Only conventional left-handed neutrinos are ruled out as significant HDM. It is rarely mentioned amongst all the Higgs back-slapping, that the Standard Model d

Only conventional left-handed neutrinos are ruled out as significant HDM. It is rarely mentioned amongst all the Higgs back-slapping, that the Standard Model does not yet have a complete and verified theory of neutrino physics: masses? Majorana/Dirac? self-anti-particle? chiralities? ... There may be right-handed neutrinos that do not interact via the weak force (which is maximally parity-violating). They would only interact gravitationally and play a role dark matter: https://en.wikipedia.org/wiki/Sterile_neutrino https://en.wikipedia.org/wiki/Sterile_neutrino