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
Generalized cotorsion locally compact abelian groups - MaRDI portal

Generalized cotorsion locally compact abelian groups (Q442632)

From MaRDI portal





scientific article; zbMATH DE number 6063120
Language Label Description Also known as
English
Generalized cotorsion locally compact abelian groups
scientific article; zbMATH DE number 6063120

    Statements

    Generalized cotorsion locally compact abelian groups (English)
    0 references
    3 August 2012
    0 references
    locally compact groups
    0 references
    character group
    0 references
    homological characteristics of groups
    0 references
    cotorsion groups
    0 references
    A discrete group \(A\) is called a cotorsion group iff \(Ext(Q,A)=0\), where \(Q\) is the additive group of rational numbers. (Here \(Ext(Q,A)=0\) is the group of all extensions of \(A\) by \(Q\).) Cotorsion groups play an important role in the theory of abelian groups. In the paper, a new class of locally compact abelian groups is constructed, which contains the class of cotorsion groups and its dual. The objects of this new class are called generalized cotorsion groups.NEWLINENEWLINE One of the main results of the paper: Theorem. The class of generalized cotorsion locally compact groups is closed under taking:NEWLINENEWLINE 1) extensions;NEWLINENEWLINE 2) finite direct sums;NEWLINENEWLINE 3) topologically direct summands;NEWLINENEWLINE 4) compact subgroups;NEWLINENEWLINE 5) discrete epimorphic images.NEWLINENEWLINE Some homological properties of generalized cotorsion groups are given.NEWLINENEWLINE Some results on the classification of generalized cotorsion groups are obtained.
    0 references

    Identifiers

    0 references
    0 references
    0 references
    0 references
    0 references