Localization of massive fermions on the baby-Skyrmion branes in 6 dimensions

Abstract

We construct brane solutions in 6-dimensional Einstein-Skyrme systems. A class of baby skyrmion solutions realizes warped compactification of the extra dimensions and gravity localization on the brane for negative bulk cosmological constant. Coupling of the fermions with the brane skyrmions lead to the brane localized fermions. In terms of the level crossing picture, emergence of the massive localized modes are observed. Nonlinear nature of the skyrmions brings richer information for the fermions level structure. It comprises doubly degenerate lowest plus single excited modes. The three generation of the fundamental fermions is associated with this distinctive structure. The mass hierarchy of quarks or leptons is appeared in terms of a slightly deformed baby-skyrmions with topological charge three.

Topological energy bounds in generalized Skyrme models

“…The baby Skyrme model in d = 2 space dimensions [46] - [49] has been studied quite intensely, both as a toy model for the full Skyrme model and because it has some independent applications, mainly in condensed matter physics (see,e.g., [50], [51]). The investigation of Skyrme models in higher dimensions has not been developed thus far until now, although they, too, may be of some interest, e.g., in the context of brane cosmology [52] - [54]. The central idea of brane cosmology is that our 3 + 1 dimensional universe is a topological defect within a higher-dimensional bulk universe [55], [56].…”

Extended supersymmetry and BPS solutions in baby Skyrme models

“…First of all, our BPS equations hold completely generally for any N = 2 supersymmetric field theory of (gauged or ungauged) chiral superfields, so it can obviously be used to find BPS equations for other models. Baby Skyrmions as such have found some applications in brane cosmology [34][35][36], so their supersymmetric extensions may be of interest in this context. Another interesting issue is related to generalizations to higher dimensions.…”

“…The baby Skyrme model was introduced originally as a planar analogue of the three dimensional Skyrme model [18]- [31], although it has found its own applications, e.g., in condensed matter physics [32,33] or in brane cosmology [34][35][36]. Its target space is simplified accordingly, as well (S 2 instead of the SU(2) target space of the Skyrme model), such that static field configurations again can be classified by a winding number.…”

Bulk matter fields on two-field thick branes

“…It has been proved that in order to have normalizable zero modes the fermion fields should couple with the background scalars. With different scalar-fermion coupling, there may exist a single bound state and a continuous gapless spectrum of massive fermion KK states [17,[39][40][41][42], or exist finite discrete KK states (mass gap) and a continuous gapless spectrum starting at a positive m 2 [32,[43][44][45], or even only exist bound KK modes [46,47]. While in this paper, we will show that with one scalar-fermion coupling to both background scalars, there will exist the above three cases with different relation between the unique parameter b and the dilaton-fermion coupling constant.…”