Studies in molecular dynamics. XVI. Fluctuation driven resonance

Abstract

The natural fluctuations in a system of hard spheres that is placed between closely spaced parallel hard walls lead to resonance for those wavelengths which correspond to the spacing, or integer fractions thereof. The temporal behavior of this resonance is shown to be quantitatively equivalent to the autocorrelation function of the appropriate sum over modes of longitudinal currents which are calculated separately by molecular dynamics for a periodic system at an equivalent density. The decay of this resonance is also analyzed in terms of hydrodynamic and kinetic theory, and the regions of their validity is delineated.