{
  "id": "1211.2362",
  "version": "v1",
  "published": "2012-11-11T00:45:53.000Z",
  "updated": "2012-11-11T00:45:53.000Z",
  "title": "Shear viscosity: velocity gradient as a constraint on wave function",
  "authors": [
    "M. -L. Zhang",
    "D. A. Drabold"
  ],
  "comment": "16 pages, 1 figure, submitted to Phys. Rev. E",
  "categories": [
    "cond-mat.stat-mech"
  ],
  "abstract": "By viewing a velocity gradient in a fluid as an internal disturbance and treating it as a constraint on the wave function of a system, a linear evolution equation for the wave function is obtained from the Lagrange multiplier method. It allows us to define the microscopic response to a velocity gradient in a pure state. Taking a spatial coarse-graining average over this microscopic response and averaging it over admissible initial states, we achieve the observed macroscopic response and transport coefficient. In this scheme, temporal coarse-graining is not needed. The dissipation caused by a velocity gradient depends on the square of initial occupation probability, whereas the dissipation caused by a mechanical perturbation depends on the initial occupation probability itself. We apply the method of variation of constants to solve the time-dependent Schrodinger equation with constraints. The various time scales appearing in the momentum transport are estimated. The relation\\ between the present work and previous theories is discussed.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2012-11-11T00:45:53.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "wave function",
      "shear viscosity",
      "constraint",
      "initial occupation probability",
      "microscopic response"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 16,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2012arXiv1211.2362Z"
    }
  }
}