvature perturbations and decaying modes.

Findings

Large local non-Gaussianity in the squeezed limit.

Violation of the standard non-Gaussianity consistency relation.

Curvature perturbations are not conserved on super-horizon scales.

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-atractor 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.