  Mixed dark matter models with one low-mass (e.g. 2.4eV) neutrino flavor are
shown to be in good agreement with observations if the neutrinos have non-zero
chemical potentials. This agreement holds (except for the problem with a
low-age Universe) even for high values of the Hubble-parameter. Massless
neutrinos with non-zero chemical potentials may reconcile cold dark matter with
observations. Some fine-tuning is required to avoid problems with Big Bang
nucleosynthesis.
