2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/104884An integral stability estimate is proved for refraction coefficients of two conformal metrics in a plane domain in terms of its travel times. No assumption on absence of conjugate points of geodesics is made.Differential GeometryMathematical Physics53C24; 35R30Conformal equivalent metrics in a plane domain are uniquely determined from travel timestext