Mathematics professor at Rutgers University in Newark. Researcher in Topology, Geometry, and Geometric Group Theory. Currently specializing in the large scale geometry of $Out(F_n)$, the outer automorphism group of a free group of finite rank $n$.
22 Why is Banach–Tarski's paradox so interesting? sep 28 '14
21 Are there surfaces with more than two sides? apr 12 '14
13 Can asymptotes be curved? jun 28 '14
9 Examples of perfect sets. may 5 '12