Anomalous decay rate of quasinormal modes in Reissner-Nordstr\"om black holes

The anomalous decay rate of the quasinormal modes occurs when the longest-lived modes are the ones with higher angular number for small field masses and those with lower angular momentum as of a critical mass of the field. Such behaviour has been recently studied in different static spacetimes, for scalar and fermionic perturbations, being observed in both cases. In this work, we extend the existent studies to the charged spacetimes, namely, the Reissner-Nordstr\"om, the Reissner-Nordstr\"om-de Sitter and the Reissner-Nordstr\"om-Anti-de Sitter black holes. We show that the anomalous decay rate behaviour of the scalar field perturbations is present for every charged geometry in the photon sphere modes, with the existence of a critical scalar field mass whenever $\Lambda \geq 0$. We also study the dominant mode/family for massless and massive scalar field in these geometries.