Reconsidering the quantization of electrodynamics with boundary conditions and some measurable consequences

We reconsider the quantization of electctrodynamics with conductor boundary conditions using an approach suggested earlier where the boundary conditions for the field strengths are taken as constraints for the electromagnetic potentials. We consider in detail the difference to the traditional approach where one first chooses Coulomb gauge and after that applies the boundary conditions to the potentials which in this way appear to be stronger than the original ones resulting in an additional interaction with the conducting surface which must be considered as unphysical. We show that both approaches deliver different results for measurable quantities like the force acting on a charge in front of a conducting plane or on an neutral atom which constitutes the first result in the famous paper by Casimir and Polder in 1948. In the new approach this force comes out reduced by 13%. We point out that and why so important applications like the second result in the mentioned paper, i.e., the retarded force acting between two atoms, and the Casimir effect between parallel planes are not affected.