The Big Bang nucleosynthesis abundances of the light elements using improved thermonuclear reaction rates

Big Bang Nucleosynthesis and the observed abundances of light elements

The standard model of the early universe is extraordinarily simple: it just assumes a globally isotropic and uniform universe. In the simplest version there is no structure of any kind on scales larger than individual elementary particles; indeed the contents are determined by “just physics”— global expansion governed by relativity, particle interactions governed by the Standard Model, and dist...

Big Bang Nucleosynthesis and Abundances of Light Elements

Big Bang nucleosynthesis (BBNS) theory is sketched, indicating the dependence of primordial abundances of D, 3He, 4He and 7Li on the mean baryonic density of the universe and the dependence of 4He on the number of neutrino families and the neutron half-life. Observational data and inferred primordial abundances of these elements are reviewed and shown to be consistent (within errors) either wit...

The Nacre Thermonuclear Reaction Compilation and Big Bang Nucleosynthesis

The theoretical predictions of big bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction cross sections. In this paper, we examine the impact on BBN of the recent compilation of nuclear data and thermonuclear reactions rates by the NACRE collaboration. We confirm that the adopted rates do not make large overall changes in central values of predictions, but do a...

Abundances of Big Bang elements

In this paper we review the present status of observations of the Big Bang elements D, 3He, 4He and 7Li and of their extrapolation to the primordial values. It is shown that, within the errors, the abundances are consistent with the predictions of the standard Big Bang nucleosynthesis for 1 ≤ η10 ≤ 6, which corresponds to 0.004 ≤ Ωbh 2 0 ≤ 0.02. Narrower consistencies in η10 are still possible ...

Big Bang Nucleosynthesis