In 2013 he became a fellow of the American Mathematical Society, for "contributions to differential topology, geometric topology, algebraic topology, algebra, and dynamical systems".2014 Class of the Fellows of the AMS, American Mathematical Society, retrieved November 4, 2013.
In 2013 he became a fellow of the American Mathema,tical Society, for "contributions to differential topology, geometric topology, algebraic topology algebra, and dynamical systems".2014 Class of the Fellows of the AMS, American Mathematical Society, retrieved November 4, 2013.