The Spectrum of Static Subtracted Geometries

TL;DR

This paper investigates the conformal symmetry properties of linearized gravitational and matter fluctuations on static subtracted geometries, revealing a subset of modes that exhibit conformal symmetry and highlighting differences in quasinormal mode spectra based on effective actions.

Contribution

It demonstrates that only a subsector of fluctuations on static subtracted geometries display conformal symmetry, and compares how different effective actions influence quasinormal mode spectra.

Findings

Some modes exhibit conformal symmetry

Quasinormal mode spectra vary with effective action

Not all fluctuations preserve conformal symmetry

Abstract

Subtracted geometries are black hole solutions of the four dimensional STU model with rather interesting ties to asymptotically flat black holes. A peculiar feature is that the solutions to the Klein-Gordon equation on this subtracted background can be organized according to representations of the conformal group $SO(2,2)$. We test if this behavior persists for the linearized fluctuations of gravitational and matter fields on static, electrically charged backgrounds of this kind. We find that there is a subsector of the modes that do display conformal symmetry, while some modes do not. We also discuss two different effective actions that describe these subtracted geometries and how the spectrum of quasinormal modes is dramatically different depending upon the action used.