Dilatonic Topological Defects in 3+1 Dimensions and their Embeddings

TL;DR

This paper explores how dilatonic couplings in 3+1 dimensional topological defects alter their core properties, stability, and effective charges, with detailed analysis of vortices and monopoles.

Contribution

It introduces the concept of dilatonic couplings in topological defects and analyzes their effects on defect core scale, stability, and effective charges in various models.

Findings

Dilatonic couplings modify the defect core size.

Stability properties of embedded defects are affected.

Effective gauge charge and mass become spatially dependent.

Abstract

We consider Lagrangians in 3+1 dimensions admitting topological defects where there is an additional coupling between the defect scalar field $\Phi$ and the gauge field kinetic term (eg $B(\vert \Phi \vert^2) F_{\mu \nu}F^{\mu \nu}$). Such a {\it dilatonic} coupling in the context of a static defect, induces a spatially dependent effective gauge charge and effective mass for the scalar field which leads to modified properties of the defect core. In particular, the scale of the core gets modified while the stability properties of the corresponding embedded defects are also affected. These modifications are illustrated for gauged (Nielsen-Olesen) vortices and for gauged ('t Hooft-Polyakov) monopoles. The corresponding dilatonic global defects are also studied in the presence of an external gauge field.