Light scattering in the kinetic regime

The dynamic structure factor as well as the generalized Landau–Placzek relation are calculated from a set of equations describing a monatomic gas in the moderately dense region. These studies start from the 13-moment Gradʹs approximation to solve the Enskog equation giving us a description of the system which is valid out of the hydrodynamic regime. The hydrodynamic matrix is written in terms of the generalized transport coefficients up to second order in the density, where the bulk viscosity is taken into account.