{ "id": "1607.03599", "version": "v1", "published": "2016-07-13T06:10:10.000Z", "updated": "2016-07-13T06:10:10.000Z", "title": "Topological spaces with a local $ω^ω$-base have the strong Pytkeev$^*$ property", "authors": [ "Taras Banakh" ], "comment": "10 pages. arXiv admin note: text overlap with arXiv:1412.4268", "categories": [ "math.GN" ], "abstract": "Modifying the known definition of a Pytkeev network, we introduce a notion of Pytkeev$^*$ network and prove that a topological space has a countable Pytkeev network at a point $x\\in X$ if and only if $X$ is countably tight at $x$ and has a countable Pykeev$^*$ network at $x$. We define a topological space $X$ to have the strong Pytkeev$^*$ property if $X$ has a Pytkeev$^*$ network at each point. Our main theorem says that a topological space $X$ has a countable Pytkeev$^*$ network at point $x\\in X$ if $X$ has a local $\\omega^\\omega$-base at $x$ (i.e., a neighborhood base $(U_\\alpha)_{\\alpha\\in\\omega^\\omega}$ at $x$ such that $U_\\beta\\subset U_\\alpha$ for all $\\alpha\\le\\beta$ in $\\omega^\\omega$). Consequently, each countably tight space with a local $\\omega^\\omega$-base has the strong Pytkeev property.", "revisions": [ { "version": "v1", "updated": "2016-07-13T06:10:10.000Z" } ], "analyses": { "subjects": [ "54D70", "54E18" ], "keywords": [ "topological space", "strong pytkeev property", "main theorem says", "countable pytkeev network", "countably tight space" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }