Year: 2025
Type: article
Abstract: This paper targets to generalize the notion of Hopfian groups in the commutative case by defining the so-called relatively Hopfian groups and weakly Hopfian groups, respectively, and to establish some their crucial properties and characterizations. Specifically, we prove that for a reduced Abelian p-group G such that [Formula: see text] is Hopfian (in particular, is finite), the notions of relative Hopficity and ordinary Hopficity do coincide. We also show that if G is a reduced Abelian p-group such that [Formula: see text] is bounded and [Formula: see text] is Hopfian, then G is relatively Hopfian. This allows us to construct a reduced relatively Hopfian Abelian p-group G with [Formula: see text] an infinite elementary group such that G is not Hopfian. In contrast, for reduced torsion-free groups, we establish that the relative and ordinary Hopficity are equivalent. Moreover, the mixed case is explored as well, showing that the structure of both relatively and weakly Hopfian groups can be quite complicated.
Language: English
Topic: Rings, Modules, and Algebras
Subfield: Algebra and Number Theory
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
Funder: Junta de Andalucía
Awards: G1737173237, G4863683459
OpenAlex ID: W4414923887
