Jean-Christophe Yoccoz

Jean-Christophe Yoccoz (May 29, 1957 – September 3, 2016) was a French mathematician. He was awarded a Fields Medal in 1994, for his work on dynamical systems.[1][2]

Jean-Christophe Yoccoz
Jean-Christophe Yoccoz.jpg
Jean-Christophe Yoccoz
Born(1957-05-29)May 29, 1957
Paris, France
DiedSeptember 3, 2016(2016-09-03) (aged 59)
Alma materÉcole Normale Supérieure
École Polytechnique
Known forDynamical systems
Yoccoz puzzle
AwardsSalem Prize (1988)
Fields Medal (1994)
Scientific career
InstitutionsCentre de mathématiques Laurent-Schwartz
Paris-Sud 11 University
Collège de France
Doctoral advisorMichael Herman
Doctoral studentsSylvain Crovisier [de]
Ricardo Pérez-Marco


Yoccoz attended the Lycée Louis-le-Grand,[3] during which time he was a silver medalist at the 1973 International Mathematical Olympiad and a gold medalist in 1974.[4][5] He entered the École Normale Supérieure in 1975, and completed an agrégation in mathematics in 1977.[6] After completing military service in Brazil, he completed his Ph.D. under Michael Herman in 1985 at Centre de mathématiques Laurent-Schwartz, which is a research unit jointly operated by the French National Center for Scientific Research (CNRS) and Ecole polytechnique.[6][7][8] He took up a position at the University of Paris-Sud in 1987, and became a professor at the Collège de France in 1997, where he remained until his death.[2] He was a member of Bourbaki.[9]

Yoccoz won the Salem Prize in 1988. He was an invited speaker at the International Congress of Mathematicians in 1990 at Kyoto,[10] and was awarded the Fields Medal at the International Congress of Mathematicians in 1994 in Zürich.[11][10] He joined the French Academy of Sciences and Brazilian Academy of Sciences in 1994, became a chevalier in the French Legion of Honor in 1995, and was awarded the Grand Cross of the Brazilian National Order of Scientific Merit in 1998.[5]

Mathematical workEdit

Yoccoz's worked on the theory of dynamical systems, his contributions include advances to KAM theory, and the introduction of the method of Yoccoz puzzles, a combinatorial technique which proved useful to the study of Julia sets.[5]

Notable publicationsEdit

  • Yoccoz, J.-C. Conjugaison différentiable des difféomorphismes du cercle dont le nombre de rotation vérifie une condition diophantienne. Ann. Sci. École Norm. Sup. (4) 17 (1984), no. 3, 333–359. doi:10.24033/asens.1475
  • Yoccoz, Jean-Christophe. Théorème de Siegel, nombres de Bruno et polynômes quadratiques. Petits diviseurs en dimension 1. Astérisque No. 231 (1995), 3–88. MR1367353