Hopf property of a topologically finitely generated profinite group
ID: hopf-property-of-a-topologically-finitely-generated-profinite-group
Every topologically finitely generated group that is profinite has the topological Hopf property. There are only finitely many open subgroups of each given index, and inverse image under a surjective endomorphism permutes them. The endomorphism kernel consequently lies in every open normal subgroup and is trivial.
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