TY - JOUR

T1 - Pseudospectrum of horizonless compact objects

T2 - A bootstrap instability mechanism

AU - Boyanov, Valentin

AU - Destounis, Kyriakos

AU - Macedo, Rodrigo Panosso

AU - Cardoso, Vitor

AU - Jaramillo, Jose Luis

PY - 2023/3/15

Y1 - 2023/3/15

N2 - Recent investigations of the pseudospectrum in black hole spacetimes have shown that quasinormal mode frequencies suffer from spectral instabilities. This phenomenon may severely affect gravitationalwave spectroscopy and limit precision tests of general relativity. We extend the pseudospectrum analysis to horizonless exotic compact objects that possess a reflective surface arbitrarily close to the Schwarzschild radius and find that their quasinormal modes also suffer from an overall spectral instability. Even though all the modes themselves decay monotonically, the pseudospectrum contours of equal resonance magnitude around the fundamental mode and the lowest overtones can cross the real axis into the unstable regime of the complex plane, unveiling the existence of nonmodal pseudoresonances. A pseudospectrum analysis further predicts that fluctuations to the system may destabilize the object when next to leading-order effects are considered, as the triggering of pseudoresonant growth can break the order expansion of black hole perturbation theory.

AB - Recent investigations of the pseudospectrum in black hole spacetimes have shown that quasinormal mode frequencies suffer from spectral instabilities. This phenomenon may severely affect gravitationalwave spectroscopy and limit precision tests of general relativity. We extend the pseudospectrum analysis to horizonless exotic compact objects that possess a reflective surface arbitrarily close to the Schwarzschild radius and find that their quasinormal modes also suffer from an overall spectral instability. Even though all the modes themselves decay monotonically, the pseudospectrum contours of equal resonance magnitude around the fundamental mode and the lowest overtones can cross the real axis into the unstable regime of the complex plane, unveiling the existence of nonmodal pseudoresonances. A pseudospectrum analysis further predicts that fluctuations to the system may destabilize the object when next to leading-order effects are considered, as the triggering of pseudoresonant growth can break the order expansion of black hole perturbation theory.

KW - BLACK-HOLES

KW - STABILITY

KW - COLLAPSE

KW - MODES

U2 - 10.1103/PhysRevD.107.064012

DO - 10.1103/PhysRevD.107.064012

M3 - Journal article

VL - 107

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 6

M1 - 064012

ER -