Ringing Non-Gaussianity from inflation with a step in the second derivative of the potential

TL;DR

This paper explores an inflationary model with a step in the second derivative of the potential, revealing distinctive ringing non-Gaussianity in the 3-point function that persists over a broad range of scales.

Contribution

It introduces a new inflationary potential feature causing unique ringing non-Gaussianity and analyzes its shape, scale dependence, and observational distinguishability.

Findings

The model exhibits long-lasting oscillations in $f_{NL}$.

The ringing behavior is more extended than in previous models.

Distinctive scale-dependent non-Gaussianity can differentiate this model from others.

Abstract

Inflationary model driven by a scalar field whose potential has a step in the second derivative with respect to the field is considered. For the best fit potential parameter values, the 3-point function and the non-Gaussianity associated with the featured model is calculated. We study the shape and scale dependence of the 3-point function. The distinctive feature of this model is its characteristic ringing behaviour of $f_{NL}$. We can see that the oscillations in $f_{NL}$ in this model last for a much longer range of k values, as compared to the previously studied models. In that sense, this model is potentially distinguishable from models with other features in the potential.