Standard Model of Primordial Nucleosynthesis: A Few General Remarks

Abstract

Primordial nucleosynthesis plays indeed a major role both in cosmology and in particle and nuclear physics. The comparison between the observations of the abundances of the light elements (D, ³He, ⁴He and ⁷Li) and the predictions coming from the Standard Model provides information on the following facts:

• it indicates that the baryonic density of the Universe is at most 10% of the critical density. This means that most of the dark matter should be of non-baryonic nature

• There is only room for three different flavours of neutrinos and leptons which is consistent both with the simplest Grand-Unification schemes and with the results of the LEP and SLC particle physics experiments.