Difficulties in the Kinetic Theory of Dense Gases

Abstract

For the determination of the transport coefficients of a dense gas, the long‐time behavior of the pair distribution function F₂ for small intermolecular distances is obtained from a density expansion in terms of the first distribution function F₁. On the basis of the dynamics of small groups of particles, it is shown that this expansion contains divergences so that it cannot be used for (a) the computation of the long‐time behavior of F₂ beyond O(n); (b) the demonstration of the decay of the initial state beyond O(n²). Similar divergences are encountered in the computation of the transport coefficients from time‐correlation functions. The nature of the divergences suggests (a) there is no kinetic stage in the approach of a dense gas to equilibrium, in the sense of Bogoliubov; (b) a weak logarithmic density dependence of the transport coefficients.