1951-

American mathematician who received his Ph.D. from Princeton University in 1973. He is best known for his work in solving the longstanding Poincaré conjecture in four dimensions, for which he received the Fields Medal, the highest honor in mathematics. He has been the recipient of numerous awards including Sloan and Guggenheim fellowships, a MacArthur Fellowship, and the National Medal of Science. He was an elected member of National Academy of Science.