Big Bang Nucleosynthesis constraints and light element abundance estimates

To elucidate the significance of the effect of systematic uncertainties in light element abundance estimates on cosmological bounds derivable from Big Bang Nucleosynthesis (BBN) we present tables giving bounds on Ωbaryon and Nv as one changes the limits on primordial 4He and 7Li. This allows us to derive new relations between these estimates and constraints on Ωbaryon and Nv. For example, only if the helium mass fraction, Yp ⩾.245 does 7Li (or D) presently play a role in placing an upper limit on the baryon density, and only if Yp >/.250 does 4He cease to play a role in bounding η10. All the elements combine together tend to give a stringent upper bound of.16 on Ωbaryon. We also find that ϒP must exceed .239 for consistency between theory and observation if D+3HeH is less than 10−4. Updated nuclear reaction rates, an updated neutron half life, Monte Carlo techniques, and correlations between the predicted abundances are incorporated in our analysis. We also discuss the handling of systematic uncertainties in the context of statistical analyses of BBN predictions.