{ "id": "1210.8074", "version": "v2", "published": "2012-10-30T16:35:19.000Z", "updated": "2013-08-07T18:10:53.000Z", "title": "One-point extensions and local topological properties", "authors": [ "M. R. Koushesh" ], "comment": "4 pages", "journal": "Bull. Aust. Math. Soc. 88 (2013), 12-16", "categories": [ "math.GN" ], "abstract": "A space $Y$ is called an extension of a space $X$ if $Y$ contains $X$ as a dense subspace. An extension $Y$ of $X$ is called a one-point extension of $X$ if $Y\\backslash X$ is a singleton. P. Alexandroff proved that any locally compact non-compact Hausdorff space $X$ has a one-point compact Hausdorff extension, called the one-point compactification of $X$. Motivated by this, S. Mr\\'{o}wka and J.H. Tsai [On local topological properties. II, Bull. Acad. Polon. Sci. S\\'{e}r. Sci. Math. Astronom. Phys. 19 (1971), 1035-1040] posed the following more general question: For what pairs of topological properties ${\\mathscr P}$ and ${\\mathscr Q}$ does a locally-${\\mathscr P}$ space $X$ having ${\\mathscr Q}$ possess a one-point extension having both ${\\mathscr P}$ and ${\\mathscr Q}$? Here, we provide an answer to this old question.", "revisions": [ { "version": "v2", "updated": "2013-08-07T18:10:53.000Z" } ], "analyses": { "subjects": [ "54D35" ], "keywords": [ "local topological properties", "one-point extension", "locally compact non-compact hausdorff space", "one-point compact hausdorff extension" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 4, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1210.8074K" } } }