2019/06/18 by Giorgio Arcadi, Oleg Lebedev, Stefan Pokorski +1 · 1 voice
Physics and Astronomy · #astro-ph.CO #hep-ph
paper · pdf · doi:10.1007/jhep08(2019)050
published as JHEP 08 (2019) 050 · 27 pages, 10 figures, correction to the caption of fig.9
arxiv published 2019/06/18 · arxiv created 2019/06/20 · arxiv updated 2019/08/13
A stable real scalar provides one of the simplest possibilities to account for dark matter. We consider the regime where its coupling to the Standard Model fields is negligibly small. Due to self-coupling, the scalar field can reach thermal or at least kinetic equilibrium, in which case the system is characterized by its temperature and effective chemical potential. We perform a fully relativistic analysis of dark matter evolution, thermalization conditions and different freeze-out regimes, including the chemical potential effects. To this end, we derive a relativistic Bose-Einstein analog of the Gelmini-Gondolo formula for a thermal averaged cross section. Finally, we perform a comprehensive parameter space analysis to determine regions consistent with observational constraints. Dark matter can be both warm and cold in this model.