Loop corrections to primordial non-Gaussianity

TL;DR

This paper examines quantum gravitational loop effects on the primordial non-Gaussianity in the CMB, revealing that loop corrections can produce excessively large non-Gaussian signals, challenging inflationary models.

Contribution

It provides a detailed analysis of loop corrections to primordial non-Gaussianity, highlighting potential conflicts with observations in scalar-driven inflation models.

Findings

Loop corrections can cause non-Gaussianity to exceed observed values by over 30 orders of magnitude.

Time dependence in zeta-zeta correlator due to loops is confirmed.

Implications for inflationary models are discussed, questioning their viability.

Abstract

We discuss quantum gravitational loop effects to observable quantities such as curvature power spectrum and primordial non-Gaussianity of cosmic microwave background (CMB) radiation. We first review the previously shown case where one gets a time dependence for zeta-zeta correlator due to loop corrections. Then we investigate the effect of loop corrections to primordial non-Gaussianity of CMB. We conclude that, even with a single scalar inflaton, one might get a huge value for non-Gaussianity which would exceed the observed value by at least 30 orders of magnitude. Finally we discuss the consequences of this result for scalar driven inflationary models.