1. Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012, USA
2. Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile
3. Université de Montréal, DMS, Pavillon André-Aisenstadt, 2920, chemin de la Tour Montréal (Québec), H3T 1J4