{ "id": "2103.09266", "version": "v1", "published": "2021-03-16T18:21:16.000Z", "updated": "2021-03-16T18:21:16.000Z", "title": "Every non-smooth $2$-dimensional Banach space has the Mazur-Ulam property", "authors": [ "Taras Banakh", "Javier Cabello Sánchez" ], "comment": "13 pages", "categories": [ "math.FA", "math.MG" ], "abstract": "A Banach space $X$ has the $Mazur$-$Ulam$ $property$ if any isometry from the unit sphere of $X$ onto the unit sphere of any other Banach space $Y$ extends to a linear isometry of the Banach spaces $X,Y$. A Banach space $X$ is called $smooth$ if the unit ball has a unique supporting functional at each point of the unit sphere. We prove that each non-smooth 2-dimensional Banach space has the Mazur-Ulam property.", "revisions": [ { "version": "v1", "updated": "2021-03-16T18:21:16.000Z" } ], "analyses": { "subjects": [ "46B04", "46B20", "52A21", "52A10", "53A04", "54E35", "54E40" ], "keywords": [ "dimensional banach space", "mazur-ulam property", "unit sphere", "non-smooth", "unit ball" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }