Theory of couplings in electromagnetism: Novel results and numerical removal of couplings

We consider the electric field due to the coupling between two arbitrary scatterers A and A´ in presence of an imperfectly conducting object. We then develop relations between the field due to the influence of A´ on A and the one due to the influence of A on A´, and original efficient expressions of them. As an example of application, we present a novel method which allows the numerical suppression of first order couplings between A´ and A by a simple and efficient post-process.