André Haefliger
Encyclopedia
André Haefliger is a Swiss mathematician
who works primarily on topology
.
He studied mathematics in Lausanne
. He received his PhD in 1958 from the University of Strasbourg
under the supervision of Charles Ehresmann
with "Structures feuilletées et cohomologie à valeurs dans un faisceau de groupoides".
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
.
Haefliger made important contributions to topology
, for example, in knot theory
and the theory of foliation
s, where he introduced Haefliger structure
s. In 1956, he also found the topological obstruction to the existence of a spin structure
on an orientable Riemannian manifold
.
In 1974-75, he was President of the Swiss Mathematical Society
.
He is an honorary doctor of ETH Zurich (1992).
His students include Vaughan Jones
.
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
who works primarily on topology
Topology
Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...
.
He studied mathematics in Lausanne
Lausanne
Lausanne is a city in Romandy, the French-speaking part of Switzerland, and is the capital of the canton of Vaud. The seat of the district of Lausanne, the city is situated on the shores of Lake Geneva . It faces the French town of Évian-les-Bains, with the Jura mountains to its north-west...
. He received his PhD in 1958 from the University of Strasbourg
University of Strasbourg
The University of Strasbourg in Strasbourg, Alsace, France, is the largest university in France, with about 43,000 students and over 4,000 researchers....
under the supervision of Charles Ehresmann
Charles Ehresmann
Charles Ehresmann was a French mathematician who worked on differential topology and category theory. He is known for work on the topology of Lie groups, the jet concept , and his seminar on category theory.He attended the École Normale Supérieure in Paris before performing one year of military...
with "Structures feuilletées et cohomologie à valeurs dans un faisceau de groupoides".
From 1959 to 1961 he worked at the Institute for Advanced Study
Institute for Advanced Study
The Institute for Advanced Study, located in Princeton, New Jersey, United States, is an independent postgraduate center for theoretical research and intellectual inquiry. It was founded in 1930 by Abraham Flexner...
in Princeton, New Jersey
Princeton, New Jersey
Princeton is a community located in Mercer County, New Jersey, United States. It is best known as the location of Princeton University, which has been sited in the community since 1756...
.
Since 1962 he has been a full professor at the University of Geneva
University of Geneva
The University of Geneva is a public research university located in Geneva, Switzerland.It was founded in 1559 by John Calvin, as a theological seminary and law school. It remained focused on theology until the 17th century, when it became a center for Enlightenment scholarship. In 1873, it...
.
Haefliger made important contributions to topology
Topology
Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...
, for example, in knot theory
Knot theory
In topology, knot theory is the study of mathematical knots. While inspired by knots which appear in daily life in shoelaces and rope, a mathematician's knot differs in that the ends are joined together so that it cannot be undone. In precise mathematical language, a knot is an embedding of a...
and the theory of foliation
Foliation
In mathematics, a foliation is a geometric device used to study manifolds, consisting of an integrable subbundle of the tangent bundle. A foliation looks locally like a decomposition of the manifold as a union of parallel submanifolds of smaller dimension....
s, where he introduced Haefliger structure
Haefliger structure
In mathematics, a Haefliger structure on a topological space is a generalization of a foliation of a manifold, introduced by . Any foliation on a manifold induces a Haefliger structure, which uniquely determines the foliation.-Definition:...
s. In 1956, he also found the topological obstruction to the existence of a spin structure
Spin structure
In differential geometry, a spin structure on an orientable Riemannian manifold \,allows one to define associated spinor bundles, giving rise to the notion of a spinor in differential geometry....
on an orientable Riemannian manifold
Riemannian manifold
In Riemannian geometry and the differential geometry of surfaces, a Riemannian manifold or Riemannian space is a real differentiable manifold M in which each tangent space is equipped with an inner product g, a Riemannian metric, which varies smoothly from point to point...
.
In 1974-75, he was President of the Swiss Mathematical Society
Swiss Mathematical Society
The Swiss Mathematical Society , founded in Basel on September 4, 1910, is the national mathematical society of Switzerland and a member society of the European Mathematical Society. Although now published by the European Mathematical Society, Commentarii Mathematici Helvetici began in 1929 with...
.
He is an honorary doctor of ETH Zurich (1992).
His students include Vaughan Jones
Vaughan Jones
Sir Vaughan Frederick Randal Jones, KNZM, FRS, FRSNZ is a New Zealand mathematician, known for his work on von Neumann algebras, knot polynomials and conformal field theory. He was awarded a Fields Medal in 1990, and famously wore a New Zealand rugby jersey when he accepted the prize...
.
External links
- André Haefliger auf der Website der Universität Genf