gftool.pole_gf_moments
- gftool.pole_gf_moments(poles, weights, order)
High-frequency moments of the pole Green’s function.
Return the moments mom of the expansion \(g(z) = \sum_m mom_m/z^m\) For the pole Green’s function we have the simple relation \(1/(z - ϵ) = \sum_{m=1} ϵ^{m-1}/z^m\).
- Parameters:
- poles, weights(…, N) float np.ndarray
Position and weight of the poles.
- order(…, M) int array_like
Order (degree) of the moments. order needs to be a positive integer.
- Returns:
- (…, M) float np.ndarray
High-frequency moments.