Velocity Correlation Functions for Moderately Dense Gases

  • J. R. Dorfman
Conference paper
Part of the Acta Physica Austriaca book series (FEWBODY, volume 10/1973)


The long-time behavior of the velocity correlation functions characteristic for transport coefficients has been calculated for a gas of hard disks or hard spheres on the basis of an appropriate generalized Boltzmann equation. In d-dimensions one finds that, after several mean free times t0, these correlation functions exhibit a decay proportional to (t/t0)−d/2. This decay can be understood as the result of the same sequences of binary collisions that are responsible for the divergences encountered in the virial expansion of the transport coefficients. This long-time behavior in two dimensions is consistent with the results of computer studies of velocity correlation functions for hard disk gases. The possible implications for hydrodynamics of the t−d/2 behavior of the correlation functions is discussed.


Correlation Function Boltzmann Equation Hard Sphere Transport Coefficient Binary Collision 
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Copyright information

© Springer-Verlag 1973

Authors and Affiliations

  • J. R. Dorfman
    • 1
  1. 1.Institute for Fluid Dynamics and Applied Mathematics and Department of Physics and AstronomyUniversity of MarylandCollege ParkUSA

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