Sterile Neutrinos as Dark Matter, Prof. Oleg Ruchayskiy (CERN)

I will review the status of sterile neutrino dark matter and discuss astrophysical and cosmological bounds on its properties as well as future prospects for its experimental searches. I will argue that if sterile neutrinos are the dominant fraction of dark matter, detecting an astrophysical signal from their decay may be the only way to identify these particles experimentally. However, it may be possible to check the dark matter origin of the observed signal unambiguously using its characteristic properties and/or using synergy with accelerator experiments, searching for other sterile neutrinos, responsible for neutrino flavour oscillations. I will also argue that to fully explore this possibility a dedicated cosmic mission -- an X-ray spectrometer -- is needed.