English

On Hopfian(co-Hopfian) and Fitting S-acts (I)

Group Theory 2022-10-12 v1

Abstract

The main purpose of the present work is an investigation of the notions Hopfian (co-Hopfian) acts whose their surjective (injective) endomorphisms are isomorphisms. While we investigate conditions that are relevant to these classes of acts, their interrelationship with some other concepts for example quasi-injective and Dedekind-finite acts is studied. Using Hopfian and co-Hopfian concepts, several conditions are given for a quasi-injective act to be Dedekind-finite. Moreover we bring out some properties of strongly Hopfian and strongly co-Hopfian SS-acts. Ultimately we introduce and study the concept of Fitting acts and over a monoid SS, some equivalent conditions are found to have all its finitely generated (cyclic) acts Fitting. It is shown that an SS-act is Fitting if and only if it is both strongly Hopfian and strongly co-Hopfian.

Keywords

Cite

@article{arxiv.2210.04970,
  title  = {On Hopfian(co-Hopfian) and Fitting S-acts (I)},
  author = {Mohammad Roueentan and Roghaieh Khosravi},
  journal= {arXiv preprint arXiv:2210.04970},
  year   = {2022}
}

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13 pages