Approach to transport theory using generalized Langevin equations

The use of generalized Langevin equations in the study of transport in simple classical liquids is extended by the derivation of the second such equation in the hierarchy of coupled phase-space transport equations. This set of generalized Langevin equations is applied to the description of self-diffusion. An approximation is made to simplify the second generalized Langevin equation, and a perturbation solution is presented for the velocity autocorrelation function. The method introduced is related to the Mori continued-fraction representation, but poses a different point of view for analysis.