Oscillations in the bispectrum

TL;DR

This paper explores models of inflation producing oscillatory primordial bispectra and proposes a method using mode expansion to detect and reconstruct these spectra from data, enabling observational constraints.

Contribution

It introduces a mode expansion approach to reconstruct oscillatory bispectra from data, facilitating the testing of inflation models with complex bispectral features.

Findings

Mode expansion can effectively reconstruct oscillatory bispectra.

The method enables potential observational constraints on inflation models.

It provides a framework for detecting complex primordial non-Gaussianities.

Abstract

There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting such bispectra in the data. We explain how the recently proposed method of mode expansion of bispectra might be able to reconstruct these spectra from separable basis functions. Extracting these basis functions from the data might then lead to observational constraints on these models.