Comments on the Holographic Picture of the Randall-Sundrum Model

TL;DR

This paper probes the holographic picture of the Randall-Sundrum model, arguing that its 5D braneworld corresponds to a 4D CFT with spontaneously broken conformal invariance, with the radion acting as the dilaton. The authors show that the radion couples conformally to external metrics and reinterpret the Goldberger-Wise stabilization as a near-marginal deformation of the CFT, yielding a natural hierarchy through dimensional transmutation. They further analyze how electroweak effects could stabilize the radion and discuss Natural Flavor Conservation within the RS/CFT framework, outlining testable predictions for flavor structure and KK modes. The work strengthens the AdS/CFT-based intuition for RS and provides concrete links between 5D dynamics and 4D conformal field theory data, including potential phenomenological implications such as a light radion.

Abstract

We discuss some issues about the holographic interpretation of the compact Randall-Sundrum model, which is conjectured to be dual to a 4d field theory with non-linearly realized conformal symmetry. We make several checks of this conjecture. In particular, we show that the radion couples conformally to a background 4d metric. We also discuss the interpretation of the Goldberger-Wise mechanism for stabilizing the radion. We consider situations where the electroweak breaking stabilizes the radion and we discuss the issue of natural conservation of flavor quantum numbers.