triqs.gfs.semicirc.g_semicirc_z

triqs.gfs.semicirc.g_semicirc_z(z, D)

Semi-circular Green’s function for complex frequency without [-D, D].

For general complex arguments \(z\) not on the cut \([-D, D]\), the Green’s function is given by

\[G(z) = \frac{2}{D^2}\bigl(z - \sqrt{z^2 - D^2}\bigr)\]

Parameters:

zcomplex or array_like of complex frequencies not on the cut [-D, D].

Dfloat, half-bandwidth (D > 0)

Returns:

Gcomplex or ndarray

Value of the Green’s function at the supplied frequencies.