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1.
Certain Convolution Operators for Meromorphic Functions 总被引:3,自引:0,他引:3
Dinggong Yang 《Southeast Asian Bulletin of Mathematics》2001,25(1):175-186
Let (p N) be the class of functions
analytic in 0 < |z| < 1. A convolution operator Lp(a, c) on p is introduced. This paper gives some sharp inequalities for f(z) satisfying Re{(1 – )zpLp(a, c) f(z) + zpLp(a + 1, c) f(z)} > , where 0, < 1, a > 0 and c 0, –1, –2,....AMS Subject Classification (1991) 30C45 30A10 相似文献
2.
We establish the connection between the boundedness of convolution operators on Hp(ℝN) and some related operators on Hp(ℤN). The results we obtain here extend the already known for Lp spaces with p > 1. We also study similar results for maximal operators given by convolution with the dilation of a fixed kernel. Our main tools are some known results about functions of exponential type already presented in [BC1] that, in particular, allow us to prove a sampling theorem for functions of exponential type belonging to Hardy spaces 相似文献
3.
In this paper, some approximation formulae for a class of convolution type double singular integral operators depending on three parameters of the type(T_λf)(x, y) = ∫_a~b ∫_a~b f(t, s)K_λ(t-x,s-y)dsdt, x,y ∈(a,b), λ∈Λ [0,∞),(0.1)are given. Here f belongs to the function space L_1( a,b ~2), where a,b is an arbitrary interval in R. In this paper three theorems are proved, one for existence of the operator(T_λf)(x, y) and the others for its Fatou-type pointwise convergence to f(x_0, y_0), as(x,y,λ) tends to(x_0, y_0, λ_0). In contrast to previous works, the kernel functions K_λ(u,v)don't have to be 2π-periodic, positive, even and radial. Our results improve and extend some of the previous results of [1, 6, 8, 10, 11, 13] in three dimensional frame and especially the very recent paper [15]. 相似文献
4.
We consider matrix convolution operators with integrable kernels on expanding polyhedra. We study their connection with convolution operators on the cones at the vertices of polyhedra. We prove that the norm of the inverse operator on a polyhedron tends to the maximum of the norms of the inverse operators on the cones, and the pseudospectrum tends to the union of the corresponding pseudospectra. The study bases on the local method adapted to this kind of problems. 相似文献
5.
Pedro A. Santos 《Mathematische Nachrichten》2001,232(1):95-127
The purpose of this paper is to obtain necessary and sufficient conditions for maximum defect spline approximation methods with uniform meshes to be stable. The methods are applied to operators belonging to the closed subalgebra of ℒ︁ (L2 (ℝ)) generated by operators of multiplication by piecewise continuous functions on ℝ and convolution operators also with piecewise continuousgenerating functions. To that purpose, a C*-algebra of sequences is introduced, which contains the special sequences of approximating operators we are interested in. There is a direct relationship between the applicability of the approximation method to a given operator and invertibility of the corresponding sequence in this C*-algebra. Exploring this relationship, applicability criteria are derived by the use of C*-algebra and Banach algebra techniques (essentialization, localization andidentification of the local algebras by means of construction of locally equivalent representations). Finally, examples are presented, including explicit conditions for the applicability of spline Galerkin methods to Wiener-Hopf operators with piecewise continuous symbols. 相似文献
6.
C. AparicioA.R. Villena 《Journal of Functional Analysis》2002,196(1):155-161
Let G be a locally compact abelian group, let μ be a bounded complex-valued Borel measure on G, and let Tμ be the corresponding convolution operator on L1(G). Let X be a Banach space and let S be a continuous linear operator on X. Then we show that every linear operator Φ: X→L1(G) such that ΦS=TμΦ is continuous if and only if the pair (S,Tμ) has no critical eigenvalue. 相似文献
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8.
The translation operator and the convolution for the finite Legendre transformation are investigated in the space ??(?1,1) of testing-functions and its dual through an approach that emphasizes the close similarity existing between this transform and the infinite Mehler - Fock transformation. The theory developed is used in solving some distributional boundary-value problems. 相似文献
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10.
J. M. ALDAZ Juan L. VARONA 《数学学报(英文版)》2007,23(3):487-490
We show that in the study of certain convolution operators, functions can be replaced by measures without changing the size of the constants appearing in weak type (1, 1) inequalities. As an application, we prove that the best constants for the centered Hardy-Littlewood maximal operator associated with parallelotopes do not decrease with the dimension. 相似文献
11.
In this paper, we describe coefficient multipliers, study the action of fractional derivatives of spaces of BMOA type and the action of Toeplitz operators in these classes. 相似文献
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13.
本文证明了当α=n1-1q时,强奇异积分算子是从齐次加权Herz型Hardy空间HKα,pq(w1;w2)到齐次加权Herz空间Kα,pq(w1;w2)上的有界算子.而且,该算子在非齐次加权Herz型Hardy空间HKα,pq(w1;w2)上的有界性也被考查. 相似文献
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15.
Mike Zabrocki 《Journal of Algebraic Combinatorics》2001,13(1):83-101
We present formulas for operators which add a row or a column to the partition indexing the power, monomial, forgotten, Schur, homogeneous and elementary symmetric functions. As an application of these operators we show that the operator that adds a column to the Schur unctions can be used to calculate a formula for the number of pairs of standard tableaux the same shape and height less than or equal to a fixed k. 相似文献
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17.
Xue Yinchuan 《数学季刊》1996,(1)
On the Approximation by the Iterates of Stancu Operators and Its Modified OperatorsOntheApproximationbytheIteratesofStancuOpe... 相似文献
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19.
I. B. Simonenko 《Mathematical Notes》2005,78(1-2):239-250
We study the asymptotic behavior of the averaged f-trace of a truncated generalized multidimensional discrete convolution operator as the truncation domain expands. By definition, the averaged f-trace of a finite-dimensional operator A is equal to
, where n is the dimension of the space in which the operator A acts, the set of numbers γk, k = 1,..., n, is the complete collection of eigenvalues of the operator A, counting multiplicity; a generalized discrete convolution is an operator from the closure of the algebra generated by discrete convolution operators and by operators of multiplication by functions admitting a continuous continuation onto the sphere at infinity.__________Translated from Matematicheskie Zametki, vol. 78, no. 2, 2005, pp. 265–277.Original Russian Text Copyright © 2005 by I. B. Simonenko. 相似文献
20.
S. P. Eveson 《Integral Equations and Operator Theory》2008,62(4):585-589
We show that if V
α (α > 0) is the Riemann-Liouville fractional integration operator and T is an invertible operator on L
2(0, 1) which commutes with V , then TV
α is not supercyclic on L
2(0, 1); in particular, many Volterra convolution operators are not supercyclic. The technique is based on an argument used
by Gallardo-Gutiérrez and Montes-Rodríguez to show that V is not supercyclic. 相似文献