Karl Stein (mathematician)

from Wikipedia, the free encyclopedia
Karl Stein in Eichstätt , 1968

Karl Stein (born January 1, 1913 in Hamm , † October 19, 2000 in Ebersbach an der Fils ) was a German mathematician . His research area was the complex analysis of several variables. The concept of Stein's manifold goes back to him.

Life

Karl Stein studied from 1932 to 1936 at the Westphalian Wilhelms University in Münster as well as in Hamburg and Berlin and received his doctorate in 1937 under Heinrich Behnke . The title of his dissertation was On Theory of the Functions of Several Complex Variables; The regularity hulls of low-dimensional manifolds . In 1938 he stayed in Heidelberg on a scholarship. In 1940 he completed his habilitation in Münster.

During the Second World War , he was head of division in the encryption department of the Wehrmacht High Command in Section IVa Security Control of its own key procedures under Erich Hüttenhain . He himself was responsible for the secret writer and the Lorenz key machine , his colleague Gisbert Hasenjaeger for the Enigma . In 1946 he became a lecturer and later an adjunct professor in Münster. After a guest stay in Paris in 1953/54, he was appointed to the Ludwig Maximilians University in Munich in 1955 - to the Chair of Mathematics I , which he previously held. a. Ferdinand von Lindemann and Constantin Carathéodory held. There he remained active after his retirement in 1981.

Act

In 1941, in his habilitation, he gave topological conditions for solving the cousin problem . It is about the question of the existence of globally analytical functions in several variables with given zero and pole areas. Stein takes up works by the Japanese Kiyoshi Oka .

In 1951 he introduced the Steinian manifolds, so named shortly afterwards by Henri Cartan and Jean-Pierre Serre , a generalization of open Riemannian surfaces in several complex dimensions. In the same year 1951 he and Behnke developed a geometrical theory of complex spaces based on Riemann - roughly at the same time as the more algebraic definition by Henri Cartan ("analytic sets"), whose theory Stein expanded with Reinhold Remmert in 1953. In 1958 Hans Grauert and Remmert show the equivalence of the two definitions.

Appreciations

In 1990 he was the first mathematician to be awarded the Georg Cantor Medal .

He had been a member of the Bavarian Academy of Sciences since 1962, a corresponding member of the Göttingen Academy of Sciences since 1970 and of the Austrian Academy of Sciences since 1982 . In 1973 he received an honorary doctorate from the University of Münster. In 1966 he was President of the German Mathematicians Association .

His doctoral students and students include Reinhold Remmert , Michael Schneider (University of Bayreuth), Otto Forster , Ivo Schneider , Gunther Schmidt , Konrad Königsberger and Martin Schottenloher .

Fonts

literature

  • Reinhold Remmert : Karl Stein - holder of the Cantor medal. In: Annual report DMV. Volume 93, 1991, p. 1.
  • Henri Cartan on Karl Stein in Volume 2 of his works, p. 896.

Web links

Individual evidence

  1. ↑ Article at Heise.de
  2. ^ Chronological overview of the chairs for mathematics on the website of the mathematical institute of the LMU
personal data
SURNAME Stein, Karl
BRIEF DESCRIPTION German mathematician
DATE OF BIRTH January 1, 1913
PLACE OF BIRTH Hamm
DATE OF DEATH October 19, 2000
Place of death Ebersbach an der Fils