Affiliation: | (1) école Polytechnique, Fédérale de Lausanne, 1015 Lausanne, Switzerland;(2) Courant Institute of Mathematical Sciences, 251 Mercer Street, New York, N.Y. 10012-1185, USA;(3) Weierstrass Institute for Applied Analysis and Stochastics (WIAS), Mohrenstr. 39, 10117 Berlin, Germany;(4) Département de Mathématiques, école Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland |