Candidates for sigmasub(ac) and Hsub(ac)

The purpose of this paper is to order and briefly describe, via two diagrams, various spectra and subspaces that are closely related to scattering spectra and scattering subspaces. This is done from the operator-theoretic viewpoint and the orderings are obtained primarily via Fredholm theory and Fourier theory, respectively. Both self-adjoint and non-self-adjoint operators are considered, inasmuch as non-self-adjoint operators and methods are now being used in scattering theory. (Auth.)