Structure of normally and finitely non-co-Hopfian groups
نویسندگان
چکیده
A group G is (finitely) co-Hopfian if it does not contain any proper (finite-index) subgroups isomorphic to itself. We study finitely generated groups that admit a descending chain of normal finite-index subgroups, each which G. prove up finite index, these are always obtained by pulling back from free abelian quotient. give two applications: First, we show characteristic subgroup arises the abelianization, and secondly, special cases (for subgroups) conjectures Benjamini Nekrashevych--Pete regarding classification scale-invariant groups.
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ژورنال
عنوان ژورنال: Groups, Geometry, and Dynamics
سال: 2021
ISSN: ['1661-7207', '1661-7215']
DOI: https://doi.org/10.4171/ggd/603