Complement to the Wigner-Kirkwood expansion
We extend the region of applicability of phase-space techniques, for the study of quantum systems, by developing an expansion for the Wigner distribution function and correlation functions, in powers of an interaction potential. These results are not restricted to the near-classical regime (expansion in powers of Latin small letter h with stroke), in contrast to the Wigner-Kirkwood expansion. The relation to other perturbation methods (Lindstedt- Poincaré, Green's function) is explored. © 1985 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review Letters
Dickman, R., & O'Connell, R. (1985). Complement to the Wigner-Kirkwood expansion. Physical Review Letters, 55 (17), 1703-1706. https://doi.org/10.1103/PhysRevLett.55.1703