triqs.gfs.tools.make_delta

triqs.gfs.tools.make_delta(V, eps, mesh, block_names=None)[source]

Hybridization function built from bath hoppings and energies.

\[\Delta_{kl}(i\omega_n) = \sum_{j=1}^{N_b} V_{kj}\, S_j\, V_{jl}^*,\]

where the bath propagator is

\[S_j = \frac{1}{i\omega_n - \varepsilon_j} \qquad \text{(Matsubara)} \qquad\text{or}\qquad S_j = -\frac{e^{-\tau\varepsilon_j}}{1 + e^{-\beta\varepsilon_j}} \qquad \text{(imaginary time).}\]

Parameters:

Vnumpy.ndarray, or list thereof: Bath hopping matrix. A list of arrays produces a BlockGf, one block per array.
epslist of float, or list of list of float: Bath energies. Must match V block-by-block.
meshMeshImFreq or MeshImTime: Mesh of the resulting hybridization function.
block_nameslist of str, optional: Names used to label the blocks when V / eps are lists. Defaults to ['0', '1', ...].

Returns:

Gf or BlockGf: Hybridization function on mesh.