Lars Hörmander

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

Life

Hörmanders father was a teacher in Mjallby, a small fishing village in southern Sweden. Even as a student at the high school in Lund Hörmander learned from his teacher mathematics at university level. In 1948 he began to study at the university under Marcel Riesz and received his degree in 1950, the filosofi magister ( equivalent to the Master ). He worked then continue with mathematics, especially with partial differential equations, made ​​1953/54, his military service and was founded in 1955 by Marcel Riesz - but 1952 already retired and then went to the United States - and Lars Garding doctorate ( On the theory of general partial differential equations ). He stayed 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 was one of the centers for research in partial differential equations then. 1957 Lars Hörmander received a professorship at the University of Stockholm, but continued to travel a lot in the U.S., particularly to Stanford and Princeton, New Jersey to the Institute for Advanced Study (1960 /61).

In 1962 he was awarded the Fields Medal for his achievements in the field of linear partial differential operators at the International Congress of Mathematicians in Stockholm. While ( especially those important in mathematical physics ) Operators of this type satisfactory solution theories could previously be set up for any special, Hörmander proved profound sentences for general linear partial differential operators. An example is the set of Hörmander, alleging singularities propagate in partial differential equations only along characteristics. Hörmander 's also one of the founders of the theory of pseudo - differential operators, a generalization of partial differential equations.

After he had originally intended to spread his teaching to Stockholm and Stanford, he received an offer permanent member of the Institute for Advanced Study in Princeton to become what he remained from 1964 to 1968. He then accepted a professorship at the University of Lund, but taught regularly in the U.S., particularly at Stanford and at the Institute for Advanced Study (for example, 1977/78 ). Between 1979 and 1984 he wrote The analysis of linear partial differential operators, a work in four volumes, which comprehensively represents the theory of linear differential operators. 1984 to 1986 he was director of the Mittag-Leffler Institute, but what he did not renew because it was the associated administrative tasks annoying. In 1996 he retired, Lund.

In 1988 he was awarded the Wolf Prize and in 2006 he was awarded the Leroy P. Steele Prize of the American Mathematical Society ( AMS). He was a Fellow of the AMS.

In 1970 he gave a plenary lecture at the ICM in Nice ( linear differential operator ).

Writings

• 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-Verlag
• 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