Quasinormal modes as probes of black hole reentrant phase transitions
Phys. Rev. D 114, 084045 – Published 15 October, 2026
DOI: https://doi.org/10.1103/fz75-ltnc
Abstract
We investigate the interplay between thermodynamic phase transitions and the dynamical behavior of quasinormal modes (QNMs) in weakly nonlinear charged anti-de Sitter black holes. In a nonextended phase space, we identify a reentrant large-small-large(intermediate) phase transition for these black holes. Employing the shooting method to solve the Klein-Gordon equation for a massless scalar field, we compute QNM frequencies across these phases, revealing distinct behaviors in different phases. Specifically, to the best of our knowledge, this is the first report of utilizing QNMs as dynamical probes of thermodynamic phases during reentrant phase transitions including zeroth and first-order transitions. These findings establish QNMs as a powerful dynamical probe for thermodynamic phase transitions, providing new insights into the thermodynamic and dynamical properties of nonlinear charged black holes as well.