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arXiv · 0704.3645

Cancellation for inclusions of C*-algebras of finite depth

Ja A Jeong·Hiroyuki Osaka·N. Christopher Phillips·Tamotsu Teruya
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Abstract

Let B be a unital C*-algebra, let A be a unital subalgebra, and let E be a conditional expectation from B to A with index-finite type and a quasi-basis of n elements. Then the topological stable rank satisfies \tsr (B) \leq \tsr (A) + n - 1. As an application, we show that if a unital inclusion A \subset B of C*-algebras has index-finite type and finite depth, and A is simple with stable rank one and Property (SP), then B has cancellation. In particular, if A is a simple unital C*-algebra with stable rank one and Property (SP), and a finite group G acts on A, then the crossed product has cancellation. Separately, if the group is the integers, we obtain cancellation under the additional hypotheses that the group action is outer and is trivial on K_0 (A).

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Ja A Jeong, Hiroyuki Osaka, N. Christopher Phillips, Tamotsu Teruya. 2007-04-27. Cancellation for inclusions of C*-algebras of finite depth. https://arxiv.org/abs/0704.3645

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