Reconciling Sterile Neutrinos with Big Bang Nucleosynthesis

R. Foot, R. R. Volkas
1995 Physical Review Letters  
We re-examine the big bang nucleosynthesis (BBN) bounds on the mixing of neutrinos with sterile species. These bounds depend on the assumption that the relic neutrino asymmetry L_ν is very small. We show that for L_ν large enough (greater than about 10^-5) the standard BBN bounds do not apply. We apply this result to the sterile neutrino solution to the atmospheric neutrino anomaly and show that for L_ν > 7 × 10^-5 it is consistent with BBN. The BBN bounds on sterile neutrinos mixing with electron neutrinos can also be weakened considerably.
doi:10.1103/physrevlett.75.4350 pmid:10059887 fatcat:djllgqmtzrblhg6b4tcfaiopxm