Onsager-Zerlegung und generalisierte Langevin-Theorie für ein Brownsches Teilchen in der harmonischen Kette

Abstract

To illustrate the so-called Onsager separability of dynamic correlation functions (which is fundamental to the Statistical Mechanics of phenomenological processes) we consider the exact generalized Langevin equation for the momentum of a Brownian particle in a harmonic chain. The time dependence of the Langevin force and its dynamic autocorrelation (the after effect kernel) are calculated and shown to have no hydrodynamic part—in contrast to the particle's momentum correlation.