Dark matter-radiation interactions: the impact on dark matter haloes

Schewtschenko, Jascha; Wilkinson, Ryan; Baugh, Carlton; Boehm, Celine; Pascoli, Silvia

Abstract

Interactions between dark matter (DM) and radiation (photons or neutrinos) in the early Universe suppress density fluctuations on small mass scales. Here, we perform a thorough analysis of structure formation in the fully non-linear regime using N-body simulations for models with DM–radiation interactions and compare the results to a traditional calculation in which DM only interacts gravitationally. Significant differences arise due to the presence of interactions, in terms of the number of low-mass DM haloes and their properties, such as their spin and density profile. These differences are clearly seen even for haloes more massive than the scale on which density fluctuations are suppressed. We also show that semi-analytical descriptions of the matter distribution in the non-linear regime fail to reproduce our numerical results, emphasizing the challenge of predicting structure formation in models with physics beyond collisionless DM.

Citation

Schewtschenko, J., Wilkinson, R., Baugh, C., Boehm, C., & Pascoli, S. (2015). Dark matter-radiation interactions: the impact on dark matter haloes. Monthly Notices of the Royal Astronomical Society, 449(4), 3587-3596. https://doi.org/10.1093/mnras/stv431

• Journal Article Type: Article
• Acceptance Date: Feb 24, 2015
• Online Publication Date: Apr 10, 2015
• Publication Date: Jun 1, 2015
• Deposit Date: Dec 17, 2014
• Publicly Available Date: Apr 22, 2015
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 449
• Issue: 4
• Pages: 3587-3596
• DOI: https://doi.org/10.1093/mnras/stv431
• Keywords: Astroparticle physics, Galaxies: haloes, Dark matter, Large-scale structure of Universe.
• Public URL: https://durham-repository.worktribe.com/output/1415184
• Related Public URLs: http://arxiv.org/abs/1412.4905