is the Chancellor’s Professor of Mathematics in the Department of Mathematics at Brown University. His research interests lie in geometry and dynamical systems, especially in the computer-assisted exploration of these topics. In particular, he is known for the proof of quasi-isometric rigidity of rank one lattices, the proof of the Goldman-Parker Conjecture about complex hyperbolic ideal triangle groups, the solution of the Moser-Neumann problem about unbounded orbits of outer billiards, and the solution of Thomson’s 5-electron problem. He was an Invited Speaker at the 2002 International Congress of Mathematicians inBeijing, and has held Sloan, Guggenheim, Clay, and Simons Fellowships. Hisresearch has long been supported by the U.S. National Science Foundation.
His other interests include computer programming, writing children’s books, cycling, yoga, tennis, weight-lifting, and spending time with his family.