Hahn began his academic career in 1898 when he began studying law at the University of Vienna. After a year he turned to mathematics and studied in Strasbourg and Munich. In 1901 Hahn returned to Vienna, where in 1902 he completed his doctorate on the subject of "On the theory of the second variation of simple integrals" and thus received a Dr. phil. was appointed. During his time at the Technical University in Vienna, he became friends with Paul Ehrenfest , Heinrich Tietze and Gustav Herglotz . In 1905 he completed his habilitation at the University of Vienna with the thesis “Comments on the calculus of variations” . He taught in Czernowitz , Bonn and from 1921 as a full university professor at the University of Vienna . Also in 1921 he was elected a member of the Leopoldina . His most famous student was Kurt Gödel , who completed his doctoral thesis in 1929.
Hahn was also very interested in philosophy and an active member of the Vienna Circle . Hahn was involved in university politics as chairman of the Association of Socialist University Lecturers and in local politics as a member of the Vienna City School Council . He protested against the discrimination against Jewish students and professors and was the target of an anti-Semitic defamation campaign by the Deutschösterreichische Tages-Zeitung in 1924. Hahn demanded unrestricted freedom of teaching and learning, free tuition and a habilitation process based exclusively on academic achievement.
In 1934 he died of an operation at the age of 54.
The name Hans Hahn is best known from Hahn-Banach's sentence . In addition, Hahn made other important contributions to functional analysis , to measure theory ( Hahn's decomposition theorem , theorem of Vitali-Hahn-Saks ), to harmonic analysis and to general topology . The majority of Hahn's publications are the above-mentioned writings of mathematical content. Hans Hahn did not publish texts with a philosophical content until the early 1930s. These deal with epistemological considerations for the natural sciences.
- Logic, mathematics and knowledge of nature . In: Hubert Schleichert (Ed.): Logical Empiricism - Der Wiener Kreis , Munich (1975).
- Superfluous entities ( Occam's razor ) . ibid.
- Scientific worldview - The Vienna Circle . (together with Rudolf Carnap and Otto Neurath ) ibid.
- Empiricism, logic, mathematics. With an introduction by Karl Menger. Edited by Brian McGuiness. Frankfurt (1988).
- About linear systems of equations in linear spaces . In: Journal for pure and applied mathematics 157 (1927), p. 214-229. (Original version of Hahn-Banach's theorem )
- Real functions . Academic Publishing Society Leipzig (1932)
- Friedrich Stadler : Studies on the Vienna Circle - Origin, Development and Effect of Logical Empiricism in Context , Frankfurt am Main (1997). Biography and bibliography on pages 693–703.
- Friedrich Stadler : Vienna Circle. In: Dan Diner (Ed.): Encyclopedia of Jewish History and Culture (EJGK). Volume 6: Ta-Z. Metzler, Stuttgart / Weimar 2015, ISBN 978-3-476-02506-7 , pp. 401–404.
- Austrian Biographical Lexicon 1815–1950 (ÖBL). Volume 2, Verlag der Österreichischen Akademie der Wissenschaften, Vienna 1959, p. 147. In:
- Josef Lense : In: New German Biography (NDB). Volume 7, Duncker & Humblot, Berlin 1966, ISBN 3-428-00188-5 , p. 506 ( ).
- Literature by and about Hans Hahn in the catalog of the German National Library
- John J. O'Connor, Edmund F. Robertson : Hans Hahn. In: MacTutor History of Mathematics archive .
- Entry on Hans Hahn in the Austria Forum (in the AEIOU Austria Lexicon )
|BRIEF DESCRIPTION||Austrian mathematician|
|DATE OF BIRTH||September 27, 1879|
|PLACE OF BIRTH||Vienna , Austria|
|DATE OF DEATH||July 24, 1934|
|Place of death||Vienna , Austria|