Emmanuel Breuillard is a Professor at the Laboratoire de Mathématiques, Université Paris-Sud Orsay. He was recently awarded an EMS Prize by the European Mathematical Society for his work in group theory. Hee Oh is a Professor of Mathematics at Brown University. She is an inaugural Fellow of the American Mathematical Society and has given a joint AMS-MAA invited address at the 2012 Joint Mathematics meetings and an invited lecture at the International Congress of Mathematicians in 2010.