Big Bang Nucleosynthesis and a New Approach to Galactic Chemical Evolution

Abstract

Big bang production of deuterium is the best indicator of the baryon density; however, only the present abundance of D is known (and only locally) and its chemical evolution is intertwined with that of 3 based on D and 3 He. Because Galactic abundances are spatially heterogeneous, mean chemical-evolution models are not well suited for extrapolating the pre-solar D and 3 explicitly addresses heterogeneity by statistically tracing the history of the pre-solar material back to its primeval beginning. We show that the decade-old concordance interval founded. He abundances to their primeval values. We introduce a new approach which 2 (2–8)  1010 He is well