PRIMORDIAL MOLECULES IN A MODEL OF GRAVIT ATIONAL COLLAPSE

It is now well known that a primordial chemistry, involving light elem ents produced during the nucleosynthesis period might develop during t he hydrogen post-recombination era. In particular, molecular ions and primordial molecules such as H-2, HD and LiH will be produced. We summ arize this primordial chemistry after the recombination epoch, and the n present a simple gravitational collapse model of a cloud (M = 10(9) M.) including molecules. As a result, abundances are seen to be modifi ed during the collapse where in particular the HD abundance is conside rably lowered while H-2 and LiH productions are correspondingly enhanc ed. We discuss these evolutions and present what, in our opinion, coul d be further developed and clarified from this simple model.