Can decaying sterile neutrinos account for all dark matter?

TL;DR

This paper proposes that decaying sterile neutrinos with specific masses can explain unexplained X-ray lines and account for all dark matter, fitting observational constraints without free parameters.

Contribution

It introduces a model where 80% of dark matter is 7.1 keV sterile neutrinos and 20% is 17.4 keV sterile neutrinos, explaining X-ray lines and matching observational data.

Findings

80% of dark matter as 7.1 keV sterile neutrinos

20% of dark matter as 17.4 keV sterile neutrinos

Compatible with large-scale structure constraints

Abstract

The recent discovery of unexplained X-ray line of $3.5-3.6$ keV emitted from the Perseus cluster of galaxies and M31 and the excess X-ray line of $8.7$ keV emitted from the Milky Way center may indicate that dark matter would decay. In this article, I show that approximately 80 \% of dark matter being 7.1 keV sterile neutrinos and 20 \% of dark matter being 17.4 keV sterile neutrinos can satisfactorily explain the observed X-ray lines and account for all missing mass. No free parameter is needed in this model. This scenario is also compatible with current robust observational constraints from the matter power spectrum in large-scale structures and would alleviate the challenges faced by the existing dark matter models.