2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67837This paper is concerned with the square root problem of Kato for the "sum" of linear operators in a Hilbert space ${\mathbb H}$. Under suitable assumptions, we show that if $A$ and $B$ are respectively m-scetroial linear operators satisfying the square root problem of Kato. Then the same conclusion still holds for their "sum". As application, we consider perturbed Schrödinger operators.13 pagesFunctional Analysis47A07; 47B44; 47B25text