{ "id": "1610.05642", "version": "v1", "published": "2016-10-18T14:35:27.000Z", "updated": "2016-10-18T14:35:27.000Z", "title": "Weak Compactness and Fixed Point Property for Affine Bi-Lipschitz Maps", "authors": [ "C. S. Barroso", "V. Ferreira" ], "categories": [ "math.FA" ], "abstract": "In this paper we show that if $(y_n)$ is a seminormalized sequence in a Banach space which does not have any weakly convergent subsequence, then it contains a wide-$(s)$ subsequence $(x_n)$ which admits an equivalent convex basic sequence. This fact is used to characterize weak-compactness of bounded, closed convex sets in terms of the generic fixed point property ($\\mathcal{G}$-$FPP$) for the class of affine bi-Lipschitz maps. This result generalizes a theorem by Benavides, Jap\\'on Pineda and Prus previously proved for the class of continuous maps. We also introduce a relaxation of this notion ($\\mathcal{WG}$-$FPP$) and observe that a closed convex bounded subset of a Banach space is weakly compact iff it has the $\\mathcal{WG}$-$FPP$ for affine $1$-Lipschitz maps. Related results are also proved. For example, a complete convex bounded subset $C$ of a Hlcs $X$ is weakly compact iff it has the $\\mathcal{G}$-$FPP$ for the class of affine continuous maps $f\\colon C\\to X$ with weak-approximate fixed point nets.", "revisions": [ { "version": "v1", "updated": "2016-10-18T14:35:27.000Z" } ], "analyses": { "keywords": [ "affine bi-lipschitz maps", "fixed point property", "weak compactness", "equivalent convex basic sequence", "banach space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }