Kazhdan groups with infinite 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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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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H"{o}lder in 1893 characterized all groups of order $pqr$ where $p>q>r$ are prime numbers. In this paper, by using new presentations of these groups, we compute their full automorphism group.
متن کاملOn Outer Automorphism Groups of Coxeter Groups
It is shown that the outer automorphism group of a Coxeter group W of nite rank is nite if the Coxeter graph contains no innnite bonds. A key step in the proof is to show that if the group is irreducible and 1 and 2 any two bases of the root system of W, then 2 = w 1 for some w 2 W. The proof of this latter fact employs some properties of the dominance order on the root system introduced by Bri...
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ژورنال
عنوان ژورنال: Transactions of the American Mathematical Society
سال: 2006
ISSN: 0002-9947,1088-6850
DOI: 10.1090/s0002-9947-06-03941-9