A New Approach to Probing Primordial Non-Gaussianity

TL;DR

This paper introduces a new statistical method, the bispectrum-related power spectrum, to detect and distinguish primordial non-Gaussianity in the Cosmic Microwave Background, accounting for realistic observational challenges.

Contribution

A novel bispectrum-related power spectrum estimator optimized for primordial non-Gaussianity detection and contamination assessment in CMB data.

Findings

Effective in distinguishing primordial from secondary non-Gaussianity.

Optimized for partial sky coverage and inhomogeneous noise.

Retains ability to assess foreground contamination.

Abstract

We address the dual challenge of estimating deviations from Gaussianity arising in models of the Early Universe, whilst retaining information necessary to assess whether a detection of non-Gaussianity is primordial. We do this by constructing a new statistic, the bispectrum-related power spectrum, which is constructed from a map of the Cosmic Microwave Background. The estimator is optimised for primordial non-Gaussianity detection, but can also be useful in distinguishing primordial non-Gaussianity from secondary non-Gaussianity, such as may arise from unsubtracted point sources, or residuals from component separation. Extending earlier studies we present unbiased non-Gaussianity estimators optimised for partial sky coverage and inhomogeneous noise associated with realistic scan strategies, but which retain the ability to assess foreground contamination.