Abstract
Earlier results (Tip 1977) concerning the analytic behaviour of the non-Born part of the exchange amplitude for elastic forward electron-ground-state-atom scattering are improved. This amplitude besides being analytic in the complex plane outside the real axis is also meromorphic through a gap stretching from the bottom of the continuous spectrum of the Hamiltonian to the left over a distance B, B being the ionisation energy of the atom.

This publication has 3 references indexed in Scilit: