Grigory Perelman (right) says, "If the proof is correct, then no other recognition is needed." Shing-Tung Yau isn’t so sure.Pierre Le-Tan On the evening of June 20th, several hundred physicists, including a Nobel laureate, assembled in an auditorium at the Friendship Hotel in Beijing for a lecture by the Chinese mathematician Shing-Tung Yau. In the late nineteen-seventies, when Yau was in his twen