Spontaneous decay of an excited atom in an absorbing dielectric

We have computed the spontaneous decay rate of an atom placed inside an absorbing dielectric adopting the real cavity model. The calculations are performed applying a quantization scheme which is causal and fully consistent with the dissipation-fluctuation theorem. We have started with a full electric field operator and found that the decay rate contains only contributions from the transverse field and sensitively depends on the cavity radius - results that contradict earlier results derived on the basis of heuristic introduction of local-field correction factors.