On the interactions of Skyrmions with domain walls

TL;DR

This paper investigates the interactions between Skyrmions and domain walls in a modified Skyrme model, revealing attractive forces, bound states, and potential implications for baryogenesis and the universe's matter-antimatter asymmetry.

Contribution

It demonstrates the existence of attractive interactions, bound states, and wave emissions between Skyrmions and domain walls, providing new insights into their dynamics and potential cosmological relevance.

Findings

Skyrmions are attracted to and captured by domain walls.

Bound states of Skyrmions and walls exist under certain mass terms.

Captured Skyrmions can transform into topological waves spreading on the wall.

Abstract

We study classical solutions of a particular version of the modified Skyrme model in (3+1) dimensions. The model possesses Skyrmion solutions as well as stable domain walls that connect different vacua of the theory. We show that there is an attractive interaction between Skyrmions and domain walls. Thus Skyrmions can be captured by the domain walls. We show also that, when the mass term is of a special type, the model possesses bound states of Skyrmions and of the domain wall. They look like deformed 2-dimensional Skyrmions captured by the wall. The field configurations of these solutions can interpreted as having come from the evolution of the 3-dimensional Skyrmions captured by the domain wall. For more conventional choices of the mass term of the model in the model the attraction between the Skyrmions and the wall leads to the capture of the Skyrmions which are then turned into topological waves which spread out on the wall. We have observed, numerically, such captures and the emission of the waves. We speculate that this observation may be useful in the explanation of the problem of baryogenesis and baryon-antibaryon asymmetry of the Universe.