Lars Hörmander

from Wikipedia, the free encyclopedia
Lars Valter Hörmander

Lars Valter Hörmander (born January 24, 1931 in Mjällby , Sölvesborg municipality , † November 25, 2012 in Lund ) was a Swedish mathematician and recipient of the Fields Medal and the Wolf Prize .

Life

Hörmander's father was a teacher in Mjällby, a small fishing village in southern Sweden. As a student at the grammar school in Lund , Hörmander learned mathematics at university level from his teacher. In 1948 he started at the university there with Marcel Riesz to study and received his degree in 1950, the filosofi magister (equivalent to Master ). He then continued to occupy himself with mathematics, especially with partial differential equations , did his military service in 1953/54 and received his doctorate from Marcel Riesz in 1955 - who, however, already retired in 1952 and then went to the United States - and Lars Gårding ( On the theory of general partial differential equations ). This was followed by stays in the United States ( University of Chicago , University of Kansas , University of Michigan ), where he met Richard Courant at the Courant Institute in New York City , which at the time was one of the centers for research into partial differential equations. In 1957 Lars Hörmander received a professorship at Stockholm University , but continued to travel extensively to the United States, especially to Stanford and Princeton, New Jersey to the Institute for Advanced Study (1960/61).

In 1962 he received the Fields Medal for his achievements in the field of linear partial differential operators at the International Congress of Mathematicians in Stockholm. While previously satisfactory solution theories could be established for special operators of this kind (especially those that are important in mathematical physics), Hörmander proved in-depth theories for general linear partial differential operators. One example is Hörmander's theorem, according to which singularities in partial differential equations only propagate along characteristics . Hörmander is also one of the co-founders of the theory of pseudo differential operators , a generalization of partial differential equations.

After initially planning to split his teaching activities between Stockholm and Stanford, he received an offer to become a permanent member of the Institute for Advanced Study at Princeton, where he stayed from 1964 to 1968. He then accepted a professorship at Lund University , but taught regularly in the USA, especially at Stanford and at the Institute for Advanced Study (for example in 1977/78). Between 1979 and 1984 he wrote The analysis of linear partial differential operators , a work in four volumes that comprehensively presents the theory of linear differential operators. From 1984 to 1986 he was director of the Mittag-Leffler Institute , which he did not extend because the associated administrative tasks were bothersome to him. In 1996 he retired in Lund.

In 1970 he gave a plenary lecture at the ICM in Nice ( Linear Differential Operators ), and in 1962 he was invited speaker at the ICM in Stockholm ( Existence, uniqueness and regularity of solutions of linear differential equations ).

Honors

In 1967 Hörmander was elected to the American Academy of Arts and Sciences , and in 1976 to the National Academy of Sciences . In 1988 he received the Wolf Prize and in 2006 he was honored with the Leroy P. Steele Prize of the American Mathematical Society (AMS). He was a Fellow of the AMS and a member of the Royal Danish Academy of Sciences , the Royal Physiographical Society in Lund and the Royal Swedish Academy of Sciences .

Fonts

  • Linear Partial Differential Operators. Springer-Verlag, 1963.
  • The Analysis of Linear Partial Differential Operators I: Distribution Theory and Fourier Analysis. Springer-Verlag, 2nd edition 1990.
  • The Analysis of Linear Partial Differential Operators II: Differential Operators with Constant Coefficients. Springer publishing house.
  • The Analysis of Linear Partial Differential Operators III: Pseudo-Differential Operators. Springer-Verlag 1985.
  • The Analysis of Linear Partial Differential Operators IV: Fourier Integral Operators. Springer-Verlag 1985.
  • An Introduction to Complex Analysis in Several Variables. 1966, 3rd edition, North Holland 1990.
  • Notions of Convexity. Birkhäuser Verlag, 1994, ISBN 0-8176-3799-0 .
  • Lectures on nonlinear hyperbolic differential equations. Springer 1997.

Web links

Individual evidence

  1. ^ Mathematics Genealogy Project
  2. ↑ Book of Members 1780 – present, Chapter H. (PDF; 1.2 MB) In: American Academy of Arts and Sciences (amacad.org). Accessed March 28, 2018 (English).
  3. ↑ royalacademy.dk
  4. ↑ Hörmander, Lars . In: Sten Lagerström, Elvan Sölvén (ed.): Vem är det. Svensk biografisk handbok 1969 . 29th year PA Norstedt & Söners Förlag, 1968, ISSN  0347-3341 , p. 448 (Swedish, runeberg.org ).
personal data
SURNAME Hörmander, Lars
ALTERNATIVE NAMES Hörmander, Lars Valter (full name)
BRIEF DESCRIPTION Swedish mathematician and Fields Medalist
DATE OF BIRTH January 24, 1931
PLACE OF BIRTH Mjällby , Solvesborg , Sweden
DATE OF DEATH November 25, 2012
Place of death Lund , Sweden