Laurent Carl Siebenmann (the first name is sometimes spelled Laurence or Larry) (born 1939) is a

Canadian Canadians () are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of their being ''C ...

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

based at the

Université de Paris-Sud Paris-Sud University (), also known as the University of Paris — XI (or as the Orsay Faculty of Sciences, University of Paris before 1971), was a French research university distributed among several campuses in the southern suburbs of Paris, ...

Orsay Orsay () is a Communes of France, commune in the Essonne Departments of France, department in Île-de-France in northern France. It is located in the southwestern suburbs of Paris, France, from the Kilometre Zero, centre of Paris. A fortifie ...

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

. After working for several years as a Professor at Orsay he became a Directeur de Recherches at the

Centre national de la recherche scientifique The French National Centre for Scientific Research (, , CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 staff, including 11,137 tenured researchers, 13,415 eng ...

in 1976. He is a

topologist Topology (from the Greek words , and ) is the branch of mathematics concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without ...

who works on manifolds and who co-discovered the

Kirby–Siebenmann class In mathematics, more specifically in geometric topology, the Kirby–Siebenmann class is an obstruction for topological manifolds to allow a ''PL''-structure. The KS-class For a topological manifold ''M'', the Kirby–Siebenmann class \kappa(M) \in ...

Education

Siebenmann's undergraduate studies were at the

University of Toronto The University of Toronto (UToronto or U of T) is a public university, public research university whose main campus is located on the grounds that surround Queen's Park (Toronto), Queen's Park in Toronto, Ontario, Canada. It was founded by ...

. He received a

Ph.D. A Doctor of Philosophy (PhD, DPhil; or ) is a terminal degree that usually denotes the highest level of academic achievement in a given discipline and is awarded following a course of graduate study and original research. The name of the deg ...

from

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

under the supervision of

John Milnor John Willard Milnor (born February 20, 1931) is an American mathematician known for his work in differential topology, algebraic K-theory and low-dimensional holomorphic dynamical systems. Milnor is a distinguished professor at Stony Brook Uni ...

in 1965 with the dissertation ''The obstruction to finding a boundary for an open manifold of dimension greater than five''. His doctoral students at Orsay included Francis Bonahon and Albert Fathi.

Recognition

In 1985 he was awarded the

Jeffery–Williams Prize The Jeffery–Williams Prize is a mathematics award presented annually by the Canadian Mathematical Society. The award is presented to individuals in recognition of outstanding contributions to mathematical research. The first award was present ...

by the

Canadian Mathematical Society The Canadian Mathematical Society (CMS; French: ''Société mathématique du Canada'') is an association of professional mathematicians dedicated to advancing mathematical research, outreach, scholarship and education in Canada. The Society se ...

. In 2012 he became a fellow of the

American Mathematical Society The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings, ...

.List of Fellows of the American Mathematical Society
retrieved 2013-07-20.

Selected publications

References

External links

a talk by Siebenmann * ttp://owpdb.mfo.de/person_detail?id=3837 Photos at Oberwolfachbr>Home page
* {{DEFAULTSORT:Siebenmann, Laurent C. 1939 births Living people Topologists Princeton University alumni University of Toronto alumni Academic staff of Paris-Sud University Fellows of the American Mathematical Society Canadian mathematicians Scientists from Toronto 20th-century French mathematicians