The Trispectrum of the 4 Year COBE-DMR data

Preprint

4 February 2002

preprint
Published by arXiv in arXiv

https://doi.org/10.48550/arXiv.astro-ph/0111250

Abstract

We propose an estimator for the trispectrum of a scalar random field on a sphere, discuss its geometrical and statistical properties, and outline its implementation. By estimating the trispectrum of the 4 year COBE-DMR data (in HEALPix pixelization) we find new evidence of a non-Gaussian signal associated with a known systematic effect. We find that by removing data from the sky maps for those periods of time perturbed by this effect, the amplitudes of the trispectrum coefficients become completely consistent with predictions for a Gaussian sky. These results reinforce the importance of statistical methods based in harmonic space for quantifying non-Gaussianity.

Keywords

All Related Versions

Version 1, 2001-11-13, ArXiv
Version 2, 2002-02-04, ArXiv
Published version: The Astrophysical Journal, 563 (2), L99.

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