A note on paratopological groups
Commentationes Mathematicae Universitatis Carolinae, Tome 47 (2006) no. 4, pp. 633-640
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In this paper, it is proved that a first-countable paratopological group has a regular $G_{\delta}$-diagonal, which gives an affirmative answer to Arhangel'skii and Burke's question [{\it Spaces with a regular $G_{\delta}$-diagonal\/}, Topology Appl. {\bf 153} (2006), 1917--1929]. If $G$ is a symmetrizable paratopological group, then $G$ is a developable space. We also discuss copies of $S_\omega$ and of $S_2$ in paratopological groups and generalize some Nyikos [{\it Metrizability and the Fréchet-Urysohn property in topological groups\/}, Proc. Amer. Math. Soc. {\bf 83} (1981), no. 4, 793--801] and Svetlichnyi [{\it Intersection of topologies and metrizability in topological groups\/}, Vestnik Moskov. Univ. Ser. I Mat. Mekh. {\bf 4} (1989), 79--81] results.
In this paper, it is proved that a first-countable paratopological group has a regular $G_{\delta}$-diagonal, which gives an affirmative answer to Arhangel'skii and Burke's question [{\it Spaces with a regular $G_{\delta}$-diagonal\/}, Topology Appl. {\bf 153} (2006), 1917--1929]. If $G$ is a symmetrizable paratopological group, then $G$ is a developable space. We also discuss copies of $S_\omega$ and of $S_2$ in paratopological groups and generalize some Nyikos [{\it Metrizability and the Fréchet-Urysohn property in topological groups\/}, Proc. Amer. Math. Soc. {\bf 83} (1981), no. 4, 793--801] and Svetlichnyi [{\it Intersection of topologies and metrizability in topological groups\/}, Vestnik Moskov. Univ. Ser. I Mat. Mekh. {\bf 4} (1989), 79--81] results.
Classification :
22A30, 54E30, 54H13, 54H99
Keywords: paratopological group; symmetrizable spaces; regular $G_{\delta}$-diagonal; weak bases; Arens space
Keywords: paratopological group; symmetrizable spaces; regular $G_{\delta}$-diagonal; weak bases; Arens space
@article{CMUC_2006_47_4_a8,
author = {Liu, Chuan},
title = {A note on paratopological groups},
journal = {Commentationes Mathematicae Universitatis Carolinae},
pages = {633--640},
year = {2006},
volume = {47},
number = {4},
mrnumber = {2337418},
zbl = {1150.54036},
language = {en},
url = {http://geodesic.mathdoc.fr/item/CMUC_2006_47_4_a8/}
}
Liu, Chuan. A note on paratopological groups. Commentationes Mathematicae Universitatis Carolinae, Tome 47 (2006) no. 4, pp. 633-640. http://geodesic.mathdoc.fr/item/CMUC_2006_47_4_a8/