Szlenk and $w^\ast$-dentability indices of C$^\ast$-algebras

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Cheng, Lixin, Yu, Zhizheng
Formato: Preprint
Publicado: 2023
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866929302767927296
author Cheng, Lixin
Yu, Zhizheng
author_facet Cheng, Lixin
Yu, Zhizheng
contents Let $\mathcal A$ be a infinite dimensional C*-algebra and $1<p<\infty$. We compute the Szlenk index of $\mathcal A$ and $L_p(\mathcal A)$, and show that $Sz(\mathcal A)=Γ'(i(\mathcal A))$ and $Dz(\mathcal A)=Sz(L_p(\mathcal A))=ωSz(\mathcal A)=ωΓ'(i(\mathcal A))$, where $i(\mathcal A)$ is the noncommutative Cantor-Bendixson index, $Γ'(ξ)$ is the minimum ordinal number which is greater than $ξ$ of the form $ω^ζ$ for some $ζ$ and we agree that $Γ'(\infty)=\infty$ and $ω\cdot\infty=\infty$. As a application, we compute the Szlenk index [respectively, $w^\ast$-dentability index] of a C*-tensor product $\mathcal A\otimes_β\mathcal B$ of non-zero C*-algebras $\mathcal A$ and $\mathcal B$ in terms of $Sz(\mathcal A)$ and $Sz(\mathcal B)$ [respectively, $Dz(\mathcal A)$ and $Dz(\mathcal B)$]. When $\mathcal A$ is a separable C*-algebra, we show that there exists $a\in \mathcal A_h$ such that $Sz(\mathcal A)=Sz(C^\ast(a))$ and $Dz(\mathcal A)=Dz(C^\ast(a))$, where $C^\ast(a)$ is the C*-subalgebra of $\mathcal A$ generated by $a$.
format Preprint
id arxiv_https___arxiv_org_abs_2306_08515
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Szlenk and $w^\ast$-dentability indices of C$^\ast$-algebras
Cheng, Lixin
Yu, Zhizheng
Functional Analysis
Operator Algebras
Let $\mathcal A$ be a infinite dimensional C*-algebra and $1<p<\infty$. We compute the Szlenk index of $\mathcal A$ and $L_p(\mathcal A)$, and show that $Sz(\mathcal A)=Γ'(i(\mathcal A))$ and $Dz(\mathcal A)=Sz(L_p(\mathcal A))=ωSz(\mathcal A)=ωΓ'(i(\mathcal A))$, where $i(\mathcal A)$ is the noncommutative Cantor-Bendixson index, $Γ'(ξ)$ is the minimum ordinal number which is greater than $ξ$ of the form $ω^ζ$ for some $ζ$ and we agree that $Γ'(\infty)=\infty$ and $ω\cdot\infty=\infty$. As a application, we compute the Szlenk index [respectively, $w^\ast$-dentability index] of a C*-tensor product $\mathcal A\otimes_β\mathcal B$ of non-zero C*-algebras $\mathcal A$ and $\mathcal B$ in terms of $Sz(\mathcal A)$ and $Sz(\mathcal B)$ [respectively, $Dz(\mathcal A)$ and $Dz(\mathcal B)$]. When $\mathcal A$ is a separable C*-algebra, we show that there exists $a\in \mathcal A_h$ such that $Sz(\mathcal A)=Sz(C^\ast(a))$ and $Dz(\mathcal A)=Dz(C^\ast(a))$, where $C^\ast(a)$ is the C*-subalgebra of $\mathcal A$ generated by $a$.
title Szlenk and $w^\ast$-dentability indices of C$^\ast$-algebras
topic Functional Analysis
Operator Algebras
url https://arxiv.org/abs/2306.08515