Intimate Relationship between Sterile Neutrino Dark Matter and Δ Neff
Abstract
The self-interacting neutrino hypothesis is well motivated for addressing the tension between the origin of sterile neutrino dark matter and indirect detection constraints. It can also result in a number of testable signals from the laboratories to the cosmos. We show that, in a broad class of models, where the sterile neutrino dark matter relic density is generated by a light neutrinophilic mediator, there must be a lower bound on the amount of extra radiation in early Universe, in particular, Δ Neff>0.12 at the cosmic microwave background (CMB) epoch. This lower bound will be further strengthened with an improved x-ray search at the Athena observatory. Such an intimate relationship will be unambiguously tested by the upcoming CMB Stage 4 project.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 2021
- DOI:
- 10.1103/PhysRevLett.127.041101
- arXiv:
- arXiv:2011.02487
- Bibcode:
- 2021PhRvL.127d1101K
- Keywords:
-
- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Experiment
- E-Print:
- 5+5 pages, 7 figures, matches published version