2008/07/31 by Le Zhang, G. Sigl, Guenter Sigl
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #astro-ph #hep-ph
paper · pdf · doi:10.1088/1475-7516/2008/09/027
published as JCAP 0809:027,2008 · 30 papes, jcap preprint format, 11 figures; final version, very minor changes
openalex publication_date 2008/09/30 · arxiv created 2008/10/02 · arxiv updated 2011/07/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We calculate the intensity and the angular power spectrum of the cosmological background of synchrotron emission from cold dark matter annihilations into electron–positron pairs. We compare this background with the intensity and anisotropy of astrophysical and cosmological radio backgrounds, such as those from normal galaxies, radio galaxies and galaxy cluster accretion shocks, with the cosmic microwave background and with Galactic foregrounds. Under modest assumptions for the dark matter clustering we find that around 2 GHz average intensity and fluctuations of the radio background at sub-degree scales allow us to probe dark matter masses GeV and annihilation cross sections not far from the natural values required to reproduce the correct relic density of thermal dark matter. The angular power spectrum of the signal from dark matter annihilation tends to be flatter than that from astrophysical radio backgrounds. Furthermore, radio source counts have comparable constraining power. Such signatures are interesting, especially for future radio detectors such as SKA.