Arnaud Denjoy

Arnaud Denjoy (1884 to 1974) was a French mathematician born in Auch, in the Gers department. His contributions include work in harmonic analysis and differential equations, and the Denjoy integral, the first integral able to integrate every derivative; the broader version is also known as the Khinchin integral. Gustave Choquet was among his students. He was an invited speaker at the International Congress of Mathematicians in Strasbourg in 1920 and in Cambridge, Massachusetts in 1950, president of the Societe Mathematique de France in 1931, a member of the Academie des sciences from 1942 and its president in 1962. His publications include a 1912 extension of the Lebesgue integral, a 1937 introduction to the theory of functions of real variables, a four-volume work on transfinite enumeration and a collection of academic notes covering 1906 to 1956. He married in 1923 and had three sons, was an atheist with strong interests in philosophy, psychology and social questions, and died in Paris in 1974. The asteroid 19349 Denjoy is named for him.