2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/231320Electromagnetic modes with parabolic-cylindrical symmetry and their dynamical variables are studied both in the classical and quantum realm. As a result, a new dynamical constant for the electromagnetic field is identified and linked to the symmetry operator which supports it.11 pages, 1 figureQuantum Physicstext