High Energy Field Theory in Truncated AdS Backgrounds

TL;DR

The paper investigates high-energy behavior of gauge fields in Randall-Sundrum-type warped extra dimensions, focusing on which observables admit reliable EFT descriptions. Using AdS/CFT, it computes Planck-brane vacuum polarization from bulk charged fields and shows that Planck-brane correlators exhibit universal logarithmic running above the KK scale, while zero-mode observables can fail to be EFT-friendly beyond TeV scales. It argues that, in RS scenarios with bulk gauge fields, low-energy gauge coupling evolution can resemble 4D desert running, enabling predictions for high-energy couplings and possible unification, with the Higgs confined to the TeV brane and fermions potentially in the bulk or on the TeV brane. Threshold effects and the curvature scale set the UV behavior, guiding viable model-building and UV completions within a warped extra-dimensional framework.

Abstract

In this letter we show that, in five-dimensional anti-deSitter space (AdS) truncated by boundary branes, effective field theory techniques are reliable at high energy (much higher than the scale suggested by the Kaluza-Klein mass gap), provided one computes suitable observables. We argue that in the model of Randall and Sundrum for generating the weak scale from the AdS warp factor, the high energy behavior of gauge fields can be calculated in a {\em cutoff independent manner}, provided one restricts Green's functions to external points on the Planck brane. Using the AdS/CFT correspondence, we calculate the one-loop correction to the Planck brane gauge propagator due to charged bulk fields. These effects give rise to non-universal logarithmic energy dependence for a range of scales above the Kaluza-Klein gap.