Subgroups of $\Bbb R$-factorizable groups
Commentationes Mathematicae Universitatis Carolinae, Tome 39 (1998) no. 2, pp. 371-378
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The properties of $\Bbb R$-factorizable groups and their subgroups are studied. We show that a locally compact group $G$ is $\Bbb R$-factorizable if and only if $G$ is $\sigma$-compact. It is proved that a subgroup $H$ of an $\Bbb R$-factorizable group $G$ is $\Bbb R$-factorizable if and only if $H$ is $z$-embedded in $G$. Therefore, a subgroup of an $\Bbb R$-factorizable group need not be $\Bbb R$-factorizable, and we present a method for constructing non-$\Bbb R$-factorizable dense subgroups of a special class of $\Bbb R$-factorizable groups. Finally, we construct a closed $G_{\delta}$-subgroup of an $\Bbb R$-fac\-torizable group which is not $\Bbb R$-factorizable.
The properties of $\Bbb R$-factorizable groups and their subgroups are studied. We show that a locally compact group $G$ is $\Bbb R$-factorizable if and only if $G$ is $\sigma$-compact. It is proved that a subgroup $H$ of an $\Bbb R$-factorizable group $G$ is $\Bbb R$-factorizable if and only if $H$ is $z$-embedded in $G$. Therefore, a subgroup of an $\Bbb R$-factorizable group need not be $\Bbb R$-factorizable, and we present a method for constructing non-$\Bbb R$-factorizable dense subgroups of a special class of $\Bbb R$-factorizable groups. Finally, we construct a closed $G_{\delta}$-subgroup of an $\Bbb R$-fac\-torizable group which is not $\Bbb R$-factorizable.
Classification :
22A05, 22D05, 54C50, 54H11
Keywords: $\Bbb R$-factorizable group; $z$-embedded set; $\aleph_0$-bounded group; $P$-group; Lindelöf group
Keywords: $\Bbb R$-factorizable group; $z$-embedded set; $\aleph_0$-bounded group; $P$-group; Lindelöf group
@article{CMUC_1998_39_2_a13,
author = {Hern\'andez, Constancio and Tka\v{c}enko, Michael},
title = {Subgroups of $\Bbb R$-factorizable groups},
journal = {Commentationes Mathematicae Universitatis Carolinae},
pages = {371--378},
year = {1998},
volume = {39},
number = {2},
mrnumber = {1651979},
zbl = {1100.54026},
language = {en},
url = {http://geodesic.mathdoc.fr/item/CMUC_1998_39_2_a13/}
}
TY - JOUR AU - Hernández, Constancio AU - Tkačenko, Michael TI - Subgroups of $\Bbb R$-factorizable groups JO - Commentationes Mathematicae Universitatis Carolinae PY - 1998 SP - 371 EP - 378 VL - 39 IS - 2 UR - http://geodesic.mathdoc.fr/item/CMUC_1998_39_2_a13/ LA - en ID - CMUC_1998_39_2_a13 ER -
Hernández, Constancio; Tkačenko, Michael. Subgroups of $\Bbb R$-factorizable groups. Commentationes Mathematicae Universitatis Carolinae, Tome 39 (1998) no. 2, pp. 371-378. http://geodesic.mathdoc.fr/item/CMUC_1998_39_2_a13/