Physics of warped dimensions: discrete and continuous spectra

TL;DR

This paper investigates the spectral properties of fields in two warped 5D models with branes, analyzing discrete and continuous spectra, Green's functions, and couplings to Standard Model matter.

Contribution

It compares two warped 5D models, one with discrete KK modes and another with a continuous spectrum, providing insights into their spectral and coupling properties.

Findings

First model exhibits a discrete KK spectrum.

Second model features a continuous spectrum above a mass gap.

Analyzes positivity of spectral functions and field couplings.

Abstract

Using two different warped five-dimensional (5D) models with two branes along the extra dimension, we study the Green's functions and the spectral properties of some of the fields propagating in the bulk. While the first model has a discrete spectrum of Kaluza-Klein (KK) modes, the second one has a continuous spectrum above a mass gap. We also study the positivity of the spectral functions, as well as the coupling of the graviton and the radion with SM matter fields.