Simple Green function formulation of n-interface problem

A simple one-dimensional reformulation of earlier treatments of the factorisation method is initially described. This method, which has proved so useful and versatile in enabling interface Green functions to be calculated for a variety of one and two interface problems, is then generalised to the n-interface case. In essence, the extension to the multiple-interface situation is based on the knowledge obtained in studying the simpler single- and double-interface systems. The so-called linkage Green function is the key to obtaining the closed form of the n-interface Green function by way of an iterative procedure.