2014/01/31 by E. Sefusatti, Emiliano Sefusatti, Gabrijela Zaharijas +6
Physics and Astronomy · #Annihilation #Astrophysics #Astrophysics and Cosmic Phenomena #Cosmology #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Matter power spectrum #Particle physics #Physics #Redshift #Statistical physics #Supernova #Theoretical physics #Weak gravitational lensing #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.1093/mnras/stu686
published as MNRAS (July 1, 2014) 441 (3): 1861-1878 · 20 pages, 9 figures, 1 table. Updated to match the published version. New material and figures added, conclusions unchanged
openalex publication_date 2014/05/12 · arxiv created 2014/06/03 · arxiv updated 2014/06/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We re-evaluate the extragalactic gamma-ray flux prediction from dark matter annihilation in the approach of integrating over the non-linear matter power spectrum, extrapolated to the free-streaming scale. We provide an estimate of the uncertainty based entirely on available N-body simulation results and minimal theoretical assumptions. We illustrate how an improvement in the simulation resolution, exemplified by the comparison between the Millennium and Millennium II simulations, affects our estimate of the flux uncertainty and we provide a ‘best guess’ value for the flux multiplier, based on the assumption of stable clustering for the dark matter perturbations described as a collision-less fluid. We achieve results comparable to traditional halo model calculations, but with a much simpler procedure and a more general approach, as it relies only on one, directly measurable quantity. In addition, we discuss the extension of our calculation to include baryonic effects as modelled in hydrodynamical cosmological simulations and other possible sources of uncertainty that would in turn affect indirect dark matter signals. Upper limits on the integrated power spectrum from supernovae lensing magnification are also derived and compared with theoretical expectations.