Pseudospectrum and black hole quasi-normal mode (in)stability

Understand

We study the stability of quasinormal modes (QNM) in asymptotically flat black hole spacetimes by means of a pseudospectrum analysis.

• The construction of the Schwarzschild QNM pseudospectrum reveals the following: (i) the stability of the slowest-decaying QNM under perturbations respecting the asymptotic structure, reassessing the instability of the fundamental QNM discussed by Nollert [H.
• P.
• Nollert, About the Significance of Quasinormal Modes of Black Holes, Phys.