Dynamic exchange-correlation effects in the strongly coupled electron liquid

We present the first quasi-exact ab initio path integral Monte Carlo (PIMC) results for the dynamic local field correction G(q,zₗ;rₛ,Θ) in the imaginary Matsubara frequency domain, focusing on the strongly coupled finite temperature uniform electron gas. These allow us to investigate the impact of dynamic exchange--correlation effects onto the static structure factor. Our results provide a straightforward explanation for previously reported spurious effects in the so-called static approximation [Dornheim et al., Phys.~Rev.~Lett.~125, 235001 (2020)], where the frequency-dependence of the local field correction is neglected. Our findings hint at the intriguing possibility of constructing an analytical four-parameter representation of G(q,zₗ;rₛ,Θ) valid for a substantial part of the phase diagram, which would constitute key input for thermal density functional theory simulations.