{ "id": "1911.02072", "version": "v1", "published": "2019-11-05T20:24:54.000Z", "updated": "2019-11-05T20:24:54.000Z", "title": "Weak compactness and fixed point property for affine bi-Lipschitz maps", "authors": [ "Cleon S. Barroso", "Valdir Ferreira" ], "comment": "This is an update for arXiv:1610.05642v2. The new version of the manuscript contains improvements of old results and also brings new ones", "categories": [ "math.FA" ], "abstract": "Let $X$ be a Banach space and let $C$ be a closed convex bounded subset of $X$. It is proved that $C$ is weakly compact if, and only if, $C$ has the {it generic} fixed point property ($\\mathcal{G}$-FPP) for the class of $L$-bi-Lipschitz affine mappings for every $L>1$. It is also proved that if $X$ has Pe\\l czy\\'nski's property $(u)$, then either $C$ is weakly compact, contains an $\\ell_1$-sequence or a $\\mathrm{c}_0$-summing basic sequence. In this case, weak compactness of $C$ is equivalent to the $\\mathcal{G}$-FPP for the strengthened class of affine mappings that are uniformly bi-Lipschitz. We also introduce a generalized form of property $(u)$, called {it property $(\\mathfrak{su})$}, and use it to prove that if $X$ has property $(\\mathfrak{su})$ then either $C$ is weakly compact or contains a wide-$(s)$ sequence which is uniformly shift equivalent. In this case, weak compactness in such spaces can also be characterized in terms of the $\\mathcal{G}$-FPP for affine uniformly bi-Lipschitz mappings. It is also proved that every Banach space with a spreading basis has property $(\\mathfrak{su})$, thus property $(\\mathfrak{su})$ is stronger than property $(u)$. These results yield a significant strengthening of an important theorem of Benavides, Jap\\'on-Pineda and Prus published in 2004.", "revisions": [ { "version": "v1", "updated": "2019-11-05T20:24:54.000Z" } ], "analyses": { "keywords": [ "fixed point property", "weak compactness", "affine bi-lipschitz maps", "weakly compact", "banach space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }