A perturbation expansion for correlation functions via the Wigner distribution
Document Type
Article
Publication Date
1-1-1986
Abstract
We compute the coordinate correlation 1 2 the Wigner phase space distribution, for a system with Hamiltonian H = H0 + λH1, where the canonical ensemble Wigner distribution corresponding to H0 is known exactly. Perturbation expansions in powers of λ, for the correlation function and the Wigner distribution, are developed. By avoiding an expansion in powers of h{stroke}, we obtain results whose validity is not restricted to the near-classical regime, in contrast to the Wigner-Kirkwood approach. We illustrate our results by application to the one-dimensional anharmonic oscillator, and the relation to other perturbation methods (Lindstedt-Poincaré, Green's Function) is explored. By virtue of the fluctuation-dissipation theorem, it is anticipated that such results will also be useful for the investigation of transport problems. © 1986.
Publication Source (Journal or Book title)
Superlattices and Microstructures
First Page
57
Last Page
64
Recommended Citation
Dickman, R., & O'Connell, R. (1986). A perturbation expansion for correlation functions via the Wigner distribution. Superlattices and Microstructures, 2 (1), 57-64. https://doi.org/10.1016/0749-6036(86)90154-0