{ "id": "1811.00660", "version": "v1", "published": "2018-11-01T22:26:53.000Z", "updated": "2018-11-01T22:26:53.000Z", "title": "Cardinal invariants of cellular-Lindelof spaces", "authors": [ "Angelo Bella", "Santi Spadaro" ], "categories": [ "math.GN" ], "abstract": "A space $X$ is said to be \"cellular-Lindel\\\"of\" if for every cellular family $\\mathcal{U}$ there is a Lindel\\\"of subspace $L$ of $X$ which meets every element of $\\mathcal{U}$. Cellular-Lindel\\\"of spaces generalize both Lindel\\\"of spaces and spaces with the countable chain condition. Solving questions of Xuan and Song, we prove that every cellular-Lindel\\\"of monotonically normal space is Lindel\\\"of and that every cellular-Lindel\\\"of space with a regular $G_\\delta$-diagonal has cardinality at most $2^\\mathfrak{c}$. We also prove that every normal cellular-Lindel\\\"of first-countable space has cardinality at most continuum under $2^{<\\mathfrak{c}}=\\mathfrak{c}$ and that every normal cellular Lindel\\\"of space with a $G_\\delta$-diagonal of rank $2$ has cardinality at most continuum.", "revisions": [ { "version": "v1", "updated": "2018-11-01T22:26:53.000Z" } ], "analyses": { "keywords": [ "cardinal invariants", "cellular-lindelof spaces", "cardinality", "countable chain condition", "monotonically normal space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }