{ "id": "2212.09954", "version": "v1", "published": "2022-12-20T02:03:30.000Z", "updated": "2022-12-20T02:03:30.000Z", "title": "Singularities of Fitzpatrick and convex functions", "authors": [ "Dmitry Kramkov", "Mihai Sîrbu" ], "comment": "21 pages, submitted", "categories": [ "math.CA" ], "abstract": "Zaj\\'{\\i}\\v{c}ek [19] shows that the singularities of a convex function $f$ can be covered by a countable collection of $c-c$ surfaces. We study the geometry of these surfaces and show that their normals are restricted to the cone generated by $F-F$, where $F:= \\textrm{cl} \\ \\textrm{range} \\nabla f$. The singularities of projections on monotone sets in pseudo-Euclidean spaces and of the associated Fitzpatrick functions are studied and classified as a case of special interest.", "revisions": [ { "version": "v1", "updated": "2022-12-20T02:03:30.000Z" } ], "analyses": { "keywords": [ "convex function", "singularities", "monotone sets", "pseudo-euclidean spaces", "associated fitzpatrick functions" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }