Mapping theorems on -spaces

Masami Sakai

Commentationes Mathematicae Universitatis Carolinae (2008)

  • Volume: 49, Issue: 1, page 163-167
  • ISSN: 0010-2628

Abstract

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In this paper we improve some mapping theorems on -spaces. For instance we show that an -space is preserved by a closed and countably bi-quotient map. This is an improvement of Yun Ziqiu’s theorem: an -space is preserved by a closed and open map.

How to cite

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Sakai, Masami. "Mapping theorems on $\aleph $-spaces." Commentationes Mathematicae Universitatis Carolinae 49.1 (2008): 163-167. <http://eudml.org/doc/250293>.

@article{Sakai2008,
abstract = {In this paper we improve some mapping theorems on $\aleph $-spaces. For instance we show that an $\aleph $-space is preserved by a closed and countably bi-quotient map. This is an improvement of Yun Ziqiu’s theorem: an $\aleph $-space is preserved by a closed and open map.},
author = {Sakai, Masami},
journal = {Commentationes Mathematicae Universitatis Carolinae},
keywords = {$\aleph $-space; $k$-network; closed map; countably bi-quotient map; -space; -network; closed map; countably bi-quotient map},
language = {eng},
number = {1},
pages = {163-167},
publisher = {Charles University in Prague, Faculty of Mathematics and Physics},
title = {Mapping theorems on $\aleph $-spaces},
url = {http://eudml.org/doc/250293},
volume = {49},
year = {2008},
}

TY - JOUR
AU - Sakai, Masami
TI - Mapping theorems on $\aleph $-spaces
JO - Commentationes Mathematicae Universitatis Carolinae
PY - 2008
PB - Charles University in Prague, Faculty of Mathematics and Physics
VL - 49
IS - 1
SP - 163
EP - 167
AB - In this paper we improve some mapping theorems on $\aleph $-spaces. For instance we show that an $\aleph $-space is preserved by a closed and countably bi-quotient map. This is an improvement of Yun Ziqiu’s theorem: an $\aleph $-space is preserved by a closed and open map.
LA - eng
KW - $\aleph $-space; $k$-network; closed map; countably bi-quotient map; -space; -network; closed map; countably bi-quotient map
UR - http://eudml.org/doc/250293
ER -

References

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  9. Siwiec F., Mancuso V.J., 10.1016/0016-660X(71)90108-5, General Topology Appl. 1 (1971), 33-41. (1971) Zbl0216.44203MR0282347DOI10.1016/0016-660X(71)90108-5
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  11. Ziqiu Y., A new characterization of -spaces, Topology Proc. 16 (1991), 253-256. (1991) Zbl0784.54029

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