{ "id": "0710.3991", "version": "v1", "published": "2007-10-22T08:11:34.000Z", "updated": "2007-10-22T08:11:34.000Z", "title": "Dirichlet Duality and the Nonlinear Dirichlet Problem", "authors": [ "F. Reese Harvey", "H. Blaine Lawson, Jr" ], "categories": [ "math.AP", "math.CV", "math.DG" ], "abstract": "We study the Dirichlet problem for fully nonlinear, degenerate elliptic equations of the form f(Hess, u)=0 on a smoothly bounded domain D in R^n. In our approach the equation is replaced by a subset F of the space of symmetric nxn-matrices, with bdy(F) contined in the set {f=0}. We establish the existence and uniqueness of continuous solutions under an explicit geometric ``F-convexity'' assumption on the boundary bdy(F). The topological structure of F-convex domains is also studied and a theorem of Andreotti-Frankel type is proved for them. Two key ingredients in the analysis are the use of subaffine functions and Dirichlet duality, both introduced here. Associated to F is a Dirichlet dual set F* which gives a dual Dirichlet problem. This pairing is a true duality in that the dual of F* is F and in the analysis the roles of F and F* are interchangeable. The duality also clarifies many features of the problem including the appropriate conditions on the boundary. Many interesting examples are covered by these results including: All branches of the homogeneous Monge-Ampere equation over R, C and H; equations appearing naturally in calibrated geometry, Lagrangian geometry and p-convex riemannian geometry, and all branches of the Special Lagrangian potential equation.", "revisions": [ { "version": "v1", "updated": "2007-10-22T08:11:34.000Z" } ], "analyses": { "subjects": [ "35J25", "35J70", "32W20" ], "keywords": [ "nonlinear dirichlet problem", "dirichlet duality", "special lagrangian potential equation", "degenerate elliptic equations", "dual dirichlet problem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0710.3991R" } } }