{ "id": "0909.3707", "version": "v1", "published": "2009-09-21T08:41:37.000Z", "updated": "2009-09-21T08:41:37.000Z", "title": "An H^1 setting for the Navier-Stokes equations: quantitative estimates", "authors": [ "Carlo Morosi", "Livio Pizzocchero" ], "comment": "LaTeX; 33 pages", "journal": "Nonlinear Analysis: TMA 74(6) (2011), 2398-2414 (in a slightly revised version)", "doi": "10.1016/j.na.2010.11.043", "categories": [ "math.AP" ], "abstract": "We consider the incompressible Navier-Stokes (NS) equations on a torus, in the setting of the spaces L^2 and H^1; our approach is based on a general framework for semi- or quasi-linear parabolic equations proposed in the previous work [9]. We present some estimates on the linear semigroup generated by the Laplacian and on the quadratic NS nonlinearity; these are fully quantitative, i.e., all the constants appearing therein are given explicitly. As an application we show that, on a three dimensional torus T^3, the (mild) solution of the NS Cauchy problem is global for each H^1 initial datum u_0 with zero mean, such that || curl u_0 ||_{L^2} <= 0.407; this improves the bound for global existence || curl u_0 ||_{L^2} <= 0.00724, derived recently by Robinson and Sadowski [10]. We announce some future applications, based again on the H^1 framework and on the general scheme of [9].", "revisions": [ { "version": "v1", "updated": "2009-09-21T08:41:37.000Z" } ], "analyses": { "subjects": [ "35Q30", "76D03", "76D05" ], "keywords": [ "navier-stokes equations", "quantitative estimates", "quasi-linear parabolic equations", "ns cauchy problem", "quadratic ns nonlinearity" ], "tags": [ "journal article" ], "note": { "typesetting": "LaTeX", "pages": 33, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0909.3707M" } } }