Bulletin of the Belgian Mathematical Society - Simon Stevin

Notes on $C_0$-representations and the Haagerup property

Paul Jolissaint

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For any locally compact group $G$, we show the existence and uniqueness up to quasi-equivalence of a unitary $C_0$-representation $\pi_0$ of $G$ such that the coefficient functions of $C_0$-representations of $G$ are exactly the coefficient functions of $\pi_0$. The present work, strongly influenced by [4] (which dealt exclusively with discrete groups), leads to new characterizations of the Haagerup property: $G$ has that property if and only if the representation $\pi_0$ induces a $*$-isomorphism of $C^*(G)$ onto $C^*_{\pi_0}(G)$. When $G$ is discrete and countable, we also relate the Haagerup property to relative strong mixing properties in the sense of [9] of the group von Neumann algebra $L(G)$ into finite von Neumann algebras.

Article information

Bull. Belg. Math. Soc. Simon Stevin, Volume 21, Number 2 (2014), 263-274.

First available in Project Euclid: 20 May 2014

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Digital Object Identifier

Mathematical Reviews number (MathSciNet)

Zentralblatt MATH identifier

Primary: 22D10: Unitary representations of locally compact groups 22D25: $C^*$-algebras and $W^*$-algebras in relation to group representations [See also 46Lxx]
Secondary: 46L10: General theory of von Neumann algebras

Locally compact groups unitary representations $C^*$-algebras von Neumann algebras strong mixing Følner sequences


Jolissaint, Paul. Notes on $C_0$-representations and the Haagerup property. Bull. Belg. Math. Soc. Simon Stevin 21 (2014), no. 2, 263--274. doi:10.36045/bbms/1400592624. https://projecteuclid.org/euclid.bbms/1400592624

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