I am a Mathematics Professor at Bryn Mawr College, where I have been since 1981.  I am actively engaged in research in three and four dimensional topology, and enjoy communicating mathematics at all levels.

I received my Ph.D. from U.C. Berkeley in 1977, working with Rob Kirby.  After a pair of postdoctoral positions at U.W. Madison and U.C. Santa Barbara, I joined the faculty at Bryn Mawr in 1981.  I have since held sabbatical research positions at Stanford University (1988-89 and Fall 2020), the Newton Institute in Cambridge, England (Fall 1992), the Institute for Advanced Study in Princeton (2002-03 and Fall 2016) and the Mathematical Sciences Research Institute in Berkeley (1996-97 and 2009-10), and have been supported by grants from the National Science Foundation, the American Institute of Mathematics, and the Mellon Foundation.  I am currently on the Steering Committee for the Park City Mathematics Institute.

Those who have problems accessing any documents on this website should email me for assistance.