2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/229875In the reduced phase space of electromagnetism, the generator of duality rotations in the usual Poisson bracket is shown to generate Maxwell's equations in a second, much simpler Poisson bracket. This gives rise to a hierarchy of bi-Hamiltonian evolution equations in the standard way. The result can be extended to linearized Yang-Mills theory, linearized gravity and massless higher spin gauge fields.10 pages Latex file, cosmetic changes, agrees with published versionHigh Energy Physics - TheoryMathematical PhysicsExactly Solvable and Integrable Systemstext