Theoretical study of spectra of depolarized light scattered from dense rare-gas fluids

Abstract

A theory is presented to study the depolarized light scattered by dense rare-gas fluids. This theory is based on the Zwanzig-Mori theory of Brownian motion; the transport matrix is estimated by a lattice-gas model. Two modes are theoretically predicted, a dissipative mode due to the translational diffusion of rare-gas atoms and an oscillatory mode associated with their oscillations around a given site in the fluid. The resulting profile has a Lorentzian shape at low frequencies and non-Lorentzian wings at high frequencies. The electron-overlap effect modifies the integrated intensity of the scattered light but has only a minor influence on its spectral density.