COSMOLOGICAL BOUNDS TO THE MAGNETIC-MOMENT OF HEAVY TAU-NEUTRINO

The magnetic moment of tau neutrinos in the MeV mass range may he larg e enough to modify the cosmological freeze-out calculation and determi ne the tau-neutrino relic density. In this paper we reexamine such a p ossibility, We calculate the evolution and freeze-our of the tau-neutr ino number density as a function of its mass and magnetic moment. We t hen determine its relic density; then calculate its effect upon primor dial nucleo-synthesis including previously neglected effects.