Displaying similar documents to “Outer automorphism groups of Bieberbach groups.”

Finite-finitary, polycyclic-finitary and Chernikov-finitary automorphism groups

B. A. F. Wehrfritz (2015)

Colloquium Mathematicae

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If X is a property or a class of groups, an automorphism ϕ of a group G is X-finitary if there is a normal subgroup N of G centralized by ϕ such that G/N is an X-group. Groups of such automorphisms for G a module over some ring have been very extensively studied over many years. However, for groups in general almost nothing seems to have been done. In 2009 V. V. Belyaev and D. A. Shved considered the general case for X the class of finite groups. Here we look further at the finite case...

Affinely equivalent complete flat manifolds

Michal Sadowski (2004)

Open Mathematics

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Let E Aff(Γ,G, m) be the set of affine equivalence classes of m-dimensional complete flat manifolds with a fixed fundamental group Γ and a fixed holonomy group G. Let n be the dimension of a closed flat manifold whose fundamental group is isomorphic to Γ. We describe E Aff(Γ,G, m) in terms of equivalence classes of pairs (ε, ρ), consisting of epimorphisms of Γ onto G and representations of G in ℝm-n. As an application we give some estimates of card E Aff(Γ,G, m).

On a question of M. Conder

M. Chiara Tamburini, Paola Zucca (2000)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

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We show that the special linear group S ⁢ L ⁢ 3 , Z , over the integers, is not 2 , 3 -generated. This gives a negative answer to a question of M. Conder.