{ "id": "math/0202243", "version": "v1", "published": "2002-02-23T07:45:13.000Z", "updated": "2002-02-23T07:45:13.000Z", "title": "Combining solutions of semilinear partial differential equations in R^n with critical exponent", "authors": [ "Man Chun Leung" ], "comment": "35 pages", "categories": [ "math.AP", "math.DG" ], "abstract": "Let $u_1$ and $u_2$ be two different positive smooth solutions of the equation $\\Delta u + n (n - 2) u^{{n + 2}\\over {n - 2}} = 0$ in $R^n (n \\ge 3).$ By a result of Gidas, Ni and Nirenberg, $u_1$ and $u_2$ are radially symmetric above the points $\\xi_1$ and $\\xi_2$, respectively. Let $u$ be a positive $C^2$-function on $R^n$ such that $u = u_1$ in $\\Omega_1$ and $u = u_2$ in $\\Omega_2$, where $\\Omega_1$ and $\\Omega_2$ are disjoint non-empty open domains in ${\\R}^n$. $u$ satisfies the equation $\\Delta u + n (n - 2) K u^{{n + 2}\\over {n - 2}} = 0$ in $R^n.$ By the same result of Gidas, Ni and Nirenberg, $K \\not\\equiv 1$ in $R^n$. In this paper we discuss lower bounds on $\\displaystyle{\\sup_{\\R^n} |K - 1|} .$ Relation with decay estimates at the isolated singularity via the Kelvin transform is also considered.", "revisions": [ { "version": "v1", "updated": "2002-02-23T07:45:13.000Z" } ], "analyses": { "subjects": [ "35J60", "53C21" ], "keywords": [ "semilinear partial differential equations", "critical exponent", "combining solutions", "disjoint non-empty open domains", "positive smooth solutions" ], "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2002math......2243L" } } }