Luc Illusie

Luc Illusie
Illusie in September 2014, while lecturing at the Institut des Hautes Études Scientifiques, Bures-sur-Yvette, France.
Born	1940 (age 76–77)
Nationality	French
Fields	Mathematics
Institutions	University of Paris-Sud
Doctoral advisor	Alexander Grothendieck
Doctoral students	Torsten Ekedahl Michel Gros Gérard Laumon Abdellah Mokrane
Notable awards	Émile Picard Medal (2012)

Luc Illusie (French: [ilyzi]; born 1940) is a French mathematician, specializing in algebraic geometry. His most important work concerns the theory of the cotangent complex and deformations, crystalline cohomology and the De Rham–Witt complex, and logarithmic geometry. In 2012, he was awarded the Émile Picard Medal of the French Academy of Sciences.

Luc Illusie enters the École Normale Supérieure in 1959. At first a student of the mathematician Henri Cartan, he participated in the Cartan–Schwartz seminar of 1963–1964. In 1964, following Cartan’s advice, he begins to work with Alexandre Grothendieck, collaborating with him on two volumes of the latter’s Séminaire de Géométrie Algébrique du Bois Marie. In 1970, Illusie introduces the concept of the cotangent complex.

A researcher in the Centre national de la recherche scientifique from 1964 to 1976, Illusie then becomes a professor at the University of Paris-Sud, retiring as emeritus professor in 2005. Between 1984 and 1995, he is the director of the arithmetic and algebraic geometry group in the department of mathematics of that university. Torsten Ekedahl () and Gérard Laumon are among his students.

In May 1971, Illusie defended a state doctorate ((French) Thèse d’État) entitled "Cotangent complex; application to the theory of deformations" at the University of Paris-Sud, in front of a jury composed of Alexander Grothendieck, Michel Demazure and Jean-Pierre Serre and presided by Henri Cartan.