Education
In 1975 he earned his Doctor of Philosophy from the University of California, Berkeley as a student of Robion Kirby.
mathematician university professor topologist
In 1975 he earned his Doctor of Philosophy from the University of California, Berkeley as a student of Robion Kirby.
His research is in topology. In topology, he has worked on handlebody theory, low-dimensional manifolds, symplectic topology, G2 manifolds. He has developed 4-dimensional handlebody techniques, settling conjectures and solving problems about 4-manifolds, such as Zeeman conjecture, Harer-Kas-Kirby conjecture, Scharlemann problem, and Cappell-Shaneson problems.
His most recent results concern the 4-dimensional smooth Poincare conjecture.
He has supervised 10 Doctor of Philosophy students as of 2011. He has more than 80 papers and 2 books published, and several books edited.
He was a visiting scholar several times at the Institute for Advanced Study (in 1975-1976, 1980-1981, 2002, and 2005).