Divergence in the Density Expansion of the Transport Coefficients of a Two-Dimensional Gas

Abstract

An analysis is presented of the first density correction to the viscosity and thermal conductivity coefficient of a two-dimensional gas of rigid disks. The existence of a divergence in the density expansion is established explicitly. For a two-dimensional gas the triple collision contribution to the transport coefficients diverges logarithmically with the time between collisions. In particular, for rigid disks the coefficient of the logarithmic singularity in the viscosity and thermal conductivity is evaluated in the first Enskog approximation. The possibility that as a consequence the transport coefficients depend logarithmically on the density is discussed.