Brillouin 1933 / Wigner 1935 variant of Rayleigh-Schrödinger PT in which the exact eigenvalue E_n appears in the energy denominators instead of the unperturbed E_n^(0). Advantage: each order is rational rather than polynomial in V, which…
Brillouin 1933 / Wigner 1935 variant of Rayleigh-Schrödinger PT in which the exact eigenvalue E_n appears in the energy denominators instead of the unperturbed E_n^(0). Advantage: each order is rational rather than polynomial in V, which…