共查询到20条相似文献,搜索用时 344 毫秒
1.
本文讨论了Szasz-Kantorovich算子的保形问题,得到了算子在保持函数曲线几何性质方面的一系列结果,结果表明该算子在保形方面与Szasz-Mirakjan算子是有差异的。 相似文献
2.
刘岚哲 《数学物理学报(A辑)》1997,17(2):200-206
该文在齐型空间上定义了一类广义Carleson测度和Poisson型位势算子,该算子具有与Poisson核相似的性质,研究了该算子在Lp、Hp和Tent空间与Lorentz空间上的有界性. 相似文献
3.
艾尼·吾甫尔 《应用泛函分析学报》2005,7(4):299-316
研究了带无穷多个部件的,由一个可靠机器,一个不可靠机器与一个缓冲库构成的系统解的渐近性质.先讨论了对应于该系统的主算子的谱特征并且得到了在虚轴上除了0点外其它所有点都属于该主算子的豫解集,0是该主算子及其共轭算子几何重数为1的特征值.然后将该结果与作者以前的结果结合起来推出该系统的时间依赖解当时刻趋向于无穷时趋向于该系统的稳态解. 相似文献
4.
在[1]中构造了一系列一元及多元线性算子,其中包括二元Baskakov算子,本文讨论该算子在C空间的逼近性质. 相似文献
5.
本文构造一种二元Meyer-KonigandZeler算子,讨论该算子在正方形域上的一致逼近,建立了两种形式的等价定理 相似文献
6.
艾尼·吾甫尔 《应用泛函分析学报》2004,6(2):106-121
首先运用Phillips定理和Fattorini定理证明M/M^k,^B/1排队模型概率瞬态解的存在唯一性,然后通过研究对应于M/M^k,^B/1排队模型的主算子的共轭算子的豫解集得到该主算子的豫解集:在虚轴上除了零点外其它所有点都属于该主算子的豫解集. 相似文献
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本文在上定义了一个二维的Szasz-Durrmeyer算子,并给出了该算子在C空间上的逼近等价定理. 相似文献
9.
本文运用概率方法研究了Feller-Trotter概率型算子对有界变差函数的收敛速度。由于该算子包括许多常见的算子,从而由关于该算子的一般结论可导出许多常见算子对有界变差。函数的收敛速度。作为一般结论的应用,本文列举了Baskakov算子、Szasz-Mirakjan算子、Gauss-Weierstrass算子、Gramma算子、Post-Gamma算子对有界变差函数的收敛速度。其中,关于Szasz-Mirakjan算子的结论推广并改进了Fuhua Cheng的结论,其它结论是作者首次得到。 相似文献
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We give a necessary and sufficient condition for the nilpotent operators to be similiar to irreducible operators, and give
an answer to D. A. Herrero Conjectures for nilpotent operators. 相似文献
12.
Nathan S. Feldman 《Proceedings of the American Mathematical Society》1999,127(4):1171-1181
An operator is essentially subnormal if its image in the Calkin algebra is subnormal. We shall characterize the essentially subnormal operators as those operators with an essentially normal extension. In fact, it is shown that an essentially subnormal operator has an extension of the form ``normal plus compact'.
The essential normal spectrum is defined and is used to characterize the essential isometries. It is shown that every essentially subnormal operator may be decomposed as the direct sum of a subnormal operator and some irreducible essentially subnormal operators. An essential version of Putnam's Inequality is proven for these operators. Also, it is shown that essential normality is a similarity invariant within the class of essentially subnormal operators. The class of essentially hyponormal operators is also briefly discussed and several examples of essentially subnormal operators are given.
13.
M. Yahdi 《Proceedings of the American Mathematical Society》2006,134(9):2613-2620
The aim of this work is to study operators naturally connected to Ergodic operators in infinite-dimensional Banach spaces, such as Uniform-Ergodic, Cesaro-bounded and Power-bounded operators, as well as stable and superstable operators. In particular, super-Ergodic operators are introduced and shown to be strictly between Ergodic and Uniform-Ergodic operators, and that any power bounded operator is super-Ergodic in a superreflexive space. New relationships between these operators are shown, others are proven to be optimal or can be ameliorated according to structural properties of the Banach space, such as the superreflexivity or with unconditional basis.
14.
Products of integral-type operators and composition operators between Bloch-type spaces 总被引:1,自引:0,他引:1
Songxiao Li 《Journal of Mathematical Analysis and Applications》2009,349(2):596-610
A complete picture on the boundedness and compactness of the products of integral-type operators and composition operators between Bloch-type spaces of holomorphic functions on the unit disk is given in this paper. 相似文献
15.
In this paper, we obtain the continuity for some multilinear operators related to certain non-convolution operators on the
Triebel-Lizorkin space. The operators include Littlewood-Paley operator and Marcinkiewicz operator. 相似文献
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Liqun Qi 《Mathematical Programming》1990,49(1-3):263-271
Quasidifferentials are studied with the theory of maximal normal operators. The quasidifferential of a normally quasidifferentiable function is a pair of upper and lower semicontinuous operators, which are special maximal normal operators. The function sum of the upper and lower semicontinuous operators is the Clarke subdifferential of this function. Basic calculus and minimal forms of quasidifferentials are also discussed. 相似文献
18.
Athanossios Tzouvaras 《Mathematical Logic Quarterly》2003,49(3):284-292
The powerset operator, ??, is compared with other operators of similar type and logical complexity. Namely we examine positive operators whose defining formula has a canonical form containing at most a string of universal quantifiers. We call them ?‐operators. The question we address in this paper is: How is the class of ?‐operators generated ? It is shown that every positive ?‐operator Γ such that Γ(??) ≠ ??, is finitely generated from ??, the identity operator Id, constant operators and certain trivial ones by composition, ∪ and ∩. This extends results of [3] concerning bounded positive operators. 相似文献
19.
The composition operators on H2 whose symbols are hyperbolic automorphisms of the unit disk fixing ±1 comprise a one-parameter group and the analytic Toeplitz operators coming from covering maps of annuli centered at the origin whose radii are reciprocals also form a one-parameter group. Using the eigenvectors of the composition operators and of the adjoints of the Toeplitz operators, a direct unitary equivalence is found between the restrictions to zH2 of the group of Toeplitz operators and the group of adjoints of these composition operators. On the other hand, it is shown that there is not a unitary equivalence of the groups of Toeplitz operators and the adjoints of the composition operators on the whole of H2, but there is a similarity between them. 相似文献
20.
Andrzej Daniluk 《Journal of Mathematical Analysis and Applications》2011,376(1):342-348
We show two examples of operators acting on some Hilbert space and having invariant domains: a paranormal operator, which is not closable and a paranormal and closable operator, which closure is not paranormal. We start by establishing some general lemmas and propositions associating the families of operators mentioned above. 相似文献