Dickson, Leonard Eugene (1874-1954)

US mathematician. He gave the first extensive exposition of the theory of fields. In History of the Theory of Numbers (1919-23), now a standard work, he investigated abundant numbers, perfect numbers, and Pierre de Fermat's last theorem.

Dickson's work in mathematics spanned many topics, including the theory of finite and infinite groups, the theory of numbers, algebras and their arithmetics, and the history of mathematics. Investigating the history of the theory of numbers, Dickson studied the work of Diophantus, who lived in Alexandria in the 3rd century AD. Diophantus assumed that every positive integer is the sum of four squares, and Dickson proved an extension of this theory.

Dickson was born in Independence, Iowa, and studied at the universities of Texas and Chicago, spending nearly all his academic career at the latter and becoming professor in 1910.