Hendrik Kloosterman

Hendrik Douwe Kloosterman ( born April 9, 1900 in Rottevalle, The Netherlands, † May 6, 1968 in Leiden ) was a Dutch mathematician.

Life and work

Hendrik Kloosterman attended school in The Hague and studied mathematics at Leiden University, where he received his diploma in 1922. In 1924 he received his doctorate with Jan Cornelis Kluyver in Leiden, after he spent the mediation of Paul Ehrenfest some time with Harald Bohr in Copenhagen and Godfrey Harold Hardy at Oxford University. In his dissertation he examined the asymptotic number of solutions of a positive definite quadratic form ( in diagonal form ) in more than five variables. He turned it to the Hardy - Littlewood'sche circle method. Since this was calculated for the case of four variables ( the already Joseph -Louis Lagrange solved ) does not apply, this led to a follow-up operation in the Acta Mathematica in 1926, in which he introduced his Kloosterman sums, special trigonometric sums that many applications found in analytic number theory and the theory of modular forms and extended the Hardy - Littlewood method significantly. 1926/27, he was a Rockefeller fellowship at the University of Göttingen and in 1927/28 in Hamburg with Erich Hecke, where he applied his method to the determination of the Fourier coefficients of modular forms. From 1928 he was an assistant at the Westfälische Wilhelms-Universität in Münster, and then in 1930 Associate Professor ( Lector ) at the University are suffering. During the war, when his university was closed, he worked on representations of finite subgroups of the modular group in the theta-functions. From 1947 he was a professor in Leiden.

He was a member of the Royal Netherlands Academy of Sciences since 1950. In 1950 he was invited speaker at the International Congress of Mathematicians (ICM ) in Cambridge (Massachusetts ) (The characters of binary modular congruence groups).

His doctoral counts Tonny Albert Springer.