2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/188131This is a non-technical summary of the subtleties of quantum corrections on extra-dimensional theories: should one first renormalize and then mode expand, or first expand in four-dimensional modes and then renormalize?9 pages, based on a talk at IRGAC 2006, BarcelonaHigh Energy Physics - Phenomenologytext