{ "id": "1510.01539", "version": "v1", "published": "2015-10-06T11:52:56.000Z", "updated": "2015-10-06T11:52:56.000Z", "title": "Global existence and smoothness for solutions of viscous Burgers equation. (2) The unbounded case: a characteristic flow study", "authors": [ "Jeremie Unterberger" ], "comment": "37 pages", "categories": [ "math.AP" ], "abstract": "We show that the homogeneous viscous Burgers equation $(\\partial_t-\\eta\\Delta) u(t,x)+(u\\cdot\\nabla)u(t,x)=0,\\ (t,x)\\in{\\mathbb{R}}_+\\times{\\mathbb{R}}^d$ $(d\\ge 1, \\eta>0)$ has a globally defined smooth solution if the initial condition $u_0$ is a smooth function growing like $o(|x|)$ at infinity. The proof relies mostly on estimates of the random characteristic flow defined by a Feynman-Kac representation of the solution. Viscosity independent a priori bounds for the solution are derived from these. The regularity of the solution is then proved for fixed $\\eta>0$ using Schauder estimates. The result extends with few modifications to initial conditions growing abnormally large in regions with small relative volume, separated by well-behaved bulk regions, provided these are stable under the characteristic flow with high probability. We provide a large family of examples for which this loose criterion may be verified by hand.", "revisions": [ { "version": "v1", "updated": "2015-10-06T11:52:56.000Z" } ], "analyses": { "subjects": [ "35A01", "35B45", "35B50", "35K15", "35Q30", "35Q35", "35L65", "76N10" ], "keywords": [ "viscous burgers equation", "characteristic flow study", "global existence", "unbounded case", "smoothness" ], "note": { "typesetting": "TeX", "pages": 37, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv151001539U" } } }