Orthogonality Exponents in Low-Dimensional Metals

The Anderson orthogonality exponents K+ for introducing a localized perturbation into an electron gas and K(a) for displacing the localized potential by a vector a are discussed for one and two-dimensional systems. It is shown that the “smoothness” of the potential enters very differently in the exponents K+ and K(a). The controversial point of the boundedness of the two exponents is clarified.