T matrix for electromagnetic scattering from an arbitrary number of scatterers and representations of E(3)

The T-matrix formulation of electromagnetic scattering given previously by Waterman for the case of one scatterer is extended to the case of an arbitrary number of scatterers. The resulting total T matrix is expressed in terms of the individual T matrices by an iterative procedure. The essential tools used in the extension are the expansions associated with a translation of the origin for the spherical-wave solutions of Helmholtz's equation. The connection between these expansions and the unitary irreducible representations and associated local representations of the threedimensional Euclidean group E(3) is emphasized. Some applications to two spheres are given. (auth)