Feynman's Relativistic Cut-Off for Quantum Electrodynamics

Feynman’s modification to electrodynamics and its application to the calculation of self-energy of a free spin-$\frac{1}{2}$ particle, appearing in his 1948 Physical Review paper, is shown to be applicable for the self-energy calculation of a free spin-0 particle as well. Feynman’s modification to electrodynamics is shown to be equivalent to a Hamiltonian approach developed by Podolsky.