Quasinormal modes of a massless charged scalar field on a small Reissner-Nordstroem-anti-de Sitter black hole

We investigate quasinormal modes of a massless charged scalar field on a small Reissner-Nordstroem-anti-de Sitter (RN-AdS) black hole both with analytical and numerical approaches. In the analytical approach, by using the small black hole approximation (r+<(3/eL)Qc, where Q, Qc, and e are the charge of the black hole, the critical (maximum) charge of the black hole, and the charge of the scalar field, respectively. In the numerical approach, we calculate the quasinormal modes for the small RN-AdS black holes with r+< or approx. 0.8Qc, 0.78Qc, and 0.76Qc, respectively.