On a property of groups with coverings.
On almost normal subgroups of supersoluble groups
Un sottogruppo di un gruppo si dice «almost normal» se ha soltanto un numero finito di coniugati in , e ovviamente l'insieme costituito dai sottogruppi almost normal di è un sottoreticolo del reticolo di tutti i sottogruppi di . In questo articolo vengono studiati gli isomorfismi tra reticoli di sottogruppi almost normal, provando in particolare che se è un gruppo supersolubile e è un gruppo FC-risolubile tale che i reticoli e sono isomorfi, allora anche è supersolubile, e...
On certain characterizations of barely transitive groups
On deficient products in infinite groups
On minimal Artinian modules and minimal Artinian linear groups.
On minimal non CC-groups.
In this work it is shown that a locally graded minimal non CC-group G has an epimorphic image which is a minimal non FC-group and there is no element in G whose centralizer is nilpotent-by-Chernikov. Furthermore Theorem 3 shows that in a locally nilpotent p-group which is a minimal non FC-group, the hypercentral and hypocentral lengths of proper subgroups are bounded.
On minimal non-PC-groups
A group is said to be a PC-group, if is a polycyclic-by-finite group for all . A minimal non-PC-group is a group which is not a PC-group but all of whose proper subgroups are PC-groups. Our main result is that a minimal non-PC-group having a non-trivial finite factor group is a finite cyclic extension of a divisible abelian group of finite rank.
On permutation properties in groups and semigroups.
On the number of isomorphism classes of derived subgroups
We show that a finite nonabelian characteristically simple group satisfies if and only if , where is the number of isomorphism classes of derived subgroups of and is the set of prime divisors of the group . Also, we give a negative answer to a question raised in M. Zarrin (2014).
On totally inert simple groups
A subgroup H of a group G is inert if |H: H ∩ H g| is finite for all g ∈ G and a group G is totally inert if every subgroup H of G is inert. We investigate the structure of minimal normal subgroups of totally inert groups and show that infinite locally graded simple groups cannot be totally inert.