Gerhard Thomsen

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Gerhard Thomsen (born June 23, 1899 in Hamburg , † January 4, 1934 in Papendorf near Rostock ) was a German mathematician who dealt with geometry.

Life

Thomsen was the son of a doctor and graduated from the Johanneum School of Academics in Hamburg in 1917 (where he had attended since 1908), and then did his military service in World War I until 1919. From 1919 he studied mathematics and natural sciences at the newly founded University of Hamburg and (for a short time) at the University of Heidelberg , with the conclusion of the state examination for the higher teaching post in Hamburg in November 1922. In Heidelberg Thomsen became a member of the Vineta fraternity . A year later in 1923 he received his doctorate under Wilhelm Blaschke ( basics of the conformal surface theory ). As a post-doctoral student he was assistant for descriptive geometry at the TH Karlsruhe and from 1925 assistant to Blaschke in Hamburg. In 1926/27 he spent a year in Rome as a Rockefeller Fellow with Tullio Levi-Civita . After his habilitation (geometry, group theory) in Hamburg in 1928 on a topic of general relativity ( on the movement of a small rigid test body in any given gravitational field ) he was a private lecturer in Hamburg. From 1929 he was a full professor at the University of Rostock and director of the mathematical seminar there. He was run over by a train in 1934 and a suicide is suspected. On November 22, 1933, he had given a lecture at the University of Rostock on the decline of teaching in the natural sciences and mathematics in schools and universities, which did not express any open opposition to the National Socialists and on the contrary expressed the importance of mathematics and natural sciences for wanted to highlight a new Germany , but shortly before his death led to an investigation by the public prosecutor. According to Max Pinl, the lecture received a lot of attention at the time. It was reprinted in the Physikalische Blätter (the in-house journal of the German Physical Society ) in 1943.

Thomsen was a member of the German Mathematicians Association from 1923 and a member of the Hamburg Mathematical Society from 1925.

plant

After Max Pinl, Thomsen was one of Wilhelm Blaschke's most successful employees in his implementation of Felix Klein's Erlangen program for differential geometry, that is, the systematic exploration of differential geometry according to the underlying transformation groups (especially affine transformations, Möbius and Laguerre transformations, conformal transformations ). Under the influence of Levi-Civita, he also turned to mathematical aspects of general relativity (he published much of his work in Italian).

In a book published in 1933, based on the work of Johannes Hjelmslev, he gave a group theoretical treatment of the structure of Euclidean elementary geometry with reflections. Arnold Schmidt treated the case of Absolute Geometry in group theory in the 1940s .

Special minimal surfaces that he introduced in 1923 are named after him. They are defined by the fact that they are both minimal surfaces in Euclidean space and affine minimal surfaces in the sense of Wilhelm Blaschke . Thomsen characterized them and gave first examples of it (special cases of Thomsen's minimal surfaces are the helicoids and Enneper's criminal surface ). They were fully classified by Woldemar Barthel, Reinhard Volkmer, and Imme Haubitz in 1980.

As an assistant to Blaschke, he was involved in several of his publications (for example in various editions of his lectures on differential geometry and the publication of Felix Klein's lectures on higher geometry).

Fonts

  • Fundamentals of elementary geometry in group algebraic treatment , Hamburger Mathematische Einzelschriften 15, Leipzig, 1933.
  • On a New Branch of Geometric Axiomatics and a New Kind of Analytical Geometry , Mathematische Zeitschrift, Volume 34, 1932, pp. 668-720, online
  • To the geometrical mirror calculus, Mathematische Zeitschrift, Volume 37, 1933, pp. 561-565, online
  • On differential geometry in three-dimensional space , annual report DMV, volume 34, 1926, p. 131 online

literature

  • Wolfgang Engel Mathematics and mathematician at the University of Rostock , Rostock Mathematical Colloquium, Volume 27, 1985, pp. 41–79, new edition in Rostock Mathematical Colloquium, Issue 60, 2005, p. 38
  • Sanford Segal Mathematicians under the Nazis , Princeton University Press 2003, pp. 217ff
  • Max Pinl Colleagues in Difficult Times , Annual Report DMV, Volume 73, 1972, pp. 205-206, online
  • Obituary in treatises Math. Seminar of the University of Hamburg, Volume 10, 1934 with list of publications

See also

Web links

Individual evidence

  1. ^ Mathematics Genealogy Project
  2. ↑ Published as About conformal geometry 1: Foundations of conformal surface theory , treatises from the Mathematical Seminar of the University of Hamburg, Volume 3, 1923, pp. 31–56
  3. ↑ Published in Mathematische Zeitschrift, Volume 29, 1928, pp. 96–128, online , correction in Volume 30
  4. ↑ Renate Tobies, website of the DMV, after Pinl associate professor
  5. ↑ Thomsen On the Danger of Exact Natural Sciences being pushed back in schools and universities , New Yearbooks for Science and Youth Education 1934, pp. 164–175. Excerpt in English translation from Sanford Segal Mathematicians under the Nazis , p. 218
  6. ↑ Renate Tobies, DMV website. Max Pinl writes about the reasons for the suicide: probably because the secret police were interested in him , Annual Report DMV, 1972, p. 206
  7. ^ Sanford Segal
  8. ↑ Friedrich Bachmann mentions it in the chapter on absolute geometry in Behnke et al. a. Fundamentals of Mathematics , MIT Press, Volume 2 (Geometry), 1983, p. 131, the first completely consistent representation of the structure of Euclidean elementary geometry on the reflection calculus
  9. ↑ Thomsen About affine geometry XXXIX: About affine minimal surfaces, which are also minimal surfaces , Abh. Math. Sem. Univ. Hamburg, 2, 1923, pp. 71-73
  10. ^ W. Barthel, R. Volkmer Reinhard, I. Haubitz, Tomsensche minimal surfaces analytical and vivid. Result Math., 3, 1980; No. 2, pp. 129-154
  11. ^ Ulrich Dierkes, Stefan Hildebrandt, Friedrich Sauvigny, Minimal Surfaces, Grundlehren der Mathematischen Wissenschaften, Springer 1992, 2010, p. 156
  12. ↑ Volume 1 in the 3rd edition 1930 and Volume 3 (differential geometry of circles and spheres) 1929
personal data
SURNAME Thomsen, Gerhard
BRIEF DESCRIPTION German mathematician
DATE OF BIRTH June 23, 1899
PLACE OF BIRTH Hamburg
DATE OF DEATH January 4, 1934
Place of death Papendorf (Warnow)