After a short introduction on the history of dark matter research, we review the current state of knowledge on both dark matter and sterile neutrinos, motivating sterile neutrinos as a dark matter...Show moreAfter a short introduction on the history of dark matter research, we review the current state of knowledge on both dark matter and sterile neutrinos, motivating sterile neutrinos as a dark matter candidate. We then investigate the dependence of current constraints on the sterile neutrino parameter space on the fraction $\chi_N$ of the dark matter mass density that is due to sterile neutrinos, and derive a lower bound on the fraction assuming the 3.5 keV spectral line detected in galaxies and galaxy clusters is caused by sterile neutrino decay: $\chi_N \gtrsim 0.1$.Show less
