{ "id": "1403.2461", "version": "v6", "published": "2014-03-11T02:14:26.000Z", "updated": "2021-08-23T03:48:16.000Z", "title": "Ill-posedness for the Navier-Stokes equations in critical Besov spaces $\\dot B^{-1}_{\\infty,q}$", "authors": [ "Baoxiang Wang" ], "comment": "25 Pages, in this new version, we add a reference of Iwabuchi T. and Nakamura M", "categories": [ "math.AP" ], "abstract": "We study the Cauchy problem for the incompressible Navier-Stokes equation \\begin{align} u_t -\\Delta u+u\\cdot \\nabla u +\\nabla p=0, \\ \\ {\\rm div} u=0, \\ \\ u(0,x)= \\delta u_0. \\label{NS} \\end{align} For arbitrarily small $\\delta>0$, we show that the solution map $\\delta u_0 \\to u$ in critical Besov spaces $\\dot B^{-1}_{\\infty,q}$ ($\\forall \\ q\\in [1,2]$) is discontinuous at origin. It is known that the Navier-Stokes equation is globally well-posed for small data in $BMO^{-1}$. Taking notice of the embedding $\\dot B^{-1}_{\\infty,q} \\subset BMO^{-1}$ ($q\\le 2$), we see that for sufficiently small $\\delta>0$, $u_0\\in \\dot B^{-1}_{\\infty,q} $ ($q\\le 2$) can guarantee that the Navier-Stokes equation has a unique global solution in $BMO^{-1}$, however, this solution is instable in $ \\dot B^{-1}_{\\infty,q} $ and the solution can have an inflation in $\\dot B^{-1}_{\\infty,q}$ for certain initial data. So, our result indicates that two different topological structures in the same space may determine the well and ill posedness, respectively.", "revisions": [ { "version": "v5", "updated": "2014-05-22T14:13:45.000Z", "comment": "25 Pages, in this new version, we correct some misprints and a mistake, the real valued case is considered", "journal": null, "doi": null }, { "version": "v6", "updated": "2021-08-23T03:48:16.000Z" } ], "analyses": { "subjects": [ "35Q30", "35K55" ], "keywords": [ "critical besov spaces", "ill-posedness", "unique global solution", "incompressible navier-stokes equation", "small data" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1403.2461W" } } }