A subgroup H of a group G is called F-z-supplemented in G if there exists a subgroup K of G, such that G = HK and H∩K≤ Z∞F（G）, where Z∞F（G） is the F-hypercenter of G. We obtain some results about the F-z-suppl...A subgroup H of a group G is called F-z-supplemented in G if there exists a subgroup K of G, such that G = HK and H∩K≤ Z∞F（G）, where Z∞F（G） is the F-hypercenter of G. We obtain some results about the F-z-supplemented subgroups and use them to determine the structure of some groups.展开更多
Let P be a Sylow p-subgroup of a group G with the smallest generator number d, where p is a prime. Denote by Md（P） = （P1, P2,..., Pd） a set of maximal subgroups of P such that φ（P） = ∩n^d=1Pn. In this paper, w...Let P be a Sylow p-subgroup of a group G with the smallest generator number d, where p is a prime. Denote by Md（P） = （P1, P2,..., Pd） a set of maximal subgroups of P such that φ（P） = ∩n^d=1Pn. In this paper, we investigate the structure of a finite group G under the assumption that the maximal subgroups in Md（P） are weakly s-permutably embedded in G, some interesting results are obtained which generalize some recent results. Finally, we give some further results in terms of weakly s-permutably embedded subgroups.展开更多
Let G be a finite group and N(G)be its norm.Then N(G)is a characteristic subgroup of G which normalizes every subgroup of G.In this paper,we will study the structure of G under one of the following conditions:1)norm q...Let G be a finite group and N(G)be its norm.Then N(G)is a characteristic subgroup of G which normalizes every subgroup of G.In this paper,we will study the structure of G under one of the following conditions:1)norm quotient group G/N(G)is cyclic;2)all Sylow subgroups of G/N(G)are cyclic and in particular if the order of G/N(G)is a square-free number.展开更多
Let G be a hyper finite locally solvable group, A a minimax ZG-medule, a locally defined formation consisting of locally solvable groups, A has no nonzero infinite irreducible ZG-factors, and G ∈ . The following resu...Let G be a hyper finite locally solvable group, A a minimax ZG-medule, a locally defined formation consisting of locally solvable groups, A has no nonzero infinite irreducible ZG-factors, and G ∈ . The following results are proved： if A has a maximal submodule B such that A/B is , central in G and B has no nonzero central ZG-factors, then A has an decomposition; ifA has an irreducible central submodule B such that all ZG-composition factors of A/B are o^eccentric, then A has an decomposition.展开更多
On the basis of the quasi-isomorphism of finite groups, a new mapping, weak isomorphism, from a finite group to another finite group is defined. Let G and H be two finite groups and G be weak-isomorphic to H. Then G≌...On the basis of the quasi-isomorphism of finite groups, a new mapping, weak isomorphism, from a finite group to another finite group is defined. Let G and H be two finite groups and G be weak-isomorphic to H. Then G≌H if G satisfies one of the following conditions. 1） G is a finite Abelian group. 2） The order of G is p^3. 3 ） The order of G is p^n＋1 and G has a cyclic normal subgroup N = 〈a〉 of order p^n. 4） G is a nilpotent group and if p^││G│, then for any P ∈ Sylp （G）, P has a cyclic maximal subgroup, where p is a prime; 5） G is a maximal class group of order p4（p〉3）.展开更多
Let G be a finite group.We denote byν(G)the probability that two randomly chosen elements of G generate a nilpotent subgroup.In this paper,we characterize the structure of finite groups G with lower bounds\({1\over p...Let G be a finite group.We denote byν(G)the probability that two randomly chosen elements of G generate a nilpotent subgroup.In this paper,we characterize the structure of finite groups G with lower bounds\({1\over p},\,{{p^{2}+8}\over{9p^{2}}}\)and\({p+3}\over{4p}\)onν(G),where p is a prime divisor of∣G∣.展开更多
Let G be a finite group.A generating set X of G is said to be minimal if no proper subset of X generates G.Let d(G)and m(G)denote the smallest size and the largest size of a minimal generating set of G,respectively.In...Let G be a finite group.A generating set X of G is said to be minimal if no proper subset of X generates G.Let d(G)and m(G)denote the smallest size and the largest size of a minimal generating set of G,respectively.In this paper we present a characterization for finite solvable groups G such that m(G)-d(G)=1 and m(G)≥m(G/N)+m(N)for any non-trivial normal subgroup N of G.展开更多
For a characterχof a finite group G,the number cod(χ) := ∣G:ker(χ)∣/χ(1)is called the codegree ofχ.In this paper,we give a solvability criterion for a finite group G depending on the minimum of the ratioχ(1)^(...For a characterχof a finite group G,the number cod(χ) := ∣G:ker(χ)∣/χ(1)is called the codegree ofχ.In this paper,we give a solvability criterion for a finite group G depending on the minimum of the ratioχ(1)^(2)/cod(χ),whenχvaries among the irreducible characters of G.展开更多
In this paper,the structure of finite groups in whichmaximal subgroups of some Sylow subgroups have aσ-soluble orσ-nilpotent supplement,whereσis a partition of the set of all prime numbers,is investigated.Some solu...In this paper,the structure of finite groups in whichmaximal subgroups of some Sylow subgroups have aσ-soluble orσ-nilpotent supplement,whereσis a partition of the set of all prime numbers,is investigated.Some solubility,σ-solubility andσ-nilpotency criteria leading to some significant improvements of earlier results are given.展开更多
The reduced power graph of a group G,denoted by RP(G),is the graph whose vertex set is the set of all elements of G and two vertices u and u are adjacent in RP(G)if and only if(u)C(u)or(u)C(u).In this paper,we study t...The reduced power graph of a group G,denoted by RP(G),is the graph whose vertex set is the set of all elements of G and two vertices u and u are adjacent in RP(G)if and only if(u)C(u)or(u)C(u).In this paper,we study the adjacency spectrum of the reduced power graph of Z_(n),Z^(n)_(p2),Z_(p2) x Z_(p),dihedral group,quaternion group and semi-dihedral group.展开更多
In recent years,a series of papers about cover-avoiding property of subgroups appeared and all the studies were connected with chief factors of a finite group.However,about the cover-avoiding property of subgroups for...In recent years,a series of papers about cover-avoiding property of subgroups appeared and all the studies were connected with chief factors of a finite group.However,about the cover-avoiding property of subgroups for non-chief factor,there is no study up to now.The purpose of this paper is to build the theory.Let A be a subgroup of a finite group G and Σ:G0≤G1≤…≤Gn some subgroup series of G.Suppose that for each pair(K,H) such that K is a maximal subgroup of H and G i 1 K < H G i for some i,either A ∩ H = A ∩ K or AH = AK.Then we say that A is Σ-embedded in G.In this paper,we study the finite groups with given systems of Σ-embedded subgroups.The basic properties of Σ-embedded subgroups are established and some new characterizations of some classes of finite groups are given and some known results are generalized.展开更多
In this paper we study the influence of the partial cover and avoidance property on the subgroups of some relevant families of subgroups in a finite group.
A subgroup E of a finite group G is called hypercyclically embedded in G if every chief factor of G below E is cyclic.Let A be a subgroup of a group G.Then we call any chief factor H/AG of G a G-boundary factor of A.F...A subgroup E of a finite group G is called hypercyclically embedded in G if every chief factor of G below E is cyclic.Let A be a subgroup of a group G.Then we call any chief factor H/AG of G a G-boundary factor of A.For any G-boundary factor H/AG of A,we call the subgroup(A∩H)/AG of G/AG a G-trace of A.On the basis of these notions,we give some new characterizations of hypercyclically embedded subgroups.展开更多
A subgroup H of a group G is called s-conditionally permutable in G if for every Sylow subgroup T of G there exists an element x ∈ G such that HTx = TxH. Using the concept of s-conditionally permutable subgroups, som...A subgroup H of a group G is called s-conditionally permutable in G if for every Sylow subgroup T of G there exists an element x ∈ G such that HTx = TxH. Using the concept of s-conditionally permutable subgroups, some new characterizations of finite groups are obtained and several interesting results are generalized.展开更多
A subgroup H of a finite group G is said to be complemented in G if there exists a subgroup K of G such that G = HK and H n X = 1. In this easel K is called a complement of H in G. In this note some results on complem...A subgroup H of a finite group G is said to be complemented in G if there exists a subgroup K of G such that G = HK and H n X = 1. In this easel K is called a complement of H in G. In this note some results on complemented subgroups of finite groups are obtained.展开更多
Let H be a subgroup of a group G. Then H is said to be S-quasinormal in G if HP = PH 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...Let H be a subgroup of a group G. Then H is said to be S-quasinormal in G if HP = PH 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 VIT ≤ HSE, where HSE denotes the subgroup of H generated by all those subgroups of H which are S-quasinormally embedded in G. Some results about the influence of weakly S-embedded subgroups on the structure of finite groups are given.展开更多
In this note,we show that if every maximal subgroup of a Sylow p-subgroup of a finite group has a p-solvable supplement then the group is necessarily p-solvable.This gives a positive answer to Problem 17.111 of the Ko...In this note,we show that if every maximal subgroup of a Sylow p-subgroup of a finite group has a p-solvable supplement then the group is necessarily p-solvable.This gives a positive answer to Problem 17.111 of the Kourovka Notebook(Unsolved Problems in Group Theory),which was posed by Skiba.展开更多
Thompson＇s theorem indicates that a finite group with a nilpotent maximal subgroup of odd order is solvable. As an important application of Thompson＇s theorem, a finite group is solvable if it has an abelian maximal...Thompson＇s theorem indicates that a finite group with a nilpotent maximal subgroup of odd order is solvable. As an important application of Thompson＇s theorem, a finite group is solvable if it has an abelian maximal subgroup. In this paper, we give some sufficient conditions on the number of non-abelian subgroups of a finite group to be solvable.展开更多
文摘A subgroup H of a group G is called F-z-supplemented in G if there exists a subgroup K of G, such that G = HK and H∩K≤ Z∞F（G）, where Z∞F（G） is the F-hypercenter of G. We obtain some results about the F-z-supplemented subgroups and use them to determine the structure of some groups.
基金the National Natural Science Foundation of China(Grant Nos.1120108211171353)+2 种基金China Postdoctoral Science Foundation(Grant No.2013T60866)the Natural Science Foundation of Guangdong Province(Grant No.S201204007267)Outstanding Young Teachers Training Project of Guangdong Province(GrantNo.Yq2013061)
文摘Let P be a Sylow p-subgroup of a group G with the smallest generator number d, where p is a prime. Denote by Md（P） = （P1, P2,..., Pd） a set of maximal subgroups of P such that φ（P） = ∩n^d=1Pn. In this paper, we investigate the structure of a finite group G under the assumption that the maximal subgroups in Md（P） are weakly s-permutably embedded in G, some interesting results are obtained which generalize some recent results. Finally, we give some further results in terms of weakly s-permutably embedded subgroups.
基金Supported by the National Natural Science Foundation of China(Grant No.11661023)the Service Industry Development Guide of Guizhou Province(Grant No.Qian Fa Gai Fu Wu[2018]1181)。
文摘Let G be a finite group and N(G)be its norm.Then N(G)is a characteristic subgroup of G which normalizes every subgroup of G.In this paper,we will study the structure of G under one of the following conditions:1)norm quotient group G/N(G)is cyclic;2)all Sylow subgroups of G/N(G)are cyclic and in particular if the order of G/N(G)is a square-free number.
文摘Let G be a hyper finite locally solvable group, A a minimax ZG-medule, a locally defined formation consisting of locally solvable groups, A has no nonzero infinite irreducible ZG-factors, and G ∈ . The following results are proved： if A has a maximal submodule B such that A/B is , central in G and B has no nonzero central ZG-factors, then A has an decomposition; ifA has an irreducible central submodule B such that all ZG-composition factors of A/B are o^eccentric, then A has an decomposition.
文摘On the basis of the quasi-isomorphism of finite groups, a new mapping, weak isomorphism, from a finite group to another finite group is defined. Let G and H be two finite groups and G be weak-isomorphic to H. Then G≌H if G satisfies one of the following conditions. 1） G is a finite Abelian group. 2） The order of G is p^3. 3 ） The order of G is p^n＋1 and G has a cyclic normal subgroup N = 〈a〉 of order p^n. 4） G is a nilpotent group and if p^││G│, then for any P ∈ Sylp （G）, P has a cyclic maximal subgroup, where p is a prime; 5） G is a maximal class group of order p4（p〉3）.
基金Supported by NSF of China(Grant No.12061011)NSF of Guangxi(Grant Nos.2020GXNSFDA238014,2021GXNSFAA220105)。
文摘Let G be a finite group.We denote byν(G)the probability that two randomly chosen elements of G generate a nilpotent subgroup.In this paper,we characterize the structure of finite groups G with lower bounds\({1\over p},\,{{p^{2}+8}\over{9p^{2}}}\)and\({p+3}\over{4p}\)onν(G),where p is a prime divisor of∣G∣.
基金Supported by China Scholarship Council(Grant No.202208360148)the National Natural Science Foundation of China(Grant Nos.12126415,12261042,12301026)the Natural Science Foundation of Jiangxi Province(Grant No.20232BAB211006).
文摘Let G be a finite group.A generating set X of G is said to be minimal if no proper subset of X generates G.Let d(G)and m(G)denote the smallest size and the largest size of a minimal generating set of G,respectively.In this paper we present a characterization for finite solvable groups G such that m(G)-d(G)=1 and m(G)≥m(G/N)+m(N)for any non-trivial normal subgroup N of G.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11971391,12071376,12301018,12171058,12326356)the Natural Science Foundation of Jiangsu Province(Grant No.BK20231356)+1 种基金the Natural Science Foundation for the Universities in Jiangsu Province(Grant No.23KJB110002)The first and second authors are supported by the Chinese Scholarship Council。
文摘For a characterχof a finite group G,the number cod(χ) := ∣G:ker(χ)∣/χ(1)is called the codegree ofχ.In this paper,we give a solvability criterion for a finite group G depending on the minimum of the ratioχ(1)^(2)/cod(χ),whenχvaries among the irreducible characters of G.
基金supported by the Grant PGC2018-095140-B-I00,funded by MCIN/AEI/10.13039/501100011033supported by Grant PROMETEO/2017/057 funded by GVA/10.13039/501100003359+1 种基金supported by Ministry of Education of the Republic of Belarus(Grant 20211779“Convergence-2025”)supported by the Belarusian Republican Foundation for Fundamental Research(Grant F20R-291).
文摘In this paper,the structure of finite groups in whichmaximal subgroups of some Sylow subgroups have aσ-soluble orσ-nilpotent supplement,whereσis a partition of the set of all prime numbers,is investigated.Some solubility,σ-solubility andσ-nilpotency criteria leading to some significant improvements of earlier results are given.
文摘The reduced power graph of a group G,denoted by RP(G),is the graph whose vertex set is the set of all elements of G and two vertices u and u are adjacent in RP(G)if and only if(u)C(u)or(u)C(u).In this paper,we study the adjacency spectrum of the reduced power graph of Z_(n),Z^(n)_(p2),Z_(p2) x Z_(p),dihedral group,quaternion group and semi-dihedral group.
基金supported by National Natural Science Foundation of China (Grant No.11071229)Chinese Academy of Sciences Visiting Professorship for Senior International Scientists (Grant No.2010T2J12)
文摘In recent years,a series of papers about cover-avoiding property of subgroups appeared and all the studies were connected with chief factors of a finite group.However,about the cover-avoiding property of subgroups for non-chief factor,there is no study up to now.The purpose of this paper is to build the theory.Let A be a subgroup of a finite group G and Σ:G0≤G1≤…≤Gn some subgroup series of G.Suppose that for each pair(K,H) such that K is a maximal subgroup of H and G i 1 K < H G i for some i,either A ∩ H = A ∩ K or AH = AK.Then we say that A is Σ-embedded in G.In this paper,we study the finite groups with given systems of Σ-embedded subgroups.The basic properties of Σ-embedded subgroups are established and some new characterizations of some classes of finite groups are given and some known results are generalized.
基金Proyecto MTM 2007-68010-C03-02MTM 2007-68010-C03-01,respectively,of Ministerio de Educación y Ciencia of Spain
文摘In this paper we study the influence of the partial cover and avoidance property on the subgroups of some relevant families of subgroups in a finite group.
基金Research of the first author is supported by aNNSFgrant ofChina(Grant#11371335)WuWen-Tsun Key Laboratory of Mathematics,USTC,Chinese Academy of Sciences.Research of the second author supported by Chinese Academy of Sciences Visiting Professorship for Senior International Scientists(Grant No.2010T2J12).
文摘A subgroup E of a finite group G is called hypercyclically embedded in G if every chief factor of G below E is cyclic.Let A be a subgroup of a group G.Then we call any chief factor H/AG of G a G-boundary factor of A.For any G-boundary factor H/AG of A,we call the subgroup(A∩H)/AG of G/AG a G-trace of A.On the basis of these notions,we give some new characterizations of hypercyclically embedded subgroups.
基金supported by National Natural Science Foundation of China (Grant No. 10771180)Scientific Research Fund of Sichuan Provincial Education Department (Grant No. 08zb059)Research Programme of Chengdu University of Information Technology
文摘A subgroup H of a group G is called s-conditionally permutable in G if for every Sylow subgroup T of G there exists an element x ∈ G such that HTx = TxH. Using the concept of s-conditionally permutable subgroups, some new characterizations of finite groups are obtained and several interesting results are generalized.
基金Project supported by the National Natural Science Foundation of China (No.19671073) and theYouth Science Foundation of Shanxi
文摘A subgroup H of a finite group G is said to be complemented in G if there exists a subgroup K of G such that G = HK and H n X = 1. In this easel K is called a complement of H in G. In this note some results on complemented subgroups of finite groups are obtained.
基金supported by National Natural Science Foundation of China (Grant Nos.10771172,11001226)Postgraduate Innovation Foundation of Southwest University (Grant Nos. ky2009013,ky2010007)
文摘Let H be a subgroup of a group G. Then H is said to be S-quasinormal in G if HP = PH 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 VIT ≤ HSE, where HSE denotes the subgroup of H generated by all those subgroups of H which are S-quasinormally embedded in G. Some results about the influence of weakly S-embedded subgroups on the structure of finite groups are given.
基金supported by National Natural Science Foundation of China(Grant Nos.11101055 and 11171364)
文摘In this note,we show that if every maximal subgroup of a Sylow p-subgroup of a finite group has a p-solvable supplement then the group is necessarily p-solvable.This gives a positive answer to Problem 17.111 of the Kourovka Notebook(Unsolved Problems in Group Theory),which was posed by Skiba.
基金Supported by the National Natural Science Foundation of Chinathe Natural Science Foundation of Guangxi Autonomous Region (No.0249001)
文摘For any saturated formation F of finite groups containing all supersolvable groups, the groups in F are characterized by F-abnormal maximal subgroups.
基金Supported by National Natural Science Foundation of China （Grant No. 10871032）, China Postdoctoral Science Foundation （Grant No. 20100470136） the second author is supported in part by ＂Agencija za raziskovalno dejavnost Republike Slovenije＂, proj. mladi raziskovalci, ＂Agencija za raziskovalno dejavnost Republike Slovenije＂, Research Program P1-0285
文摘Thompson＇s theorem indicates that a finite group with a nilpotent maximal subgroup of odd order is solvable. As an important application of Thompson＇s theorem, a finite group is solvable if it has an abelian maximal subgroup. In this paper, we give some sufficient conditions on the number of non-abelian subgroups of a finite group to be solvable.
