Possible Duplicate: How do we know Dark Matter isn't simply Neutrinos? If there are primardian neutrinos and since they have some mass however low, could neutrinos form the dark matter ...
What evidence is there that dark matter isn't one of the known types of neutrinos? If it were, how would this be measurable?
There has been recent activity by astrophysicists to determine whether a fourth flavor of neutrino, a sterile neutrino, exists. It would likely be more massive than electron, muon or tau neutrinos. ...