Inhomogeneous big bang nucleosynthesis and the high baryon density suggested by Boomerang and MAXIMA

Abstract

The recent Boomerang and MAXIMA data on the cosmic microwave background suggest a large value for the baryonic matter density of the universe, ${\ensuremath{\omega}}_{b}\ensuremath{\sim}0.03.$ This density is larger than allowed by standard big bang nucleosynthesis theory and observations on the abundances of the light elements. We explore here the possibility of accommodating this high density in inhomogeneous big bang nucleosynthesis (IBBN). It turns out that in IBBN the observed $\mathrm{D}$ and ${Y}_{p}$ values are quite consistent with this high density. However, IBBN is not able to reduce the ${}^{7}\mathrm{Li}$ yield by more than about a factor of two. For IBBN to be the solution, one has to accept that the ${}^{7}\mathrm{Li}$ plateau in population II halo stars is depleted from the primordial abundance by at least a factor of two.