2003/12/31 by Stacy McGaugh · 4 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Particle physics theoretical and experimental studies #astro-ph
paper · pdf · doi:10.1086/421895
published as Astrophys.J. 611 (2004) 26-39 · ApJ, in press. 33 pages, 7 figures
openalex publication_date 2004/08/10 · arxiv created 2004/09/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
I present a model devoid of nonbaryonic cold dark matter (CDM) that provides an acceptable fit to the Wilkinson Microwave Anisotropy Probe ( WMAP ) data for the power spectrum of temperature fluctuations in the cosmic background radiation. An a priori prediction of such no-CDM models was a first-to-second peak amplitude ratio A 1 : 2 ≈ 2.4. WMAP measures A 1 : 2 = 2.34 ± 0.09. The baryon content is the dominant factor in fixing this ratio; no-CDM models that are consistent with the WMAP data are also consistent with constraints on the baryon density from the primordial abundances of 2 H, 4 He, and 7 Li. However, in order to match the modest width of the acoustic peaks observed by WMAP , a substantial neutrino mass is implied: m ν ≈ 1 eV. Even with such a heavy neutrino, structure is expected to form rapidly under the influence of modified Newtonian dynamics. Consequently, the epoch of reionization should occur earlier than is nominally expected in ΛCDM. This prediction is realized in the polarization signal measured by WMAP . An outstanding test is in the amplitude of the third acoustic peak. Experiments that probe high l appear to favor a third peak that is larger than predicted by the no-CDM model.