John Arthur Todd

John Arthur Todd (born August 23, 1908 in Liverpool , † December 22, 1994 in Croydon ) was a British mathematician who mainly dealt 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 . He graduated in 1928 and then studied further under Henry Frederick Baker , specializing in geometry. In 1930 he won the Smith Prize, but did not receive a Trinity College Research Fellowship (instead, she received his fellow student HSM Coxeter on one occasion ). In 1931 he went to Manchester as an assistant to Louis Mordell . His doctorate at Baker took place in 1932. 1933/34 he was in Princeton as a Rockefeller scholarship with Solomon Lefschetz . In 1937 he became a lecturer at Cambridge, where he worked with William Hodge , Baker's successor, to establish more modern developments in algebraic geometry in England. In 1948 he became a Fellow of the Royal Society. When, despite his merits, he was not elected a Fellow of Trinity several times, he went to Downing College in 1958, where he became a reader in 1960 and retired in 1973.

Todd is still known today for the introduction of the Todd genus and Todd polynomials in topology, which emerged from his work on invariant theory. For example, they play a role in the Atiyah-Singer index theorem . In 1936, in group theory, he and Coxeter developed a calculation method for enumerating the secondary classes (cosets) of a subgroup of finite index.

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

He should not be confused with the numerical mathematician John Todd (1911–2007).

literature

• Michael Atiyah in Biographical Memoirs of Fellows of the Royal Society, Vol. 42, 1996, p. 483

Web links

• John J. O'Connor, Edmund F. Robertson :  John Arthur Todd. In: MacTutor History of Mathematics archive .

Remarks

1. ↑ Atiyah suspected that this was due to his left-wing attitudes