My research interests include the nature of dark matter and dark energy, the assembly of cosmic structures including galaxy clusters, and the evolution of galaxies on cosmological timescales. I pursue research in many of these areas within the Local Cluster Substructure Survey (LoCuSS), of which I am the PI.
Much of my research relies on gravitational lensing, observations of galaxy clusters obtained with the Hubble Space Telescope, and large ground-based telescopes, including those of the W. M. Keck Observatory in Hawaii.
Some interesting review articles on gravitational lensing, galaxy clusters and related topics can be found here.