Modal expansions for resonance scattering phenomena

This paper very briefly reviews certain approaches commonly used to predict scattering in the region between those amenable to either high or low frequency approximations. As an alternative to extensions of such approximations into this so-called "resonance region," the suggestion is made that the concept of modal expansions of fields be investigated. The existence of such characteristic modes is reasoned heuristically and certain speculations are presented concerning their properties and their determination.