ABSTRACT AST 94-19400 Turner, Edwin Gravitational lensing is a tool for studying fundamental problems in cosmology and astrophysics. Three aspects will be studied: First, a new 3.5 meter telescope with remote observing capabilities will be used to monitor the brightness of images in candidate and known lenses. The light curves will be used to measure the value of the Hubble constant, test the lens hypothesis for controversial systems, and detect microlensing events, which have implications about the nature of dark matter and the very small scale structure of quasars. Second, observations of new candidate lenses to be identified in the Sloan Digital Sky Survey data sets will enable the assembly of a large (several hundred) well controlled statistical sample, thus allowing measures of fundamental cosmological parameters. Third, advanced cosmic simulation and numerical lensing codes will be employed to predict the lensing consequences of various scenarios for the formation and evolution of galaxies and large scale structure. These predictions will be compared to observations to test the theories.
