COSMOLOGICAL DARK-MATTER

The basic arguments for cosmological dark matter are reviewed. It is s hown that the Big Bang Nucleosynthesis constraints on the cosmological baryon density, when compared with dynamical arguments, demonstrate t hat the bulk of the baryons are dark and also that the bulk of the mat ter in the universe is nonbaryonic. The recent extragalactic deuterium observations as well as the other light element abundances were exami ned in detail as is the argument on the number of neutrino flavors. Ar guments from recent MACHO/EROS observations of halo dark matter seem t o imply that at least some of the dark baryons are in the halos of gal axies. Comparison of baryonic density arguments with recent x-ray clus ter data is also made. Discussion of the interface of density and age arguments is also presented.