Cosmological simulations with rare and frequent dark matter self-interactions

Fischer, Moritz S.; Brueggen, Marcus; Schmidt-Hoberg, Kai; Dolag, Klaus; Kahlhoefer, Felix; Ragagnin, Antonio und Robertson, Andrew (2022): Cosmological simulations with rare and frequent dark matter self-interactions. In: Monthly Notices of the Royal Astronomical Society, Bd. 516, Nr. 2: S. 1923-1940

Abstract

Dark matter (DM) with self-interactions is a promising solution for the small-scale problems of the standard cosmological model. Here we perform the first cosmological simulation of frequent DM self-interactions, corresponding to small-angle DM scatterings. The focus of our analysis lies in finding and understanding differences to the traditionally assumed rare DM (large-angle) self-scatterings. For this purpose, we compute the distribution of DM densities, the matter power spectrum, the two-point correlation function, and the halo and subhalo mass functions. Furthermore, we investigate the density profiles of the DM haloes and their shapes. We find that overall large-angle and small-angle scatterings behave fairly similarly with a few exceptions. In particular, the number of satellites is considerably suppressed for frequent compared to rare self-interactions with the same cross-section. Overall, we observe that while differences between the two cases may be difficult to establish using a single measure, the degeneracy may be broken through a combination of multiple ones. For instance, the combination of satellite counts with halo density or shape profiles could allow discriminating between rare and frequent self-interactions. As a by-product of our analysis, we provide - for the first time - upper limits on the cross-section for frequent self-interactions.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0035-8711
• Sprache: Englisch
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 390783311
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 390833306