Yau, Horng-Tzer2017-05-182010Yau, Horng-Tzer. "The work of Cedric Villani." 2010. In Proceedings of the International Congress of Mathematicians (ICM 2010), Hyderabad, India, August 19-27, 2010, vol. 1: 87.978-981-4324-30-4http://nrs.harvard.edu/urn-3:HUL.InstRepos:32706715The starting point of C´edric Villani’s work goes back to the introduction of entropy in the nineteenth century by L. Carnot and R. Clausius. At the time, entropy was a vague concept and its rigorous definition had to wait until the fundamental work of L. Boltzmann who introduced nonequilibrium statistical physics and the famous H functional. Boltzmann’s work, though a fundamental breakthrough, did not resolve the question concerning the nature of entropy and time arrow; the debate on this central question continued for a century until today. J. von Neumann, in recommending C. Shannon to use entropy for his uncertainty function, quipped that entropy is a good name because “nobody knows what entropy really is, so in a debate you will always have the advantage”en-USConference Paper2017-05-1810.1142/9789814324359_0004