Bags, junctions, and networks of BPS and non-BPS defects

TL;DR

This paper explores models with various symmetries supporting stable and unstable topological defect solutions, revealing the formation of complex networks like hexagonal arrangements of domain walls.

Contribution

It introduces models with multiple symmetries supporting both BPS and non-BPS topological defects, including stable networks of domain walls.

Findings

Non-BPS defects can form stable networks.

A specific Z_3 model produces a stable hexagonal domain wall network.

BPS solutions are inherently stable, non-BPS stability depends on parameters.

Abstract

We investigate several models of coupled scalar fields that present discrete Z_2, Z_2 x Z_2, Z_3 and other symmetries. These models support topological domain wall solutions of the BPS and non-BPS type. The BPS solutions are stable, but the stability of the non-BPS solutions may depend on the parameters that specify the models. The BPS and non-BPS states give rise to bags, and also to three-junctions that may allow the presence of networks of topological defects. In particular, we show that the non-BPS defects of a specific model that engenders the Z_3 symmetry give rise to a stable regular hexagonal network of domain walls.