Institution: | 1. University of Appl. Sciences, 40474 Düsseldorf, Germany;2. Inst. Physics, Carl-von-Ossietzky-Univ., 26111 Oldenburg, Germany;3. Inst. Mathematics, Hebrew University of Jerusalem, Israel;4. Jerusalem College of Technology, Israel;5. Inst. Theor. Physics, University of Cologne, 50923 Köln, Germany;6. Department of Physics & Astron., University of Missouri, Columbia, MO 65211, USA |