Big Bang Nucleosynthesis of Lithium-7 and the Baryon Density of the Universe

Abstract.

Thanks to recent nuclear physic compilations, we update Standard Big Bang Nucleosynthesis (SBBN) calculations. By a Monte-Carlo technique, we calculate the uncertainties on the light element yields related to nuclear reactions. The results are compared to astrophysical observations. The baryonic density obtained is confronted to other estimates deduced from recent independent approaches as the observations of the anisotropies of the Cosmic Microwave Background or the $Ly\alpha$ forest at high redshift. Lithium-7 could lead to more stringent constraints on the baryonic density of the universe than deuterium, because of a much higher observation statistics and an easier extrapolation to primordial values.