{ "id": "2303.14477", "version": "v1", "published": "2023-03-25T14:09:59.000Z", "updated": "2023-03-25T14:09:59.000Z", "title": "A primer on quasi-convex functions in nonlinear potential theories", "authors": [ "Kevin R. Payne", "Davide F. Redaelli" ], "comment": "96 pages, 2 figures", "categories": [ "math.AP" ], "abstract": "We present a self-contained introduction to the fundamental role that quasi-convex functions play in general (nonlinear second order) potential theories, which concerns the study of generalized subharmonics associated to a suitable closed subset of the space of 2-jets. Quasi-convex functions build a bridge between classical and viscosity notions of solutions of the natural Dirichlet problem in any potential theory. Moreover, following a program initiated by Harvey and Lawson in 2009, a potential theoretic-approach is widely being applied for treating nonlinear partial differential equations (PDEs). This viewpoint revisits the conventional viscosity approach to nonlinear PDEs under a more geometric prospective inspired by Krylov and takes much insight from classical pluripotential theory. The possibility of a symbiotic and productive relationship between general potential theories and nonlinear PDEs relies heavily on the class of quasi-convex functions, which are themselves the protagonists of a particular (and important) pure second order potential theory.", "revisions": [ { "version": "v1", "updated": "2023-03-25T14:09:59.000Z" } ], "analyses": { "subjects": [ "35D40", "35B51", "35J60", "35J70", "26B05", "26B25" ], "keywords": [ "quasi-convex functions", "nonlinear potential theories", "pure second order potential theory", "nonlinear pdes", "treating nonlinear partial differential equations" ], "note": { "typesetting": "TeX", "pages": 96, "language": "en", "license": "arXiv", "status": "editable" } } }