Causality Conditions and Dispersion Relations. I. Boson Fields

Abstract

The dispersion relations of Kramers and Kronig as generalized for charged and neutral Bose particles with finite rest mass are derived in a new way using the formalism of quantum field theory. The alternative forms of dispersion relations obtained by making various assumptions on the high-frequency limit of total cross sections are used to obtain information about the high-frequency behavior of the total cross section for the scattering of $\gamma$ rays by electrons.