  Primordial Heavy neutrinos of 4th generation might explain different
astrophysical puzzles: indeed the simplest 4th neutrino scenario may be still
consistent with known 4th neutrino physics, cosmic ray anti-matter and gamma
fluxes and signals in underground detectors for a very narrow neutrino mass
windows (46-47 GeV). We have analyzed extended Heavy neutrino models related to
the clumpiness of neutrino density, new interactions in Heavy neutrino
annihilation, neutrino asymmetry, neutrino decay. We found that in these models
the underground signals maybe better combined with the cosmic ray imprint
leading to a wider windows for neutrino mass (46-75 GeV) coinciding with the
whole range allowed from uncertainties of electro-weak parameters.
