Abstract:
Recently it was pointed out that a non-zero cosmological constant can play a role in the formation of neutrino halos only in the case of neutrinos of very low rest mass (mν ≤ 0.1 eV). However, phase-space considerations would require mν > 50 eV if neutrinos dominate the missing mass in halos of large spiral galaxies and moreover mν > 200 eV is implied in the case of dwarf spheroidals. These larger neutrino masses would be in conflict with observed constraints on the age of the Universe unless a cosmological constant is invoked.
