Garit, V. P.; Zamorzaev, A. M. On a subgroup of finite index in the \(n\)-dimensional discrete group of affine transformations. (Russian) Zbl 0722.20035 Mat. Issled. 103, 43-51 (1988). It is proved that if H is a subgroup of finite index in the group of affine motions G, then for G to be n-dimensional and discrete it is necessary and sufficient for H to be n-dimensional and discrete. Reviewer: K.Riives (Tartu) MSC: 20H15 Other geometric groups, including crystallographic groups 20E07 Subgroup theorems; subgroup growth 57S30 Discontinuous groups of transformations 22E40 Discrete subgroups of Lie groups 51F15 Reflection groups, reflection geometries Keywords:subgroup of finite index; group of affine motions PDF BibTeX XML Cite \textit{V. P. Garit} and \textit{A. M. Zamorzaev}, Mat. Issled. 103, 43--51 (1988; Zbl 0722.20035) Full Text: EuDML