{ "id": "2011.14299", "version": "v1", "published": "2020-11-29T06:20:02.000Z", "updated": "2020-11-29T06:20:02.000Z", "title": "A characterization of $X$ for which spaces $C_p(X)$ are distinguished and its applications", "authors": [ "Jerzy Kakol", "Arkady Leiderman" ], "categories": [ "math.GN", "math.FA" ], "abstract": "We prove that the locally convex space $C_{p}(X)$ of continuous real-valued functions on a Tychonoff space $X$ equipped with the topology of pointwise convergence is distinguished if and only if $X$ is a $\\Delta$-space in the sense of \\cite {Knight}. As an application of this characterization theorem we obtain the following results: 1) If $X$ is a \\v{C}ech-complete (in particular, compact) space such that $C_p(X)$ is distinguished, then $X$ is scattered. 2) For every separable compact space of the Isbell--Mr\\'owka type $X$, the space $C_p(X)$ is distinguished. 3) If $X$ is the compact space of ordinals $[0,\\omega_1]$, then $C_p(X)$ is not distinguished. We observe that the existence of an uncountable separable metrizable space $X$ such that $C_p(X)$ is distinguished, is independent of ZFC. We explore also the question to which extent the class of $\\Delta$-spaces is invariant under basic topological operations.", "revisions": [ { "version": "v1", "updated": "2020-11-29T06:20:02.000Z" } ], "analyses": { "subjects": [ "54C35", "54G12", "54H05", "46A03" ], "keywords": [ "application", "locally convex space", "basic topological operations", "separable compact space", "tychonoff space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }