Effects of primordial fluctuations on the abundances of light elements

Some of the effects of primordial inhomogeneities on the production of 2H, 3He, and 7Li are investigated. For the most part, temperature fluctuations have only small effects on the abundances. The density fluctuations are modeled by a unimodal distribution so that the Universe is characterized by the mean density and the relative amplitude of the density variations. We have found that the constraint which 2H production imposes on the mean mass density is eased somewhat by allowing for density inhomogeneities. However, unless the composition of the interstellar matter is atypical of most of the matter in the Universe, the mass density will be at least a factor of 3 below the critical density. For reasonable estimates of the pregalactic abundances, sufficient 3He and 7Li cannot be produced in the same model universe. Production of both 7Li and 2H requires large-amplitude primordial fluctuations, while sufficient 3He and 2H can be formed in very low density, fairly homogeneous universes