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1.
We characterize the boundedness and compactness of weighted composition operators on weighted Dirichlet spaces in terms of Nevanlinna counting functions and Carleson measure.  相似文献   

2.
We characterize the compactness of composition operators acting on a large family of Hilbert spaces of analytic functions which lie between Bergman and Dirichlet spaces. Our characterization is given in terms of generalized Nevanlinna counting functions.  相似文献   

3.
Composition operators between Bergman and Hardy spaces   总被引:21,自引:0,他引:21  
We study composition operators between weighted Bergman spaces. Certain growth conditions for generalized Nevanlinna counting functions of the inducing map are shown to be necessary and sufficient for such operators to be bounded or compact. Particular choices for the weights yield results on composition operators between the classical unweighted Bergman and Hardy spaces.

  相似文献   


4.
Our purpose is to define composition operators acting upon Hardy spaces of Riemann surfaces. In terms of counting functions related to analytic self-map on Riemann surfaces, the boundedness and compactness are characterized.  相似文献   

5.
We study the spectral properties of the Hamiltonian H n of n pseudorelativistic electrons in the Coulomb field of k fixed nuclei in spaces of functions having arbitrary given types of permutational and point symmetry. For this operator, we establish the location of the essential spectrum, obtain two-sided estimates of the discrete spectrum counting function in terms of the counting functions of the discrete spectrum of some two-particle nonrelativistic operators, and find the leading term of the spectral asymptotics.  相似文献   

6.
We obtain several estimates of the essential norms of the products of differentiation operators and weighted composition operators between weighted Banach spaces of analytic functions with general weights.As applications,we also give estimates of the essential norms of weighted composition operators between weighted Banach space of analytic functions and Bloch-type spaces.  相似文献   

7.
吴树宏 《数学杂志》2005,25(5):575-578
本文用算子函数论的方法,研究了解析算子函数的Banach空间X,X0上的复合算子.给出此复合算子为有界的条件,并刻划了此复合算子在X0上为紧的特征.  相似文献   

8.
在齐型空间上讨论由分数次积分算子、奇异积分算子及BMO函数所构成的几类Toeplitz型算子的有界性.  相似文献   

9.
杨向东  胡学敏 《数学杂志》2015,35(5):1103-1108
本文研究了复合算子的遍历性问题.利用经典算子理论的方法,获得了单位圆上加权Banach空间中复合算子遍历性的结果,我们还得到单位圆上Hardy空间中类似的结果,我们的结论是对乘子算子相关结果的推广.  相似文献   

10.
Perturbations of definitizable operators in Krein space are studied in this paper. Firsts, the convergence of resolvents and spectral functions is discussed if a sequence of definitizable operators converges in a general sense. Second, for the operational calculus relating to continuous functions, varions convergence of operator functions are studied. At last, the relation for the convergence of the sequence of resolvents and that of one-parameter unitary groups is studied. The main theorems of this paper can be regarded as the generalization of the results for self-adjoint operators in Hilbert space.  相似文献   

11.
张茂柱  孙炯  敖继军 《数学杂志》2012,32(2):331-338
本文研究了加权的高阶微分算子的谱. 利用分解的方法和不等式的估计, 得到了一些高阶对称微分算子的任何自共轭扩张的谱离散的充分条件, 推广了 Pfeiffer , Sun, Glazman 等人的结果,利用这些结果可以判别某些微分算子谱的离散性.  相似文献   

12.
多元Bernstein算子的导数与函数的光滑性   总被引:2,自引:0,他引:2  
利用一个新的光滑性度量刻画多元Bernstein算子方向导数的特征,建立Bernstein算子的导数与逼近函数光滑性之间的等价关系。同时,一个关于一元Bernstein算子的相应结果被推广到多元情形。  相似文献   

13.
 This paper gives several different ways in which operator norms characterize those composition operators that arise from holomorphic self-maps ϕ of the unit disc that are inner functions. The setting is the Hardy space H 2 of the disc, and the key result is a characterization of inner functions in terms of the asymptotic behavior of the Nevanlinna counting function. The case offers an interesting surprise.  相似文献   

14.
In this article, we prove the boundedness of commutators generated by BochnerRiesz operators below the critical index and BMO functions on the class of radial functions in L p (R n ) with | 1/p -1/2 | < (1 + 2α)/(2n).  相似文献   

15.
王春 《数学杂志》2012,32(1):49-54
本文研究了一类具有再生核的多复变量函数空间上偏微分算子的有界性和紧性.利用算子理论的方法,获得了偏微分算子是有界的和紧的充分必要条件,推广了文献[1]中的结果.  相似文献   

16.
In the paper we investigate convolution properties related to the prestarlike functions and various inclusion relationships between defined classes of functions. Interest-ing applications involving the well-known classes of functions defined by linear operators are also considered.  相似文献   

17.
Bent函数的一般构造法   总被引:7,自引:0,他引:7  
本文用概率方法给出小项表示的布尔函数谱的性质,据此得到了Bent函数的特征矩阵的等价刻画,原则上给出了Bent函数的一般构造法,并为Bent函数的计数问题提供了一个模型。文中还提出了Bent矩阵的概念,考察了Bent矩阵的性质,并借助Bent矩阵得到由已知Bent函数构造新的Bent函数构造新的Bent函数的方法。  相似文献   

18.
We obtain subordination, superordination and sandwich-preserving new theorems for certain integral operators defined on the space of normalized analytic functions in the open unit disk. The sandwich-type theorem for these integral operators is also derived, and the results generalize some recently ones.  相似文献   

19.
We investigate a uniqueness topic of entire functions with finite order sharing some values with their difference operators and obtain one result that if△f(≠0)and entire function f share a,b CM(counting multiplicities),then△f≡f.This result partially confirms a conjecture due to Chen and Yi(2013).  相似文献   

20.
沙震 《数学学报》1979,22(1):54-68
<正> 我们知道当ρ_k~(n)≡1时,U_n(f,x)即为富里埃级数的部份和;又若u_n(t)≥0(0≤t≤2π),那末U_n(f,x)即所谓线性正算子,关于正算子的逼近问题,文[1]和[2]都作了详细的讨论,其中有这样的一个结果(参阅[1]第73页定理14):  相似文献   

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