Critical Light Scattering in Pure Liquids

Light-scattering experiments near the critical point (Tc , \c) in fluid systems and, in particular, the central Rayleigh peak in the frequency spectrum are reviewed. Within a nonasymptotic renormalization-group theory, the crossover function is calculated between several regions: (i) from the background to the asymptotic region, (ii) from the hydrodynamic region (wave length>>correlation length) to the critical region (wave length<