Is the force between solitons with same charge always repulsive?

Question

I know the one-dimensional case in which the force is proportional to $e^{-R}$ and the force is attractive for solitons with opposite charge and repulsive for solitons with same charge. I was calculating in an approximated model in 3+1 dimensions the force between solitons and I obtain repulsive for different charge and attractive for same charge. This result seems strange. Is there some law or theorem that doesnt allow this? Do you know any model where this happens?

Answer 1

Skyrme model leads to an attractive interaction for two several separated solitons of topological charge Q=1. See Manton, topological solitons, section 9.8.