{ "id": "0710.1604", "version": "v5", "published": "2007-10-08T17:58:11.000Z", "updated": "2009-05-21T18:01:19.000Z", "title": "A quantitative formulation of the global regularity problem for the periodic Navier-Stokes equation", "authors": [ "Terence Tao" ], "comment": "12 pages, no figures. More minor corrections (not appearing in the published version)", "journal": "Dynamics of PDE 4 (2007), 293--302", "categories": [ "math.AP" ], "abstract": "The global regularity problem for the periodic Navier-Stokes system asks whether to every smooth divergence-free initial datum $u_0: (\\R/\\Z)^3 \\to \\R^3$ there exists a global smooth solution u. In this note we observe (using a simple compactness argument) that this qualitative question is equivalent to the more quantitative assertion that there exists a non-decreasing function $F: \\R^+ \\to \\R^+$ for which one has a local-in-time \\emph{a priori} bound $$ \\| u(T) \\|_{H^1_x((\\R/\\Z)^3)} \\leq F(\\|u_0\\|_{H^1_x((\\R/\\Z)^3)})$$ for all $0 < T \\leq 1$ and all smooth solutions $u: [0,T] \\times (\\R/\\Z)^3 \\to \\R^3$ to the Navier-Stokes system. We also show that this local-in-time bound is equivalent to the corresponding global-in-time bound.", "revisions": [ { "version": "v5", "updated": "2009-05-21T18:01:19.000Z" } ], "analyses": { "subjects": [ "35Q30" ], "keywords": [ "global regularity problem", "periodic navier-stokes equation", "quantitative formulation", "periodic navier-stokes system asks", "smooth divergence-free initial datum" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0710.1604T" } } }