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1.
对于完备格L上给定的|I|×|I|的矩阵R,若存在|I|×|I|的L上的矩阵S满足S☉S=R,则称S为R的平方根,其中|I|表示指标集I的基数,☉在本文中指的是sup-(J)合成算子并且(J)是无限Ⅴ分配的保序的算子,本文给出了完备格上基于sup-(J)合成算子的矩阵平方根存在的充要条件以及相应的理论上的算法求解所有的平方根.  相似文献   

2.
讨论伪统一模与剩余格之间的关系,证明完备格上无穷∨-分配伪统一模和它的剩余蕴涵算子构成一个完备剩余格,并说明任给一个完备剩余格L=(L,∧,∨,*,e→,,*是无穷∨-分配的伪统一模,→和(?)是*的剩余蕴涵算子.  相似文献   

3.
设M_R=(T R O S)是定义在Banach空间X⊕Y上的2×2上三角算子矩阵,则T和S满足性质(gw)(或性质(gb))推不出M_R满足性质(gw)(或性质(gb)),即使R=0.文章主要利用局部谱理论的知识,研究了Banach空间上2×2上三角算子矩阵在什么情况下满足性质(gb)和性质(gw).  相似文献   

4.
1引言设Rn×m表示所有n×m实矩阵集合,I表示单位矩阵,AT表示矩阵A的转置矩阵, ORn×n={P|PTP=I)表示列正交矩阵集,SORn×n={P|PT=P,P2=I}表示对称正交对称矩阵集.如无特别说明,本文中的矩阵P均指这类对称正交对称矩阵.在Rn×m上定义内积为  相似文献   

5.
Fourier-Laplace级数的强逼近   总被引:1,自引:0,他引:1  
张希荣  戴峰 《数学进展》2004,33(5):626-630
设f是Rn(n≥3)中单位球面∑n-1上的可积函数,Sθ(f)是步长为θ∈R的平移算子.σδN(f)是Fourier-Laplace级数的δ阶Ceaaro平均.如果∫π0 |Sθ(f)-f|p/θ2dθ∈ L∞ (∑n- 1 ),则∑∞k=0 |σλk(f)-f|p∈L∞(∑n-1)且∑∞k=0(f)-f|p∈L∞(∑n-1 ),其中Eλk(f)为Cesaro平均σλk的等收敛算子.  相似文献   

6.
称T∈B(H)有广义Kato分解,若存在一对T的闭的不变子空间(M,N)使得H=M⊕Ⅳ,其中T|_M为上半Fredholm算子且具有非负的指标,T|_N是幂零的本文利用算子的广义Kato分解性质,研究了Weyl型定理在紧摄动下的稳定性.此外还研究了2×2上三角算子矩阵的Weyl型定理在紧摄动下的稳定性.  相似文献   

7.
本文在全序完备格L上定义了双蕴含算子“(?)”。讨论了L上及L-Fuzzy矩阵上算子“(?)”的若干性质,分别得到了Fuzzy关系方程AX=A(XA=A)及Fuzzy不等方程AX≤A(XA≤A)的解,给出了L-Fuzzy矩阵有广义下逆的一个充分必要条件及幂等阵的两个广义逆。  相似文献   

8.
[1]中提出如下的问题:若S是Hilbert空间H上次正常算子,而且S~*S-SS~*是有限秩算子。能否绐出S的一般形式。当S~*S-SS~*是一秩算子时,S=aI bU_ ,这儿U-是单向平移算子。在[2]中对自对偶次正常算子情况,给出了一个表示。这里我们从另一个角度来部分回答上述问题。 Hilbert空间H上算子S称为次正常算子是指存在一个Hilbert空间R(?)H上正常算子N,NH(?)H,而S=N|H。称N为S的正常延拓,相对于R=H(?)H-,正常算子N有表示  相似文献   

9.
利用完备分配格L上的s-模定义格L上的矩阵运算,给出这些运算的一些基本性质,并且定义格L上的s-幂零矩阵,给出一些全新的结果.  相似文献   

10.
设T,S为R(K)循环的次正常算子,R(K)为Dirichlet代数。T的极小正常扩张mne(T)的谱σ(mneT)(?)K。T与S为拟相似。本文完全刻画了T的不变子空间。此外引进了超不变算子,并且给出了S|_M为超不变算子的充要条件。  相似文献   

11.
12.
张丽娜  吴建华 《数学进展》2008,37(1):115-117
One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the'living world. In his seminal paper "The Chemical Basis of Morphogenesis", Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates(1990) on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing's prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows  相似文献   

13.
In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).  相似文献   

14.
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   

15.
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

16.
正Guest Editors:Hong Chen,Shanghai Jiao Tong University,Shanghai,China Guohua Wan,Shanghai Jiao Tong University,Shanghai,China David Yao,Columbia University,New York,USA Scope:Healthcare delivery worldwide has been fraught with high cost,low efficiency and poor quality of patient care service.For the field of operations research(OR),healthcare offers some of the biggest challenges as well as best opportunities in  相似文献   

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18.
Due to the resolution of current laser technology, the accuracy of corneal topography as measured by the videokeratoscope is no longer adequate to provide precise enough data for refractive surgery or for the fitting of customized contact lenses. We present an algorithm for recovering corneal topography that makes use of modern differential geometric techniques and numerical descent in Sobolev spaces. We believe this algorithm may be used with the photo- and videokeratoscope to increase the accuracy of the recovered corneal topography.  相似文献   

19.
Let {Ln(A,λ)(x)}n≥0 be the sequence of monic Laguerre matrix polynomials defined on [0, ∞) by Ln(A,λ)(x)=n!/(-λ)n∑nk=0(-λ)κ/k!(n-1)! (A I)n[(A I)k]-1 xk,where A ∈ Cr×r. It is known that {Ln(A,λ)(x)}n≥0 is orthogonal with respect to a matrix moment functional when A satisfies the spectral condition that Re(z) > - 1 for every z ∈σ(A).In this note we show that forA such that σ(A) does not contain negative integers, the Laguerre matrix polynomials Ln(A,λ) (x) are orthogonal with respect to a non-diagonal SobolevLaguerre matrix moment functional, which extends two cases: the above matrix case and the known scalar case.  相似文献   

20.
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