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1.
可容许极拓扑全体上的不变性   总被引:7,自引:0,他引:7  
本文找到了一个就可容许极拓扑全体而言的不平凡的不变性质:设X是Hausdorf局部凸空间,其对偶为X′,λ=c0或lp(1p<+∞),{xj}∈X.若对每个{tj}∈λ级数∑∞j=1tjxj依最弱的可容许极拓扑σ(X,X′)收敛,则对每个{tj}∈λ级数∑∞j=1tjxj依最强的可容许极拓扑β(X,X′)也收敛.  相似文献   

2.
§1LetXv={xnk,ynμ}beamatrixofnodessatisfying-1≤xn1<xn2<...<xnn≤1, -1≤yn1<yn2<...<ynl≤1,xnk≠ynμ,k=1,...,n,μ=1,...,l,n≥1,lv=l(n)≥0(1)  Forsimplicityweshalloftenomitthesuperfluousnotations.DefinebyPnthesetofpolynomialsofdegree≤n.Nowforanarbitraryfixedint…  相似文献   

3.
X1,…,Xm;Y1,…,Yn为独立随机样本,X,X1,…,Xm同分布,X-F,F(0)=0,Y,Y1,…,Ynm同分布,Y的分布函数为G(y)=1/μ∫yω(t,β)dF(t),y≥0,其中,β∈R,μ=∫0^∞ω(t,β)dF(t),0〈μ,ω(t,β)〈∞,F,μ和β均未知,ω(t,β)的形式已知,设θ为一待估参数,且存在一已知函数ψ(X,θ)满足EFψ(X,θ)=0,本文利用经验似然法给出  相似文献   

4.
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   

5.
一类指数型整函数插值算子的逼近性质   总被引:3,自引:0,他引:3  
设(Uσf)(x)=∑k∈Zf(Xk)Aσ(X-Xk),Xk=2kπσ,k∈Z,σ>0,f是R上的有界函数,而Aσ(y)=2σ∫σ0sinm(σ-X)hsinm(σ-X)h+sinmxhcosxydx,m为奇自然数,0<h<πσ,本文研究了此插值算子的收敛与饱和问题.  相似文献   

6.
袁敏英  李怡君 《数学季刊》1998,13(4):99-102
ByaBCI-algebrawemeananalgebra(X;,0)oftype(2,0)satisfyingtheaxioms:(1)((xy)(xz))(zy)=0;(2)(x(xy))y=0;(3)xx=0;(4)xy=yx=0x=yforanyx,yandzinX.ForanyBCI-algebraX,therelation≤definedbyx≤yifandonlyifxy=0isapartialorderonX[1].InanyBCI-algebraX,…  相似文献   

7.
设X1;…,Xn(n>p)是来自多元正态分布Np(μ,∑)的一个样本,其中μ∈R~p,∑>0均未知.本文在熵损失 L(sum from to ~,∑)=tr(∑~-1,sum from to ~)-log|∑~-1sum from to~|-p下证明了协方差矩阵∑的最佳仿射同变估计是不容许的,且给出了其改进估计.  相似文献   

8.
A.Pietsch^[1]在讨论核局部凸空间时给出了两类矢值序列空间l1[X]和l1{X}。本文建立了矢值序列空间l1[X]及l1{X}和连续线性算子空间L(c0,X)及绝对可和算子空间AS(c0,X)之间的拓扑同胚关系。通过c0上的矢值算子类L(c0,X)和AS(c0,X)及其上的拓扑等价关系,对局部凸空间X是核空间给出了一个新的特征刻划。  相似文献   

9.
对完备格 L;记v(L)为 L上的上拓扑之闭集格本文证明了完备格 L为 F-分配格当且仅当映射sup:v(L)→L为满完备格同态;若L为F-分配的Boole格,则L同构于某幂集格、对T1格 L,证明了下述各条件等价。(1) L同构于某幂集格;(2) L上的区间拓扑是 Hausdorff的;(3)是有限分离的;(4) L是连续的对马空间(X,O(X)),进一步证明了 O(X)上的区间拓扑不可能为 Hausdorff的,除非(X, O(X))是离散空间.  相似文献   

10.
万勇  宋鸿藻 《数学季刊》1998,13(4):103-105
§1. PreliminariesLetMbea(2n+1)-dimensionalcontactmetricmanifoldwithstructuretensors(Φ-,ξ-,η-,g).ThentheysatisfyΦ-ξ-=0,η-(ξ-)=1,Φ-2=-I+η-ξ-,η-(X)=g(X,ξ-),   g(Φ-X,Φ-Y)=g(X,Y)-η-(X)η-(Y),g(X,Φ-Y)=dη-(X,Y)(1.1)ForanyvectorfieldsXandY…  相似文献   

11.
It is well known that (see, for example, [H. Render, Nonstandard topology on function spaces with applications to hyperspaces, Trans. Amer. Math. Soc. 336 (1) (1993) 101-119; M. Escardo, J. Lawson, A. Simpson, Comparing cartesian closed categories of (core) compactly generated spaces, Topology Appl. 143 (2004) 105-145; D.N. Georgiou, S.D. Iliadis, F. Mynard, in: Elliott Pearl (Ed.), Function Space Topologies, Open Problems in Topology, vol. 2, Elsevier, 2007, pp. 15-22]) the intersection of all admissible topologies on the set C(Y,Z) of all continuous maps of an arbitrary space Y into an arbitrary space Z, is always the greatest splitting topology. However, this intersection maybe not admissible. In the case, where Y is a locally compact Hausdorff space the compact-open topology on the set C(Y,Z) is splitting and admissible (see [R.H. Fox, On topologies for function spaces, Bull. Amer. Math. Soc. 51 (1945) 429-432; R. Arens, A topology for spaces of transformations, Ann. of Math. 47 (1946) 480-495; R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31]), which means that the intersection of all admissible topologies on C(Y,Z) is admissible. In [R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31] an example of a non-locally compact Hausdorff space Y is given having the same property for the case, where Z=[0,1], that is on the set C(Y,[0,1]) the compact-open topology is splitting and admissible. This space Y is the set [0,1] with a topology τ, whose semi-regular reduction coincides with the usual topology on [0,1]. Also, in [R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31, Theorem 5.3] another example of a non-locally compact space Y is given such that the compact-open topology on the set C(Y,[0,1]) is distinct from the greatest splitting topology.In this paper first we construct non-locally compact Hausdorff spaces Y such that the intersection of all admissible topologies on the set C(Y,Z), where Z is an arbitrary regular space, is admissible. Furthermore, for a Hausdorff splitting topology t on C(Y,Z) we find sufficient conditions in order that t to be distinct from the greatest splitting topology. Using this result, we construct some concrete non-locally compact spaces Y such that the compact-open topology on C(Y,Z), where Z is a Hausdorff space, is distinct from the greatest splitting topology. Finally, we give some open problems.  相似文献   

12.
It is known (see, for example, [H. Render, Nonstandard topology on function spaces with applications to hyperspaces, Trans. Amer. Math. Soc. 336 (1) (1993) 101-119; M. Escardo, J. Lawson, A. Simpson, Comparing cartesian closed categories of (core) compactly generated spaces, Topology Appl. 143 (2004) 105-145; D.N. Georgiou, S.D. Iliadis, F. Mynard, Function space topologies, in: Open Problems in Topology 2, Elsevier, 2007, pp. 15-23]) that the intersection of all admissible topologies on the set C(Y,Z) of all continuous maps of an arbitrary space Y into an arbitrary space Z, is always the greatest splitting topology (which in general is not admissible). The following, interesting in our opinion, problem is arised: when a given splitting topology (for example, the compact-open topology, the Isbell topology, and the greatest splitting topology) is the intersection of k admissible topologies, where k is a finite number. Of course, in this case this splitting topology will be the greatest splitting.In the case, where a given splitting topology is admissible the above number k is equal to one. For example, if Y is a locally compact Hausdorff space, then k=1 for the compact-open topology (see [R.H. Fox, On topologies for function spaces, Bull. Amer. Math. Soc. 51 (1945) 429-432; R. Arens, A topology for spaces of transformations, Ann. of Math. 47 (1946) 480-495; R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31]). Also, if Y is a corecompact space, then k=1 for the Isbell topology (see [P. Lambrinos, B.K. Papadopoulos, The (strong) Isbell topology and (weakly) continuous lattices, in: Continuous Lattices and Applications, in: Lect. Notes Pure Appl. Math., vol. 101, Marcel Dekker, New York, 1984, pp. 191-211; F. Schwarz, S. Weck, Scott topology, Isbell topology, and continuous convergence, in: Lect. Notes Pure Appl. Math., vol. 101, Marcel Dekker, New York, 1984, pp. 251-271]).In [R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31] a non-locally compact completely regular space Y is constructed such that the compact-open topology on C(Y,S), where S is the Sierpinski space, coincides with the greatest splitting topology (which is not admissible). This fact is proved by the construction of two admissible topologies on C(Y,S) whose intersection is the compact-open topology, that is k=2.In the present paper improving the method of [R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31] we construct some other non-locally compact spaces Y such that the compact-open topology on C(Y,S) is the intersection of two admissible topologies. Also, we give some concrete problems concerning the above arised general problem.  相似文献   

13.
Let X be a Tychonoff space, H(X) the group of all self-homeomorphisms of X with the usual composition and the evaluation function. Topologies on H(X) providing continuity of the evaluation function are called admissible. Topologies on H(X) compatible with the group operations are called group topologies. Whenever X is locally compact T2, there is the minimum among all admissible group topologies on H(X). That can be described simply as a set-open topology, further agreeing with the compact-open topology if X is also locally connected. We show the same result in two essentially different cases of rim-compactness. The former one, where X is rim-compact T2 and locally connected. The latter one, where X agrees with the rational number space Q equipped with the euclidean topology. In the first case the minimal admissible group topology on H(X) is the closed-open topology determined by all closed sets with compact boundaries contained in some component of X. Moreover, whenever X is also separable metric, it is Polish. In the rational case the minimal admissible group topology on H(Q) is just the closed-open topology. In both cases the minimal admissible group topology on H(X) is closely linked to the Freudenthal compactification of X. The Freudenthal compactification in rim-compactness plays a key role as the one-point compactification does in local compactness. In the rational case we investigate whether the fine or Whitney topology on H(Q) induces an admissible group topology on H(Q) stronger than the closed-open topology.  相似文献   

14.
This paper presents a construction of the n = 2 (mod 4) Clifford algebra Cl n,0-valued admissible wavelet transform using the admissible similitude group SIM(n), a subgroup of the affine group of \mathbbRn{\mathbb{R}^{n}} . We express the admissibility condition in terms of the Cl n,0 Clifford Fourier transform (CFT). We show that its fundamental properties such as inner product, norm relation, and inversion formula can be established whenever the Clifford admissible wavelet satisfies a particular admissibility condition. As an application we derive a Heisenberg type uncertainty principle for the Clifford algebra Cl n,0-valued admissible wavelet transform. Finally, we provide some basic examples of these extended wavelets such as Clifford Morlet wavelets and Clifford Hermite wavelets.  相似文献   

15.
Let CL(X) denote the nonempty closed subsets of a metrizable space X. We show that the Vietoris topology on CL(X) is the weakest topology on CL(X) such that A - d(x, A) is continuous for each x X and each admissible metric d. We also give a concrete presentation of the analogous weak topology for uniformly equivalent metrics, and are led to consider for an admissible metric d the weakest topology on CL(X) such that the gap functional (A, B) - {d(ta, b): a A, b B} is continuous on CL(X) × CL(X).Visiting the University of Minnesota.Visiting California State University, Los Angeles.  相似文献   

16.
The Pontryagin-van Kampen (P-vK) duality, defined for topological Abelian groups, is given in terms of the compact-open topology. Polar reflexive spaces, introduced by Köthe, are those locally convex spaces satisfying duality when the dual space is equipped with the precompact-open topology. It is known that the additive groups of polar reflexive spaces satisfy P-vK duality. In this note we consider the duality of topological Abelian groups when the topology of the dual is the precompact-open topology. We characterize the precompact reflexive groups, i.e., topological groups satisfying the group duality defined in terms of the precompact-open topology. As a consequence, we obtain a new characterization of polar reflexive spaces. We also present an example of a space which satisfies P-vK duality and is not polar reflexive. Some of our results respond to questions appearing in the literature.  相似文献   

17.
We give a necessary condition for the existence of a feasible solution for the transportation problem through a set of admissible cells, and an algorithm to find a set of admissible cells that satisfies the necessary condition. Either there exists a feasible solution through the admissible cells (which is therefore optimal since the complementary slackness conditions hold) or we could begin using the primal–dual algorithm (PDA) at this point. Our approach has two important advantages: Our O(mn) procedure for updating dual variables takes much less computing time than any procedure for solving a maximum flow problem in the primal phase of the PDA. We are never concerned by the degeneracy problem as we are not seeking basic solutions, but admissible cells. An example is presented for illustrating our approach. We finally provide computational results for a set of 30 randomly generated instances. Comparison of our method with the PDA reveals a real speed up.  相似文献   

18.
In models of economic equilibrium in markets with infinitely many commodities, the commodity space is an ordered topological vector space endowed with additional structure. In the present paper, we consider ordered topological vector spaces which are admissible (for equilibrium analysis) in the sense that every economy which is reasonably well behaved posesses an equilibrium. It turns out that this condition may be characterized in terms of topology and order. This characterization implies that the commodity space has the structure of a Kakutani space.  相似文献   

19.
Let Ω be a local perturbation of the n-dimensional domain Ω0 = Ropf;n ? 1 × (0, π). In a previous paper8 we have introduced the notion of an admissible standing wave. We shall prove that the principle of limiting absorption holds for the Dirichlet problem of the reduced wave equation in Ω at ω ≥ 0 if Ω does not allow admissible standing waves with frequency ω. From Reference 8, this condition is satisfied for every ω ≥ 0 if Ω ≠ Ω0, and v · x ′ ≤ 0 on δΩ, where x′ = ( x 1,…, xn ? 1, 0) and v is the normal unit vector on δΩ pointing into the complement of Ω. In contrast to this, the principle of limiting absorption is violated in the case of the unperturbed domain Ω0 at the frequencies ω = 1,2,… if n ≤ 3. The second part of our investigation, which will appear in a subsequent paper, is devoted to the principle of limit amplitude.  相似文献   

20.
The enumeration of normal surfaces is a key bottleneck in computational three-dimensional topology. The underlying procedure is the enumeration of admissible vertices of a high-dimensional polytope, where admissibility is a powerful but non-linear and non-convex constraint. The main results of this paper are significant improvements upon the best known asymptotic bounds on the number of admissible vertices, using polytopes in both the standard normal surface coordinate system and the streamlined quadrilateral coordinate system.To achieve these results we examine the layout of admissible points within these polytopes. We show that these points correspond to well-behaved substructures of the face lattice, and we study properties of the corresponding “admissible faces”. Key lemmata include upper bounds on the number of maximal admissible faces of each dimension, and a bijection between the maximal admissible faces in the two coordinate systems mentioned above.  相似文献   

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