1. Национальный исследовательский университет "Высшая школа экономики", Москва, Россия
2. National Research University Higher School of Economics, Pokrovskii bul. 11, Moscow, 109028 Russia
3. Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany
4. Max Planck Institute for Mathematics in the Sciences, Inselstrasse 22, 04103 Leipzig, Germany
5. Независимый московский университет, Москва, Россия
6. Department of Mathematics, University of Toronto, Toronto, Canada
7. Independent University of Moscow, Bol'shoi Vlas'evskii per. 11, Moscow, 119002 Russia
8. Department of Mathematics, University of Toronto, 40 St. George St., Toronto, M5S 2E4, Canada