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The solvability of differential equations

Dencker, Nils LU (2010) International Congress of Mathematicians 2010, ICM 2010 3. p.1958-1984
Abstract

It was a great surprise when Hans Lewy in 1957 presented a non-vanishing complex vector field that is not locally solvable. Actually, the vector field is the tangential Cauchy-Riemann operator on the boundary of a strictly pseudoconvex domain. Hörmander proved in 1960 that almost all linear partial differential equations are not locally solvable. This also has connections with the spectral instability of non-selfadjoint semiclassical operators. Nirenberg and Treves formulated their well-known conjecture in 1970: that condition (Ψ) is necessary and sufficient for the local solvability of differential equations of principal type. Principal type essentially means simple characteristics, and condition (Ψ) only involves the sign changes of... (More)

It was a great surprise when Hans Lewy in 1957 presented a non-vanishing complex vector field that is not locally solvable. Actually, the vector field is the tangential Cauchy-Riemann operator on the boundary of a strictly pseudoconvex domain. Hörmander proved in 1960 that almost all linear partial differential equations are not locally solvable. This also has connections with the spectral instability of non-selfadjoint semiclassical operators. Nirenberg and Treves formulated their well-known conjecture in 1970: that condition (Ψ) is necessary and sufficient for the local solvability of differential equations of principal type. Principal type essentially means simple characteristics, and condition (Ψ) only involves the sign changes of the imaginary part of the highest order terms along the bicharacteristics of the real part. The Nirenberg-Treves conjecture was finally proved in 2006. We shall present the background, the main ideas of the proof and some open problems.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Principal type, Pseudodifferential operators, Pseudospectrum, Solvability, Systems of differential equations
host publication
Proceedings of the International Congress of Mathematicians 2010, ICM 2010
volume
3
pages
27 pages
publisher
Hindustan Book Agency
conference name
International Congress of Mathematicians 2010, ICM 2010
conference location
Hyderabad, India
conference dates
2010-08-19 - 2010-08-27
external identifiers
  • scopus:84877891801
ISBN
9789814324342
language
English
LU publication?
yes
id
038a6e96-e81d-4a16-84d0-b5b0cc9e12c1
date added to LUP
2019-06-24 10:45:54
date last changed
2022-12-08 14:17:49
@inproceedings{038a6e96-e81d-4a16-84d0-b5b0cc9e12c1,
  abstract     = {{<p>It was a great surprise when Hans Lewy in 1957 presented a non-vanishing complex vector field that is not locally solvable. Actually, the vector field is the tangential Cauchy-Riemann operator on the boundary of a strictly pseudoconvex domain. Hörmander proved in 1960 that almost all linear partial differential equations are not locally solvable. This also has connections with the spectral instability of non-selfadjoint semiclassical operators. Nirenberg and Treves formulated their well-known conjecture in 1970: that condition (Ψ) is necessary and sufficient for the local solvability of differential equations of principal type. Principal type essentially means simple characteristics, and condition (Ψ) only involves the sign changes of the imaginary part of the highest order terms along the bicharacteristics of the real part. The Nirenberg-Treves conjecture was finally proved in 2006. We shall present the background, the main ideas of the proof and some open problems.</p>}},
  author       = {{Dencker, Nils}},
  booktitle    = {{Proceedings of the International Congress of Mathematicians 2010, ICM 2010}},
  isbn         = {{9789814324342}},
  keywords     = {{Principal type; Pseudodifferential operators; Pseudospectrum; Solvability; Systems of differential equations}},
  language     = {{eng}},
  month        = {{12}},
  pages        = {{1958--1984}},
  publisher    = {{Hindustan Book Agency}},
  title        = {{The solvability of differential equations}},
  volume       = {{3}},
  year         = {{2010}},
}