Large-angle non-Gaussianity in simulated high-resolution CMB maps

TL;DR

This paper analyzes high-resolution simulated CMB maps with local-type primordial non-Gaussianity to evaluate the effectiveness of skewness and kurtosis indicators in detecting non-Gaussian signals.

Contribution

It extends previous work by applying non-Gaussianity detection methods to high-resolution simulations with realistic non-Gaussian features.

Findings

Skewness and kurtosis indicators can detect non-Gaussianity in simulated CMB maps.

The analysis helps understand the impact of systematics and foregrounds on non-Gaussianity detection.

Results support the use of these indicators for future CMB data analysis.

Abstract

A detection or nondetection of primordial non-Gaussianity by using the cosmic microwave background radiation (CMB) offers a way of discriminating inflationary scenarios and testing alternative models of the early universe. This has motivated the considerable effort that has recently gone into the study of theoretical features of primordial non-Gaussianity and its detection in CMB data. Among such attempts to detect non-Gaussianity, there is a procedure that is based upon two indicators constructed from the skewness and kurtosis of large-angle patches of CMB maps, which have been proposed and used to study deviation from Gaussianity in the WMAP data. Simulated CMB maps equipped with realistic primordial non-Gaussianity are essential tools to test the viability of non-Gaussian indicators in practice, and also to understand the effect of systematics, foregrounds and other contaminants. In this work we extend and complement the results of our previous works by performing an analysis of non-Gaussianity of the high-angular resolution simulated CMB temperature maps endowed with non-Gaussianity of the local type, for which the level of non-Gaussianity is characterized by the dimensionless parameter $f_{\rm NL}^{\rm local}$