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

Canadian Canadians (french: Canadiens) 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 ...

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

Orsay Orsay () is a commune in the Essonne department in Île-de-France in northern France. It is located in the southwestern suburbs of Paris, France, from the centre of Paris. A fortified location of the Chevreuse valley since the 8th century a ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...

. 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 (french: link=no, Centre national de la recherche scientifique, CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 ...

in 1976. He is a

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

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) \i ...

Education

Siebenmann's undergraduate studies were at the

University of Toronto The University of Toronto (UToronto or U of T) is a public research university in Toronto, Ontario, Canada, located on the grounds that surround Queen's Park. It was founded by royal charter in 1827 as King's College, the first institu ...

. He received a

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

from

Princeton University Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the n ...

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 Un ...

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 Francis Bonahon (9 September 1955, Tarbes) is a French mathematician, specializing in low-dimensional topology. Biography Bonahon received in 1972 his ''baccalauréat'', and was accepted in 1974 into the École Normale Supérieure. He received ...

and

Albert Fathi Albert Fathi (born 27 October 1951, in Egypt) is an Egyptian-French mathematician. He specializes in dynamical systems and is currently a professor at the Georgia Institute of Technology. Fathi attended the ''Collège des frères Lasalle'' in C ...

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 presen ...

by the

Canadian Mathematical Society The Canadian Mathematical Society (CMS) (french: Société mathématique du Canada) is an association of professional mathematicians dedicated to the interests of mathematical research, outreach, scholarship and education in Canada. It serves the ...

. 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