Application of Wick's theorem in the strong-potential approximation
Application of Wick's theorem in the strong-potential approximation is a scholarly work, published in 1983 in ''Physical Review A, General Physics''. The main subjects of the publication include classical mechanics, electron, physics, invariant, quantum electrodynamics, mathematical physics, Born approximation, quantum mechanics, Born–Huang approximation, ultracold atom, density functional theory, and low-energy electron diffraction. It is shown that in the strong-potential approximation using the full-peaking approximation the cross section for electron capture is invariant when any term which depends on the internuclear coordinate $R$ is added to the expansion potential.