Mechanisms will be investigated for the description of the interaction of intermediate energy nucleons with nuclei in terms of nucleon-nucleon scattering. Particular attention will be paid to relativistic effects. The three body system of two nucleons and an antinucleon will be studied through the Faddeev equations, with an emphasis on the nuclear shifts and widths of the antiproton-deuteron atom. Methods of treating relativistic effects in three body systems will be explored for simple models. Consistency of field-theoretic models of the pion- nucleon and nucleon systems will be considered.
