Gravity seminar - Daniel Arean Seminar

Abstract: Quasinormal modes (QNMs) of black holes in asymptotically Anti-de Sitter (AdS) geometries are key objects in gauge/gravity duality, and thus play a crucial role in the study of quantum many-body systems. The associated quasinormal frequencies are eigenvalues of non-Hermitian operators and therefore expected to be unstable under small perturbations. We employ pseudospectrum analysis to study the instability of QNMs in AdS. All the cases studied show unstable QNMs, with the instability decreasing as the QNM gets closer to the real axis. QNMs are also unstable under local potential perturbations localized near the horizon. We will discuss the possible consequences of these results and discuss the limitations and possible next steps of this pseudospectra analysis.