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1.
刘浩培 《数学研究》1999,32(1):38-39,47
证明了若M(G)为图G的匹配多面体,M1,M2为M(G)的两个距离为d的顶点,则M1,M2间有d条内部不相交的最短路.  相似文献   

2.
吳文俊  李培信 《数学学报》1962,12(2):203-215
<正> 前言 对于任意微分流形M,可定义Stiefe-Whitney示性类W~i(M)∈H~i(M,Z_2)与示性类P~(4k)(M)∈H~(4k)(M).对于任意复流形M,則可定义陈省身示性类C~(2i)(M),这时視M为实微分流形时,W~i(M)与P~(4k)(M)都可自C~(2i)(M)定出(見[8]).一些重要流形的示性类的具体計算虽原則上有一般方法,但并不簡单,其巳知者就作者所知犹如下述:  相似文献   

3.
设M为闭极大三角代数S的σ-弱闭双边模且满足MS,证明了模M交换子C(A,M)= M.进而,如果MAlgLat S,得到H~n(S,AlgLat S)=H~n(S,M)(n≥1);若dimH〧≤1,则H~n(S,M)=0.  相似文献   

4.
We investigate the nilpotence of a Malcev algebra M and of its standard enveloping Lie algebra L(M)=M D(M, M). The main result shows that an ideal A of M is nilpotent in M if and only if the corresponding ideal Ⅰ(A) = A D(A, M)is nilpotent in L(M).  相似文献   

5.
设M是紧致微分流形,M或者无边,或者带边,但边界M的每个分支的欧拉示性数为0,以X(M)记M的欧拉示性数,本文将证明:当X(M)≠0时,对任一非空闭集A M,存在M的微分同胚f,使f的不动点集Fix(f)=A;当X(M)=0时,对任一闭集A M,存在M的微分同胚f,使Fix(f)=A.还将证明,X(M)=0对任意自然数m,存在M的微分同胚f,使f,f~2,…,f~m均无不动点. 设dimM=n.x∈M,以M_x记M在x处的切空间.  相似文献   

6.
董浙 《数学年刊A辑》2007,28(1):27-32
设M为闭极大三角代数S的σ-弱闭双边模且满足M(∩)S,证明了模M交换子C(A,M)=M.进而,如果M(∩)AlgLat S,得到Hn(S,AlgLat S)=Hn(S,M)(n≥1);若dim H(⊥-)≤1,则Hn(S,M)=0.  相似文献   

7.
R0代数上的MP滤子格   总被引:1,自引:1,他引:0  
在R0代数M的全体M P滤子集F(M)上定义格运算和伴随对,证明如此定义的M P滤子格F(M)也构成一个剩余格。在R0代数M的强素M P滤子子格F P(M)上引进一个逆序对合对应,得到了强素M P滤子子格F P(M)是一个拟布尔代数。  相似文献   

8.
1 命题及其证明命题 如图 1所示 ,若直线 l⊥线段 AB于 H ,则M1 A2 - MA2 =M1 B2 - MB2 (1)反之 ,若式 (1)成立 ,则 M1 M所在的直线 l⊥AB.图 1证明 ∵  l⊥线段AB,∴ 由勾股定理得 :AM21 - AH 2 =H M21 ,AM2 - AH 2 =H M2 .两式相减得AM21 - AM2 =H M21 - H M2 . 1同理可得BM21 - BM2 =H M21 - H M2 . 2由 1、2得AM21 - AM2 =BM21 - BM2 .反过来 ,可设∠ AH M1 =θ,则∠ BH M1 =π -θ,∴  M1 A2 - AM2  =AH 2 +H M21 - 2 AH . H M1 cosθ- AH 2 - H M2 +2 AH . MH . cosθ  =H M21 - H M2 - 2 …  相似文献   

9.
有限群的Deskins极大完备   总被引:1,自引:0,他引:1  
李世荣 《数学年刊A辑》2003,24(2):145-150
对于有限群G的一个极大子群M,Deskins称子群C为M的一个完备,如果C M,但C的G-不变真子群包含在M中.令I(M)表示M的所有完备之集.I(M)的一个极大元叫做M的一个极大完备.利用极大完备,本文获得关于群的可解性和超可解性某些新的刻划.  相似文献   

10.
对于有限群G的一个极大予群M,Deskins称子群C为M的一个完备,如果C(?)M,但C的G-不变真子群包含在M中.令I(M)表示M的所有完备之集. I(M)的一个极大元叫做M的一个极大完备.利用极大完备,本文获得关于群的可解性和超可解性某些新的刻划.  相似文献   

11.
钟勇  贾厚玉 《数学学报》2011,(5):721-730
本文得到了极大函数M_ω)(|f|~p)~1/p和M(f)在加权Orlicz-Morrey空间上的有界性,同时也给出了极大函数M_ω(|f|~p)~1/p在其上有界的必要条件.  相似文献   

12.
对一个图G,设μ(G,x)表示它的匹配多项式,M(G,x)表示μ(G,x)的最大实数根.令Г_1={G|M(G,x)<2}和Г2={G|M(G,x)≤2}.给出了Г_i(i=1,2)中的两个图G和H匹配等价的充要条件.  相似文献   

13.
黄红 《数学研究》2010,43(2):131-134
要设(Mn,go)(n奇数)是紧Riemannian流形,λ(go)〉0,这里λ(go)是算子-4△go+R(go)的第一特征值,R(go)是(Mn,go)的数量曲率.设以(Mn,go)为初值的规范化的Ricci流的极大解g(t)满足|R(g(t))|≤C和λ(对某个常数C一致成立).我们证明这个解有子列收敛于一个Ricci收缩孤立子.进一步,当n=3时,条件fM |Rm(g(t))+n/2dμt ≤ C可去.  相似文献   

14.
In this paper we are concerned with the Hölder estimates of solutions of the Cauchy problem for the degenerate parabolic Eq. (1) with the initial data (2), where the diffusion function G ( u ) can be a constant on a non-zero measure set, such as the equations of two-phase Stefan's type. Under the condition | GG "/ G ' 2 | h g , g 2 h 1/2 N , the global estimates | o ( G f ( u ))| h M , on R N ‐ R + , is obtained by using the maximum principle, where f is a constant given in (9).  相似文献   

15.
Let ■ be the open unit disk in the complex plane ■.For α-1,let dA_α(z)=(1+α)1-|z|~2αd A(z) be the weighted Lebesgue measure on ■.For a positive function ω∈L~1(■,dA_α),the generalized weighted Bergman-Orlicz space A_ω~ψ(■,dA_α)isthe space of all analytic functions such that ||f||_ω~ψ=∫_■ψ(|f(z)|)ω(z)dA_α(z)∞,where ψ is a strictly convex Orlicz function that satisfies other technical hypotheses.Let G be a measurable subset of ■,we say G satisfies the reverse Carleson condition for A_ω~ψ(■,dA_α) if there exists a positive constant C such that ∫_Gψ(|f(z)|)ω(z)dA_α(z)≥C∫_■ψ(|f(z)|)ω(z)dA_α(z),for all f∈A_ω~ψ(■,dA_α).Let μ be a positive Borel measure,we say μ satisfies the direct Carleson condition if there exists a positive constant M such that for all f∈A_ω~ψ(■,dA_α),∫_■ψ(|f(z)|)dμ(z)≤M∫_■ψ(|f(z)|)ω(z)dA_α(z).In this paper,we study the direct and reverse Carleson condition on the generalized weighted Bergman-Orlicz space A_ω~ψ(■,dA_α).We present conditions on the set G such that the reverse Carleson condition holds.Moreover,we give a sufficient conditionfor the finite positive Borel measureμto satisfy the direct carleson condition on the generalized weighted Bergman-Orlicz spaces.  相似文献   

16.
This paper proves the existence of solution for the following quasilinear subelliptic Dirichlet problem: {Σ^m_{j=1}X^∗_ja_j(X, v, Xv)+ a_o(x, v, Xv) + H(x,v, Xv) = 0 v ∈ M^{1,p}_0(Ω) ∩ L^∞(Ω) Here X = {X_1 , …, X_m} is a system of vector fields defined in an open domain M of R^n, n ≥ 2, Ω ⊂ ⊂ M, and X satisfies the so-called Hormander's condition at the order of r > 1 on M. M_{1,p}_0(Ω) is the weighted Sobolev's space associated with the system X . The Hamiltonian H grows at most like |Xv|^p.  相似文献   

17.
本文研究金融市场中一类特殊半鞅模型,其价格过程具有X=LD的形式,这里L是局部有界鞅,D是可料有限变差过程.对这类模型我们导出其等价鞅测度存在的充分必要条件.另外,我们将[2]中的条件/△M/≤C推广到M为局部有界鞅,得到相应的结果.  相似文献   

18.
We shall consider semigroups with O, which contain a unique maximal right ideal generated by a finite number of independent generators and in which every proper right ideal is contained in the unique maximal right ideal and investigate when these semigroups are multiplicative semigroups of a ring. We prove in particular that the necessary condition for this class of semigroups S to admit ring structure is S=S2 if |S|>2. Furthermore the admissible ring structure of S is determined when the product of every two generators of the maximal right ideal M is O and when S satisfies one of the two conditions, namely S is commutative without idempotents except O and 1 or every generator of M is nilpotent.  相似文献   

19.
In [3], a kind of matrix-valued rational interpolants (MRIs) in the form of Rn(x) = M(x)/D(x) with the divisibility condition D(x) | ||M(x)||^2, was defined, and the characterization theorem and uniqueness theorem for MRIs were proved. However this divisibility condition is found not necessary in some cases. In this paper, we re- move this restricted condition, define the generalized matrix-valued rational interpolants (GMRIs) and establish the characterization theorem and uniqueness theorem for GMRIs. One can see that the characterization theorem and uniqueness theorem for MRIs are the special cases of those for GMRIs. Moreover, by defining a kind of inner product, we succeed in unifying the Samelson inverses for a vector and a matrix.  相似文献   

20.
Let M be a compact Riemann surface, h(x) a positive smooth function on M, and f(x) a smooth function on M which satisfies that $∫_Me^φdV_g=1$. In this paper, we consider the functional $J(u)=½∫_M|∇u|^2e^φdV_g+8πc∫_Mue^φdV_g-8πclog∫_Mhe^{u+φ}dV_g$. We give a sufficient condition under which J achieves its minimum for $c≤inf_{x∈M^{e^φ(x)}}$.  相似文献   

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