2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/136317We establish a boundary Harnack principle for a large class of subordinate Brownian motion, including mixtures of symmetric stable processes, in bounded $κ$-fat open set (disconnected analogue of John domains). As an application of the boundary Harnack principle, we identify the Martin boundary and the minimal Martin boundary of bounded $κ$-fat open sets with respect to these processes with their Euclidean boundary.34 pagesProbability60J45, 60J25, 60J51text