PreprintCC BY 4.0arXiv
Certain Cuntz semigroup properties of extension C*-algebras
Abstract
Let 0 xrightarrowI xrightarrow A xrightarrow A/I xrightarrow 0 be a short exact sequence of C*-algebras. In this paper, we prove that if dim(Cu(I))≤ n and dim(Cu(A/I))≤ m, then dim(Cu(A))≤ n+m+1, this result gives an affirmative answer to a problem concerning the Cu-semigroup of C*-algebras raised by Thiel and Vilalta. We further show that certain comparison and divisibility properties satisfied by I and A/I are inherited by the extension algebra A. As an application, we provide an alternative proof of equivalence that A is pure if and only if I and A/I, a result originally proven by Perera, Thiel, and Vilalta.
Related
- The Cuntz semigroup of rings with stable rank one
- The Cuntz semigroup of the graph C*-algebra of a finite graph
- Homotopies of constant Cuntz classes in pure C*-algebras
- Stabilization theorem and symmetric structure of Cuntz--Pimsner algebras
- Integral quiver presentations for ℛ-trivial semigroup algebras
BibTeX
@misc{fan2026certain,
title = {{Certain Cuntz semigroup properties of extension C*-algebras}},
author = {Qingzhai Fan},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.27694},
eprint = {2609.27694},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.27694},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Certain Cuntz semigroup properties of extension C*-algebras
AU - Qingzhai Fan
PY - 2026
DA - 2026/09/23
PB - arXiv
DO - 10.48550/arxiv.2609.27694
UR - https://arxiv.org/abs/2609.27694
AB - Let 0 xrightarrowI xrightarrow A xrightarrow A/I xrightarrow 0 be a short exact sequence of C*-algebras. In this paper, we prove that if dim(Cu(I))≤ n and dim(Cu(A/I))≤ m, then dim(Cu(A))≤ n+m+1, this result gives an affirmative answer to a problem concerning the Cu-semigroup of C*-algebras raised by Thiel and Vilalta. We further show that certain comparison and divisibility properties satisfied by I and A/I are inherited by the extension algebra A. As an application, we provide an alternative proof of equivalence that A is pure if and only if I and A/I, a result originally proven by Perera, Thiel, and Vilalta.
ER -