On projection operator method in statistical mechanics; derivation of the Balescu–Lenard master equation

In this article, a method of deriving Balescu–Lenard master equation for a homogeneous one-component gas of charged particles is proposed. This method is based on the use of the Zwanzig time-independent projection operator. It is thus shown that the projection technique allows to deal with systems for which second-order Born approximation cannot be invoked. But for such a system, a diagram technique is needed as in the Balescuʹs derivation although the projection technique has been used primarily to avoid such a cumbersome treatment