Perturbation theory for a degenerate level

K. T. Hecht

Brian P. Anderson

G. Oberlechner, F. Owono-N’-Guema, J. Richert

A. N. Vasil’ev, A. L. Kitanin

Wei Ming

According to the way of the second level amendment of the energy and the wave function in the non-degenerate perturbation theory,the second level amendment of the energy and the wave function are induced in degenerate perturbation theory, which forms the formula of the second level amendment.

B. Y. Tong

To supplement Huby's rules in the Rayleigh-Schrödinger perturbation theory of non-degenerate discrete levels, an expression for the total number of terms contained in the n th order is derived. The number of terms in the n th order having v + 1 disconnected factors is also found.