Results 21 to 30 of about 1,746 (160)
Joins of Almost Subnormal Subgroups [PDF]
Proceedings of the Edinburgh Mathematical Society, 1979 Following (1) we say that a subgroup H of a group G is almost subnormal in G if H is of finite index in some subnormal subgroup of G, or, equivalently, if |Hn : H| is finite for some n, where Hn is the n-th term of the normal closure series of H in G. The aim of this article is to prove, in answer to a question of R. Baer, the following analogue of the
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Finite groups in which normality, permutability or Sylow permutability is transitive
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014 Y. Li gave a characterization of the class of finite soluble groups in which every subnormal subgroup is normal by means of NE-subgroups: a subgroup H of a group G is called an NE-subgroup of G if NG(H) ∩ HG = H. We obtain a new characterization of these
Malinowska Izabela Agata
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Finite groups whose maximal subgroups of even order are MSN-groups
Open Mathematics, 2022 A finite group GG is called an MSN-group if all maximal subgroups of the Sylow subgroups of GG are subnormal in GG. In this article, we investigate the structure of finite groups GG such that GG is a non-MSN-group of even order in which every maximal ...
Wang Wanlin, Guo Pengfei
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International Journal of Mathematics and Mathematical Sciences, 1997 Let G be a finite group and H be an operator group of G. In this short note, we show a relationship between subnormal subgroup chains and H-invariant subgroup chains.
Yanming Wang
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On σ-Residuals of Subgroups of Finite Soluble Groups
Mathematics, 2023 Let σ={σi:i∈I} be a partition of the set of all prime numbers. A subgroup H of a finite group G is said to be σ-subnormal in G if H can be joined to G by a chain of subgroups H=H0⊆H1⊆⋯⊆Hn=G where, for every j=1,⋯,n, Hj−1 is normal in Hj or Hj/CoreHj(Hj−1)
A. A. Heliel +3 more
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A Survey of Subnormal Subgroups
Irish Mathematical Society Bulletin, 1990 The author gives a survey (without proofs) of the high points of the theory of subnormal subgroups developed over the last fifty years. The article is intended as an introduction to the book by Lennox and Stonehewer.
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Groups with conjugacy classes of coprime sizes
Bulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.Abstract Suppose that x$x$, y$y$ are elements of a finite group G$G$ lying in conjugacy classes of coprime sizes. We prove that ⟨xG⟩∩⟨yG⟩$\langle x^G \rangle \cap \langle y^G \rangle$ is an abelian normal subgroup of G$G$ and, as a consequence, that if x$x$ and y$y$ are π$\pi$‐regular elements for some set of primes π$\pi$, then xGyG$x^G y^G$ is a π ...
R. D. Camina +8 more
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Joins of $\sigma$-subnormal subgroups
, 2023 Let $\sigma=\{\sigma_j\,:\, j\in J\}$ be a partition of the set $\mathbb{P}$ of all prime numbers. A subgroup $X$ of a finite group $G$ is~\textit{$\sigma$-subnormal} in $G$ if there exists a chain of subgroups $$X=X_0\leq X_1\leq\ldots\leq X_n=G$$ such that, for each $1\leq i\leq n-1$, $X_{i-1}\trianglelefteq X_i$ or $X_i/(X_{i-1})_{X_i}$ is a ...
Ferrara, Maria, Trombetti, Marco
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On the join of subnormal subgroups [PDF]
Proceedings of the American Mathematical Society, 1974 Let G \mathfrak {G} be the class of finitely generated groups. If the join of finitely many subnormal X = s n X \mathfrak {X} = sn\mathfrak {X} subgroups is always an X \mathfrak {X} -group and
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Acta Ophthalmologica, Volume 104, Issue 1, Page 65-74, February 2026.Abstract Purpose The Extremely Preterm Infants in Sweden Study (EXPRESS) followed a national cohort of extremely preterm born (EPT, i.e. <27 weeks) children until 12 years of age. This study aimed to investigate the longitudinal development of visual acuity (VA) in children born EPT, explore the predictive value of early visual assessments, and ...
Despoina Tsamadou +12 more
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