Under this award, Dr. Hogan will conduct three experiments in observational cosmology. The first will be a search for cosmic deuterium in the absorption spectra of distant quasars. The statistics of quasars are well enough understood to make it possible to infer from such data how nucleosynthesis occurred during the big bang. The second experiment will be a study with the Very Large Array of small scale irregularities in the background radiation. This will enable the investigators to put better experimental limits on theories of the formation of cosmic structure. Finally, a long standing search for Lyman-alpha emission from galaxies at very high redshift will be continued. Recent advances in technology will permit interesting new limits to be placed on processes occurring during the formation of the very first galaxies. Dr. Hogan, a leading young theorist, has been very active in designing and performing observations to test critical aspects of modern cosmological theories.
