2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/105752After explaining the physical origin of the quasinormal modes of perturbations in the background geometry of a black hole, I critically review the recent proposal for the quantization of the black-hole area based on the real part of quasinormal modes. As instantons due to the barriers of black-hole potentials lie at the root of a discrete set of complex quasinormal modes frequencies, it is likely that the physics of quasinormal modes can be learned from quantum theory. I propose a connection of a system of quasinormal modes of black holes with a dissipative open system, in particular, the Feshbach-Tikochinsky oscillator. This argument is supported in part by the fact that these two systems have the same group structure SU(1,1) and the same group representation of Hamiltonians; thereby, their quantum states exhibit the same behavior.RevTex 9 pages, one figure; Talks at Black Hole V, Canada, 2005 and 9th Italian-Korean Symposium, Korea, 2005; note and references added in proofGeneral Relativity and Quantum CosmologyAstrophysicsHigh Energy Physics - Theorytext