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Finitely presentable, non-Hopfian groups with Kazhdan's Property (T) and infinite outer automorphism group

Yves de Cornulier
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Abstract

We give simple examples of Kazhdan groups with infinite outer automorphism groups. This answers a question of Paulin, independently answered by Ollivier and Wise by completely different methods. As arithmetic lattices in (non-semisimple) Lie groups, our examples are in addition finitely presented. We also use results of Abels about compact presentability of p-adic groups to exhibit a finitely presented non-Hopfian Kazhdan group. This answers a question of Ollivier and Wise.

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BibTeXRIS

Yves de Cornulier. 2005-02-07. Finitely presentable, non-Hopfian groups with Kazhdan's Property (T) and infinite outer automorphism group. https://doi.org/10.1090/s0002-9939-06-08588-1

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