triqs_tprf::split_into_dynamic_wk_and_constant_k

#include <triqs_tprf.hpp>

Synopsis

std::tuple<chi_wk_t, chi_k_t> split_into_dynamic_wk_and_constant_k (chi_wk_cvt chi_wk)

Splits a rank 4 tensor-valued Green’s function into dynamic and constant parts by tail fitting

Splits a general rank 4 tensor-valued Green’s function \(\chi_{abcd}(i\omega_n, \mathbf{k})\) into a dynamic and a constant part in Matsubara frequency space by fitting the high-frequency tail.

\[\chi_{abcd}(i\omega_n, \mathbf{k}) = \chi^{(dyn)}_{abcd}(i\omega_n, \mathbf{k}) + \chi^{(stat)}_{abcd}(\mathbf{k})\]

Parameters

• chi_wk : general rank 4 tensor-valued Green’s function \(\chi_{abcd}(i\omega_n, \mathbf{k})\).

Returns

Tuple of chi_dyn_wk, the dynamic part of chi \(\chi^{(dyn)}_{abcd}(i\omega_n, \mathbf{k})\), which converges to zero for \(\omega_n \rightarrow \infty\), and chi_const_k, the part of chi that is constant in Matsubara frequency space \(\chi^{(stat)}_{abcd}(\mathbf{k})\).