Department Colloquium | BBN Concordance: What’s the Matter with Li

Speaker: Keith Olive (University of Minnesota)

An overview of the standard model of big bang nucleosynthesis (BBN) in the post-WMAP era is presented. With the value of the baryon-to-photon ratio determine to relatively high precision by WMAP, standard BBN no longer has any free parameters. In this context, the theoretical prediction for the abundances of D, He4, and Li7 is discussed. The observational determination of the light nuclides is also discussed. While concordance for D is excellent, and acceptable within the uncertainties for He4, the prediction for Li7 exceeds the observational determination by a factor of about four.