Monolayers polarizable perpendicularly: The Maxwellian response functions

Though calculations in the Coulomb gauge need never touch on radiative reaction, one can see retrospectively that at each oscillator the reactive part of the field it itself has emitted, call it the self-field, is appreciably different from (though comparable to) that of an isolated oscillator with the same history. The difference is crucial to deriving exact results, because it invalidates the assumption, common in other approaches, that the two fields are the same, or that the reactive self-fields in the monolayer are zero.