Abstract:
Only finite groups are considered. The notion of ω-local formation of groups, where ω is a nonempty set of primes, is a well-known generalization of the notion of local formation. For an arbitrary partition σ of the set of all primes, A. N. Skiba developed the σ-theory of finite groups and applied its methods for constructing σ-local formations. The concept of ω-fiberedness introduced by V. A. Vedernikov for classes of groups made it possible to construct an infinite series of ω-fibered formations, while ω-local formations formed one of the types of this series. In this paper, we study ˉω‑fibered formations of groups, where ˉω is an arbitrary partition of the set ω, constructed on the basis of Skiba's σ-approach applied to ω-fibered formations. Consider functions f:ˉω∪{ˉω′}→{formations of groups} and γ:ˉω→{nonempty Fitting formations of groups}, where f(ˉω′)≠∅ and the class of groups γ(ωi) contains all ωi′-groups for any ωi∈ˉω. A formation F=(G∈G|G/Oω(G)∈f(ˉω′) and G/Gγ(ωi)∈f(ωi) for any ωi∈ˉω∩π(G)) is called an ˉω-fibered formation with direction γ and ˉω-satellite f. In this paper we study inner ˉω-satellites of ˉω-fibered formations, i.e., ˉω-satellites whose values are contained in the considered formation. The following problems are solved: the existence of a canonical ˉω-satellite of an ˉω-fibered formation is proved, and the structure of a maximal inner ˉω-satellite of an ˉω-fibered formation is described.
Keywords:
finite group, class of groups, formation, ˉω-fibered formation, direction of an ˉω-fibered formation, ˉω-satellite of an ˉω-fibered formation.
Citation:
A. A. Gorepekina, M. M. Sorokina, “ˉω-Satellites of ˉω-fibered formations of finite groups”, Trudy Inst. Mat. i Mekh. UrO RAN, 28, no. 2, 2022, 106–113