Recent developments in the search for baryonic dark matter
Abstract
Description
Cosmological nucleosynthesis calculations imply that many of the baryons in the Universe must be dark. We discuss the likelihood that some of these dark baryons may reside in galaxies as Massive Compact Halo Objects (MACHOs), the remnants of a first generation of pregalactic or protogalactic stars. Various candidates have been proposed for such remnants and we review the many types of observations which can be used to detect or exclude them. Claims to have found positive evidence for some of the candidates have generally turned out to be spurious or questionable, so the status of the MACHO scenario remains controversial. However, it would be premature to reject MACHOs altogether and further observations are likely to resolve the issue soon.
Lecture delivered at the Nato Advanced Study Institute: Phase Transitions in the Early Universe: Theory and Observations. Erice 6th-17th December 2000. Eds. H.J.de Vega, I.Khalatnikov, N.Sanchez
Lecture delivered at the Nato Advanced Study Institute: Phase Transitions in the Early Universe: Theory and Observations. Erice 6th-17th December 2000. Eds. H.J.de Vega, I.Khalatnikov, N.Sanchez