Skew-spectra: a generalization to spin-$s$

TL;DR

This paper extends skew-spectra methodology to arbitrary spin-$s$ fields, enabling efficient extraction of non-Gaussian information from cosmological data like cosmic shear and CMB polarization, avoiding complex three-point statistics.

Contribution

It introduces a novel formalism for skew-spectra of spin-$s$ fields, applicable to weak lensing and CMB polarization, simplifying non-Gaussian analysis in cosmology.

Findings

Demonstrates the formalism with $b1$CDM models

Provides plots of skew-spectra for varying cosmological parameters

Shows how to combine fields to build skew-spectra without mass-mapping issues

Abstract

Skew-spectra allow us to extract non-Gaussian information by taking the square of a map and finding the power spectrum of this new map with the original map. This allows us to use much of the infrastructure of power spectra and avoid the intricacies of estimating three point statistics. In this paper we present the first extension of skew-spectra to arbitrary spin-$s$ fields, as a means to extract non-Gaussian information efficiently from cosmological data sets like cosmic shear or CMB polarization. We apply the formalism to weak lensing in the context of large scale structure, and discuss different ways of combining fields to build skew-spectra, all while avoiding the problems associated with mass-mapping. We provide plots of these new statistics for $\Lambda$CDM and vary cosmological parameters.