Limits on neutrino degeneracy from early nucleosynthesis

The abundances of 4He and 2H are calculated in terms of the baryon density and neutrino degeneration, under the assumption, that the present dynamical properties of the Universe are determined by neutrinos, as it is suggested by recent measurements. It is shown, that only a limited range of these parameters gives the abundances in agreement with observations. This provides a limit on both rhosub(B), the baryon density of the Universe, and xi, the neutrino degeneration parameter. These limits are 2.10-31 g/cm3<rhosub(B)<3.10-30 g/cm3; -0.2<xi<0.05 which are in agreement with the observed amount of visible matter, rho*=3.10-31 g/cm3, and the value xi=10-9, expected from SU(5) Grand Unification. (author)