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1.
尚莉  张和平 《中国科学A辑》2009,39(9):1065-1071
已经证明,当m≤3时,λ(m)-连通图G满足λ(m)(G)≤ξm(G)。当m≥4时,Bonsma等人指出不等式λ(m)(G)≤ξm(G)一般不再成立。最近,欧见平证明阶大于等于11的λ4-连通图G满足λ4(G)≤ξ4(G).本文通过研究满足λ(m)(G)〉ξm(G)的λm-连通图所具有的结构性质,不仅易得以上结论,还得到如下一般结论:当m≥5时,阶大于m(m-1)的λm-连通图G均满足λm(G)≤ξm(G).最后,通过构造例子说明本文给出的条件是最好的.  相似文献   

2.
设{X(t):t≥0}为零初值纯生过程,出生率为λnn≥0,在本文中,我们证明了Faddy[7]的一个猜测:当生率为单调增加序列λ0≤λ1≤λ2≤…时,Var{X(t)}≥E{X(t)};当出生率为单调减少序列时,Var{X(t)≤E{X(t)}。  相似文献   

3.
应用矩阵A=(aij)∈Cn×n的弗罗伯尼范数AF和谱范数AS,研究厄米特矩阵的迹的性质,得到几个结论:Tr(AB)=∑ni=1λi∑nj=1tijμj(λi,μj分别为A,B的特征值,0≤tij≤1,且∑ni=1tij=1,j=1,2,…,n);Tr(AB)≤Tr(A)BS;Tr(AB)H(AB)]≤Tr(AHA)[max1≤i≤nλi]2(λi是B的特征值)等.  相似文献   

4.
吕广世 《中国科学A辑》2009,39(8):1023-1028
设f(z)∈Sk(Γ)是全模群的一个全纯尖形式,且为所有Hecke算子的特征函数,λ(n)表示其第n个正规化的Fourier系数.Sankaranarayanan在他的一篇文章中提到:得到和式∑n≤xλ(n^3)的非显然估计是一个公开问题.在本文中,我们利用对称幂L函数的解析性质解决了这一问题.具体说来,我们证明了∑n≤xλ(n^3)≤x^3/4+ε,∑n≤xλ(n^4)≤x7/9+ε.  相似文献   

5.
几类不具有捏制轨道系列完整性的单峰函数族   总被引:1,自引:0,他引:1  
本文证明,存在着由单峰函数构成的Co-函数族{fλ),{gλ}及具有下列性质:(i)各fλ均是分段线性的单峰平顶函数,各gλ及均是C∞-单峰平顶函数.但族{fλ},{gλ}及均非一致平顶;(ii)族{fλ}及{gλ}均满足一致的Lipschitz条件,但在峰顶处均非一致地可微;(iii)族在峰顶处一致地可微,但不满足一致的Lipschitz条件;(iv)当0≤λ≤7/8时捏制序列K(fλ),K(gλ)及以均不大于RLC,当7/8<λ-≤1时K(fλ),K(gλ)及K均不小于RLL(RLR)∞,因而族{fλ},{gλ}及均不具有捏制轨道系列的完整性.本文的结果解答了文[5]中提出的两个猜测.  相似文献   

6.
引入K-泛函K(f,t)n对Szász-Durrmeyer算子证明了其强逆不等式,推广了此算子关于ω~(2φ~λ)(f,t)(0≤λ≤1)的逆结果.  相似文献   

7.
第二类Feigenbaum函数方程凸解的构造   总被引:3,自引:0,他引:3  
考虑第二类Feigenbaum函数方程{f(x)=1/λf(f(λx)),0〈λ〈1,f(0)=1,0≤f(x)≤1,x∈[0,1]对于给定的初始函数,利用构造性方法讨论上述方程的连续凸解、C^1-凸解和C^2-凸解的存在性及唯一性.  相似文献   

8.
文[1]给出了如下不等式: 设a,b〉0,0〈λ≤2,则 √a/a+λb+√b/λa+b≤2/√1+λ(1)  相似文献   

9.
张庆德 《数学学报》1999,42(2):351-358
对于单位圆周上的任一非空闭集E,任意正数λ及任意实数μ(0≤μ≤λ);构造了一个单位国内的λ级亚纯函数,以{(L(θ)|θ∈E}为Borel半径集,并且{L(θ)|θ|E}都不是Julia半径,同时N(r,f)的级为θ.  相似文献   

10.
关于代数体函数的微分多项式   总被引:1,自引:0,他引:1  
黄斌 《数学杂志》2001,21(1):53-56
本文证明υ值代数函数的微分多项式是一λ值(1≤λ≤υ)代数体函数,即υ值代数体函数ω=ω(z)的微分多项式p(ω)可以被如下方程确定:[ελ(z)p^λ ελ-1(z)p^λ-1 … ε0(z)]^k=0这里ε0(z),ε1(z),…,ελ(z)为整函数且无公共零点,λ和k为正整数且λk=υ。  相似文献   

11.
As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years (2001-2005). The main topics are: convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.  相似文献   

12.
In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.  相似文献   

13.
In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p(R^n) into the Lebesgue space L^p with p 〈 1.  相似文献   

14.
15.
<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists  相似文献   

16.
<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by  相似文献   

17.
Let P(z)=∑↓j=0↑n ajx^j be a polynomial of degree n. In this paper we prove a more general result which interalia improves upon the bounds of a class of polynomials. We also prove a result which includes some extensions and generalizations of Enestrǒm-Kakeya theorem.  相似文献   

18.
Shanzhen  Lu  Lifang  Xu 《分析论及其应用》2004,20(3):215-230
In this paper, the authors study the boundedness of the operator [μΩ, b], the commutator generated by a function b ∈ Lipβ(Rn)(0 <β≤ 1) and the Marcinkiewicz integrals μΩ, on the classical Hardy spaces and the Herz-type Hardy spaces in the case Ω∈ Lipα(Sn-1)(0 <α≤ 1).  相似文献   

19.
Given the Laplace transform F(s) of a function f(t), we develop a new algorithm to find an approximation to f(t) by the use of the classical Jacobi polynomials. The main contribution of our work is the development of a new and very effective method to determine the coefficients in the finite series expansion that approximation f(t) in terms of Jacobi polynomials. Some numerical examples are illustrated.  相似文献   

20.
In applications it is useful to compute the local average empirical statistics on u. A very simple relation exists when of a function f(u) of an input u from the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. These products are characterized by a Strang and Fix like condition. An explicit construction of these product operators is exhibited for piecewise polynomial functions, using Hermite interpolation. The averaging relation which holds for the Haar approximation is then recovered when the product is defined by a two point Hermite interpolation.  相似文献   

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