Linearized Gravity in the Karch-Randall Braneworld

TL;DR

This paper investigates linearized gravity in a Karch-Randall braneworld setup, identifying graviton modes and a radion that couples to matter, providing insights into gravity localization in curved brane models.

Contribution

It introduces a detailed analysis of graviton spectra and radion modes in the Karch-Randall braneworld, highlighting the embedding's role in radion dynamics.

Findings

Identification of massive Karch-Randall graviton and Kaluza-Klein tower

Discovery of a radion mode coupling to the energy-momentum trace

Radion arises from brane embedding in the bulk space

Abstract

We present a linearized gravity investigation of the bent braneworld, where an AdS_4 brane is embedded in AdS_5. While we focus on static spherically symmetric mass distributions on the brane, much of the analysis continues to hold for more general configurations. In addition to the identification of the massive Karch-Randall graviton and a tower of Kaluza-Klein gravitons, we find a radion mode that couples to the trace of the energy-momentum tensor on the brane. The Karch-Randall radion arises as a property of the embedding of the brane in the bulk space, even in the context of a single brane model.