2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/178112Starting from a formal Hamiltonian as found in the physics literature -- omitting photons -- we define a renormalized Hamiltonian through charge and mass renormalization. We show that the restriction to the one-electron subspace is well-defined. Our construction is non-perturbative and does not use a cut-off. The Hamiltonian is relevant for the description of the Lamb shift in muonic atoms.Reformulation of main theorem, minor changes in the proofMathematical PhysicsHigh Energy Physics - Theorytext