triqs_tprf::chi_from_gg2_PP

#include <triqs_tprf.hpp>

Synopsis

g2_iw_t chi_from_gg2_PP (g_iw_vt g, g2_iw_vt g2)

Generalized susceptibility \(\chi = G^{(2)} - GG\) in the Particle-Particle channel

Computes

\[\chi_{\bar{a}b\bar{c}d}(\omega, \nu, \nu') = G^{(2)}_{\bar{a}b\bar{c}d}(\omega, \nu, \nu') - \beta \delta_{\nu + \nu' - \omega} G_{ba}(\nu) \cdot G_{dc}(\nu')\]

Parameters

g single particle Green’s function \(G_{ab}(\nu)\)

g2 two-particle Green’s function \(G^{(2)}_{\bar{a}b\bar{c}d}(\omega, \nu, \nu')\)

Returns

chi generalized particle-hole susceptibility: \(\chi_{\bar{a}b\bar{c}d}(\omega, \nu,\nu')\)