Inner amenability and conjugation operators

Paschke, William L.

doi:10.1090/S0002-9939-1978-0473849-5

Inner amenability and conjugation operators

Author: William L. Paschke
Journal: Proc. Amer. Math. Soc. 71 (1978), 117-118
MSC: Primary 46L05; Secondary 22D25
DOI: https://doi.org/10.1090/S0002-9939-1978-0473849-5
MathSciNet review: 0473849
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Abstract: It is shown that an infinite discrete group G is inner amenable if and only if the ${C^ \ast }$ -algebra generated by the unitaries on ${l^2}(G)$ corresponding to conjugation by s $(s \in G)$ does not contain the projection on the point-mass at the identity.

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