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1.
一类K_n-E(G)型图的色唯一性 总被引:2,自引:0,他引:2
设Km-E(G)表示从完全图Km中删去一个和G同构的子图的所有边而得到的图.本文证明了,当G=k1Ps1∪k2PS2∪…∪krPsr,(si>1,si≠4,i=1,2,…,r),且Psi都是不可约路时,图Km-E(G)是色唯一的. 相似文献
2.
设 G是一个图,若对于 G的任意一边 G都有{P_2,Ci|i->3}-因子含有这条边,则称G是{P_2,Ci|i->3}-覆盖图.本文给出连通非二分图G是{P2,Ci|i->3}-覆盖图的充要条件为任给S■V(G),V(G)≠S≠■有i(G-S)_>|S|-1成立. 相似文献
3.
三维欧氏空间的Child不等式 总被引:3,自引:1,他引:2
三维欧氏空间的Child不等式杨世国(安徽教育学院数学系230061)1主要结果设△A1A2A3内部任一点P到三角形各顶点之距离为Ri=|PAi|(i=1,2,3),点P到三角形各边之距离为ri=(i=1,2,3),J.M.Child获得下述一个重要... 相似文献
4.
设G是一个图,若对于G的任意一边G都有{P2,Ci│i≥3}-因子含有这条边,则称G是{P2,Ci│i≥3}-覆盖图。本文给出连通非二分图G是{P2,Ci│i≥3}-覆盖图的充要条件为任给S包含于V(G),V(G)≠S≠ф有i(G-S)≤│S│-1成立。 相似文献
5.
本文证明了有限群G是Abel群当且仅当G_r满足下列条件:(Ⅰ) G有一个幂自同构 a使得 CG(a)是一个初等 AbelZ一群.(Ⅱ)G没有子群与2-群<a,b|a~2~n=b~2~m=1,a~b=a~(1+2)~(n-1)>同构,其中n≥3,n≥m.利用该结果,作者还证明若有限群G有一个幂自同构a使得C_G(a)是一个初等Abel2-群,则G是幂零群 相似文献
6.
本文结果是:设A是φ-满射环R上的非拟纯量可逆n×n矩阵,βj,γj(尔≤j≤n)是R中任意元素,它们满足Πnj=1βjγj=detA,则存在n阶阵B和C满足PAP-1=BC,其中B是下三角阵,C是上三角阵,P∈GLn(R).进一步,可以取B使βj(1≤j≤n)位于B的主对角线上,同时可以取C使γj(1≤j≤n)位于C的主对角线上. 相似文献
7.
8.
本文给出了有限交换局部环R上无限线性群GL(R)=∪nGLnR的Sylowp-子群的形式.令M是有限交换局部环R的唯一极大理想,k=R/M为R的剩余类域.用X(k)表示k的特征,并假定P与x(k)互素.作者证明了:GL(R)的任一Sylowp-子群S或者同构于的可数无限直积与P(j)的无限直积的直积(当P≠2或P=2,X(k)β≡1(mod4))或者同构于Pi的无限直积与P(j)的无限直积的直积(当P=2,X(k)β≡3(mod4)),这里,只是GL(epi)R(分别地,GL(2ri)R)的Sylowp-子群,P(j))同构于P=∪i∈Ipi,I是可数集. 相似文献
9.
10.
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
11.
具拟不变测度群胚流上的交叉积 总被引:2,自引:0,他引:2
设G为第二可数局部紧有Haar系{λu}的群胚,A为G上左不变作用的交换群,则我们有C-动力系统(C(G),A,β).本文我们研究具有一定性质的拟不变测度,用此测度,得到了一些有关群胚C-代数及交叉积的重要结果, 相似文献
12.
Groupoid的诱导表示 总被引:1,自引:1,他引:0
设G为第二可数局部紧有Haar系的Groupoid, H为子Groupoid闭于G,则可得Groupoid H\G2,我们证明了C*(H)与C*(H\G2)是Morita等价的,从而回答了[1]中的问题.利用此非本原双模及定义C*(G)到M(C*(H\G2))的映射,得到了由C*(H)到C*(G)的诱导表示.特别在群丛情形,我们定义了C*(H)→M(C*(G))的映射,并具体得到了诱导表示的积分形式的表达式. 相似文献
13.
Jean-louis Tu 《K-Theory》1999,17(3):215-264
We show, using the construction of Higson and Kasparov, that the Baum–Connes Conjecture holds for foliations whose holonomy groupoid is Hausdorff and amenable. More generally, for every locally compact, -compact and Hausdorff groupoid G acting continuously and isometrically on a continuous field of affine Euclidean spaces, the Baum–Connes conjecture with coefficients is an isomorphism, and G amenable in K-theory. In addition, we show that C*(G) satisfies the Universal Coefficient Theorem. 相似文献
14.
Pierre-yves Le Gall 《K-Theory》1999,16(4):361-390
Let
be a locally compact topological groupoid, A and B two C*-algebras endowed with a continuous action of
. We define an operator K-theory group K K
(A,B). We describe two basic properties of this theory: the existence of a Kasparov product and functoriality with respect to groupoid cocycles. 相似文献
15.
图的倍图与补倍图 总被引:7,自引:0,他引:7
计算机科学数据库的关系中遇到了可归为倍图或补倍图的参数和哈密顿圈的问题.对简单图C,如果V(D(G)):V(G)∪V(G′)E(D(G))=E(C)∪E(C″)U{vivj′|vi∈V(G),Vj′∈V(G′)且vivj∈E(G))那么,称D(C)是C的倍图,如果V(D(G))=V(C)∪V(G′),E(D(C)):E(C)∪E(G′)∪{vivj′}vi∈V(G),vj′∈V(G’)and vivj∈(G)),称D(C)是G的补倍图,这里G′是G的拷贝.本文研究了D(G)和D的色数,边色数,欧拉性,哈密顿性和提出了D(G) 的边色数是D(G)的最大度等公开问题. 相似文献
16.
We extend the notion of the enveloping semigroup of a locally compact group to the enveloping semigroupoid of a locally compact groupopid and show that there is a universal enveloping semigroupoid which is unique up to isomorphism. As in the group case, we associate the Ellis semigroupoid to an action of a locally compact groupoid on a fibrewise compact space. We define the notion of proximality for groupoid actions and characterize it in terms of Ellis semigroupoid.
相似文献17.
Lisa Orloff Clark Astrid an Huef 《Proceedings of the American Mathematical Society》2008,136(2):623-634
Suppose is a second countable, locally compact, Hausdorff, principal groupoid with a fixed left Haar system. We define a notion of integrability for groupoids and show is integrable if and only if the groupoid -algebra has bounded trace.
18.
P. Milnes 《Acta Mathematica Hungarica》1999,83(1-2):1-15
In each of 3 and 4 dimensions there is a unique (up to isomorphism) connected, simply connected, nilpotent Lie group, called G3 and G4, respectively. In 5 dimensions there are 6 such groups G5,i, 1 i 6. In [2] operator equations (analogous to UV = VU for the irrational rotaton algebra A) were used to find cocompact subgroups H5,i G5,i that would be analogous to the integer Heisenberg group H3 G3. The main thrust in [2] was to identify the infinite dimensional simple quotients of C* (H5,i), both the faithful ones Ai (generated by a faithful representation of H5,i) and the non-faithful ones, and also to give matrix presentations over lower dimensional algebras for as many of the non-faithful quotients as possible. In the course of this work, a small number of the C*-crossed product presentations of the Ai's were mentioned. The purpose of this paper is to display explicitly all the C*-crossed product presentations of the Ai's that are of potential interest and usefulness; they are analogous to C* (C(T), Z) and C*(C, Z2), the flow and cocycle presentations of A. 相似文献
19.
设G为一个离散群,(G,G_ )为一个拟偏序群使得G_ ~0=G_ ∩G_ ~(-1)为G的非平凡子群。令[G]为G关于G_ ~0的左倍集全体,|G_ |为[G]的正部。记T~(G_ )和T~([G_ ])为相应的Toeplitz代数。当存在一个从G到G_ ~0上的形变收缩映照时,我们证明了T~(G_ )酉同构于T~([G_ ])×C_r~*(G_ ~0)的一个C_-~*c子代数。若进一步,G_ ~0还为G的一个正规子群,则T~(G_ )与T~([G_ ])×C_r~*(G_ ~0)酉同构。 相似文献
20.
设Fk*是满足以下条件的3-正则2-连通平面图G所组成的图类,在G中存在这样的圈C,使得G-E(C)产生k个不相交的树T1,…,Tk(|E(Ti)|≥3,i=1,…,k),且这些树是按C的指定方向C*依次粘在圈C上的.本文主要证明了如下结果:Fk*中的图都是Hamilton的. 相似文献