Near Extremal Schwarzschild-de Sitter Black Hole Area Spectrum from Quasi-normal Modes

Using the quasi-normal modes frequency of near extremal Schwarzschild-de Sitter black holes, we obtain area and entropy spectrum for black hole horizon. By using Boher-Sommerfeld quantization for an adiabatic invariant I = ∫ dE ω(E) , which E is the energy of system and ω(E) is vibrational frequency, we leads to an equally spaced mass spectrum. In the other term we extend directly the Kunstatter’s approach [7] to determine mass and entropy spectrum of near extremal Schwarzschildde Sitter black holes which is asymptotically de Sitter rather than asymptotically flat. ∗E-mail: [email protected]