Biography:André Haefliger

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Short description: Swiss mathematician (1929–2023)
André Haefliger
Born(1929-05-22)22 May 1929
Nyon, Switzerland
Died7 March 2023(2023-03-07) (aged 93)
NationalitySwiss
Alma materUniversity of Lausanne
University of Paris
Known forHaefliger structure
AwardsLeroy P. Steele Prize
Scientific career
FieldsMathematics
InstitutionsUniversity of Geneva
ThesisStructures feuilletées et cohomologie à valeurs dans un faisceau de groupoides (1958)
Doctoral advisorCharles Ehresmann
Doctoral studentsAugustin Banyaga
Vaughan Jones
Websitehttps://www.unige.ch/math/folks/haefliger/

André Haefliger (de-CH; 22 May 1929 – 7 March 2023) was a Swiss mathematician who worked primarily on topology.

Education and career

Haefliger went to school in Nyon and then attended his final years at Collège de Genève in Geneva. He studied mathematics at the University of Lausanne from 1948 to 1952. He worked for two years as a teaching assistant at École Polytechnique de l'Université de Lausanne. He then moved to University of Strasbourg, then he followed Charles Ehresmann in Paris, where he received his Ph.D. degree in 1958.[1] His thesis was entitled "Structures feuilletées et cohomologie à valeurs dans un faisceau de groupoïdes" and was written under the supervision of Charles Ehresmann.[2]

Haefliger got a research fellowship for one year at the University of Paris, where he participated in the seminar of Henri Cartan, and then from 1959 to 1961 he worked at the Institute for Advanced Study in Princeton, New Jersey. Since 1962 he has been a full professor at the University of Geneva until his retirement in 1996.[3]

In 1966 Haefliger was invited speaker at the International Congress of Mathematicians in Moscow.[4] In 1974–75, he was president of the Swiss Mathematical Society.[5]

Haefliger obtained a Doctorate honoris causa from the ETH Zurich in 1992 and from the University of Dijon in 1997. In 2020 Haefliger and Martin Bridson were awarded the American Mathematical Society's Leroy P. Steele Prize for Mathematical Exposition, for their book Metric Spaces of Non-Positive Curvature (Springer Verlag, 1999).[6]

Haefliger died on 7 March 2023, at the age of 93.[7]

Research

Haefliger's main research interests were differential topology and geometry.

Haefliger found the topological obstruction to the existence of a spin structure on an orientable Riemannian manifold.[8] In two papers in the Annals he studied various embedding of spheres in relations to knot theory.[9][10] He has also made important contributions in the theory of foliations, introducing the notion of Haefliger structures.[11]

From left to right: Beno Eckmann, Peter Hilton, Jean-Pierre Serre, and André Haefliger in Zürich in 2007

He wrote more than 80 papers in peer review journals[12] and had 20 Ph.D. students, including Augustin Banyaga and the future Field Medalist Vaughan Jones.[2]

Selected works

References

  1. ↑ Max-Albert Knus, 'André Haefliger', Historical Dictionary of Switzerland, retrieved 22 March 2023.
  2. ↑ 2.0 2.1 André Haefliger at the Mathematics Genealogy Project
  3. ↑ "Celebratio Mathematica — Haefliger — Jackson" (in en). https://celebratio.org/Haefliger_A/article/705/. 
  4. ↑ "ICM Plenary and Invited Speakers | International Mathematical Union (IMU)". https://www.mathunion.org/icm-plenary-and-invited-speakers?combine=&order=field_speakers_congress_city&sort=asc&page=83. 
  5. ↑ "Organisation » Past Presidents | The Swiss Mathematical Society". https://www.math.ch/organisation/past-presidents/. 
  6. ↑ "News from the AMS" (in en). https://www.ams.org/tools/news?news_id=5574. 
  7. ↑ "In memoriam André Haefliger". 9 March 2023. https://www.unige.ch/math/la-une/memoriam-andre-haefliger. 
  8. ↑ A. Haefliger (1956). "Sur l'extension du groupe structural d'un espace fibré". C. R. Acad. Sci. Paris 243: 558–560. 
  9. ↑ Haefliger, Andre (1962). "Knotted (4k - 1)-Spheres in 6k-Space". Annals of Mathematics 75 (3): 452–466. doi:10.2307/1970208. ISSN 0003-486X. https://www.jstor.org/stable/1970208. 
  10. ↑ Haefliger, Andre (1966). "Differentiable Embeddings of Sn in Sn+q for $q > 2$". Annals of Mathematics 83 (3): 402–436. doi:10.2307/1970475. ISSN 0003-486X. https://www.jstor.org/stable/1970475. 
  11. ↑ Haefliger, A. (1970). "Feuilletages sur les variétés ouvertes" (in en). Topology 9 (2): 183–194. doi:10.1016/0040-9383(70)90040-6. 
  12. ↑ "zbMATH Open - the first resource for mathematics". https://zbmath.org/authors/?q=ai:haefliger.andre. 

External links



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