One way to generate neutrino masses is to add right-handed neutrinos to the Standard Model, the so-called sterile neutrinos. This new species would not feel any of the Standard Model interactions but it could mix with the active neutrinos. Relic sterile neutrinos in the keV range are ideal candidates for the so-called Warm Dark Matter. They can explain mass distributions in the sub-galactic scale and thereby resolve the tensions in purely cold dark matter scenarios.
A heavy sterile neutrino would manifest itself as a tiny kink away from the decay endpoint in the beta spectrum. In this talk a sensitivity study of a tritium beta decay experiment, such as KATRIN, to detect sterile keV-neutrinos will be presented. Different analysis techniques based on spectral fits and discrete wavelet transform and possible technical realizations of such an experiment will be discussed.