Unified spectral approach for quasinormal modes of Lee-Wick black holes

In this paper, we undertake a comprehensive examination of quasinormal modes linked to Lee-Wick black holes, delving into scalar, electromagnetic, and gravitational perturbations using the spectral method. Such black holes can display a rich structure of horizons, and our analysis considers all the representative scenarios, including extremal and nonextremal situations. In particular, we show that purely imaginary quasinormal modes emerge for extremal and near-extremal configurations, suggesting a rapid return to equilibrium without oscillation.