共查询到20条相似文献,搜索用时 548 毫秒
1.
By means of vector-valued product Calderón-Zygmund operators and some subtle estimates,the boundedness in product Hardy spaces on R^n × R^m of Calderón-Zygmund operators introduced by J.L. Journé is established. 相似文献
2.
Jean-Paul Penot 《Optimization》2019,68(7):1411-1427
AbstractWe survey the role of generalized dualities when dealing with generalized monotone operators, observing that for many conjugacies the coupling function is neither bilinear nor finitely valued. We also make a comparison with the use of bifunctions considered in a similar perspective. We introduce a class of operators close to the class of accretive operators and we raise some open questions. 相似文献
3.
M. Engliš 《Acta Appl Math》2004,81(1):51-71
We discuss some problems concerning the operators K
m
(Z,Z
*), where K
m
is the reproducing kernel of the Peter–Weyl space with signature m and Z stands for the commuting tuple of operators of multiplication by the coordinate variables on a bounded symmetric domain. These problems have applications for construction of operator models, as well as for a possible generalization of the recent dilation theory for row contractions due to Arveson. 相似文献
4.
《Quaestiones Mathematicae》2013,36(2):253-261
Abstract In this paper we study the connections between the nuclear operators and the multiple summing bilinear ones defined on c 0 × c 0. We also give an example of a bilinear operator on c 0 × c 0, for which the condition to be nuclear and multiple p-summing is connected to vector-valued sequence spaces. 相似文献
5.
《代数通讯》2013,41(11):4387-4413
Abstract In the paper, the deriviation algebras of the associative algebras of the one-variable (resp. multivariable) q-differential operators and of their corresponding Lie algebras are determined. The completeness of the derivation algebras of the algebras of q-differential operators is also discussed. Finally, we calculate H 2(𝒟 q (n)?, C) for n ≥ 1, as well as H 2(g l n (𝒟 q ), C) under the assumption that q is transcendental over the rational numbers field Q. 相似文献
6.
7.
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
8.
《Numerical Functional Analysis & Optimization》2013,34(2):157-175
ABSTRACT We distinguish classes of operators T with fixed points on a real Hilbert space by comparing the distances of a point x and its image Tx to the (set of) fixed points of T; this leads to a ranking of those classes, based on a nonnegative parameter. That same parameter also lets us conclude about the sign of and an upper bound for a characteristic inner product result that arises in iterative processes to obtain a common fixed point of a set of operators. We use that parameter as the starting point for a geometrically-inclined study of specific iterative algorithms intended to find a common fixed point of operators belonging to such class. 相似文献
9.
The Hilbert and Riesz transforms can be characterized up to scalar as the translation invariant operators that satisfy additionally
certain relative invariance of conformal transformation groups. In this article, we initiate a systematic study of translation
invariant operators from group theoretic viewpoints, and formalize a geometric condition that characterizes specific multiplier
operators uniquely up to scalar by means of relative invariance of affine subgroups. After providing some interesting examples
of multiplier operators having “large symmetry”, we classify which of these examples can be extended to continuous operators
on L
p
(R
n
) (1 < p < ∞).
T. Kobayashi was partially supported by Grant-in-Aid for Scientific Research 18340037, Japan Society for the Promotion of
Science. A. Nilsson was partially supported by Japan Society for the Promotion of Science. 相似文献
10.
《偏微分方程通讯》2012,37(1):1-31
AbstractWe study nonlocal operators acting on functions in the Euclidean space. The operators under consideration generate anisotropic jump processes, e.g., a jump process that behaves like a stable process in each direction but with a different index of stability. Its generator is the sum of one-dimensional fractional Laplace operators with different orders of differentiability. We study such operators in the general framework of bounded measurable coefficients. We prove a weak Harnack inequality and Hölder regularity results for solutions to corresponding integro-differential equations. 相似文献
11.
The composition operators with closed rangc on H2(B
n) are characterized, and the Fredholmness of products of Toeplitz and composition operators discussed. Moreover, using composition
operators, the spectra of Toeplitz operators are studied.
Project supported by the National Natural Sciencc Foundation of China and the Postdoctoral Science Foundation of China. 相似文献
12.
We study approximation properties of certain nonlinear integral operators L
n
* obtained by a modification of given operators L
n
. The operators L
n;r
and L
n;r
* of r-times differentiable functions are also studied.
We give theorems on approximation orders of functions by these operators in polynomial weight spaces. 相似文献
13.
Maofa Wang 《Numerical Functional Analysis & Optimization》2013,34(12):1291-1315
AbstractIn this paper, we consider the boundedness and compactness of the differences of differentiation composition operators from the space of fractional Cauchy transforms to the Bloch-type spaces and the weighted Dirichlet spaces. Surprisingly, these characterizations are free from pseudo-hyperbolic metric, which is a common feature of all the preceding characterizations of difference of differentiation composition operators on various spaces of holomorphic functions. 相似文献
14.
ABSTRACT The purpose of this paper is to establish a theory of Besov spaces associated with sections under only the doubling condition on the measure and prove that Monge–Ampère singular integral operators are bounded on these spaces. 相似文献
15.
AbstractIn the present paper, we summarize the recent literature concerning the spectrum and fine spectrum with respect to Goldberg’s classification of some operators represented by an infinite matrix over certain sequence spaces. 相似文献
16.
The paper puts forth a theory of choice functions in a neat way connecting it to a theory of extensive operators and neighborhood
systems. We consider classes of heritage choice functions satisfying conditions M, N, W, and C, or combinations of these conditions. In terms of extensive operators these classes can be considered as generalizations
of symmetric, anti-symmetric and transitive binary relations. Among these classes we meet the well-known classes of matroids
and convex geometries. Using a ‘topological’ language we discuss these classes of monotone extensive operators (or heritage
choice functions) in terms of neighborhood systems. A remarkable inversion on the set of choice functions is introduced. Restricted
to the class of heritage choice functions the inversion turns out to be an involution, and under this involution the axiom
N is auto-inverse, whereas the axioms W and M change places.
This research was supported in part by NWO–RFBR grant 047.011.2004.017, by RFBR grant 05-01-02805 CNRSL_a, and the grant NSh-929.2008.6,
School Support. We want to thank B. Monjardet, the editor and a referee for discussions and useful suggestions. 相似文献
17.
This article deals with linear operators T on a complex Hilbert space ?, which are bounded with respect to the seminorm induced by a positive operator A on ?. The A-adjoint and A 1/2-adjoint of T are considered to obtain some ergodic conditions for T with respect to A. These operators are also employed to investigate the class of orthogonally mean ergodic operators as well as that of A-power bounded operators. Some classes of orthogonally mean ergodic or A-ergodic operators, which come from the theory of generalized Toeplitz operators are considered. In particular, we give an example of an A-ergodic operator (with an injective A) which is not Cesàro ergodic, such that T ?* is not a quasiaffine transform of an orthogonally mean ergodic operator. 相似文献
18.
HuaiXinCAO ZongBenXU 《数学学报(英文版)》2004,20(3):499-506
Let U and V be Banach spaces, L and N be non-linear operators from U into V. L is said to be Lipschitz if LI(L) := sup{‖Lx - Ly‖. ‖x - y‖^-1 : x ≠ y} is finite. In this paper, we give some basic properties of Lipschitz operators and then discuss the unique solvability, exact solvability,approximate solvability of the operator equations Lx = y and Lx Nx = y. Under some conditions we prove the equivalence of these solvabilities. We also give an estimation for the relative-errors of the solutions of these two systems and an application of our method to a non-linear control system. 相似文献
19.
The first-order moments and two families of commutators are proven to determine uniquely the moments of a probability measure
on ℝ
d
. These families are the commutators between the annihilation and creation operators, and the commutators between the annihilation
and preservation operators. An explicit method for recovering the moments from these commutators and first-order moments is
presented.
相似文献
20.
U. Bandelow H. -Chr. Kaiser Th. Koprucki J. Rehberg 《Numerical Functional Analysis & Optimization》2013,34(3-4):379-409
In the physics of layered semiconductor devices the k · p method in combination with the envelope function approach is a well established tool for band structure calculations. We perform a rigorous mathematical analysis of spectral properties for the corresponding spatially one dimensional k · p Schrödinger operators;thereby encompassing a wide class of such operators. This class covers many of the k · p operators prevalent in solid state physics. It includes k · p Schrödinger operators with piecewise constant coefficients, a prerequisite for dealing with the important case of semiconductor hetero-structures. In particular, we address the question of persistence of a spectral gap over the wave vector range. We also introduce a regularization of the problem which gives rise to a consistent discretization of k · p operators with jumping coefficients and describe design patterns for the numerical treatment of k · p operators. 相似文献