Stallings theorem about ends of groups

GPTKB entity

Statements (15)
Predicate Object
gptkbp:instanceOf gptkb:mathematical_concept
gptkbp:concerns ends of groups
gptkbp:field group theory
https://www.w3.org/2000/01/rdf-schema#label Stallings theorem about ends of groups
gptkbp:implies A finitely generated infinite group has 1, 2, or infinitely many ends.
gptkbp:namedAfter gptkb:John_R._Stallings
gptkbp:publishedIn gptkb:Annals_of_Mathematics
gptkbp:relatedTo gptkb:Bass–Serre_theory
gptkb:Serre's_theorem_on_trees
accessibility of groups
gptkbp:state A finitely generated group has more than one end if and only if it splits as a nontrivial amalgamated free product or HNN extension over a finite subgroup.
gptkbp:usedIn geometric group theory
gptkbp:yearProved 1971
gptkbp:bfsParent gptkb:John_R._Stallings
gptkbp:bfsLayer 7