Dynamical structure factors for a fluid binary mixture in the hydrodynamic limit

Using the correlation functions obtained by Cohen et al, the expressions for the number concentration dynamical structure factors for a binary alloy are given in the hydrodynamic limit. Kubo relations are derived and presented via some new structure factors, which, although not directly connected to the scattering in the mixture, are linearly related to the number-concentration structure factors. The second moments for the various structure factors are also given. Finally, sound attenuation in binary mixtures is briefly discussed.