3 papers
gr-qc2026
Sensitivity of black hole spectral instability to ultraviolet perturbations
Ramin G. Daghigh, Michael D. Green, Guan-Ru Li +3
Black hole quasinormal modes are known to exhibit spectral instability under ultraviolet perturbations of the effective potential. In the present work, we investigate the sensitivi…
gr-qc2025
Evolution of black hole echo modes and the causality dilemma
Ramin G. Daghigh, Guan-Ru Li, Wei-Liang Qian +1
It has been shown that black hole quasinormal modes are subject to spectral instability, typically triggered by metric perturbations. These perturbations, which can introduce a min…
gr-qc2024
On the universality of instability in the fundamental quasinormal modes of black holes
Wei-Liang Qian, Guan-Ru Li, Ramin G. Daghigh +2
We elaborate on a criterion for the emergence of instability in the fundamental mode recently observed by Cheung {\it et al.}, as a universal phenomenon in the context of black hol…