My research centers on using gravitational lensing as a tool to study
a variety of problems in astrophysics and cosmology. In the past I have
used analyses of strong lens systems to probe the physical properties
of distant elliptical galaxies, and to constrain cosmological parameters.
My recent work falls into three main categories:
(1) using the flux ratios in strong lens systems to probe small-scale
structure in galaxies and quasars;
(2) studying lens environments to understand how environment affects
galaxy evolution;
and (3) assessing prospects for using lensing by compact objects to test
theories of gravity.
I maintain a public-domain software package called GRAVLENS for
gravitational lensing calculations and lens modeling applications.
