Affiliation: | (1) Harvard University, Math. Department, Cambridge, MA 02138, USA, e-mail: kazhdan@math.harvard.edu , US;(2) Pennsylvania State University, Math. Department, University Park, PA 16802, USA, e-mail: nistor@math.psu.edu, US;(3) WWU Münster, Math. Institut, Einsteinstr. 62, D-48149 Münster, Germany, e-mail: pschnei@math.uni-muenster.de, DE |