Bulk Gauge Fields in the Bigravity Model

TL;DR

This paper investigates how bulk gauge fields behave in a bigravity model with two positive tension AdS_4 branes in AdS_5, revealing that the zero mode becomes massive and constraining model parameters.

Contribution

It analyzes the zero mode and Kaluza-Klein modes of bulk gauge fields in a specific bigravity setup, showing the zero mode is non-constant and acquiring mass.

Findings

Zero mode depends on the fifth dimension and is massive on the brane.

Model parameters are constrained by the requirement of a small gauge field mass.

Kaluza-Klein modes are also discussed.

Abstract

Motivated by a recently proposed "bigravity" model with two positive tension $AdS_4$ branes in $AdS_5$ by Kogan et al.[hep-th/0011141], we study behavior of bulk gauge field in the model. In this case, the zero mode of the gauge field is not constant but depends on the fifth dimensional coordinate transverse to the brane. The zero mode then becomes massive on the brane. From the physical requirement that the mass must be small, a parameter of the model is constrained. We also discuss the Kaluza-Klein modes.