Intimate Relationship Between Sterile Neutrino Dark Matter and $\Delta N_{\rm eff}$
High Energy Physics - Phenomenology2022-06-01v3Cosmology and Nongalactic AstrophysicsHigh Energy Astrophysical PhenomenaHigh Energy Physics - Experiment
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 explore a model of neutrino self-interaction mediated by a Majoron-like scalar with sub-MeV mass, and show that explaining the relic density of sterile neutrino dark matter implies a lower bound on the amount of extra radiation in early universe, in particular ΔNeff>0.12 at the 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-S4 project.
@article{arxiv.2011.02487,
title = {Intimate Relationship Between Sterile Neutrino Dark Matter and $\Delta N_{\rm eff}$},
author = {Kevin J. Kelly and Manibrata Sen and Yue Zhang},
journal= {arXiv preprint arXiv:2011.02487},
year = {2022}
}