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1.
非退化扩散过程的极性的必要性   总被引:3,自引:1,他引:2  
设X(t)是一N维非退化扩散过程.设 E(0,∞)和 F RN都为紧集.本文给出了:P(X-1(F)∩E≠φ)>0,P(X-1(F)≠φ)>0和P(X(E)≠φ)>0的充分条件.证明了:i)设 N≥ 3,a)若 dim(F)<N-2,则 P(X-1(F)=φ)=1; b)若dim(F)>N-2,则 P(X-1(F)≠φ)>0; c)存在 F1 RN,F2 RN,dim(F1)=dim(F2)=N-2,但有P(X-1(F1)=φ)=1,P(X-1(F2)≠φ)>0.ii)设N=1,a)若dim(E)>1/2,则x∈R1,P(X-1(x)∩E≠φ)>0;b)存在E(0,∞),dim(E)=1/2,使得x∈R1,P(X-1(x)∩E≠φ)>0.以上这些结果,不仅仅是Brown运动的推广,即使就Brown运动的情形而言,其中有些结果也是新的.  相似文献   

2.
值域有界的一类非线性算子不动点的带误差迭代逼近   总被引:9,自引:1,他引:8  
设X为一致光滑实Banach空间·T:X→X为连续强增生算子·f∈X·定义算子S:X→X为Sx=f-Tx+x,x∈X·设αn{}∞n=0与βn{}∞n=0为两个给定的实数列在(0,1)中且满足条件:(ⅰ)αn→0,βn→0(n→∞)·(ⅱ)∑∞n=0αn=∞·假设un{}∞n=0和vn{}∞n=0为X中两个序列且满足‖un‖=o(αn),‖vn‖→0(n→∞)·x0∈X,迭代序列xn{}定义为:(IS)xn+1=(1-αn)xn+αnSyn+unyn=(1-βn)xn+βnSxn+vn(n≥0){若Sxn{},Syn{}有界,则xn{}强收敛于S的唯一不动点  相似文献   

3.
PID环上矩阵模的保秩1映射及应用   总被引:1,自引:1,他引:0  
刘绍武 《数学杂志》1997,17(1):99-104
设R为含1主理想整环(简记为PID),本文刻划了矩阵模Mn(R)上保秩1线性映射的形式;作为其应用,给出了域上矩阵空间的保线性群及Mn(R)上保非零行列线性映射的形式,即它们为:T(X)=PXQ,A↑X∈Mn(R),或T(X)=PXtQ,A↑X∈Mn(R)。其中det(PQ)≠0。  相似文献   

4.
设X=G0/K0是非紧致黎曼对称空间,G0的李代数g0是其复化李代数g的正规实型.若记n0=dimX,则我们在该文中证明:对于f∈Lp(X),1≤P≤2,当复数z满足Rez>δ(n0,P)=(n0-1)(1/P—1/2)时,f关于拉普拉斯算子本征函数展开的z阶Riesz平均几乎处处收敛于f.这一结论与经典的欧氏空间,以及复的和一秩的非紧致黎曼对称空间中完全相同.  相似文献   

5.
1引言与预备知识 设X为一实赋范线性空间.X·是X的对偶空间,正规对偶映射J:X→2X定义为:其中<·,·>表示X和X的广义对偶组.由[1]知若X是一致光滑Banach空间,则J(·)单值且在X的任何有界子集上为一致连续.我们用j(·)表示单值的正规对偶映射. 定义1[2]设K是X的一非空子集,算子T:K→X称为是 -强伪压缩的,如果存在一个严格增加函数 ,存在使得 定义2[2,3]T称为 强增生算子的,如果(I-T)是 -强伪压缩算子(其中I是恒等算子). 若定义1(相应地;定义2)中 (t)=k…  相似文献   

6.
本文给出Lax定理在局部凸空间中的几个推广,特别地,我们获得Lax定理的如下推广:设X和Y为自反Frechet空间,其拓扑分别由半范序列q1≤q2≤…和半范序列p1≤P2≤…所给出.设A:Y→X′为连续线性算子,则存在连续线性算子G:Y′→X使满足:(Gg,Ay)=(g,y),g∈Y′,V∈Y当且仅当:对于n,存在cn>0,使sup{1(Ay,x)|:qn(x)≤1}≤cnpm.(y),y∈Y且A的值域在互X′中具拓扑补,这里,X′和Y′分别记X和Y的强对偶.  相似文献   

7.
最佳L2局部逼近存在唯一的充分必要条件   总被引:1,自引:0,他引:1  
本文给出了最佳L2局部逼近的存在唯一性定理,设f∈L2(0,δ),Sn=span(u0,u1,...Un-1)C^n-1(0,δ),且detWn(u0,u1,...un-1;0)≠0,那么,当x→0时,网(Px(f,Sn)收敛于Sn中某元素P0(f,Sn)的充要条件为:f=Pn-1+h,其中Pn-1(t)=n-1∑i=1aiti(h,1)x=0(X^n),x→0,且P0(f,Sn)=UW^-1nA  相似文献   

8.
设A是Banach空间X上的自反算子代数,并且A的不变子空间格Lat A满足0+≠0和X_≠X,αA→A是环自同构.如果X是实空间,并且dim X±>1,则存在X上的线性有界可逆算子A,使得α(T)=ATA-1,T∈A;如果X是复空间,并且dim X±=∞,则α(T)=ATA-1,T∈A.其中AX→X是线性、或者共轭线性有界可逆算子.  相似文献   

9.
翟发辉 《数学学报》2001,44(2):307-310
本文证明了一类本质正规算子A'(Ω';1)(T∈A'(Ω';1),如果T满足(1)T,T|H(T)分别是本质正规算子;(2)σ(T)=Ω,ρF(T)∩σ(T)=Ω;(3)ind(T-λ)=-1,nul(T-λ)=0,λ∈Ω';(4)σ(T|H(T))是一完全集,这里Ω'是一连通的解析Cauchy域, Hl(T)= V{ker(T-λ)*:λ∈ρrs-F(T)}是模小紧相似的.  相似文献   

10.
命题设a1∈N+,a1≠10n(n=0,1,2,…).现构造数列{an}:ak+1是ak的各位数字的平方和.如果存在T∈N+,使得aT+1=a1,则称a1是周期为T的“周期数”.证明:(1)周期数有且只有4,16,37,58,89,145,42,20...  相似文献   

11.
12.
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   

13.
14.
正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with  相似文献   

15.
正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.  相似文献   

16.
A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].  相似文献   

17.
Résumé On décrit toutes les feuilles des laminations minimales dont un ensemble résiduel de feuilles ont 2 bouts.   相似文献   

18.
We develop a theory of downward sets for a class of normed ordered spaces. We study best approximation in a normed ordered space X by elements of downward sets, and give necessary and sufficient conditions for any element of best approximation by a closed downward subset of X. We also characterize strictly downward subsets of X, and prove that a downward subset of X is strictly downward if and only if each its boundary point is Chebyshev. The results obtained are used for examination of some Chebyshev pairs (W,x), where ∈ X and W is a closed downward subset of X  相似文献   

19.
In this paper, the author establishes the boundedness of multilinear operators on weighted Herz spaces and Herz-type Hardy spaces. The author also obtains their weak estimates on endpoints. As a special case, the conclusions may lead to the weighted estimates for multilinear Calderon-Zygmund operators.  相似文献   

20.
In this paper we present a generalized quantitative version of a result due to M. Revers concerning the exact convergence rate at zero of Lagrange interpolation polynomial to f(x) = |x|α with on equally spaced nodes in [-1, 1].  相似文献   

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