chi_from_gg2_PP

Synopsis:

triqs_tprf::g2_iw_t chi_from_gg2_PP (triqs_tprf::g_iw_vt g, triqs_tprf::g2_iw_vt g2)

Generalized susceptibility \(\chi^{(0)} = G^{(2)} - GG\) in the

Parameters

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

Return value

chi generalized particle-hole susceptibility

\(\chi_{\bar{a}b\bar{c}d}(\omega, \nu,\nu')\)

Documentation

Particle-Particle channel

Computes

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