Let G be a finite group and let σ = {σ i|i ∈ I} be some partition of the set ℙ of all primes. Then G is called σ-nilpotent if G = A 1 × ⋯ × A r , where A i is a \({\sigma _{{i_j}}}\)-group for some i j = i j (A i ). A collection ℋ of subgroups of G is a complete Hall σ-set of G if each member ≠ 1 of ℋ is a Hall σ i -subgroup of G for some i ∈ I and ℋ has exactly one Hall σ i -subgroup of G for every i such that σ i ∩ π(G) ≠ ø. A subgroup A of G is called σ-quasinormal or σ-permutable [1] in G if G possesses a complete Hall σ-set ℋ such that AH x = H x A for all H ∈ ℋ and x ∈ G. The symbol r(G) (r p (G)) denotes the rank (p-rank) of G.
Assume that ℋ is a complete Hall σ-set of G. We prove that (i) if G is soluble, r(H) ≤ r ∈ ℕ for all H ∈ ℋ, and every n-maximal subgroup of G (n > 1) is σ-quasinormal in G, then r(G) ≤ n+r − 2; (ii) if every member in ℋ is soluble and every n-minimal subgroup of G is σ-quasinormal, then G is soluble and r p (G) ≤ n + r p (H) − 1 for all H ∈ ℋ and odd p ∈ π(H).
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References
Skiba A. N., “On σ-subnormal and σ-permutable subgroups of finite groups,” J. Algebra, vol. 436, 1–16 (2015).
Huppert B., Endliche Gruppen. I, Springer-Verlag, Berlin (1967).
Huppert B., “Normalteiler und maximale Untergruppen endlicher Gruppen,” Math. Z., Bd 60, 409–434 (1954).
Agrawal R. K., “Generalized center and hypercenter of a finite group,” Proc. Amer. Math. Soc., vol. 54, 13–21 (1976).
Weinstein M. et al. (eds.), Between Nilpotent and Solvable, Polygonal Publ. House, Passaic (1982).
Ballester-Bolinches A., Esteban-Romero R., and Asaad M., Products of Finite Groups, Walter de Gruyter, Berlin and New York (2010).
Guo W., Structure Theory for Canonical Classes of Finite Groups, Walter de Gruyter, Berlin, Heidelberg, Dordrecht, and New York (2015).
Janko Z., “Finite groups with invariant fourth maximal subgroups,” Math. Z., Bd 83, 82–89 (1963).
Mann A., “Finite groups whose n-maximal subgroups are subnormal,” Trans Amer. Math. Soc., vol. 132, 395–409 (1968).
Skiba A. N., “On some results in the theory of finite partially soluble groups,” Commun. Math. Stat., vol. 4, 281–312 (2016).
Buckley J., “Finite groups whose minimal subgroups are normal,” Math. Z., Bd 116, 15–17 (1970).
Baer R., “Nilpotent characteristic subgroups of finite groups,” J. Math., vol. 75, 633–664 (1953).
Skiba A. N., “A generalization of a Hall theorem,” J. Algebra Appl., vol. 15, no. 4, 21–36 (2015).
Gorenstein D., Finite Groups, Harper & Row Publ., New York, Evanston, and London (1968).
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Original Russian Text Copyright © 2017 Zhang L., Guo W., and Skiba A.N.
Translated from Sibirskiĭ Matematicheskiĭ Zhurnal, Vol. 58, No. 5, pp. 1181–1190, September–October, 2017; DOI: 10.17377/smzh.2017.58.519.
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Zhang, L., Guo, W. & Skiba, A.N. Some notes on the rank of a finite soluble group. Sib Math J 58, 915–922 (2017). https://doi.org/10.1134/S0037446617050196
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DOI: https://doi.org/10.1134/S0037446617050196