We discuss, in the context of classical electrodynamics with a Lorentz invariant cutoff at short distances, the self-force acting on a point charged particle. It follows that the electromagnetic mass of the point charge occurs in the equation of motion in a form consistent with special relativity. We find that the exact equation of motion does not exhibit runaway solutions or non-causal behavior, when the cutoff is larger than half of the classical radius of the electron.
Curing the self-force runaway problem in finite-difference integration