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1.
Hilbert空间中算子广义逆的积分表示   总被引:2,自引:0,他引:2  
利用算子矩阵分块的技巧,得到了Hilbert空间中算子的Moore-Penrose逆和Drazin逆的积分表示.给出了较为简洁的证明,同时将有限维的结论推广到无限维的情形.  相似文献   

2.
Gabor time-frequency lattices are sets of functions of the form generated from a given function by discrete translations in time and frequency. They are potential tools for the decomposition and handling of signals that, like speech or music, seem over short intervals to have well-defined frequencies that, however, change with time. It was recently observed that the behavior of a lattice can be connected to that of a dual lattice Here we establish this interesting relationship and study its properties. We then clarify the results by applying the theory of von Neumann algebras. One outcome is a simple proof that for to span the lattice must have at least unit density. Finally, we exploit the connection between the two lattices to construct expansions having improved convergence and localization properties.  相似文献   

3.
Journal of Fourier Analysis and Applications - We calculate the norm of the Fourier operator from $$L^p(X)$$ to $$L^q({hat{X}})$$ when X is an infinite locally compact abelian group that is,...  相似文献   

4.
 In this paper we apply a time-frequency approach to the study of pseudodifferential operators. Both the Weyl and the Kohn–Nirenberg correspondences are considered. In order to quantify the time-frequency content of a function or distribution, we use certain function spaces called modulation spaces. We deduce a time-frequency characterization of the twisted product of two symbols σ and τ, and we show that modulation spaces provide the natural setting to exactly control the time-frequency content of from the time-frequency content of σ and τ. As a consequence, we discuss some boundedness and spectral properties of the corresponding operator with symbol .  相似文献   

5.
 In this paper we apply a time-frequency approach to the study of pseudodifferential operators. Both the Weyl and the Kohn–Nirenberg correspondences are considered. In order to quantify the time-frequency content of a function or distribution, we use certain function spaces called modulation spaces. We deduce a time-frequency characterization of the twisted product of two symbols σ and τ, and we show that modulation spaces provide the natural setting to exactly control the time-frequency content of from the time-frequency content of σ and τ. As a consequence, we discuss some boundedness and spectral properties of the corresponding operator with symbol . (Received 27 December 1999; in final form 9 November 2000)  相似文献   

6.
In this paper we show that every g-frame for an infinite dimensional Hilbert space H can be written as a sum of three g-orthonormal bases for H. Also, we prove that every g-frame can be represented as a linear combination of two g-orthonormal bases if and only if it is a g-Riesz basis. Further, we show each g-Bessel multiplier is a Bessel multiplier and investigate the inversion of g-frame multipliers. Finally, we introduce the concept of controlled g-frames and weighted g-frames and show that the sequence induced by each controlled g-frame (resp., weighted g-frame) is a controlled frame (resp., weighted frame).  相似文献   

7.
Multipliers and Generalized Derivatives of Performance Functions   总被引:1,自引:0,他引:1  
It is known that multipliers in mathematical programming have to do with the interpretation of generalized derivatives for the performance function of some perturbed problem. In economics, this fact is known under the term of shadow price. Here, we point out a precise relationship with the subdifferential of the performance function in the contingent sense and in the Fréchet sense, which are the simplest notions of nonsmooth analysis.  相似文献   

8.
在一个带有非负和不等式约束的优化问题有最优解的情形下,存在着广义拉格朗日乘子即资源的影子价格.本文探索给出马克思两大部类扩大再生产中的影子价格,为经典的马克思扩大再生产理论增添新的重要内容.首先使用“价值系数法”替代单纯形法,简便地求得了扩大再生产优化问题的最优解.然后运用库恩一塔克条件,确立了关于最优解与广义拉格朗日乘子的互补松弛条件的三个不等式组.进而利用这些不等式组和已知的最优解,简便地解出广义拉格朗日乘子,即两大部类扩大再生产中的影子价格.最后引用和借鉴《资本论》中的两个举例,对所获得的影子价格和目标函数最优值做了计算验证.  相似文献   

9.
We obtain a general Marcinkiewicz-type multiplier theorem for mixed systems of strongly commuting operators \(L=(L_1,\ldots ,L_d);\) where some of the operators in L have only a holomorphic functional calculus, while others have additionally a Marcinkiewicz-type functional calculus. Moreover, we prove that specific Laplace transform type multipliers of the pair \((\mathcal {L},A)\) are of certain weak type (1, 1). Here \(\mathcal {L}\) is the Ornstein-Uhlenbeck operator while A is a non-negative operator having Gaussian bounds for its heat kernel. Our results include the Riesz transforms \(A(\mathcal {L}+A)^{-1},\) \(\mathcal {L}(\mathcal {L}+A)^{-1}\).  相似文献   

10.
Xu  Jing  Huang  Jun Jie  Chen  Alatancang 《数学学报(英文版)》2023,39(2):326-338
Acta Mathematica Sinica, English Series - This paper is concerned with the representation problem of a coupled operator in a product space. A necessary and sufficient condition is given for a class...  相似文献   

11.
半格与Domain的表示   总被引:6,自引:0,他引:6  
陈仪香 《数学学报》1998,41(4):737-742
引入一种半格———D 半格,建立了D-半格的表示理论,利用它得到了L domain(即局部代数格)的表示理论;证明了L domain与稳定映射范畴对偶等价于稳定D 半格与D-半格同态范畴.  相似文献   

12.
We estimate the completely bounded norms, the completely p-nuclear norms, and the completely p-summing norms of certain multiplication operators and Schur multipliers.  相似文献   

13.
席俊 《数学季刊》1992,7(2):36-40
设T是完全非正规的次正规算子。给出了T=N+K的充要条件,其中N是正规算子,K是拟正规算子,且NK=KN。  相似文献   

14.
本文研究了可分的Hilbert空间H中的广义框架,应用算子论方法给出了广义框架是H中紧广义框架,对偶广义框架,独立广义框架的充要条件:证明了有关广义框架算子的一些结果。  相似文献   

15.
16.
This paper discusses identification of parameters of generalized ordered weighted averaging (GOWA) operators from empirical data. Similarly to ordinary OWA operators, GOWA are characterized by a vector of weights, as well as the power to which the arguments are raised. We develop optimization techniques which allow one to fit such operators to the observed data. We also generalize these methods for functional defined GOWA and generalized Choquet integral based aggregation operators.  相似文献   

17.
Mejjaoli  H.  Ben Saïd  S. 《Analysis Mathematica》2021,47(3):629-663
Analysis Mathematica - We introduce and study the k-Hankel Gabor transform. We investigate the localization operators for this transform. In particular, we study their trace class properties and we...  相似文献   

18.
We give a formula for the one-parameter strongly continuous semigroups ${e^{-tL^{\lambda}}}We give a formula for the one-parameter strongly continuous semigroups e-tLl{e^{-tL^{\lambda}}} and e-t [(A)\tilde]{e^{-t \tilde{A}}}, t > 0 generated by the generalized Hermite operator Ll, l ? R\{0}{L^{\lambda}, \lambda \in {\bf R}\backslash \{0\}} respectively by the generalized Landau operator ?. These formula are derived by means of pseudo-differential operators of the Weyl type, i.e. Weyl transforms, Fourier-Wigner transforms and Wigner transforms of some orthonormal basis for L 2(R 2n ) which consist of the eigenfunctions of the generalized Hermite operator and of the generalized Landau operator. Applications to an L 2 estimate for the solutions of initial value problems for the heat equations governed by L λ respectively ?, in terms of L p norm, 1 ≤ p ≤ ∞ of the initial data are given.  相似文献   

19.
This paper is devoted to study direct and converse approximation theorems of the generalized Bernstein operators Cn( f,sn,x) via so-called unified modulus ω2φλ( f,t), 0 ≤λ≤1. We obtain main results as follows ω2φλ( f,t) =O(tα)|Cn( f,sn,x)- f(x)| =O(n-12 δ1-λn(x))α,where δ2n(x) =max{φ2(x),1/n} and 0 α 2.  相似文献   

20.
In this paper we consider a generalization of different variants of Durrmeyer- type modifications of Baskakov and Meyer- König and Zeller operators. We prove a general result concerning the commutativity of these operators with certain differential operators. Prom this result a Rodriguez- type formula for the eigenfunctions follows as a corollary.  相似文献   

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