Affiliation: | 1. Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John’s, NL, A1C 5S7, Canada;2. Department of Mathematics and Statistics, Acadia University, Wolfville, NS, B4P 2R6, Canada;3. Department of Physics and Astronomy, University of British Columbia, Vancouver BC, V6T 1Z1, Canada;4. Department of Physics, Acadia University, Wolfville, NS, B4P 2R6, Canada |