1. LAGA, Institut Galilée, Université Paris 13, Université Sorbonne Paris Cité, Villetaneuse, FR
2. Institut Universitaire de France
3. School of Mathematics, Institute for Advanced Study, Princeton, NJ, USA
4. Department of Mathematics, University of Chicago, University Avenue, Chicago, IL, USA
5. Laboratoire AGM, UFR sciences et techniques, Adolphe Chauvin, Cergy-Pontoise Cedex, France