Strongly singular MASA's and mixing actions in finite von Neumann algebras

dc.creatorJolissaint, Paul
dc.creatorStalder, Yves
dc.date2006-02-08
dc.date2008-01-16
dc.date.accessioned2026-07-07T08:54:40Z
dc.date.available2026-07-07T08:54:40Z
dc.descriptionLet $Γ$ be a countable group and let $Γ_0$ be an infinite abelian subgroup of $Γ$. We prove that if the pair $(Γ,Γ_0)$ satisfies some combinatorial condition called (SS), then the abelian subalgebra $A=L(Γ_0)$ is a singular MASA in $M=L(Γ)$ which satisfies a weakly mixing condition. If moreover it satisfies a stronger condition called (ST), then it provides a singular MASA with a strictly stronger mixing property. We describe families of examples of both types coming from free products, HNN extentions and semidirect products, and in particular we exhibit examples of singular MASA's that satisfy the weak mixing condition but not the strong mixing one.
dc.descriptionTitle updated, examples and references added. To appear in Ergod. Th. & Dynam. Syst
dc.identifierhttps://arxiv.org/abs/math/0602158
dc.identifierhttp://arxiv.org/abs/math/0602158
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/146020
dc.subjectOperator Algebras
dc.subjectGroup Theory
dc.subject46L10; 20E06
dc.titleStrongly singular MASA's and mixing actions in finite von Neumann algebras
dc.typetext

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