Saved in:
Bibliographic Details
Main Authors: Dokuchaev, Mikhailo, Jerez, Emmanuel
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2411.09824
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910699270176768
author Dokuchaev, Mikhailo
Jerez, Emmanuel
author_facet Dokuchaev, Mikhailo
Jerez, Emmanuel
contents Given a group \( G \), a field \( κ\), and a factor set \( σ\) arising from a partial projective \( κ\)-representation of \( G \). This leads to the construction of a topological partial dynamical system \( (Ω_σ, G, \hatθ) \), where \( Ω_σ\) is a compact, totally disconnected Hausdorff space, and \( σ\) acts as a twist for \( \hatθ \). We show that the twisted partial group algebra \( κ_{par}^σ G \) can be realized as a crossed product \( {\mathscr L}(Ω_σ) \rtimes_{(\hatθ, σ)} G \), with \( {\mathscr L}(Ω_σ) \) denoting the \( κ\)-algebra of locally constant functions \( Ω_σ\to κ\). The space \( Ω_σ\) corresponds to the spectrum of a unital commutative subalgebra in \( κ_{par}^σ G \), generated by idempotents. By describing \( Ω_σ\) as a subspace of the Bernoulli space \( 2^G \), we examine conditions under which the spectral partial action \( \hatθ \) is topologically free, impacting the ideal structure of \( κ_{par}^σ G \). We further explore generating idempotent factor sets of \( G \) and present conditions on them to ensure the topological freeness of \( \hatθ \). Inspired by Exel's semigroup \( \mathcal{S}(G) \), which governs partial actions and representations of \( G \) and relates to \( κ_{par}G \), we characterize the twisted partial group algebra \( κ_{par}^σG \) as generated by a \( κ\)-cancellative inverse semigroup constructed from elements of \( Ω_σ\). When \( Ω_σ\) is discrete, we demonstrate that \( κ_{par}^σ G \) decomposes into a product of matrix algebras over twisted subgroup algebras, generalizing known results for finite \( G \).
format Preprint
id arxiv_https___arxiv_org_abs_2411_09824
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Twisted partial group algebra and related topological partial dynamical system
Dokuchaev, Mikhailo
Jerez, Emmanuel
Rings and Algebras
Primary 16S35, Secondary 20C25
Given a group \( G \), a field \( κ\), and a factor set \( σ\) arising from a partial projective \( κ\)-representation of \( G \). This leads to the construction of a topological partial dynamical system \( (Ω_σ, G, \hatθ) \), where \( Ω_σ\) is a compact, totally disconnected Hausdorff space, and \( σ\) acts as a twist for \( \hatθ \). We show that the twisted partial group algebra \( κ_{par}^σ G \) can be realized as a crossed product \( {\mathscr L}(Ω_σ) \rtimes_{(\hatθ, σ)} G \), with \( {\mathscr L}(Ω_σ) \) denoting the \( κ\)-algebra of locally constant functions \( Ω_σ\to κ\). The space \( Ω_σ\) corresponds to the spectrum of a unital commutative subalgebra in \( κ_{par}^σ G \), generated by idempotents. By describing \( Ω_σ\) as a subspace of the Bernoulli space \( 2^G \), we examine conditions under which the spectral partial action \( \hatθ \) is topologically free, impacting the ideal structure of \( κ_{par}^σ G \). We further explore generating idempotent factor sets of \( G \) and present conditions on them to ensure the topological freeness of \( \hatθ \). Inspired by Exel's semigroup \( \mathcal{S}(G) \), which governs partial actions and representations of \( G \) and relates to \( κ_{par}G \), we characterize the twisted partial group algebra \( κ_{par}^σG \) as generated by a \( κ\)-cancellative inverse semigroup constructed from elements of \( Ω_σ\). When \( Ω_σ\) is discrete, we demonstrate that \( κ_{par}^σ G \) decomposes into a product of matrix algebras over twisted subgroup algebras, generalizing known results for finite \( G \).
title Twisted partial group algebra and related topological partial dynamical system
topic Rings and Algebras
Primary 16S35, Secondary 20C25
url https://arxiv.org/abs/2411.09824