{ "id": "2304.13719", "version": "v1", "published": "2023-04-26T17:55:57.000Z", "updated": "2023-04-26T17:55:57.000Z", "title": "Towards Microscopic Theory of Decaying Turbulence", "authors": [ "Alexander Migdal" ], "comment": "8 pages, 4 figures", "categories": [ "physics.flu-dyn", "math-ph", "math.MP", "nlin.SI" ], "abstract": "We develop a quantitative microscopic theory of decaying Turbulence by studying the dimensional reduction of the Navier-Stokes loop equation for the velocity circulation. We have found a degenerate family of solutions of the \\NS{} loop equation\\cite{M93, M23PR} for the Wilson loop in decaying Turbulence in arbitrary dimension $d >2$. This family of solutions corresponds to a nonlinear random walk in complex space $\\bC^d$, described by an algebraic equation between consecutive positions. The probability measure is explicitly constructed in terms of products of conventional measures for orthogonal group $SO(d)$ and a sphere $\\bS^{d-3}$. We compute a prediction for the three-dimensional Wilson loop for a circle of radius $R$ as a universal function of $\\frac{R}{\\sqrt{2 \\nu t}}$.", "revisions": [ { "version": "v1", "updated": "2023-04-26T17:55:57.000Z" } ], "analyses": { "keywords": [ "decaying turbulence", "navier-stokes loop equation", "nonlinear random walk", "three-dimensional wilson loop", "orthogonal group" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }