Institution: | (1) Max-Planck-Institut für Mathematik, Inselstrasse 22–26, D-04103 Leipzig, Germany (e-mail: alberti@mis.mpg.de) , DE;(2) Dipartimento di Matematica Applicata “U. Dini”, via Bonanno 25/B, I-56126 Pisa, Italy (e-mail: belletti@dm.unipi.it) , IT |