Richard Courant

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Richard Courant 1969

Richard Courant (born January 8, 1888 in Lublinitz , Upper Silesia , † January 27, 1972 in New York ) was a German-American mathematician .


Richard Courant was born in Lublinitz , Silesia , in 1888 . His father Siegmund Courant was a small businessman who came from a large Jewish family. His mother Martha Courant, née Freund, was the daughter of a businessman from neighboring Oels . Edith Stein was a paternal cousin of Richard Courant.

Richard Courant (1930)

His parents often moved in his youth: to Glatz , Breslau and finally to Berlin in 1905. Richard first attended high school in Glatz and later the humanistic König-Wilhelm-Gymnasium in Breslau. After initial teething problems, he was considered a very good student there. The father's business was not doing very well and he was declared bankrupt in 1901. Finally, the father decided to move his business activities to Berlin. Richard Courant, however, who had started early to earn money as a private tutor alongside school, stayed behind in Wroclaw. In the winter semester of 1906/07 he began studying at the University of Breslau , initially in physics and later in mathematics. He found the lectures rather unsatisfactory and went to Zurich and then to Göttingen , where he became David Hilbert's assistant . In 1910 Courant received his doctorate there on the subject of the application of Dirichlet's principle to the problems of conformal mapping and completed his habilitation in 1912.

He was drafted into the First World War on August 8, 1914 , and five days later took part in the loss-making advance through Belgium to France. There he experienced a "disastrous communication chaos ", whereupon he campaigned for the development of a new type of terrestrial telegraph . He got Carl Runge , Peter Debye and Paul Scherrer to collaborate . He was soon wounded and discharged from the military. He then returned to Göttingen, where, after two years in Münster, he was appointed professor in 1922 and later head of the mathematical institute. From 1925 he was a member of the Göttingen Academy of Sciences .

After the seizure of power , Courant left Germany in the summer of 1933. He spent a year in Cambridge and then went to New York , where he became a professor in 1936. There he built a mathematical research center with Kurt Friedrichs , whom he brought from Göttingen, and the young Peter Lax . The Courant Institute for Mathematical Sciences (as it has been called since 1964) at New York University is one of the world's most respected institutes for applied mathematics . In 1953 Courant was elected to the American Philosophical Society and in 1955 to the National Academy of Sciences .

After a short marriage to Nelly Neumann, Courant was married to Nerina ( Nina ) Runge, a daughter of Carl Runge, for the second time since 1919 . His son Ernest Courant was a well-known physicist, and his daughter Gertrude Moser is a biologist and wife of the mathematician Jürgen Moser .


Richard Courant founded and successfully led a mathematical institute. He was also an outstanding mathematician. He developed the finite element method by Walter Ritz ( method by Ritz ), which was later widely used by engineers and natural scientists (but did not attract any attention from engineers when Courant was published in 1943), and clarified its mathematical principles. The method today is u. a. a standard procedure for the numerical solution of partial differential equations , because concrete error estimates are often possible. It is used as standard in quantum mechanics in particular .

His textbook Methods of Mathematical Physics with David Hilbert is a standard work even more than 80 years after its publication. It is based on lectures by Hilbert, but is almost entirely written by Richard Courant.

There is also a two-volume textbook from the 1920s ( lectures on differential and integral calculus ) for students in the first two semesters. These two volumes are also timeless and are therefore still on sale (as a “contrast”, so to speak) because, in contrast to the more abstract modern illustrations, they are very clear and understandable.

In the field of numerical flow simulation , Richard Courant is best known for the Courant-Friedrichs-Lewy number , which is important for the calculation of hyperbolic partial differential equations. Furthermore, the Courant-Fischer theorem is named after him, which gives a representation of the eigenvalues ​​of a symmetrical or Hermitian matrix as a minimum or maximum Rayleigh quotient (minimum-maximum principle).

In his dissertation Richard Courant dealt with the Dirichlet principle and its application in the theory of uniformity. He returned to this in later works on minimal surfaces and conformal mapping.

His book with Herbert Robbins “Was ist Mathematik?” (First published in 1941) is considered a first-class introduction.


Göttingen-Weende, Richard-Courant-Weg



  • Constance Reid: Richard Courant. 1888–1972 - the mathematician as a contemporary , Springer Verlag 1979, ISBN 0-387-09177-7 .

Web links

Commons : Richard Courant  - collection of images, videos and audio files

Individual evidence

  1. Arne Schirrmacher: Physics in the Great War , Physics Journal 13 (2014), No. 7, pp. 43–48.
  2. Hans Schäfer: The eavesdropping of long-distance calls and the earth telegraphy in the field. In: Polytechnisches Journal . 334, 1919, pp. 93-97.
  3. Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 62.
  4. Courant Variational methods for the solution of problems of equilibrium and vibrations , Bulletin AMS, Volume 49, 1943, pp. 1–23, (Online)