On the brane coupling of Unified orbifolds with gauge interactions in the bulk

TL;DR

This paper extends supergravity models in five dimensions with brane interactions, allowing gauge fields to propagate in the bulk and simplifying the formulation by using on-shell methods, which aids in constructing unified extra-dimensional theories.

Contribution

It introduces a novel on-shell approach for bulk-brane interactions in 5D supergravity with gauge fields propagating in the bulk, simplifying previous off-shell complexities.

Findings

Propagation of gravity and gauge fields in the bulk is feasible.

The on-shell formulation simplifies the interaction analysis.

The approach accommodates nontrivial superpotential interactions.

Abstract

In the on-shell formulation of $D=5 $, N=2 supergravity, compactified on $S^1/Z_2$, we extend the results of Mirabelli and Peskin describing the interaction of the bulk fields with matter which is assumed to be confined on the brane. The novel characteristics of this approach are : Propagation of both gravity and gauge fields in the bulk, which offers an alternative for a unified description of models in extra dimensions and use of the on-shell formulation avoiding the complexity of off-shell schemes which involve numerous auxiliary fields. We also allow for nontrivial superpotential interactions of the chiral matter fields. The method we employ uses the N{\" o}ther procedure and our findings are useful for building models advocating propagation of the gauge degrees of freedom in the bulk, in addition to gravity.