On Diagonal bimodules of étale groupoid $C^*$-algebras

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Liu, Rui, Qiang, Xiangqi, Hou, Chengjun
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866918216201142272
author Liu, Rui
Qiang, Xiangqi
Hou, Chengjun
author_facet Liu, Rui
Qiang, Xiangqi
Hou, Chengjun
contents We study diagonal bimodules of étale groupoid $C^*$-algebras over their canonical diagonal subalgebras, and establish necessary and sufficient conditions for such a bimodule to be spectral-that is, determined by its spectrum. For a class of $Γ$-graded étale groupoids, we prove that the spectrality of diagonal bimodules is equivalent to their invariance under the action of the dual group $\widehatΓ$ in the abelian case, or under the coaction of $Γ$ in the nonabelian case, on the groupoid $C^*$-algebras, both of which are induced by the underlying cocycle. This framework covers transformation groupoids arising from homeomorphism actions of countable groups, as well as from local homeomorphism actions of Ore semigroups. As applications, we characterize the spectrality of closed two-sided ideals and subalgebras that contain the diagonal subalgebra of étale groupoid $C^*$-algebras.
format Preprint
id arxiv_https___arxiv_org_abs_2511_18459
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On Diagonal bimodules of étale groupoid $C^*$-algebras
Liu, Rui
Qiang, Xiangqi
Hou, Chengjun
Operator Algebras
We study diagonal bimodules of étale groupoid $C^*$-algebras over their canonical diagonal subalgebras, and establish necessary and sufficient conditions for such a bimodule to be spectral-that is, determined by its spectrum. For a class of $Γ$-graded étale groupoids, we prove that the spectrality of diagonal bimodules is equivalent to their invariance under the action of the dual group $\widehatΓ$ in the abelian case, or under the coaction of $Γ$ in the nonabelian case, on the groupoid $C^*$-algebras, both of which are induced by the underlying cocycle. This framework covers transformation groupoids arising from homeomorphism actions of countable groups, as well as from local homeomorphism actions of Ore semigroups. As applications, we characterize the spectrality of closed two-sided ideals and subalgebras that contain the diagonal subalgebra of étale groupoid $C^*$-algebras.
title On Diagonal bimodules of étale groupoid $C^*$-algebras
topic Operator Algebras
url https://arxiv.org/abs/2511.18459