{ "id": "1504.01455", "version": "v1", "published": "2015-04-07T01:49:17.000Z", "updated": "2015-04-07T01:49:17.000Z", "title": "Regularity and geometric character of solution of a degenerate parabolic equation", "authors": [ "Jiaqing Pan" ], "comment": "18 pages", "categories": [ "math.AP" ], "abstract": "This work studies the regularity and the geometric significance of solution of the Cauchy problem for a degenerate parabolic equation $u_{t}=\\Delta{}u^{m}$. Our main objective is to improve the H$\\ddot{o}$lder estimate obtained by pioneers and then, to show the geometric characteristic of free boundary of degenerate parabolic equation. To be exact, the present work will show that: (1) the weak solution $u(x,t)\\in{}C^{\\alpha,\\frac{\\alpha}{2}}(\\mathbb{R}^{n}\\times\\mathbb{R}^{+})$, where $\\alpha\\in(0,1)$ when $m\\geq2$ and $\\alpha=1$ when $m\\in(1,2)$; (2) the surface $\\phi=(u(x,t))^{\\beta}$ is a complete Riemannian manifold, which is tangent to $\\mathbb{R}^{n}$ at the boundary of the positivity set of $u(x,t)$. (3) the function $(u(x,t))^{\\beta}$ is a classical solution to another degenerate parabolic equation if $ \\beta$ is large sufficiently; Moreover, some explicit expressions about the speed of propagation of $u(x,t)$ and the continuous dependence on the nonlinearity of the equation are obtained. Recalling the older H$\\ddot{o}$lder estimate ($u(x,t)\\in{}C^{\\alpha,\\frac{\\alpha}{2}}(\\mathbb{R}^{n}\\times\\mathbb{R}^{+})$ with $0<\\alpha<1$ for all $m>1$), we see our result (1) improves the older result and, based on this conclusion, we can obtain (2), which shows the geometric characteristic of free boundary.", "revisions": [ { "version": "v1", "updated": "2015-04-07T01:49:17.000Z" } ], "analyses": { "subjects": [ "35K15", "35K55", "35K65", "53C25" ], "keywords": [ "degenerate parabolic equation", "regularity", "free boundary", "geometric characteristic", "lder estimate" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150401455P" } } }