Institution: | (1) Department of Mathematics, Rutgers University, 08903 New Brunswick, New Jersey;(2) Shirshov Institute of Oceanology of the Academy of Sciences, 117218 Moscow, USSR;(3) Département de Physique Théorique, Université de Génève, 1211 Geneva 4, Switzerland;(4) Department of Physics, Rutgers University, 08903 New Brunswick, New Jersey;(5) Dipartimento di Matematica, Università di Roma La Sapienza,, 001187 Rome, Italy;(6) Institut für Physik, Universität Mainz, D-6500 Mainz, Germany |