The mathematician Shmuel Aaron Weinberger (born February 20, 1963) is an American topologist. The Massey product was created by William S. Massey, an American algebraic topologist. Her doctoral advisor was the topologist Edward Wilson Chittenden. This led to contact with several art collectors and with the topologist Ronnie Brown. They were invented and classified by the German topologist Friedhelm Waldhausen in 1967. Alexandrov-discrete spaces are named after the Russian topologist Pavel Alexandrov. William W. Menasco is a topologist and a professor at the University at Buffalo. Allen Edward Hatcher (born October 23, 1944) is an American topologist.