{ "id": "1412.8481", "version": "v1", "published": "2014-12-29T21:01:46.000Z", "updated": "2014-12-29T21:01:46.000Z", "title": "An application of virtual degeneracy to two-valued subsets of $L_{p}$-spaces", "authors": [ "Anthony Weston" ], "comment": "3 page note", "categories": [ "math.FA" ], "abstract": "Suppose $0 < p < 2$ and that $(\\Omega, \\mu)$ is a measure space for which $L_{p}(\\Omega, \\mu)$ is at least two-dimensional. Kelleher, Miller, Osborn and Weston have shown that if a subset $B$ of $L_{p}(\\Omega, \\mu)$ does not have strict $p$-negative type, then $B$ is affinely dependent (when $L_{p}(\\Omega, \\mu)$ is considered as a real vector space). Examples show that the converse of this statement is not true in general. In this note we describe a class of subsets of $L_{p}(\\Omega, \\mu)$ for which the converse statement holds. We prove that if a two-valued set $B \\subset L_{p}(\\Omega, \\mu)$ is affinely dependent (when $L_{p}(\\Omega, \\mu)$ is considered as a real vector space), then $B$ does not have strict $p$-negative type. This result is peculiar to two-valued subsets of $L_{p}(\\Omega, \\mu)$ and generalizes an elegant theorem of Murugan. It follows, moreover, that of certain types of isometry with range in $L_{p}(\\Omega, \\mu)$ cannot exist.", "revisions": [ { "version": "v1", "updated": "2014-12-29T21:01:46.000Z" } ], "analyses": { "subjects": [ "46B04", "46B85" ], "keywords": [ "two-valued subsets", "virtual degeneracy", "real vector space", "application", "affinely dependent" ], "note": { "typesetting": "TeX", "pages": 3, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1412.8481W" } } }