In Memoriam

Jean-Christophe Yoccoz, Fields Medallist, friend of ICTP and TWAS Fellow, died on 3 September 2016, aged 59 years old.

Yoccoz was one of the greatest experts in Dynamical Systems, with groundbreaking work and results in several areas, from the theory of circle homeomorphisms to complex dynamics on Julia sets, and from the theory of homoclinic bifurcations to the ergodic theory of Teichmuller flows. He was a professor at the prestigious Collège de France in Paris, and was awarded the most prestigious mathematical prize of all, the Fields Medal, in 1994.

Yoccoz has been a regular visitor to ICTP since 1986 within the framework of a regular series of schools and conferences on Dynamical Systems, jointly organized with IMPA in Brazil, which continue to be held with great success every 3 to 4 years. He first participated as a lecturer and, since 1995, as a course director and organizer. He fully believed and supported the mission and ideals of ICTP and was  a member of the Centre’s Scientific Council from 2004-2013, as well as a TWAS fellow since 2004.

Yoccoz’s brilliance as a mathematician was matched only by his modesty, humility, and kindness in all his human relationships. He was sociable and extremely generous with his time, happy and willing to talk to anyone and to help students, as well as young (and old) researchers, seeking advise and inspiration.

His premature departure is a great loss to all those who knew him and to mathematics in general, but he will certainly be remembered for a very long time for his mathematical accomplishments and his kind and generous personality.

--Stefano Luzzatto