Dr. Arlie O. Petters Department of Mathematics Princeton University Princeton, NJ 08544
Light rays are the carriers of practically all observational facts we know about the universe. Consequently, an understanding of how light rays are affected by the gravitational influence of matter along its path is of great physical interest. This is exactly the focus of the theory of gravitational lensing.
During the past 15 years, the subject of gravitational lensing has matured into an area where empirical observations, physical theories, numerical simulations, and the mathematics of singularity theory all converge. Today, gravitational lensing stands as an important offspring of Einstein's general theory of relativity and is one of the most vibrant and rapidly growing areas in galactic and extra galactic astronomy.
This talk will show that singularity theory provides a rigorous and natural unifying framework for gravitational lensing's central physical ideas, strengthening and advancing it theoretically. Several applications of singularity theory to the study of multiple imaging, image magnification, and caustics will be presented. We shall also discuss singular and nonsingular gravitational lenses, as well as compare single and multiplane lensing.