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951.
Ming-Yi?LeeEmail author Chin-Cheng?LinEmail author 《Integral Equations and Operator Theory》2004,49(2):211-220
A weighted norm inequality for the Marcinkiewicz integral operator
is proved when belongs to
. We also give the weighted
Lp-boundedness for a class of Marcinkiewicz integral operators with rough
kernels
and
related to the Littlewood-Paley
-function and the
area integral S, respectively. 相似文献
952.
Philippe?RambourEmail author Abdellatif?Seghier 《Integral Equations and Operator Theory》2004,50(1):83-114
We consider large finite Toeplitz matrices with symbols of the form (1– cos )p f() where p is a natural number and f is a sufficiently smooth positive function. By employing techniques based on the use of predictor polynomials, we derive exact and asymptotic formulas for the entries of the inverses of these matrices. We show in particular that asymptotically the inverse matrix mimics the Green kernel of a boundary value problem for the differential operator
Submitted: June 20, 2003 相似文献
953.
Let B(H) denote the algebra of operators on a complex separable
Hilbert space H, and let A $\in$ B(H) have the polar decomposition A = U|A|.
The Aluthge transform
is defined to be the operator
.
We say that A $\in$ B(H) is p-hyponormal,
.
Let
.
Given p-hyponormal
, such that AB is compact, this
note considers the relationship between
denotes an enumeration in decreasing order repeated according
to multiplicity of the eigenvalues of the
compact operator T (respectively,
singular values of the compact operator T).
It is proved that
is bounded above by
and below by
for all j = 1, 2, . . .
and that if also
is normal, then there exists a unitary
U1 such that
for all j = 1, 2, . . .. 相似文献
954.
We introduce a concept bounded reflexivity for a subspace of
operators on a normed space. We explore the properties of bounded reflexivity,
study the similarities and differences between bounded reflexivity and the
usual reflexivity for a subspace of operators. As applications of bounded reflexivity, we give alternative proofs of some well known results about positivity
and complete positivity of elementary operators. 相似文献
955.
We study the commuting problem for Toeplitz operators on the harmonic Bergman space of the unit disk. We show that an analytic Toeplitz operator and a co-analytic Toeplitz operator with certain noncyclicity hypothesis can commute only when one of their symbols is constant. We also obtain analogous results for semi-commutants. 相似文献
956.
In this paper we consider a class of integral operators whose kernels
satisfy certain generalizations of Hörmander condition and establish their
regularity results. 相似文献
957.
David?EschwéEmail author Matthias?LangerEmail author 《Integral Equations and Operator Theory》2004,49(3):287-321
Variational principles for eigenvalues of certain functions whose values
are possibly unbounded self-adjoint operators T() are proved. A generalised
Rayleigh functional is used that assigns to a vector x a zero of the
function T()x, x), where it is assumed that there exists at most one zero.
Since there need not exist a zero for all x, an index shift may occur. Using
this variational principle, eigenvalues of linear and quadratic polynomials
and eigenvalues of block operator matrices in a gap of the essential spectrum
are characterised. Moreover, applications are given to an elliptic eigenvalue
problem with degenerate weight, Dirac operators, strings in a medium with a
viscous friction, and a Sturm-Liouville problem that is rational in the eigenvalue
parameter. 相似文献
958.
In this work we investigate a class of string, compact Jacobi matrices with very rapidly decreasing weights. In particular, we have found Hellinger-Weyls function representation as ratio of two entire functions with known Taylor series representation. The asymptotical estimations of zeroes of this entire functions and of eigenvalues of a corresponding operator are found. The application of this theory to Rogers-Ramanujans functions is considered.Submitted: November 18, 2002 Revised: October 30, 2003 相似文献
959.
This paper studies the class of pure hyponormal operators with
rank one self-commutator satisfying the condition that their spectra are quadrature
domains. 相似文献
960.
Young Min?HanEmail author An-Hyun?KimEmail author 《Integral Equations and Operator Theory》2004,49(4):435-444
In this note we show that if either T or T* is totally *-paranormal
then Weyls theorem holds for f(T) for every f
, and also a-Weyls theorem holds for f(T) if T is totally *-paranormal. We prove that if either
T or T* is *-paranormal then the spectral mapping theorem holds for the
Weyl spectrum and for the essential approximate point spectrum. 相似文献