Quasi-normal modes of Schwarzschild-de Sitter black holes

The low-lying frequencies of characteristic quasi-normal modes (QNMs) of Schwarzschild-de Sitter (SdS) black holes have been calculated for fields of different spin using the sixth-order WKB approximation and the approximation by the Poeschl-Teller potential. The well-known asymptotic formula for large l is generalized here in a case of the SdS black hole. In the limit of the near extreme Λ term the results given by both methods are in very good agreement, and in this limit fields of different spin decay with the same rate