  It has recently been shown that Skyrmions with a fixed size can exist in
theories without a Skyrme term, providing the Skyrmion is located on a domain
wall. Here we numerically compute domain wall Skyrmions of this type, in a
(2+1)-dimensional O(3) sigma model with a potential term. Moreover, we
investigate Skyrmion dynamics, to study both Skyrmion stability and the
scattering of multi-Skyrmions. We demonstrate that scattering events in which
both Skyrmions remain on the same domain wall are effectively one-dimensional,
and at low speeds are well-approximated by kink scattering in the integrable
sine-Gordon model. However, more exotic fully two-dimensional scatterings are
also presented, in which Skyrmions that are initially on different domain walls
emerge on the same domain wall.
