Collective Symmetry Breaking and Resonant Non-Gaussianity

TL;DR

This paper explores inflationary models with collective symmetry breaking that suppresses radiative corrections, enabling significant bispectrum signals without large power spectrum deviations, exemplified through resonant non-Gaussianity.

Contribution

It introduces the concept of collective symmetry breaking in inflationary models to control radiative corrections, highlighting its role in generating prominent bispectrum features.

Findings

Collective symmetry breaking can suppress radiative corrections.

Models can produce large bispectrum signals with minimal power spectrum impact.

Resonant non-Gaussianity can exhibit oscillatory bispectrum features.

Abstract

We study inflationary models that produce a nearly scale-invariant power spectrum while breaking scale invariance significantly in the bispectrum. Under most circumstances, such models are finely-tuned, as radiative corrections generically induce a larger signal in the power spectrum. However, when scale invariance is broken collectively (i.e., it requires more than one coupling to break the symmetry), these radiative corrections may be suppressed. We illustrate the features and limitations of collective symmetry breaking in the context of resonant non-gaussianity. We discuss two examples where oscillatory features can arise predominantly in the bispectrum.