Laurent C. Siebenmann

Laurent Carl Siebenmann (the first name is sometimes spelled Laurence or Larry) (born 1939) is a Canadian mathematician based at the Université de Paris-Sud at Orsay, France.

After working for several years as a Professor at Orsay he became a Directeur de Recherches at the Centre national de la recherche scientifique in 1976. He is a topologist who works on manifolds and who co-discovered the Kirby–Siebenmann class.