Big Bang nucleosynthesis: theories and observations.

• Boesgaard, A. M.
;
• Steigman, G.

Abstract

The evidence in support of the nearly universally accepted hot big bang model of cosmology is almost exclusively related to the blackbody spectrum of the microwave background. Primordial nucleosynthesis provides a unique opportunity to test the assumptions of the 'standard' model. The present review provides a summary of the predictions of the standard model, taking into account also a critical evaluation of the implications of the current observational data. The standard hot big bang model is discussed, taking into account the epoch of nucleosynthesis, the primordial abundances, uncertainties in the predicted abundances, and possible variations on the theme of the standard model. The observed abundances are considered, giving attention to destruction and production during galactic evolution, deuterium, He-3, He-4, lithium, and an abundance summary. Predicted and observed abundances are compared, and cosmological constraints are examined.