Abstract:
Only finite groups are considered. The notion of ωω-local formation of groups, where ωω is a nonempty set of primes, is a well-known generalization of the notion of local formation. For an arbitrary partition σσ of the set of all primes, A. N. Skiba developed the σσ-theory of finite groups and applied its methods for constructing σσ-local formations. The concept of ωω-fiberedness introduced by V. A. Vedernikov for classes of groups made it possible to construct an infinite series of ωω-fibered formations, while ωω-local formations formed one of the types of this series. In this paper, we study ˉω¯ω‑fibered formations of groups, where ˉω¯ω is an arbitrary partition of the set ωω, constructed on the basis of Skiba's σσ-approach applied to ωω-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