B.S. University of Texas (1962)
Ph.D. University of Texas (1966)
My current interests are in cosmology. With colleagues we are looking at linear and nonlinear gravitational lensing corrections caused by embedding inhomogeneities (galaxies, clusters, etc.) in otherwise homogeneous models of the universe. To find nonlinear effects such as the cosmological constant's alteration of Einstein's bending angle, we found it necessary to use GR solutions historically known as Swiss cheese models. We have discovered a relatively simple expression for computing the integrated Sachs-Wolfe effect caused by embedded lenses on the CMB. Using this theory we are able to model hot and cold spots that are associated with large voids and clusters.