2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/129792We describe an expansion of the solution of the wave equation in the De Sitter - Schwarzschild metric in terms of resonances. The main term in the expansion is due to a zero resonance. The error term decays polynomially if we permit a logarithmic derivative loss in the angular directions and exponentially if we permit an small derivative loss in the angular directions.22 pages, 5 figuresAnalysis of PDEsMathematical Physics35B34; 35P25; 35Q75; 83C57text