Kinks in cuscuton-like models with two scalar fields

TL;DR

This paper investigates how the inclusion of a cuscuton term in two-scalar-field models affects localized structures, enabling control over their profiles and internal energy density structures in relativistic systems.

Contribution

It introduces a cuscuton term into two-field models, demonstrating a first-order framework that allows manipulation of topological solution profiles and internal structures.

Findings

Cuscuton term modifies the slope and internal structure of solutions.

First-order framework enables energy calculation without explicit solutions.

Enhanced control over localized structure profiles.

Abstract

This work deals with the presence of localized structures in relativistic systems described by two real scalar fields in two-dimensional spacetime. We consider the usual two-field model with the inclusion of the cuscuton term, which couples the fields regardless the potential. First we follow the steps of previous work to show that the system supports a first-order framework, allowing us to obtain the energy of solutions without knowing their explicit form. The cuscuton term brings versatility into the first-order equations, which gives rise to interesting modifications in the profiles of topological configurations, such as the smooth control over their slope and the internal structure of the energy density.