Cocycle Superrigidity for Profinite Actions of Property (T) Groups

dc.creatorIoana, Adrian
dc.date2008-05-20
dc.date.accessioned2026-07-07T09:39:50Z
dc.date.available2026-07-07T09:39:50Z
dc.descriptionConsider a free ergodic measure preserving profinite action $Γ\curvearrowright X$ (i.e. an inverse limit of actions $Γ\curvearrowright X_n$, with $X_n$ finite) of a countable property (T) group $Γ$ (more generally of a group $Γ$ which admits an infinite normal subgroup $Γ_0$ such that the inclusion $Γ_0\subsetΓ$ has relative property (T) and $Γ/Γ_0$ is finitely generated) on a standard probability space $X$. We prove that if $w:Γ\times X\to Λ$ is a measurable cocycle with values in a countable group $Λ$, then $w$ is cohomologous to a cocycle $w'$ which factors through the map $Γ\times X\to Γ\times X_n$, for some $n$. As a corollary, we show that any orbit equivalence of $Γ\curvearrowright X$ with any free ergodic measure preserving action $Λ\curvearrowright Y$ comes from a (virtual) conjugacy of actions.
dc.identifierhttps://arxiv.org/abs/0805.2998
dc.identifierhttp://arxiv.org/abs/0805.2998
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/161324
dc.subjectGroup Theory
dc.subjectOperator Algebras
dc.subject37A20 ; 46L10
dc.titleCocycle Superrigidity for Profinite Actions of Property (T) Groups
dc.typetext

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