New leading contributions to non-gaussianity in single field inflation

TL;DR

This paper calculates the bispectrum of primordial density perturbations in single field inflation, correcting previous results and highlighting significant next-to-leading order corrections in various models.

Contribution

It provides corrected second-order bispectrum calculations and demonstrates that higher-order corrections can be as impactful as leading order in many inflation models.

Findings

Corrected previous bispectrum results.

Next-to-leading order corrections are significant in many models.

Implications for interpreting CMB non-Gaussianity data.

Abstract

We compute the bispectrum of primordial density perturbations in CMB to second order in the slow-roll parameters of single field inflation. We correct previous results and found that next-to-leading order corrections can be of the same order as the leading order result in a large class of models, including hilltop inflation.