J. A. Todd

John Arthur Todd ( born August 23, 1908 in Liverpool, † December 22 1994 in Croydon ) was a British mathematician who worked mainly with group theory, topology and algebraic geometry.

Todd went to school in Liverpool and studied from 1925 at Trinity College at the University of Cambridge. In 1928 he graduated and then studied further under Henry Frederick Baker, where he specialized in geometry. In 1930 he won the Smith Prize, but gained no Research Fellowship at Trinity College ( instead she received on one occasion his fellow student HSM Coxeter ). In 1931 he went to Manchester as an assistant to Louis Mordell. His doctorate was in Baker 1932. 1933 / 34 he was in Princeton as a Rockefeller Fellow at Solomon Lefschetz. In 1937 he became a lecturer at Cambridge, where he met William Hodge, the successor Bakers, worked to establish more modern developments in algebraic geometry in England. In 1948 he became a Fellow of the Royal Society. When he was repeatedly chosen not in spite of its merits as a Fellow of Trinity, he went in 1958 to the Downing College, where he was Reader in 1960 and retired in 1973.

Todd is still known for the introduction of the Todd genus and the Todd polynomials in the topology that emerged from his invariantentheoretischen work. Example, they play the Atiyah -Singer index theorem a role. In group theory he developed in 1936 with a Coxeter calculation methods for the enumeration of the cosets ( cosets ) of a subgroup of finite index.

One of his doctoral students is Roger Penrose (1958).

It should not be confused with the numerical mathematician John Todd ( 1911-2007 ).