Massless bosons on domain walls: Jackiw-Rebbi-like mechanism for bosonic fields

AbstraktAbstract

It is important to obtain (nearly) massless localized modes for the low-energy four-dimensional effective field theory in the brane-world scenario. We propose a mechanism for bosonic zero modes using the field-dependent kinetic function in the classical field theory setup. As a particularly simple case, we consider a domain wall in five dimensions and show that massless states for scalar (0-form), vector (1-form), and tensor (2-form) fields appear on a domain wall, which may be called topological because of the robustness of their existence (insensitive to continuous deformations of parameters). The spin of localized massless bosons is selected by the shape of the nonlinear kinetic function, analogously to the chirality selection of the fermion by the well-known Jackiw-Rebbi mechanism. Several explicitly solvable examples are given. We consider not only (anti) Bogomol’nyi-Prasad-Sommerfield (BPS) domain walls in a noncompact extra dimension but also non-BPS domain walls in a compact extra dimension.

It is important to obtain (nearly) massless localized modes for the low-energy four-dimensional effective field theory in the brane-world scenario. We propose a mechanism for bosonic zero modes using the field-dependent kinetic function in the classical field theory setup. As a particularly simple case, we consider a domain wall in five dimensions and show that massless states for scalar (0-form), vector (1-form), and tensor (2-form) fields appear on a domain wall, which may be called topological because of the robustness of their existence (insensitive to continuous deformations of parameters). The spin of localized massless bosons is selected by the shape of the nonlinear kinetic function, analogously to the chirality selection of the fermion by the well-known Jackiw-Rebbi mechanism. Several explicitly solvable examples are given. We consider not only (anti) Bogomol’nyi-Prasad-Sommerfield (BPS) domain walls in a noncompact extra dimension but also non-BPS domain walls in a compact extra dimension.