  A ferromagnetic spin-1 condensate supports polar-core spin vortices (PCVs) in
the easy-plane phase. We derive a model for the dynamics of these PCVs using a
variational Lagrangian approach. The PCVs behave as massive charged particles
interacting under the two dimensional Coulomb interaction, with the mass
arising from interaction effects within the vortex core. We compare this model
to numerical simulations of the spin-1 Gross-Pitaevskii equations and find
semi-quantitative agreement. In addition, the numerical results suggest that
the PCV core couples to spin waves, and this affects the PCV dynamics even far
from the core. We identify areas of further research that could extend the
model of PCV dynamics presented here.
