2000/07/14 by S. Winitzki, Serge Winitzki, Winitzki, S. +3 · 2 citations
Engineering · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Reservoir Engineering and Simulation Methods #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0007213
42 pages, 12 figures
arxiv created 2000/07/14 · openalex publication_date 2000/07/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A description of CMB temperature fluctuations beyond the power spectrum is important for verifying models of structure formation, especially in view of forthcoming high-resolution observations. We argue that higher-order statistics of inter-scale correlations, because of their low cosmic variance, may be effective in detecting non-Gaussian features in the CMB. Inter-scale correlations are generically produced in defect-based models of structure formation. We analytically study properties of general higher-order cumulants of Fourier components of homogeneous random fields and design a new set of statistics suitable for small-scale data analysis. Using simulated non-Gaussian fields, we investigate the performance of the proposed statistics in presence of a Gaussian background and pixel noise, using the bispectrum as the underlying cumulant. Our numerical results suggest that detection of non-Gaussian features by our method is reliable if the power spectrum of the non-Gaussian components dominates that of the Gaussian background and noise within at least a certain range of accessible scales.