Self interaction near dielectrics
  We compute the force acting on a free, static electric charge outside a uniform dielectric sphere. We view this force as a self-interaction force, and compute it by applying the Lorentz force directly to the charge's electric field at its location. We regularize the divergent bare force using two different methods: A direct application of the Quinn-Wald Comparison Axiom, and Mode-Sum Regularization. 
Lior M. Burko