Fingerprints of freeze-in dark matter in an early matter-dominated era
Abstract
We study the impact of an alternate cosmological history with an early matter-dominated epoch on the freeze-in production of dark matter. Such early matter domination is triggered by a meta-stable matter field dissipating into radiation. In general, the dissipation rate has a non-trivial temperature and scale factor dependence. Compared to the usual case of dark matter production via the freeze-in mechanism in a radiation-dominated universe, in this scenario, orders of magnitude larger coupling between the visible and the dark sector can be accommodated. Finally, as a proof of principle, we consider a specific model where the dark matter is produced by a sub-GeV dark photon having a kinetic mixing with the Standard Model photon. We point out that the parameter space of this model can be probed by the experiments in the presence of an early matter-dominated era.
- Publication:
-
SciPost Physics
- Pub Date:
- August 2022
- DOI:
- 10.21468/SciPostPhys.13.2.022
- arXiv:
- arXiv:2204.03670
- Bibcode:
- 2022ScPP...13...22B
- Keywords:
-
- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Experiment
- E-Print:
- 17 pages, 3 captioned figures. Comments are welcome. v2: references updated. v3: minor revision in text, figures updated for clarification