Subgroups of -factorizable groups

Constancio Hernández; Mihail G. Tkachenko

Commentationes Mathematicae Universitatis Carolinae (1998)

  • Volume: 39, Issue: 2, page 371-378
  • ISSN: 0010-2628

Abstract

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The properties of -factorizable groups and their subgroups are studied. We show that a locally compact group is -factorizable if and only if is -compact. It is proved that a subgroup of an -factorizable group is -factorizable if and only if is -embedded in . Therefore, a subgroup of an -factorizable group need not be -factorizable, and we present a method for constructing non--factorizable dense subgroups of a special class of -factorizable groups. Finally, we construct a closed -subgroup of an -factorizable group which is not -factorizable.

How to cite

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Hernández, Constancio, and Tkachenko, Mihail G.. "Subgroups of $\mathbb {R}$-factorizable groups." Commentationes Mathematicae Universitatis Carolinae 39.2 (1998): 371-378. <http://eudml.org/doc/22345>.

@article{Hernández1998,
abstract = {The properties of $\mathbb \{R\}$-factorizable groups and their subgroups are studied. We show that a locally compact group $G$ is $\mathbb \{R\}$-factorizable if and only if $G$ is $\sigma $-compact. It is proved that a subgroup $H$ of an $\mathbb \{R\}$-factorizable group $G$ is $\mathbb \{R\}$-factorizable if and only if $H$ is $z$-embedded in $G$. Therefore, a subgroup of an $\mathbb \{R\}$-factorizable group need not be $\mathbb \{R\}$-factorizable, and we present a method for constructing non-$\mathbb \{R\}$-factorizable dense subgroups of a special class of $\mathbb \{R\}$-factorizable groups. Finally, we construct a closed $G_\{\delta \}$-subgroup of an $\mathbb \{R\}$-factorizable group which is not $\mathbb \{R\}$-factorizable.},
author = {Hernández, Constancio, Tkachenko, Mihail G.},
journal = {Commentationes Mathematicae Universitatis Carolinae},
keywords = {$\mathbb \{R\}$-factorizable group; $z$-embedded set; $\aleph _0$-bounded group; $P$-group; Lindelöf group; -space; -group; pseudo--compact; -stable; -factorizable},
language = {eng},
number = {2},
pages = {371-378},
publisher = {Charles University in Prague, Faculty of Mathematics and Physics},
title = {Subgroups of $\mathbb \{R\}$-factorizable groups},
url = {http://eudml.org/doc/22345},
volume = {39},
year = {1998},
}

TY - JOUR
AU - Hernández, Constancio
AU - Tkachenko, Mihail G.
TI - Subgroups of $\mathbb {R}$-factorizable groups
JO - Commentationes Mathematicae Universitatis Carolinae
PY - 1998
PB - Charles University in Prague, Faculty of Mathematics and Physics
VL - 39
IS - 2
SP - 371
EP - 378
AB - The properties of $\mathbb {R}$-factorizable groups and their subgroups are studied. We show that a locally compact group $G$ is $\mathbb {R}$-factorizable if and only if $G$ is $\sigma $-compact. It is proved that a subgroup $H$ of an $\mathbb {R}$-factorizable group $G$ is $\mathbb {R}$-factorizable if and only if $H$ is $z$-embedded in $G$. Therefore, a subgroup of an $\mathbb {R}$-factorizable group need not be $\mathbb {R}$-factorizable, and we present a method for constructing non-$\mathbb {R}$-factorizable dense subgroups of a special class of $\mathbb {R}$-factorizable groups. Finally, we construct a closed $G_{\delta }$-subgroup of an $\mathbb {R}$-factorizable group which is not $\mathbb {R}$-factorizable.
LA - eng
KW - $\mathbb {R}$-factorizable group; $z$-embedded set; $\aleph _0$-bounded group; $P$-group; Lindelöf group; -space; -group; pseudo--compact; -stable; -factorizable
UR - http://eudml.org/doc/22345
ER -

References

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  6. Pontryagin L.S., Continuous Groups, Princeton Univ. Press, Princeton, 1939. Zbl0659.22001
  7. Tkačenko M.G., Subgroups, quotient groups and products of -factorizable groups, Topology Proceedings 16 (1991), 201-231. (1991) MR1206464
  8. Tkačenko M.G., Factorization theorems for topological groups and their applications, Topology Appl. 38 (1991), 21-37. (1991) MR1093863

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