{ "id": "0908.2228", "version": "v3", "published": "2009-08-16T10:05:59.000Z", "updated": "2009-11-20T07:57:32.000Z", "title": "The topological structure of direct limits in the category of uniform spaces", "authors": [ "Taras Banakh", "Dusan Repovs" ], "comment": "10 pages", "journal": "Topology Appl. 157:6 (2010), 1091-1100", "doi": "10.1016/j.topol.2010.01.010", "categories": [ "math.GN", "math.CT" ], "abstract": "Let $(X_n)_{n}$ be a sequence of uniform spaces such that each space $X_n$ is a closed subspace in $X_{n+1}$. We give an explicit description of the topology and uniformity of the direct limit $u-lim X_n$ of the sequence $(X_n)$ in the category of uniform spaces. This description implies that a function $f:u-lim X_n\\to Y$ to a uniform space $Y$ is continuous if for every $n$ the restriction $f|X_n$ is continuous and regular at the subset $X_{n-1}$ in the sense that for any entourages $U\\in\\U_Y$ and $V\\in\\U_X$ there is an entourage $V\\in\\U_X$ such that for each point $x\\in B(X_{n-1},V)$ there is a point $x'\\in X_{n-1}$ with $(x,x')\\in V$ and $(f(x),f(x'))\\in U$. Also we shall compare topologies of direct limits in various categories.", "revisions": [ { "version": "v3", "updated": "2009-11-20T07:57:32.000Z" } ], "analyses": { "subjects": [ "46A13", "54B30", "54E15", "54H11" ], "keywords": [ "uniform space", "direct limit", "topological structure", "explicit description", "compare topologies" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0908.2228B" } } }