{
  "id": "cond-mat/0506256",
  "version": "v1",
  "published": "2005-06-10T23:52:14.000Z",
  "updated": "2005-06-10T23:52:14.000Z",
  "title": "Self-diffusion in granular gases: Green-Kubo versus Chapman-Enskog",
  "authors": [
    "Nikolai V. Brilliantov",
    "Thorsten Poeschel"
  ],
  "comment": "15 pages, 1 figure",
  "doi": "10.1063/1.1889266",
  "categories": [
    "cond-mat.stat-mech"
  ],
  "abstract": "We study the diffusion of tracers (self-diffusion) in a homogeneously cooling gas of dissipative particles, using the Green-Kubo relation and the Chapman-Enskog approach. The dissipative particle collisions are described by the coefficient of restitution $\\epsilon$ which for realistic material properties depends on the impact velocity. First, we consider self-diffusion using a constant coefficient of restitution, $\\epsilon=$const, as frequently used to simplify the analysis. Second, self-diffusion is studied for a simplified (stepwise) dependence of $\\epsilon$ on the impact velocity. Finally, diffusion is considered for gases of realistic viscoelastic particles. We find that for $\\epsilon=$const both methods lead to the same result for the self-diffusion coefficient. For the case of impact-velocity dependent coefficients of restitution, the Green-Kubo method is, however, either restrictive or too complicated for practical application, therefore we compute the diffusion coefficient using the Chapman-Enskog method. We conclude that in application to granular gases, the Chapman-Enskog approach is preferable for deriving kinetic coefficients.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2005-06-10T23:52:14.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "granular gases",
      "self-diffusion",
      "green-kubo",
      "chapman-enskog approach",
      "realistic material properties depends"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}