A non-separable Christensen's theorem and set tri-quotient maps
| dc.creator | Nedev, S. | |
| dc.creator | Pelant, J. | |
| dc.creator | Valov, V. | |
| dc.date | 2008-01-11 | |
| dc.date | 2008-01-19 | |
| dc.date.accessioned | 2026-07-07T08:55:14Z | |
| dc.date.available | 2026-07-07T08:55:14Z | |
| dc.description | For every space $X$ let $\mathcal K(X)$ be the set of all compact subsets of $X$. Christensen \cite{c:74} proved that if $X, Y$ are separable metrizable spaces and $F\colon\mathcal{K}(X)\to\mathcal{K}(Y)$ is a monotone map such that any $L\in\mathcal{K}(Y)$ is covered by $F(K)$ for some $K\in\mathcal{K}(X)$, then $Y$ is complete provided $X$ is complete. It is well known \cite{bgp} that this result is not true for non-separable spaces. In this paper we discuss some additional properties of $F$ which guarantee the validity of Christensen's result for more general spaces. | |
| dc.description | 11 pages | |
| dc.identifier | https://arxiv.org/abs/0801.1717 | |
| dc.identifier | http://arxiv.org/abs/0801.1717 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/146207 | |
| dc.subject | General Topology | |
| dc.subject | 54C60 (Primary); 54E50 (Secondary) | |
| dc.title | A non-separable Christensen's theorem and set tri-quotient maps | |
| dc.type | text |