Børge Jessen

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Jessen (right) with Werner Fenchel , Alexandr Alexandrow , Herbert Busemann 1954

Børge Christian Jessen (born June 19, 1907 in Copenhagen ; † March 20, 1993 ) was a Danish mathematician.

Jessen studied from 1925 to 1929 at the University of Copenhagen with Harald Bohr . In 1929 he was on a Carlsberg scholarship in Hungary at the University of Szeged with Frigyes Riesz and Alfréd Haar and then for a semester at the University of Göttingen with David Hilbert and Edmund Landau . In 1930 he received his doctorate in Copenhagen and became a lecturer at the Royal Veterinary School. In 1933/34 and 1949 he was at the Institute for Advanced Study and in the 1930s he was also frequently in Paris , Cambridge , Harvard University and Yale University . In 1935 he succeeded Tommy Bonnesen as Professor of Descriptive Geometry at the Technical University of Copenhagen (then a Polytechnic Institute). From 1942 he was the successor of Johannes Hjelmslev professor at the University of Copenhagen, where he retired in 1977. At the University of Copenhagen in the 1960s he was one of the founders of the Hans Christian Ørsted Institute, which houses the faculties of mathematics, chemistry and, in part, physics.

Jessen dealt with measure theory , integration theory and other aspects of functional analysis such as the theory of Hilbert spaces and the almost periodic functions , which he also applied with Harald Bohr to the theory of the Riemann zeta function . In the USA he worked with Salomon Bochner , Paul Halmos , George Mackey and Aurel Wintner . He also worked with Paul Erdős on graph theory and combinatorial geometry, including the decomposition equality of polyhedra, one of the Hilbert problems that Max Dehn and Hugo Hadwiger also worked on. With Erik Sparre Andersen he published a convergence theorem for Martingale in 1948 , also known as the Andersen-Jessen theorem. The roots go back to his dissertation. The Andersen-Jessen theorem is named after Andersen and him.

He was on the founding committee of the International Mathematical Union , which was founded in 1951 and had its seat in Copenhagen. From 1930 to 1942 he was secretary of the Danish Mathematical Society and from 1973 its honorary member. A diploma award from the Danish Mathematical Society is named after him. In 1954 he gave a plenary lecture at the International Congress of Mathematicians (ICM) in Amsterdam with the title Some Aspects of the Theory of Almost Periodic Functions. He was President of the Carlsberg Foundation and on the Council of the Rask Ørsted Society. In 1967 he was elected a corresponding member of the Göttingen Academy of Sciences .

literature

  • Olli Lehto: Mathematics Without Borders: A History of the International Mathematical Union. Springer, New York [u. a.] 1998, ISBN 0-387-98358-9

Web links

Footnotes

  1. ↑ Already published in Danish by Jessen in 1939 and also proven by others
  2. ^ Bernard Bru, Salah Eid: Jessen's theorem and Levy's Lemma: a correspondence. In: Electronic Journal for History of Probability and Statistics. 2009 ( PDF ), with a copy of Jessen's correspondence with Paul Lévy , but also with Joseph L. Doob and Jean Dieudonné
  3. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 124.
personal data
SURNAME Jessen, Børge
ALTERNATIVE NAMES Jessen, Børge Christian
BRIEF DESCRIPTION Danish mathematician
DATE OF BIRTH June 19, 1907
PLACE OF BIRTH Copenhagen
DATE OF DEATH March 20, 1993