Resonance spectra of caged black holes

Shahar Hod

doi:10.1140/epjc/s10052-014-3137-3

EPJ

a
b
c
d
e
ap
st
h
plus
ds
pv
ti
qt
am
n

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2014) 74: 3137
https://doi.org/10.1140/epjc/s10052-014-3137-3

Regular Article - Theoretical Physics

Resonance spectra of caged black holes

Shahar Hod¹^,2^*

¹ The Ruppin Academic Center, Emeq Hefer, 40250, Israel
² The Hadassah Institute, Jerusalem, 91010, Israel

^* e-mail: shaharhod@gmail.com

Received: 8 October 2014
Accepted: 16 October 2014
Published online: 6 November 2014

Abstract

Recent numerical studies of the coupled Einstein–Klein–Gordon system in a cavity have provided compelling evidence that confined scalar fields generically collapse to form black holes. Motivated by this intriguing discovery, we here use analytical tools in order to study the characteristic resonance spectra of the confined fields. These discrete resonant frequencies are expected to dominate the late-time dynamics of the coupled black-hole-field-cage system. We consider caged Reissner–Nordström black holes whose confining mirrors are placed in the near-horizon region $x_{\text {m}}\equiv (r_{\text {m}}-r_+)/r_+\ll \tau \equiv (r_+-r_-)/r_+$ (here $r_{\text {m}}$ is the radius of the confining mirror and $r_{\pm }$ are the radii of the black-hole horizons). We obtain a simple analytical expression for the fundamental quasinormal resonances of the coupled black-hole-field-cage system: $\omega _n=-i2\pi T_{\text {BH}} \cdot n\left[ 1+O(x^n_{\text {m}}/\tau ^n)\right]$ , where $T_{\text {BH}}$ is the temperature of the caged black hole and $$n=1,2,3,...$$ is the resonance parameter.