Lothar Collatz

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Photo from the collection of the Mathematical Research Institute Oberwolfach

Lothar Collatz (born July 6, 1910 in Arnsberg ; † September 26, 1990 in Varna ) was a German mathematician.

Live and act

Collatz passed his Abitur in March 1928 at the Marienstiftsgymnasium in Stettin. From 1928 to 1933 he studied mathematics and physics at various universities in Germany (Berlin, Munich, Greifswald and Göttingen), where he heard lectures by Erhard Schmidt , Richard von Mises , David Hilbert , Erwin Schrödinger , Richard Courant and Constantin Carathéodory .

With Schrödinger and von Mises he passed the state exams in mathematics and physics in 1933. Two years later he received his doctorate with the thesis The difference method with higher approximation for linear differential equations , with Alfred Klose and Erhard Schmidt. Von Mises, who had actually looked after him, had to leave Germany because of the Nazi seizure of power.

He then worked as an assistant at the University of Berlin, before moving to the TH Karlsruhe in 1935 and working with Theodor Pöschl and Wilhelm Quade (1898–1975) at the Institute for Technical Mechanics. There he obtained his habilitation in 1937. From mid-February to the end of March 1937, Collatz took part in a lecturer camp of the NSDDB at Tännich Castle in Thuringia. From 1938 to 1943 he worked as a private lecturer in Karlsruhe.

During the war years he was employed by Alwin Walther at the Institute for Practical Mathematics in Darmstadt and participated in the rocket program . In 1943 he accepted a call from the TH Hannover as a professor of mathematics. From 1952 to 1990 he worked as a professor for applied mathematics at the University of Hamburg . There he founded the Institute for Applied Mathematics in 1953, and during his time in Hamburg he enjoyed great international recognition. After his retirement in 1978 he was omnipresent as a lecturer and discussion leader at mathematical conferences. He died in 1990 at a conference in the Bulgarian port city of Varna .

Since 1940 Collatz was married to Martha Togny.

Lothar Collatz 1984

For many years he anonymously edited the popular “ Logeleien ” of the weekly newspaper “Die Zeit”. His doctoral students included Professors Werner Krabs , Frank Natterer , Karl-Peter Hadeler , Johann Schröder , Wolfgang Wetterling (University of Twente), Ludwig Elsner , Burkhard Monien , Claus Peter Ortlieb , Günter Bertram (Hanover), Julius Albrecht (Clausthal) and Werner Uhlmann .

The Collatz Prize is awarded in his honor .

Mathematical work

From his work as a mathematician, the Collatz problem , published in 1937, is well known, which is still unsolved today. Otherwise he has earned great recognition as an important representative of applied mathematics in the field of numerical mathematics .

He also carried out important research in the field of functional analysis and the theory of differential and integral equations . His research had already started in the 1930s with the difference methods and their error estimates. He also dealt with difference methods of higher approximations.

Work on the estimation of eigenvalues of matrices and differential equations followed. Among other things, he examined the structure of geometric ornaments , periodic spline functions , bifurcations and the spectra of graphs.

He published several standard works on numerical mathematics, which were also translated.

Fonts (selection)

  • The difference method with higher approximation for linear differential equations (= writings of the mathematical seminar and the institute for applied mathematics of the University of Berlin - Volume 3 / Issue 1), Leipzig 1935
  • Eigenvalue Problems and their Numerical Treatment. Leipzig 1945
  • Eigenvalue problems with technical applications. Leipzig 1949, 1963
  • Numerical treatment of differential equations. Berlin 1951, 1955 (English 1966)
  • Differential equations for engineers. Stuttgart 1960
  • with Wolfgang Wetterling optimization tasks Berlin 1966, 1971 (English 1975)
  • Functional analysis and numerical mathematics. Berlin 1964
  • Differential equations. An introduction with a special focus on the applications. Stuttgart, Teubner Verlag, 1966, 7th edition. 1990
  • with Julius Albrecht Exercises from applied mathematics I. Equations in one and several variables. Approximations. Berlin 1972
  • Numerical methods of approximation theory. Volume 2. Excerpts from the conference on numerical methods of approximation theory from 3. – 9. June 1973 at the Mathematical Research Institute Oberwolfach, Stuttgart 1975
  • with Werner Krabs : Approximation Theory: Tschebyscheffsche Approximation and Applications. Teubner 1973
  • with Rüdiger Nicolovius boundary and eigenvalue problems in ordinary and partial differential equations and integral equations , in Robert Sauer , Istvan Szabo The mathematical tools of the engineer , Volume 2, Springer Verlag 1969

Some articles available online:

Honorary Dr. hc.

membership

literature

  • Ingo Althöfer : Lothar Collatz between 1933 and 1950 - A partial biography. 3-Hirn-Verlag, Lage (Lippe), 2019.
  • Günter Meinardus, Günther Nürnberger: Lothar Collatz. In: Journal of Approximation Theory. Vol 65, Issue 1, April 1991.
  • Siegfried Gottwald, Hans-Joachim Ilgauds, Karl-Heinz Schlote (ed.): Lexicon of important mathematicians. Leipzig 1990.
  • Elsbeth Bredendiek et al .: Lothar Collatz 1910–1990. Inst. For Applied Mathematics, Hamburg 1991, Hamburg Contributions to Applied Mathematics, 3rd edition 2008 ( pdf; 12 MB ).
  • Klaus Biener: An important doctoral candidate at our university: Lothar Collatz. (PDF; 93 kB) In: RZ-Mitteilungen. No. 5, 1993.

Web links

Individual evidence

  1. ^ Ingo Althöfer : Lothar Collatz between 1933 and 1950 - a partial biography. 3-Hirn-Verlag, Lage (Lippe), 2019, pp. 6 and 105.
  2. ^ Ingo Althöfer: Lothar Collatz between 1933 and 1950 - a partial biography. 3-Hirn-Verlag, Lage (Lippe), 2019, p. 15.
  3. ^ Günter Meinardus, Günther Nürnberger: Lothar Collatz (July 6, 1910 - September 26, 1990). In: Journal of Approximation Theory. Vol 65, 1, April 1991, p. II.
  4. ↑ Herbert Breger Mathematician in Hanover , Uni Magazin, Hanover, No. 1/2, 2008, pdf ( Memento from December 17, 2013 in the Internet Archive )
personal data
SURNAME Collatz, Lothar
BRIEF DESCRIPTION German mathematician
DATE OF BIRTH July 6, 1910
PLACE OF BIRTH Arnsberg
DATE OF DEATH September 26, 1990
Place of death Varna