Thomas Alazard is a senior researcher at CNRS. For several years, he has taught partial differential equations, microlocal analysis and functional analysis at the Ecole Normale Supérieure and the Ecole Normale Supérieure Paris-Saclay. His research focuses on the applications of harmonic analysis and microlocal analysis to the study of nonlinear partial differential equations. Claude Zuily received his PhD from Université Paris-Sud (Orsay), where he was professor of mathematics until 2010. Currently emeritus professor at Université Paris-Saclay, he is the author of several books: Uniqueness and non uniqueness in the Cauchy problem (Birkhäuser 1983), Problèmes de distributions et d'équations aux dérivées partielles (Hermann 1995 and Cassini 2010), Analyse pour l'agrégation (with H. Queffélec) (Dunod 1995), Distributions et équations aux dérivées partielles (Dunod 2002). His primary areas of research are linear and nonlinear partial differential equations.