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

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.Comment: Revtex, 16 pages, 6 ps figures; Shorter version to be published in Phys. Rev.

Bloch Brane

“…In Ref. [21,22,23,24] it was shown that this bound can be obtained in two-field models defined by the potential…”

“…[21] one introduces a simple model, described by two real scalar fields, which support both Ising and Bloch walls -see, e.g., Ref. [22,23,24] for further details on the two-field model, and on Ising and Bloch walls. The approach introduced in Ref.…”

Wide vector solitons in systems with time- and space-modulated nonlinearities

“…We will work with BPS solutions, because they are classically stable at least at the level of the classical field model in 1 + 1 space-time dimensions [25]. In this case it can be shown that the solutions of the BPS equations…”

Nonlinear two-field models from orbit equation deformations

“…For this class of systems, one can show that the minimum energy configurations can be obtained from the equivalent system of coupled first-order differential equations [30] …”

“…where i and i are the values of the fields at the ith vacuum state of the model [30]. Instead of applying the usual trial-orbit approach [31], we note that it is possible to write the following equation…”