INDEX quantum electrodynamics

Dyson-type equations have been used extensively in quantum electrodynamics, quantum field theory, statistical mechanics, hydrodynamic instability and turbulent diffusion studies, and in investigations of electromagnetic wave propagation in a medium having a random refractive index (Tatarski, 1961). Also, this technique has recently been employed to study laser light scattering from a macromolecular solution in an electric field. 

It is possible to understand many phenomena in optics and spectroscopy in terms of classical models based on concepts of classical electrodynamics. For example, the absorption and dispersion of electromagnetic waves in matter can be described using the model of damped oscillators for the atomic electrons. This model leads to a complex refractive index and to dispersion relations which give the link between absorption and dispersion. It is not too difficult to give a quantum mechanical formulation of the classical results in most cases. The semiclassical approach will be outlined briefly. 

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