2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/213291We prove a complex and a real interpolation theorems on Besov spaces and Triebel-Lizorkin spaces associated with a selfadjoint operator $L$, without assuming the gradient estimate for its spectral kernel. The result applies to the cases where $L$ is a uniformly elliptic operator or a Schrödinger operator with electro-magnetic potential.8 pages. SubmittedAnalysis of PDEsClassical Analysis and ODEs42B35;42B25text