Basic theoretical work on atomic scattering processes will be performed. The topics to be studied are: 1. Variational approximations for scattering in a laser field. 2. Infrared corrections to scattering cross sections 3. The role of various reactions involving hydrogen in galaxy formation. 4. Semi-classical studies of atomic interactions 5. Retarded interactions and their relationship to QED. 6. Variational bounds. 7. Conditions for the non-existence of bound states.
