Cosmological Deuterium Production in Non-Standard Scenarios

Abstract

It is widely believed that the cosmic baryon density may be obtained by inferring deuterium abundances in low-metallicity quasar absorption line systems. The implicit assumptions which enter this argument are critically assessed. In particular, the production of deuterium in non-standard Big Bang nucleosynthesis scenarios, the putative production of deuterium in astrophysical environments, and the possible destruction of deuterium via non-standard chemical evolution are discussed.Comment: 11 pages, article based on a talk presented at "Deuterium in the Universe", Meudon, June 2001, to be published in Planetary and Space Scienc