Yes. "Hot" because neutrinos move quickly compared to the speed of light, "dark" because they do not feel electromagnetism, and "matter" because they couple to the metric.
They explain the anomalous momentum in beta decays, among other things, and are still difficult to detect.
To explain the anomalous momentum we infer around large scale structures at z << 1, it's pretty reasonable to consider neutrinos or neutrino-like particles that are "cold" -- moving slowly compared to the speed of light, thus more likely to "hang around" in a region of spacetime instead of quickly running away to infinity. Although they interact very weakly with matter, they still impart momentum, so hot dark matter would tend to smear apart gas clouds rather than encouraging them to collapse into denser objects like stars. Likewise, it is perfectly reasonable to search for them in ways analogous to how the neutrino itself was searched for experimentally and observationally, and like with the first detection of the neutrino, it is liable to take time to detect or let various non-detections exclude all the regions of the particle mass vs nucleon cross-section parameter space.
Moreover, the search for this sort of cold dark matter does not preclude concurrent searches for other possibilities.
So I can't agree with ThePhysicist that there is a problem here, other than that there is apparently a communications gap that affects even people with backgrounds in quantum mechanics.
They explain the anomalous momentum in beta decays, among other things, and are still difficult to detect.
To explain the anomalous momentum we infer around large scale structures at z << 1, it's pretty reasonable to consider neutrinos or neutrino-like particles that are "cold" -- moving slowly compared to the speed of light, thus more likely to "hang around" in a region of spacetime instead of quickly running away to infinity. Although they interact very weakly with matter, they still impart momentum, so hot dark matter would tend to smear apart gas clouds rather than encouraging them to collapse into denser objects like stars. Likewise, it is perfectly reasonable to search for them in ways analogous to how the neutrino itself was searched for experimentally and observationally, and like with the first detection of the neutrino, it is liable to take time to detect or let various non-detections exclude all the regions of the particle mass vs nucleon cross-section parameter space.
Moreover, the search for this sort of cold dark matter does not preclude concurrent searches for other possibilities.
So I can't agree with ThePhysicist that there is a problem here, other than that there is apparently a communications gap that affects even people with backgrounds in quantum mechanics.