An equivalent surface representation for wave scattering by inhomogeneous objects

The inhomogeneous structure of an object is accounted for by a pair of surface integral operators that provide the components of the electric and magnetic fields tangent to the object's outer surface only in terms of a single unknown density of electric current distributed on that same outer surface. This equivalent surface representation is invariant under rotation and translation, and independent of external material and illumination. The computational advantage of such a transformation is shown by a numerical example.