2008/05/09 by Shi-Chun Su, M. C. Chu, Su, Shi-Chun +2
Computer Science · Physics and Astronomy · #Astrophysics (astro-ph) #Computational Physics and Python Applications #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.0805.1316
openalex publication_date 2008/05/09 · arxiv created 2008/05/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the standard framework of cosmology, primordial density fluctuations are assumed to have an isotropic Gaussian distribution. We search for deviations from this assumption in the WMAP data for the low l modes of Cosmic Microwave Background Anisotropies (CMBA), by studying the directions of the z-axis that maximize the l=m modes and the resulting amplitudes of these modes. We find a general alignment of the directions for l=2 to 10 modes to within 1/4 of the northern hemisphere. This alignment can be regarded as a generalization of the recently discovered alignment of the l=2 and 3 modes - the so-called `Axis of Evil'. Furthermore, we find abnormally high (low) powers in the l=m=6, 12 - 17 (l=m=5) modes; the probabilities for having the anomalous amplitudes of the l=m=5, 6, 17 modes are about 0.1%, 1% and 1% respectively according to the Gaussian conjecture. The alignment and anomalous amplitudes for these low l modes are very robust against foreground contamination or different cleaning strategies, suggesting a cosmological origin and possibly supporting a non-standard inflation.