Kurt Strebel (20 April 20 1921,

Wohlen, Aargau Wohlen is a municipality in the district of Bremgarten in the canton of Aargau in Switzerland. History The earliest known settlements in Wohlen date from the late Hallstatt era (600-500 BC). This settlement left two clusters of burial moun ...

– 26 October 2013, Zurich) was a Swiss mathematician, specializing in

geometric function theory Geometric function theory is the study of geometric properties of analytic functions. A fundamental result in the theory is the Riemann mapping theorem. Topics in geometric function theory The following are some of the most important topics in ge ...

Education and career

Strebel received in 1953 his PhD from the

University of Zurich The University of Zürich (UZH, german: Universität Zürich) is a public research university located in the city of Zürich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 f ...

under

Rolf Nevanlinna Rolf Herman Nevanlinna (né Neovius; 22 October 1895 – 28 May 1980) was a Finnish mathematician who made significant contributions to complex analysis. Background Nevanlinna was born Rolf Herman Neovius, becoming Nevanlinna in 1906 when his fat ...

with thesis ''Über das Kreisnormierungsproblem der konformen Abbildung'' (On the circle normalization problem of conformal mapping). From 1953 to 1955 he was at the Institute for Advanced Study and at Stanford University. He became a professor at the

University of Fribourg The University of Fribourg (french: Université de Fribourg; german: Universität Freiburg) is a public university located in Fribourg, Switzerland. The roots of the university can be traced back to 1580, when the notable Jesuit Peter Canisius ...

in 1955 and then successor to Nevanlinna at the University of Zurich in 1963. Strebel founded the Nevanlinna Colloquium in Zurich (later also elsewhere) with another of Nevanlinna's former students, the professor Hans Künzi, to maintain contacts with Nevanlinna. The Nevanlinna Colloquium is usually held in Europe and covers most of classical complex analysis. In 1977 Strebel was elected a member of the

Finnish Academy of Sciences The Finnish Academy of Science and Letters (Finnish ''Suomalainen Tiedeakatemia''; Latin ''Academia Scientiarum Fennica'') is a Finnish learned society. It was founded in 1908 and is thus the second oldest academy in Finland. The oldest is the Fi ...

. He was an Invited Speaker at the ICM in 1974 in Vancouver. Named in his honor is the Strebel differential in the Teichmüller theory.

Strebel differential

Selected publications

Books

*''Vorlesungen über Riemannsche Flächen'', Vandenhoeck und Ruprecht, 1980.
''Quadratic Differentials.''
Ergebnisse der Mathematik und ihrer Grenzgebiete, Springer Verlag, 1984.

Articles

*''On the maximal dilation of quasiconformal mappings.'' Proc. AMS, 6, 1955, 903–909. *''Zur Frage der Eindeutigkeit extremaler quasikonformer Abbildungen des Einheitskreises.'' Comm. Math. Helv. 36, 1962, 306-323, Part 1 of article , Comm. Math. Helv. 39, 1964, 77-89, Part 2 of article *''Über quadratische Differentiale mit geschlossenen Trajektorien und extremale quasikonforme Abbildungen.'' in Festband zum 70. Geburtstag von Rolf Nevanlinna, Springer Verlag, 1966, 105–127. *with Edgar Reich: ''On quasiconformal mappings which keep the boundary points fixed.'' Trans. Amer. Math. Soc. 138, 1969, 211–222. *with Edgar Reich: ''Extremal plane quasiconformal mappings with given boundary values.'' Bull. Amer. Math. Soc. 79, 1973, 488–490. *with Edgar Reich: ''Extremal quasiconformal mappings with given boundary values.'' in ''Contributions to Analysis. A collection of papers dedicated to

Lipman Bers Lipman Bers ( Latvian: ''Lipmans Berss''; May 22, 1914 – October 29, 1993) was a Latvian-American mathematician, born in Riga, who created the theory of pseudoanalytic functions and worked on Riemann surfaces and Kleinian groups. He was also kn ...

.'' Academic Press, 1974, 375–391.

References

External links

Strebel in Zurich

Nekrologe, University of Zurich 2013
{{DEFAULTSORT:Strebel, Kurt University of Zurich alumni Academic staff of the University of Fribourg Academic staff of the University of Zurich 20th-century Swiss mathematicians 1921 births 2013 deaths