triqs_ctseg::measure_nnw
#include <triqs_ctseg.hpp>
class measure_nnw
measurement for the density-density correlation function on Matsubara frequencies
Measures the Fourier transform of
\[\chi_{a,b}^{\sigma\sigma'}(\tau)\equiv\langle\]
n_{asigma}(tau)n_{bsigma’}(0)rangle