Powered by OpenAIRE graph
Found an issue? Give us feedback
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao zbMATH Openarrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
zbMATH Open
Article . 2016
Data sources: zbMATH Open
https://doi.org/10.1112/plms/p...
Article . 2016 . Peer-reviewed
Data sources: Crossref
versions View all 2 versions
addClaim

Noncommutative topological dynamics

Authors: Rainone, Timothy;

Noncommutative topological dynamics

Abstract

When a group acts on a \(C^*\)-algebra \(A\), this induces actions on the Cuntz semigroup \(W(A)\) of \(A\) and on the \(K\)-theory group \(K_0(A)\). The present article studies to what extent important properties of the dynamics may be captured by these induced actions, which are much simpler than the original action. The article studies such notions of minimality, topological transitivity, and topological freeness. The author defines notions of \(K_0\)-minimality and \(W\)-minimality and shows that the action is \(W\)-minimal if and only if \(A\) has no ideals that are invariant under the group action. Any \(W\)-minimal action is also \(K_0\)-minimal, and the converse holds if \(A\) has cancellation and any ideal in \(A\) admits a non-zero projection. This also leads to a characterisation of minimality in terms of states on the ordered \(K_0\)-group of \(A\) if \(A\) is stably finite and all ideals in \(A\) contain non-zero projections. A group action on \(A\) should be called topologically transitive if any two non-zero invariant ideals in \(A\) have a non-zero intersection. In the presence of the intersection property, this is equivalent to the crossed product being a prime \(C^*\)-algebra. The intersection property says that any non-zero ideal in the crossed product has a non-zero intersection with \(A\). This article introduces variants of topological transitivity on the Cuntz semigroup and \(K_0\). The Cuntz semigroup version of this notion is related to the primeness of the crossed product. This suggests that it could very often be equivalent to topological transitivity as defined above. Finally, shadows of topological freeness of a group action on the Cuntz semigroup \(W(A)\) and \(K_0(A)\) are introduced. If \(A\) is commutative, then the Cuntz semigroup version of topological freeness is equivalent to ordinary topological freeness. If every non-zero hereditary subalgebra of \(A\) contains a projection and cancellation holds, then the \(K_0(A)\)- and \(W(A)\)-versions of topological freeness are equivalent.

Related Organizations
Keywords

topologically transitive group action, Cuntz semigroup, prime \(C^*\)-algebra, minimal group action, topologically free group action, simple \(C^*\)-algebra, \(K\)-theory and operator algebras (including cyclic theory), aperiodic group action, crossed product, \(K\)-theory, Noncommutative dynamical systems

  • BIP!
    Impact byBIP!
    selected citations
    These citations are derived from selected sources.
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    2
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
Powered by OpenAIRE graph
Found an issue? Give us feedback
selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
2
Average
Average
Average
Upload OA version
Are you the author of this publication? Upload your Open Access version to Zenodo!
It’s fast and easy, just two clicks!