{ "id": "1105.1526", "version": "v1", "published": "2011-05-08T15:03:54.000Z", "updated": "2011-05-08T15:03:54.000Z", "title": "Estimates on fractional higher derivatives of weak solutions for the Navier-Stokes equations", "authors": [ "Kyudong Choi", "Alexis F. Vasseur" ], "comment": "62 pages", "categories": [ "math.AP" ], "abstract": "We study weak solutions of the 3D Navier-Stokes equations in whole space with $L^2$ initial data. It will be proved that $\\nabla^\\alpha u $ is locally integrable in space-time for any real $\\alpha$ such that $1< \\alpha <3$, which says that almost third derivative is locally integrable. Up to now, only second derivative $\\nabla^2 u$ has been known to be locally integrable by standard parabolic regularization. We also present sharp estimates of those quantities in weak-$L_{loc}^{4/(\\alpha+1)}$. These estimates depend only on the $L^2$ norm of initial data and integrating domains. Moreover, they are valid even for $\\alpha\\geq 3$ as long as $u$ is smooth. The proof uses a good approximation of Navier-Stokes and a blow-up technique, which let us to focusing on a local study. For the local study, we use De Giorgi method with a new pressure decomposition. To handle non-locality of the fractional Laplacian, we will adopt some properties of the Hardy space and Maximal functions.", "revisions": [ { "version": "v1", "updated": "2011-05-08T15:03:54.000Z" } ], "analyses": { "subjects": [ "76D05", "35Q30" ], "keywords": [ "fractional higher derivatives", "local study", "initial data", "3d navier-stokes equations", "locally integrable" ], "note": { "typesetting": "TeX", "pages": 62, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1105.1526C" } } }