Scattering, Rayleigh

This review discusses the physical origin of elastic scattering of radiation (Rayleigh Scattering, RS), its relation to fluctuations in fluids and fluid mixtures, its role in the investigation of dispersions of colloidal particles. Particular emphasis is put on the Optical Theorem, which allows to relate the total RS cross section to the real and imaginary part of the refractive index. Recent advances concerning RS from degenerate quantum gases, from correlated fluids, and from suspensions of interacting particles, are presented. Finally, a brief introduction to quasi-elastic RS is given, also known as Dynamic Light Scattering, is given, together with a mention of novel techniques that blend scattering and imaging.