https://doi.org/10.1140/epjc/s10052-019-6608-8
Regular Article - Theoretical Physics
Phenomenology of self-interacting dark matter in a matter-dominated universe
1
Centro de Investigaciones, Universidad Antonio Nariño, Carrera 3 Este # 47A-15, Bogotá, Colombia
2
Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto and Centro de Física do Porto, Rua do Campo Alegre 687, 4169-007, Porto, Portugal
3
Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD, 21218, USA
4
Astronomy Unit, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
* e-mail: nicolas.bernal@uan.edu.co
Received:
8
November
2018
Accepted:
17
January
2019
Published online:
31
January
2019
We study production of self-interacting dark matter (DM) during an early matter-dominated phase. As a benchmark scenario, we consider a model where the DM consists of singlet scalar particles coupled to the visible Standard Model (SM) sector via the Higgs portal. We consider scenarios where the initial DM abundance is set by either the usual thermal freeze-out or an alternative freeze-in mechanism, where DM was never in thermal equilibrium with the SM sector. For the first time, we take the effect of self-interactions within the hidden sector into account in determining the DM abundance, reminiscent to the Strongly Interacting Massive Particle (SIMP) scenario. In all cases, the number density of DM may change considerably compared to the standard radiation-dominated case, having important observational and experimental ramifications.
© The Author(s), 2019
