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On Groups whose Contranormal Subgroups are Normally Complemented

Kurdachenko, L. A., Subbotin, I. Ya. (2011)

Serdica Mathematical Journal

2000 Mathematics Subject Classification: 20F16, 20E15.Groups in which every contranormal subgroup is normally complemented has been considered. The description of such groups G with the condition Max-n and such groups having an abelian nilpotent residual satisfying Min-G have been obtained.

On groups with linear sci growth

Louis Funar, Martha Giannoudovardi, Daniele Ettore Otera (2015)

Fundamenta Mathematicae

We prove that the semistability growth of hyperbolic groups is linear, which implies that hyperbolic groups which are sci (simply connected at infinity) have linear sci growth. Based on the linearity of the end-depth of finitely presented groups we show that the linear sci is preserved under amalgamated products over finitely generated one-ended groups. Eventually one proves that most non-uniform lattices have linear sci.

On groups with many nearly maximal subgroups

Silvana Franciosi, Francesco de Giovanni (1998)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

A subgroup M of a group G is nearly maximal if the index | G : M | is infinite but every subgroup of G properly containing M has finite index, and the group G is called nearly I M if all its subgroups of infinite index are intersections of nearly maximal subgroups. It is proved that an infinite (generalized) soluble group is nearly I M if and only if it is either cyclic or dihedral.

On groups with property

Olympia Talelli (1988)

Δελτίο της Ελληνικής Μαθηματικής Εταιρίας

On homological classification of pomonoids by GP-po-flatness ofS-posets

Xingliang Liang, Xinyang Feng, Yanfeng Luo (2016)

Open Mathematics

In this paper, we introduce GP-po-flatness property of S-posets over a pomonoid S, which lies strictly between principal weak po-flatness and po-torsion freeness. Furthermore, we investigate the homological classification problems of pomonoids by using this new property. Finally, we consider direct products of GP-po-flat S-posets. As an application, characterizations of pomonoids over which direct products of nonempty families of principally weakly po-flat S-posets are principally weakly po-flat...

On homological classification of pomonoids by regular weak injectivity properties of S-posets

Xia Zhang, Valdis Laan (2007)

Open Mathematics

If S is a partially ordered monoid then a right S-poset is a poset A on which S acts from the right in such a way that the action is compatible both with the order of S and A. By regular weak injectivity properties we mean injectivity properties with respect to all regular monomorphisms (not all monomorphisms) from different types of right ideals of S to S. We give an alternative description of such properties which uses systems of equations. Using these properties we prove several so-called homological...

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