Almost-Bieberbach groups with (in)finite outer automorphism group
نویسندگان
چکیده
منابع مشابه
Kazhdan Groups with Infinite Outer Automorphism Group
For each countable group Q we produce a short exact sequence 1 → N → G → Q → 1 where G is f.g. and has a graphical 1 6 presentation and N is f.g. and satisfies property T . As a consequence we produce a group N with property T such that Out(N) is infinite. Using the tools developed we are also able to produce examples of nonHopfian and non-coHopfian groups with property T . One of our main tool...
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Let Γ be a Bieberbach group it is a fundamental group of a flat manifold. In this paper we give necessary and sufficient conditions on Out(Γ) to be infinite. We also compare our result with the previous one ([8], Theorem 7.1) about Anosov automorphisms of flat manifolds. We give several examples of Bieberbach groups.
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We give simple examples of finitely presented Kazhdan groups with infinite outer automorphism groups, as arithmetic lattices in Lie groups. This answers a question of Paulin, independently answered by Ollivier and Wise by completely different methods. We also use results of Abels about compact presentability of p-adic groups to exhibit a finitely presented non-Hopfian Kazhdan group. This answer...
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We give simple examples of finitely presented Kazhdan groups with infinite outer automorphism groups, as arithmetic lattices in Lie groups. This answers a question of Paulin, independently answered by Ollivier and Wise by completely different methods. We also use results of Abels about compact presentability of p-adic groups to exhibit a finitely presented non-Hopfian Kazhdan group. This answer...
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ژورنال
عنوان ژورنال: Glasgow Mathematical Journal
سال: 1998
ISSN: 0017-0895,1469-509X
DOI: 10.1017/s0017089500032341