2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/223493The time reversal method in thermoacoustic tomography is used for approximating the initial pressure inside a biological object using measurements of the pressure wave made on a surface surrounding the object. This article presents error estimates for the time reversal method in the cases of variable, non-trapping sound speeds.16 pages, 6 figures, expanded "Remarks and Conclusions" section, added one figure, added referencesAnalysis of PDEsBiological Physics35L05, 92C55text