title: Noncommuting momenta of topological solitons.
abstract: We show that momentum operators of a topological soliton may not commute among themselves when the soliton is associated with the second cohomology H2 of the target space. The commutation relation is proportional to the winding number, taking a constant value within each topological sector. The noncommutativity makes it impossible to specify the momentum of a topological soliton, and induces a Magnus force.
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Haruki
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA and Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA and Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Murayama