2003/05/31 by Eiichiro Komatsu, David N. Spergel, Benjamin D. Wandelt +1 · 4 citations
Engineering · Physics and Astronomy · #Advanced Adaptive Filtering Techniques #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/491724
published as Astrophys.J. 634 (2005) 14-19 · 13 pages, 2 figures, a paper describing cubic (bispectrum) statistics used for Gaussianity tests of the WMAP data (Komatsu et al. astro-ph/0302223). Appendix has been added to show the performance of the cubic statistics. To appear in the Astrophysical Journal
arxiv created 2005/08/11 · openalex publication_date 2005/11/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We derive a fast way for measuring primordial non-Gaussianity in a nearly full-sky map of the cosmic microwave background. We find a cubic combination of sky maps combining bispectrum configurations to capture a quadratic term in primordial fluctuations. Our method takes only N 3/2 operations rather than N 5/2 , as taken by the bispectrum analysis (1000 times faster for l = 512), retaining the same sensitivity. A key component is a map of the underlying primordial fluctuations, which can be more sensitive to the primordial non-Gaussianity than a temperature map. We also derive a fast and accurate statistic for measuring non-Gaussian signals from foreground point sources. The statistic is 10 6 times faster than the full bispectrum analysis and can be used to estimate contamination from the sources. Our algorithm has been successfully applied to the Wilkinson Microwave Anisotropy Probe sky maps by Komatsu and coworkers.