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Moyennabilite interieure et extensions HNN

Yves Stalder
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Abstract

We present sufficient conditions for HNN extensions to be inner amenable, respectively ICC, which give necessary and sufficient criteria among Baumslag-Solitar groups. We deduce that such a group, viewed as acting on its Bass-Serre tree, contains non trivial elements which fix unbounded subtrees.

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Yves Stalder. 2005-09-21. Moyennabilite interieure et extensions HNN. https://arxiv.org/abs/math/0505657

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