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1.
AbstractThere has been some interest in understanding the relationship between the number of cyclic subgroups of a group and its order. This relationship is controlled in many cases by the size of the set of non-squares of the group. We improve upon previously established bounds and classify groups that obtain our new bound. 相似文献
2.
Wen Bin Guo 《数学学报(英文版)》2008,24(10):1751-1757
In this paper, we prove the following theorem: Let p be a prime number, P a Sylow psubgroup of a group G and π = π(G) / {p}. If P is seminormal in G, then the following statements hold: 1) G is a p-soluble group and P' ≤ Op(G); 2) lp(G) ≤ 2 and lπ(G) ≤ 2; 3) if a π-Hall subgroup of G is q-supersoluble for some q ∈ π, then G is q-supersoluble. 相似文献
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A subgroup H of finite group G is called pronormal in G if for every element x of G, H is conjugate to H
x
in 〈H, H
x
〉. A finite group G is called PRN-group if every cyclic subgroup of G of prime order or order 4 is pronormal in G. In this paper, we find all PRN-groups and classify minimal non-PRN-groups (non-PRN-group all of whose proper subgroups are PRN-groups). At the end of the paper, we also classify the finite group G, all of whose second maximal subgroups are PRN-groups. 相似文献
6.
Yumiko Hironaka 《代数通讯》2017,45(8):3365-3376
7.
Let G be a finite group,and H a subgroup of G.H is called s-permutably embedded in G if each Sylow subgroup of H is a Sylow subgroup of some s-permutable subgroup of G.In this paper,we use s-permutably embedding property of subgroups to characterize the p-supersolvability of finite groups,and obtain some interesting results which improve some recent results. 相似文献
8.
It follows from classical results of Neumann and Macdonald that a group G has finite commuator subgroup if and only if either the normalizers of cyclic subgroups of G have boundedly finite indices or cyclic subgroups of G have bounded indices in their normal closures. In this paper, groups with a similar condition are considered, when normality
is replaced by permutability.
相似文献
9.
LI JinBao CHEN GuiYun & CHEN RuiFang School of Mathematics Statistics Southwest University Chongqing China 《中国科学 数学(英文版)》2011,(9)
Let H be a subgroup of a group G.Then H is said to be S-quasinormal in G if HP = P H for every Sylow subgroup P of G;H is said to be S-quasinormally embedded in G if a Sylow p-subgroup of H is also a Sylow p-subgroup of some S-quasinormal subgroup of G for each prime p dividing the order of H.In this paper,we say that H is weakly S-embedded in G if G has a normal subgroup T such that HT is an S-quasinormal subgroup of G and H ∩ T≤H SE,where H SE denotes the subgroup of H generated by all those subgroups of ... 相似文献
10.
In this paper, the famous Hall theorem and the famous Schur-Zassenhaus theorem are generalized. 相似文献
11.
S. F. Kamornikov 《Siberian Mathematical Journal》2008,49(6):1044-1050
We study the partially prefrattini groups of a finite soluble group. We prove that the set of all partially prefrattini subgroups associated with the Gaschütz system of complements to crowns is a Boolean lattice. 相似文献
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Let X be a nonempty subset of a group G. We call a subgroup A of G an Xm‐semipermutable subgroup of G if A has a minimal supplement T in G such that for every maximal subgroup M of any Hall subgroup T1 of T there exists an element x ∈ X such that AMx = MxA. In this paper, we study the structure of finite groups with some given systems of Xm‐semipermutable subgroups (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Frédérique Bassino Armando Martino Cyril Nicaud Enric Ventura Pascal Weil 《Random Structures and Algorithms》2013,42(3):349-373
The usual way to investigate the statistical properties of finitely generated subgroups of free groups, and of finite presentations of groups, is based on the so‐called word‐based distribution: subgroups are generated (finite presentations are determined) by randomly chosen k ‐tuples of reduced words, whose maximal length is allowed to tend to infinity. In this paper we adopt a different, though equally natural point of view: we investigate the statistical properties of the same objects, but with respect to the so‐called graph‐based distribution, recently introduced by Bassino, Nicaud and Weil. Here, subgroups (and finite presentations) are determined by randomly chosen Stallings graphs whose number of vertices tends to infinity. Our results show that these two distributions behave quite differently from each other, shedding a new light on which properties of finitely generated subgroups can be considered frequent or rare. For example, we show that malnormal subgroups of a free group are negligible in the graph‐based distribution, while they are exponentially generic in the word‐based distribution. Quite surprisingly, a random finite presentation generically presents the trivial group in this new distribution, while in the classical one it is known to generically present an infinite hyperbolic group. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2013 相似文献
14.
CHEN GuiYun & LI JinBao School of Mathematics Statistics Southwest University Chongqing China School of Mathematical Sciences Xuzhou Normal University Xuzhou China 《中国科学A辑(英文版)》2009,(2)
Let A be a subgroup of a group G and X be a nonempty subset of G. A is said to be X-semipermutable in G if A has a supplement T in G such that A is X-permutable with every subgroup of T. In this paper, we investigate further the influence of X-semipermutability of some subgroups on the structure of finite groups. Some new criteria for a group G to be supersoluble or p-nilpotent are obtained. 相似文献
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Andrea Pachera 《代数通讯》2017,45(6):2494-2504
Given a group G denote with exp(G) its exponent, which is the least common multiple of the order of its elements. In this paper, we solve the problem of finding the finite simple groups having a proper subgroup with the same exponent. For each G with this property we will provide an explicit example of H<G with exp(G)?=?exp(H). 相似文献
17.
For a finite group G, let n(G) denote the number of conjugacy classes of non-subnormal subgroups of G. In this paper, we show that a finite group G satisfying n(G)≤2|π(G)| is solvable, and for a finite non-solvable group G, n(G) = 2|π(G)|+1 if and only if G?A5. 相似文献
18.
A non-nilpotent finite group whose proper subgroups are all nilpotent is called a Schmidt group. A subgroup A is said to be
seminormal in a group G if there exists a subgroup B such that G = AB and AB1 is a proper subgroup of G, for every proper subgroup B1 of B. Groups that contain seminormal Schmidt subgroups of even order are considered. In particular, we prove that a finite
group is solvable if all Schmidt {2, 3}-subgroups and all 5-closed {2, 5}-Schmidt subgroups of the group are seminormal; the
classification of finite groups is not used in so doing. Examples of groups are furnished which show that no one of the requirements
imposed on the groups is unnecessary.
Supported by BelFBR grant Nos. F05-341 and F06MS-017.
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Translated from Algebra i Logika, Vol. 46, No. 4, pp. 448–458, July–August, 2007. 相似文献
19.
主要研究子群置换性质对有限群结构的影响.通过子群的置换性得到一类群,即B 群.B群是全可置换群的扩展,利用全可置换群的p次中心扩张和子群的阶得到B群的一些性质并对B 群的结构进行一些刻画.应用B 群的结构得到有限p (p〉2)群为二元生成的B 群的充要条件. 相似文献
20.
On complemented subgroups of finite groups 总被引:1,自引:0,他引:1
Long Miao 《Czechoslovak Mathematical Journal》2006,56(3):1019-1028
A subgroup H of a group G is said to be complemented in G if there exists a subgroup K of G such that G = HK and H ⋂ K = 1. In this paper we determine the structure of finite groups with some complemented primary subgroups, and obtain some
new results about p-nilpotent groups. 相似文献