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EPADEL:A Semisesquicentennial History, 1926-2000

Section 4.5 Profile: Hans Rademacher (1892-1969)

Hans Rademacher was one of several émigré mathematicians to settle in the Philadelphia area during the 1930s. Born in Hamburg, Germany, it seemed as if this brilliant student would follow in the footsteps of other outstanding research mathematicians produced by the country’s superior educational system when he obtained his doctorate at Göttingen in 1917 at age 25.
From there Rademacher began to climb the steep German academic ladder. During 1919-1922 he was a Privatdocent at the University of Berlin. Then he moved back to his native Hamburg to become Professor Extraordinarius. However, he remained in Hamburg only three years before accepting a position as Professor Ordinarius (the equivalent of a full professor) at the University of Breslau in 1925. He stayed in Breslau until 1934.
That’s when Rademacher’s life changed dramatically. He was a socialist who belonged to the International League for the Rights of Man and was president of the Breslau chapter of the German Society for Peace, any one of which was sufficient to get him fired by the ruling Nazis. He was dismissed unceremoniously in 1934.
Germany’s loss was the Philadelphia Section’s gain.
In the fall of 1934 Rademacher immigrated to the University of Pennsylvania as a visiting professor under a joint grant from the Emergency Committee of Displaced German Scholars and the Rockefeller Foundation. The head of Penn’s graduate program in mathematics at the time, J. R. Kline, certainly knew the visitor’s worth. In 1936 Kline convinced Penn authorities to offer Rademacher an assistant professorship and tenure. Rademacher accepted, and he ultimately stayed at Penn until retirement in 1962, having been promoted to full professor in 1939.
Rademacher’s personal life was not without turmoil, as he married for the third time in 1949. But the third time was a charm, his wife being Irma Schoenberg Wolpe, the sister of his well-known colleague Isaac J. Schoenberg, a faculty member at Penn from 1941 to 1966.
In the meantime Rademacher was a member of the Institute for Advanced Study in Princeton during 1953 and for the academic year 1960-1961. He also spent 1954-1955 in Bombay, India, as a Guggenheim Fellow at the Tata Institute for Fundamental Research.
During his 28-year stint at Penn Rademacher directed 17 doctoral dissertations, more than anyone else at Penn except for J. R. Kline, who directed 19. (He directed four dissertations in Germany before emigrating.) Rademacher’s students have also played significant roles in two EPADEL institutions in Philadelphia. His 1959 graduate, Father Frederick Homann, became an institution at St. Joseph’s University. But Rademacher’s most enduring influence has been on Temple University, where his 1951 graduate, Albert Schild, initiated Temple’s Ph.D. program in 1967 and lured another Rademacher student, Emil Grosswald, from a professorship at Penn in West Philadelphia to Temple in North Philadelphia.
Forced retirement from Penn at age 70 did not mean the end of mathematical activity for the indefatigable Rademacher. He joined several other notable immigrants as a visiting professor at the Courant Institute in New York 1962- 1964, after which he moved to the Rockefeller University as a visiting professor 1964-1966 and an affiliate from 1966 until his death three years later. The University of Pennsylvania memorialized Rademacher’s name with a prestigious lecture series that began in 1978 with talks by Marcel Schutzenberger, I. M. Singer, and John Tate, and has numbered several Fields Medallists since then.