Jean-Christophe Yoccoz

Template:Short description Template:Use dmy dates Template:Infobox scientist Template:Commons category Jean-Christophe Yoccoz (29 May 1957 – 3 September 2016) was a French mathematician. He was awarded a Fields Medal in 1994, for his work on dynamical systems.<ref>Template:MacTutor Biography</ref><ref name="death">Template:Cite web</ref>

Biography

Yoccoz attended the Lycée Louis-le-Grand,<ref>Template:Cite web</ref> during which time he was a silver medalist at the 1973 International Mathematical Olympiad and a gold medalist in 1974.<ref>Template:IMO results</ref><ref name="heidelberg">Template:Cite web</ref> He entered the École Normale Supérieure in 1975, and completed an agrégation in mathematics in 1977.<ref name="A">Template:Cite web</ref>

After completing military service in Brazil, he completed his PhD 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 École Polytechnique.<ref name="A" /><ref>Template:Cite web</ref><ref>Template:MathGenealogy</ref>

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.<ref name="death" /> He was a member of Bourbaki.<ref>Template:Citation</ref>

Yoccoz won the Salem Prize in 1988. He was an invited speaker at the International Congress of Mathematicians in 1990 at Kyoto,<ref name="B" /> and was awarded the Fields Medal at the International Congress of Mathematicians in 1994 in Zürich.<ref>Template:Cite web</ref><ref name="B">Template:Cite web</ref> 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.<ref name="heidelberg"/>

Mathematical work

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.<ref name="heidelberg" />

Notable publications

• 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. Template:Mr