Stefan Cohn-Vossen

in Moscow, probably in 1936

Stefan Cohn-Vossen (born May 28, 1902 in Breslau , † June 25, 1936 in Moscow ) was a German mathematician who dealt with geometry .

Live and act

Stefan Cohn-Vossen received his doctorate in 1924 at the University of Breslau under Adolf Kneser ( singular points of real, simple families of curves, whose differential equation is given ). In 1929 he completed his habilitation at the University of Göttingen with Richard Courant . In 1930 he completed his habilitation at the University of Cologne, where he taught as a private lecturer.

As early as May 2, 1933, he was given leave of absence as a Jew by the National Socialists due to the law to restore the civil service and then removed from office in September. Before that, I started as a lecturer at a grammar school in Locarno , Switzerland. In 1934 he was a teacher in Zurich . In the same year he went to the Soviet Union, where in 1935 he became a professor at the Leningrad University at the Steklov Institute of Mathematics of the Soviet Academy of Sciences and in 1936 after the institute was moved to Moscow . He died of pneumonia. His widow, the doctor Elfriede geb. Ranft, was married to Alfred Kurella from 1938 until her death in 1957 . Cohn-Vossen's son was the director and screenwriter Richard Cohn-Vossen .

Cohn-Vossen dealt with Wilhelm Blaschke z. B. with the rigidity of surfaces, later mainly with differential geometry "on a large scale". Among other things, he proved the Cohn-Vossen theorem . In 1932 he published his well-known, generally understandable book with David Hilbert Illustrative Geometry , which is still considered one of the best introductory geometry books.

Subsequent appreciation

In 2014 a newly furnished lecture hall at the Mathematical Institute of the University of Cologne was named after him and inaugurated on November 7th with a commemorative colloquium in the presence of his son Richard .

Fonts

• with Hilbert: Descriptive Geometry. Springer 1932, 1996.
• Singularities of convex surfaces. Mathematische Annalen Vol. 97, No. 1, 1927, pp. 377-386.
• The parabolic curve , Mathematische Annalen, Vol. 99, No. 1, 1928, pp. 273-308.
• Rigid closed surfaces. Mathematische Annalen Vol. 102, No. 1, 1930, pp. 10-29.
• Shortest paths and total curvature on surfaces , Compositio Mathematica, Vol. 2, 1935, pp. 69-133.
• Existence of shortest routes. Compositio Mathematica, Vol. 3, 1936, pp. 441-452.
• The collineations of n-dimensional space , Mathematische Annalen, Vol. 115, No. 1, 1938, pp. 80-86.

literature

• Maximilian Pinl: colleagues in dark times. Annual report DMV, vol. 73, p. 183.
• A. Alexandrow: Stephan Cohn-Vossen. Uspekhi Matem. Nauk, Vol. 2, 1947, pp. 107-141. online in English translation
• Renate Tobies : Biographical lexicon in mathematics for post-doctoral students. 2006.

Web links

• Works by and about Stefan Cohn-Vossen  in the German Digital Library
• JJ O'Connor, EF Robertson: Stefan Emmanuilovich Cohn-Vossen , biography (English)
• Personal note on admission to NIIMM in Leningrad at mi.uni-koeln.de
• Sources and images for Cohn-Vossen at mi.uni-koeln.de