Hydrodynamics and Mesoscopic Liquid Dynamics

A recently proposed two-dimensional analysis approach is applied to investigate mesoscopic liquid dynamics. Using molecular dynamics simulations, the pressure and collective density correlations of several model glass-forming liquids are spatiotemporally mapped on a dense grid of correlation times and wavenumbers. It is shown that many features of these correlation functions in the mesoscopic regime can be qualitatively described by the classical hydrodynamic theories. Signatures of nonhydrodynamic behavior are also identified.