Deprecated: $wgMWOAuthSharedUserIDs=false is deprecated, set $wgMWOAuthSharedUserIDs=true, $wgMWOAuthSharedUserSource='local' instead [Called from MediaWiki\HookContainer\HookContainer::run in /var/www/html/w/includes/HookContainer/HookContainer.php at line 135] in /var/www/html/w/includes/Debug/MWDebug.php on line 372
On countable connected locally connected almost regular Urysohn spaces - MaRDI portal

On countable connected locally connected almost regular Urysohn spaces (Q789765)

From MaRDI portal





scientific article; zbMATH DE number 3846438
Language Label Description Also known as
English
On countable connected locally connected almost regular Urysohn spaces
scientific article; zbMATH DE number 3846438

    Statements

    On countable connected locally connected almost regular Urysohn spaces (English)
    0 references
    0 references
    0 references
    1984
    0 references
    The following question was raised by \textit{G. X. Ritter} [General Topol. Appl. 7, 65-70 (1977; Zbl 0341.54019)]: Does there exist a countable connected locally connected Urysohn space which is almost regular? We answer this question in the affirmative and in fact, show that not only are there as many as \(2^ c\) such spaces but that there are just as many rigid spaces with the same properties. Furthermore we show that every countable Urysohn space is a subspace of such a space. We also prove that every countable group is isomorphic to the group of autohomeomorphisms of some connected locally connected almost regular Urysohn space. Examples are given of groups of order c which can be represented in this manner.
    0 references
    countable connected locally connected Urysohn space
    0 references
    rigid spaces
    0 references
    countable Urysohn space
    0 references
    subspace
    0 references
    countable group
    0 references
    group of autohomeomorphisms of some connected locally connected almost regular Urysohn space
    0 references

    Identifiers