Boundaries of Reduced Free Group C*-Algebras

Narutaka Ozawa

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Boundaries of Reduced Free Group C*-Algebras

Narutaka Ozawa

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Abstract

We prove that the crossed product $C^*$-algebra $C^*_r(\Gamma,\partial\Gamma)$ of a free group $\Gamma$ with its boundary $\partial\Gamma$ naturally sits between the reduced group $C^*$-algebra $C^*_r\Gamma$ and its injective envelope $I(C^*_r\Gamma)$. In other words, we have natural inclusion $C^*_r\Gamma \subset C^*_r(\Gamma,\partial\Gamma) \subset I(C^*_r\Gamma)$ of $C^*$-algebras.

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Narutaka Ozawa. 2004-11-22. Boundaries of Reduced Free Group C*-Algebras. https://arxiv.org/abs/math/0411474

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