$p$-子群具有$p$-超可解正规化子的有限群

在已有研究中,对于$p$-子群的正规化子而言,它的$p$-幂零性质对有限$p$-幂零群的结构具有重要的影响. 本文中, 设$P$是群$G$的西罗$p$-子群, $1\leq p^d<|P|$, 对于$P$的每个阶为$p^d$的正规子群$H$H,将$N_G(H)$的$p$-幂零性质减弱为$p$-超可解性质,结合$H$的弱$M$-可补充性质,探究$p$-超可解群的结构.同时,在$N_G(P)$是$p$-幂零的条件下,利用子群$K$的弱$M$-可补充条件研究群的$p$-幂零性质,其中$K_p\leq K$且$P''\leq K_p\leq \Phi(P)$. $K_p$是$K$的西罗$p$-子群.在一定程度上,主要结果推广了Frobenius定理.     

有限群的$\Phi$-$\tau$-可补子群

假设$\tau$是一个子群算子, $H$是有限群$G$的一个$p$-子群. 令 $\bar{G}=G/H_{G}$且$\bar{H}=H/H_{G}$, 如果$\bar{G}$有一个次正规子群$\bar{T}$ 和一个包含于$\bar{H}$ 的$\tau$-子群$\bar{S}$满足$\bar{G}=\bar{H}\bar{T}$且$\bar{H}\cap\bar{T}\leq \bar{S}\Phi(\bar{H})$, 就称$H$是$G$的一个$\Phi$-$\tau$- 可补子群. 文章通过讨论群$G$的准素数子群的$\Phi$-$\tau$-可补性给出了超循环嵌入和$p$-幂零性的一些新的特征.     

关于$\mathcal{F}$-S-可补子群

设$\mathcal{F}$是一个群类. 群$G$的子群$H$称为在$G$中$\mathcal{F}$-S-可补的，如果存在$G$的一个子群$K$,使得$G=HK$且$K/K\cap{H_G}\in\mathcal{F}$, 其中$H_G=\bigcap_{g\in G}H^g$是包含在$H$中的$G$的最大正规子群．本文利用子群的$\mathcal{F}$-S-可补性, 给出了有限群的可解性, 超可解性和幂零性的一些新的刻画. 应用这些结果, 我们可以得到一系列推论, 其中包括有关已知的著名结果.     

具有幂零局部子群的有限群

一个有限非幂零群G称为PN-群,如果NC(P)是幂零的,对于每个素数p和每个满足PZ∞(G)的非正规子群p-子群P.本文将给出可解PN-群的结构和一些特征定理.     

具有幂零局部子群的有限群

一个有限非幂零群G称为PN-群,如果NG(P)是幂零的,对于每个素数p和每个满足P(∈)Z∞(G)的非正规子群p-子群P.本文将给出可解PN-群的结构和一些特征定理.     

有限$p$-幂零群的一个判定准则

设$G$为一个有限群, $H$是$G$的一个子群. 称$H$在$G$中是$s$-半置换的若对$G$的任意Sylow $p$-子群$G_p$, $HG_p=G_pH$, 其中$(p, |H|)= 1$,这里$p$是整除$G$的阶一个素数.通过假设$G$的一些子群是$s$-半置换的, 我们给出了$p$-幂零群的一个判定准则. 我们的结果推广了著名的Burnside $p$-幂零群准则.     

2-极大子群的$F_s$-拟正规性

$F$是一个群系. $G$的子群$H$在$G$中称为$F_s$-拟正规的,如果存在$G$的正规子群$T$,使得$HT$在$G$中是$s$-置换的并且$(H\cap T)H_G/H_G$包含在$G/H_G$的$F$超中心$Z^F_\infty(G/H_G)$中.本文利用$F_s$-拟正规子群研究了有限群的结构.获得了某些新的结果.     

二极大子群为TI-子群的有限群的类保持Coleman自同构

设$H$是有限群$G$的一个子群,若对任意$g\in G$, $H\cap H^g=1$或者$H$,则称$H$为TI-子群. 设$G$是一个所有二极大子群为TI-子群的有限群,本文证明了$G$的每个类保持Coleman自同构是内自同构. 作为本结果的一个直接推论,得到了这样的群$G$有正规化子性质.     

Norm商群的Sylow子群皆循环的有限群

设$G$是有限群, $N(G)$为$G$的norm, 则$N(G)$是$G$的正规化G的每个子群的特征子群. 我们在下列条件之一下,研究了$G$的结构：1) Norm商群$G/N(G)$是循环群;2) Norm商群$G/N(G)$的所有Sylow子群都是循环群,特别地当$G/N(G)$的阶是无平方因子数时.     

有限秩的幂零群的自同构(I)

研究了有限秩的幂零群的自同构, 证明了 \qquad {\heiti定理}\quad设幂零群~$G=KP$, 其中~$P$是有限秩的幂零~$p$-\!群, ~$K$ 是~$G$\,的有限秩的~$p^\prime$-\!自由的正规子群, ~$p$\, 不属于~$K$\,的谱~$S_p(K)$. 设~$\alpha$ 和~$\beta$ 是~$G$ 的两个~$p$-\!自同构,记~$I:=\langle\left(\alpha\beta(g)\right)\cdot\left(\beta\alpha(g)\right)^{-1}\, |\, g\in G \rangle, $ 则 \qquad (i) 当~$I$\, 是有限循环群时, $\alpha$ 和~$\beta$生成一个有限~$p$-\!群; \qquad 在下列2种情形下, ~$\alpha$ 和~$\beta$生成一个可解的剩余有限~$p$-\!群,它是有限生成的无挠幂零群被有限~$p$-\!群的扩张. \qquad (ii) 当~$I=Z_{p^{\infty}}$ 时; \qquad (iii) 当~$I=Z_{p^{m}}\oplus Z_{p^{\infty}}$ 时; \qquad 在下列4种情形下, $\alpha$ 和~$\beta$也生成一个可解的剩余有限~$p$-\!群, 它的幂零长度至多是~$3$. \qquad (iv) 当~$I$\, 是无挠的局部循环群时; \qquad (v) 当~$I$ 有子群列~$1< J< I, $其商因子分别为有限循环群、无挠的局部循环群时; \qquad (vi) 当~$I=Z_{p^{\infty}}\times J, $ 其中~$J$\,为无挠的局部循环群时; \qquad (vii) 当~$I$ 有正规列~$1< I_1研究了有限秩的幂零群的自同构, 证明了 \qquad {\heiti定理}\quad设幂零群~$G=KP$, 其中~$P$是有限秩的幂零~$p$-\!群, ~$K$ 是~$G$\,的有限秩的~$p^\prime$-\!自由的正规子群, ~$p$\, 不属于~$K$\,的谱~$S_p(K)$. 设~$\alpha$ 和~$\beta$ 是~$G$ 的两个~$p$-\!自同构,记~$I:=\langle\left(\alpha\beta(g)\right)\cdot\left(\beta\alpha(g)\right)^{-1}\, |\, g\in G \rangle, $ 则 \qquad (i) 当~$I$\, 是有限循环群时, $\alpha$ 和~$\beta$生成一个有限~$p$-\!群; \qquad 在下列2种情形下, ~$\alpha$ 和~$\beta$生成一个可解的剩余有限~$p$-\!群,它是有限生成的无挠幂零群被有限~$p$-\!群的扩张. \qquad (ii) 当~$I=Z_{p^{\infty}}$ 时; \qquad (iii) 当~$I=Z_{p^{m}}\oplus Z_{p^{\infty}}$ 时; \qquad 在下列4种情形下, $\alpha$ 和~$\beta$也生成一个可解的剩余有限~$p$-\!群, 它的幂零长度至多是~$3$. \qquad (iv) 当~$I$\, 是无挠的局部循环群时; \qquad (v) 当~$I$ 有子群列~$1< J< I, $其商因子分别为有限循环群、无挠的局部循环群时; \qquad (vi) 当~$I=Z_{p^{\infty}}\times J, $ 其中~$J$\,为无挠的局部循环群时; \qquad (vii) 当~$I$ 有正规列~$1< I_1研究了有限秩的幂零群的自同构, 证明了 \qquad {\heiti定理}\quad设幂零群~$G=KP$, 其中~$P$是有限秩的幂零~$p$-\!群, ~$K$ 是~$G$\,的有限秩的~$p^\prime$-\!自由的正规子群, ~$p$\, 不属于~$K$\,的谱~$S_p(K)$. 设~$\alpha$ 和~$\beta$ 是~$G$ 的两个~$p$-\!自同构,记~$I:=\langle\left(\alpha\beta(g)\right)\cdot\left(\beta\alpha(g)\right)^{-1}\, |\, g\in G \rangle, $ 则 \qquad (i) 当~$I$\, 是有限循环群时, $\alpha$ 和~$\beta$生成一个有限~$p$-\!群; \qquad 在下列2种情形下, ~$\alpha$ 和~$\beta$生成一个可解的剩余有限~$p$-\!群,它是有限生成的无挠幂零群被有限~$p$-\!群的扩张. \qquad (ii) 当~$I=Z_{p^{\infty}}$ 时; \qquad (iii) 当~$I=Z_{p^{m}}\oplus Z_{p^{\infty}}$ 时; \qquad 在下列4种情形下, $\alpha$ 和~$\beta$也生成一个可解的剩余有限~$p$-\!群, 它的幂零长度至多是~$3$. \qquad (iv) 当~$I$\, 是无挠的局部循环群时; \qquad (v) 当~$I$ 有子群列~$1< J< I, $其商因子分别为有限循环群、无挠的局部循环群时; \qquad (vi) 当~$I=Z_{p^{\infty}}\times J, $ 其中~$J$\,为无挠的局部循环群时; \qquad (vii) 当~$I$ 有正规列~$1< I_1其商因子分别为有限循环群、拟循环~$p$-\!群、无挠的局部循环群时. \qquad 特别地, 当群~$K$ 是一个~$FC$-\!群时, 在上述后4种情形下,~$\alpha$ 和~$\beta$生成的群也是有限生成的无挠幂零群被有限~$p$-\!群的扩张. \qquad 运用发展出来的方法, 还证明了几类有限秩的幂零群的自同构群的有限生成子群是剩余有限的.     

Serial Rings with T-Nilpotent Prime Radical

In this paper we consider serial rings with T-nilpotent prime radical, factor-rings of which by the prime radical are right Noetherian rings. We prove that the prime quiver of such a ring is a disconnected union of cycles and chains. In the case when the prime quiver of such a serial ring is a chain the prime radical is nilpotent. For serial rings with nilpotent prime radical we introduce an analogue of Kupisch series. Presented by Yu. Drozd Mathematics Subject Classifications (2000) 16P40, 16G10.     

Hall广义补和群的可解性

研究具有某些特殊性质的广义补,得到了一些可解性的判别条件.如果对G的任意Sylow p-子群P,p∈{2,3}∩丌(G),NG(P)在G中都存在广义补H使H/D是G/D的Hall子群且H/D为幂零群,其中D=(H∩ⅣG(P))G,那么G可解.     

Eine Bemerkung zur Nilpotenz lokal kompakter Gruppen

Let G be a locally compact group which is connected or finite dimensional and compact over its connected component. If every (closed) subgroup of G is nilpotent then G is nilpotent.     

关于有限群的一个组合问题

设ｐ是有限群Ｇ之阶ｎ的最小素因子，Ｇ之运算用“＋”来记（但不必可换），又设，本文证明了当Ｇ为幂零群及其它某些类型的群时，是满足下面条件的最小正整数：凡Ｇ的不含零元的元子集均使得Ｇ之每一个元ｇ都可表成ｇ＝ａ＿（ｉ１）＋…＋ａ＿（ｉ１），诸ｉ＿ｊ互异．     

Lie rings admitting an automorphism of order 4 with few fixed points. II

We consider a Lie ring (algebra) L that admits an automorphism φ of order 4 with a finite number m of fixed points (with a fixed-point subalgebra of finite dimension m). It is proved that L contains a subring S of m-bounded index in the additive group L (a subalgebra S of m-bounded codimension), which possesses a nilpotent ideal I of class bounded by some constant, such that the factor-ring S/I is nilpotent of class ≤2. As a consequence, it is proved that, under the same conditions, L has a subring G of m-bounded index in the additive group of L (a subalgebra G of m-bounded codimension), in which an ideal generated by the Lie subring [G, ?²]=«ng?g+g^{? 2} | g∈G»ng (the subalgebra [G, ?²]=«ng?g+g^{? 2} | g∈G»ng is an ideal in G which) is nilpotent of class bounded by some constant (and its factor-algebra G/[G, ?²] is nilpotent of class ≤2 with a derived algebra (square) of m-bounded dimension). In proofs, we use the results of [1] and develop further the version of the method of generalized centralizers employed therein.     

Locally nilpotent groups satisfying the weak minimum or maximum condition for subgroups of bounded nilpotency class

We study locally nilpotent groups containing subgroups of classc, c>1, and satisfying the weak maximum condition or the weak minimum condition on c-nilpotent subgroups. It is proved that nilpotent groups of this type are minimax and periodic locally nilpotent groups of this type are Chernikov groups. It is also proved that if a group G is either nilpotent or periodic locally nilpotent and if all of its c-nilpotent subgroups are of finite rank, then G is of finite rank. If G is a non-periodic locally nilpotent group, these results, in general, are not valid.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 44, No. 3, pp. 384–389, March, 1992.     

Finite groups in which every self-centralizing subgroup is nilpotent or subnormal or a TI-subgroup

Czechoslovak Mathematical Journal - Let G be a finite group. We prove that if every self-centralizing subgroup of G is nilpotent or subnormal or a TI-subgroup, then every subgroup of G is nilpotent...     

Finite groups with an almost regular automorphism of order four

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.     

Une caractérisation Riemannienne du groupe de Heisenberg

We study the left-invariant Riemannian metrics on a class of models of nilpotent Lie groups. In particular we prove that the Heisenberg groups are, up to local isomorphism, the only nilpotent non-decomposable Lie groups endowed with a homogeneous Riemannian naturally reductive space for every left invariant metric.

Membre du G.N.S.A.G.A., G.N.R. d'Italie et du groupe national Geometria delle varietà differenziabili, 40%, M.P.I. Italie.     

Idempotent-Conjugate Monoids with Nilpotent Unit Groups

Let M be a finite monoid with unit group G such that J-related idempotents in M are conjugate. If G is nilpotent, we prove that the complex monoid algebra CM of M is semisimple if and only if M is an inverse monoid. Conversely let G be a finite group such that for any finite idempotent-conjugate monoid M with unit group G, CM semisimple implies that M is an inverse monoid. We then show that G is a nilpotent group.