共查询到20条相似文献,搜索用时 781 毫秒
1.
GL(n,Z)中的局部有限子群的一点注记 总被引:1,自引:0,他引:1
证明了:若G是一般线性群GL(n,Z)中的局部有限子群,则G含有一个2~m阶的初等阿贝尔2-子群,且 G同构于 GL(n,Z_p)的一个子群,其中户为任意奇素数.当 n=1,2,3,4时,G的阶分别是 2,3· 2~k(k=min(4,m+1),0≤m≤4),3·2~k(k=min{5,m+1},0≤m≤5),3~2·5·2~k(k=min{9,m+6},0≤m≤9)的一个因子,而当n≥5时,G的阶是(p~i-1)的一个因子,其中p为任意素数. 相似文献
2.
广义双循环半群和Jones半群 总被引:4,自引:0,他引:4
本文刻画了广义双循环半群Bn=〈a,b|a^nb=1〉和Jones半群An=〈a,b|a^n+1b=a〉(n≥1)的结构;证明了每个An都具有P.R.Jones所发现的半群A=〈a,b|a^2b=a〉的所有重要性质,特别地,证明了An,Am可互相嵌入,从而得到:第三个D-非平凡的无幂等元「0-」单半群若不含C=〈a,b|a^2b=a,abT^2=b〉,则必含每个An或它们的对偶,作为推论,每人广义 相似文献
3.
椭圆一个定理的又一初等证明 总被引:1,自引:0,他引:1
定理 椭圆C:x2a2+y2b2=1(a>b>0)有且仅有两条对称轴:直线x=0和y=0.文[1]指出,这个定理的证明一般要用到仿射几何知识,同时文[1]给出了一个初等证明.笔者再给出这个定理的又一种初等证明如下.定理的证明 易验证直线x=0和y=0均是椭圆C的对称轴.因点B(0,b)关于直线x=k(k≠0)的对称点B′(2k,b)不在椭圆C图1上,故直线x=k(k≠0)不是椭圆C的对称轴.设F1,F2是椭圆C的两个焦点,椭圆C的长轴A1A2关于直线l:y=kx+n(k,n至少有一个不等于零)的… 相似文献
4.
苏本堂 《数学物理学报(A辑)》1999,(Z1)
设a<b是整数,G=(V(G),E(G))是一个图.G的一个支撑子图F称为G的一个[a,b]-因子,若对任意的υ∈EV(G),有a≤d_F(υ)≤b.本文得到了下列结果:设1≤a≤b是整数,G是一个阶为n的图,最小度δ(G)≥a且>(a+b)(2a+2b-3)如果对于G的任意两个不相邻的顶点u,υ有N_G(u)UN_G(υ)≥an,则G有一个[a,b]-因子. 相似文献
5.
郑权 《应用泛函分析学报》1999,(1)
设iAj(1≤j≤)是有界C_0群的可交换生成元,P(A)=∑_|μ|≤2a_μA~μ(A~μ=A_1~μ…A_n~μn)如果P是弱椭圆的且其实部是上有界的,则我们证明P(A)生成一个C_0半群. 相似文献
6.
设X为一个n元集合,Cnk为X的所有k元子集全体,若A∈A,B∈B有|A∩B|≥t,则称(A,B)为一个交叉t-相交子集族.本文得到最大交叉t-相交子集族和最大非空交叉2-相交子集族.证明如下两个结论.(1)若(A,B)为一个交叉t-相交子集族,且a≤b及a+b≤n+t-1,则|A+B|≤max{(bn),(an)},且当(A;B)=(φ,Cnb)或(Cna,φ)时达到上界.(2)若(A,B)为一个交叉2-相交子集族,且a<b,a+b≤n-1及(n,a,b)≠(2i,i-1,i)(i为任意正整数),又A,B均非空,则|A+B|≤1+(bn)-(b(n-a))-a((b-1)(n-a))且当(A,B)=({A},Cnb-{B||B|=b,|A∩B|≤1})时达到上界. 相似文献
7.
一类不能作为自同构群的奇阶群 总被引:2,自引:0,他引:2
本文考虑如下问题:怎样的有限群可以作为另一个有限群的全自同构群?我们首先证明,若有限群K有一个正规Sylowp-子群使得|K:Z(K)|p=p2,那么K有2阶自同构.利用这个结果,我们证明了,若奇阶群G具有阶Psm(1≤s≤3),p为|G|的最小素因子,pm,m无立方因子,则G不可能作为全自同构群. 相似文献
8.
Curran第三猜想的一个反例 总被引:1,自引:1,他引:0
本文证明了:当p>2,n≥6时,存在p ̄n阶群G使得|AutG|=p ̄(n+1).由此得到3-群作为有限群的自同构群的最小阶为3 ̄7.从而给出了Gurran在1989年提出的猜想的一个反例。 相似文献
9.
设A、C是一些自然数的集合。对于A中任一自然数m,每一m阶群都是Abel群;对于C中任一自然数n,每一n阶群都是循环群。本文的目的是证明下面的渐近公式:此处γ是Euler常数,logrx=log(log_(r-1)x),log_1x=logx。 相似文献
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11.
A power automorphism θ of a group G is said to be pre-fixed-point-free if CG(θ) is an elementary abelian 2-group. G is called an E-group if G has a pre-fixed-point-free power automorphism. In this paper, finite E-groups, together with all their pre-fixed-point-free power automorphisms, are completely determined. Moreover, a characteristic of finite abelian groups is given, which explains some known facts concerning power automorphisms. 相似文献
12.
Coleman自同构群的投射极限 总被引:2,自引:0,他引:2
在这篇注记中,利用群的投射极限性质给出了有限可解群的Coleman自同构群的一个具体构造.作为应用,证明了二面体群的Coleman外自同构群或者是1或者是一个初等阿贝尔2-群. 相似文献
13.
Coleman自同构群的投射极限 总被引:1,自引:1,他引:0
在这篇注记中,利用群的投射极限性质给出了有限可解群的Coleman自同构群的一个具体构造.作为应用,证明了二面体群的Coleman外自同构群或者是1或者是一个初等阿贝尔2-群. 相似文献
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15.
重新确定了广义超特殊p-群G的自同构群的结构.设|G|=p~(2n+m),|ζG|=p~m,其中n≥1,m≥2,Aut_cG是AutG中平凡地作用在ζG上的元素形成的正规子群,则(i)若p是奇素数,则AutG=〈θ〉×Aut_cG,其中θ的阶是(p-1)p~(m-1);若p=2,则AutG=〈θ_1,θ_2〉×Aut_cG,其中〈θ_1,θ_2〉=〈θ_1〉×〈θ_2〉≌Z_(2m-2)×Z_2.(ii)如果G的幂指数是p~m,那么Aut_cG/InnG≌Sp(2n,p).(iii)如果G的幂指数是p~(m+1),那么Aut_cG/InnG≌K×Sp(2n-2,p),其中K是p~(2n-1)阶超特殊p-群(若p是奇素数)或者初等Abel 2-群.特别地,当n=1时,Aut_cG/InnG≌Z_p. 相似文献
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17.
P. Shumyatsky’s question 11.126 in the “Kourovka Notebook” is answered in the affirmative: it is proved that there exist a
constant c and a function of a positive integer argument f(m) such that if a finite group G admits an automorphism ϕ of order
4 having exactly m fixed points, then G has a normal series G ⩾ H ⩽ N such that |G/H| ⩽ f(m), the quotient group H/N is nilpotent
of class ⩽ 2, and the subgroup N is nilpotent of class ⩽ c (Thm. 1). As a corollary we show that if a locally finite group
G contains an element of order 4 with finite centralizer of order m, then G has the same kind of a series as in Theorem 1.
Theorem 1 generalizes Kovács’ theorem on locally finite groups with a regular automorphism of order 4, whereby such groups
are center-by-metabelian. Earlier, the first author proved that a finite 2-group with an almost regular automorphism of order
4 is almost center-by-metabelian. The proof of Theorem 1 is based on the authors’ previous works dealing in Lie rings with
an almost regular automorphism of order 4. Reduction to nilpotent groups is carried out by using Hall-Higman type theorems.
The proof also uses Theorem 2, which is of independent interest, stating that if a finite group S contains a nilpotent subgroup
T of class c and index |S: T | = n, then S contains also a characteristic nilpotent subgroup of class ⩽ c whose index is bounded
in terms of n and c. Previously, such an assertion has been known for Abelian subgroups, that is, for c = 1.
__________
Translated from Algebra i Logika, Vol. 45, No. 5, pp. 575–602, September–October, 2006. 相似文献
18.
主要结果是如下定理:设G是有限可解群使得G/F(G)是奇阶A-群,又设p是一个素数且G不含截断q~(pn):(Z_m:Z_p)。其中q~(pn):(Z_m:Z_n))是初等交换q-群q~(pn)被Z_m:Z_p的扩张,而m=(q~(pn)-1)/(q~n-1)。则G有亏数零p-块的充要条件是O_p(G)=1。 相似文献
19.
Classifying cubic symmetric graphs of order 10p or 10p~2 总被引:1,自引:0,他引:1
KWAK Jin Ho 《中国科学A辑(英文版)》2006,49(3)
A graph is called s-regular if its automorphism group acts regularly on the set of its s-arcs. In this paper, the s-regular cyclic or elementary abelian coverings of the Petersen graph for each s ≥ 1 are classified when the fibre-preserving automorphism groups act arc-transitively. As an application of these results, all s-regular cubic graphs of order 10p or 10p2 are also classified for each s ≥ 1 and each prime p, of which the proof depends on the classification of finite simple groups. 相似文献
20.
The Wielandt subgroup of a group G,denoted by w(G),is the intersection of the normalizers of all subnormal subgroups of G.In this paper,the authors show that for a p-group of maximal class G,either wi(G) = ζi(G) for all integer i or wi(G) = ζi+1(G) for every integer i,and w(G/K) = ζ(G/K) for every normal subgroup K in G with K = 1.Meanwhile,a necessary and suflcient condition for a regular p-group of maximal class satisfying w(G) = ζ2(G) is given.Finally,the authors prove that the power automorphism group PAut(G) is an elementary abelian p-group if G is a non-abelian pgroup with elementary ζ(G) ∩ 1(G). 相似文献