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1.
The paper is devoted to study of singular integral operators with
fixed singularities at endpoints of contours on weighted Lebesgue spaces with
general Muckenhoupt weights. Compactness of certain integral operators with
fixed singularities is established. The membership of singular integral operators
with fixed singularities to Banach algebras of singular integral operators
on weighted Lebesgue spaces with slowly oscillating Muckenhoupt weights is
proved on the basis of Balakrishnans formula from the theory of strongly
continuous semi-groups of closed linear operators. Symbol calculus for such
operators, Fredholm criteria and index formulas are obtained. 相似文献
2.
3.
In this paper we consider a class of weighted integral operators onL
2 (0, ) and show that they are unitarily equivalent to Hankel operators on weighted Bergman spaces of the right half plane. We discuss conditions for the Hankel integral operator to be finite rank, Hilbert-Schmidt, nuclear and compact, expressed in terms of the kernel of the integral operator. For a particular class of weights these operators are shown to be unitarily equivalent to little Hankel operators on weighted Bergman spaces of the disc, and the symbol correspondence is given. Finally the special case of the unweighted Bergman space is considered and for this case, motivated by approximation problems in systems theory, some asymptotic results on the singular values of Hankel integral operators are provided. 相似文献
4.
New inequalities of singular values of the integral operators with smoothL
2 kernels are obtained and shown by examples to be sharp if the kernels satisfy also certain boundary conditions. These results are based on an idea of Gohberg-Krein by which the singular values of the integral operators are interrelated to the eigenvalues of some two point boundary value problems.Dedicate to Professor Ky Fan on the occasion of his 85th birthday 相似文献
5.
Aleksandr Karelin 《Complex Analysis and Operator Theory》2008,2(4):549-567
In our previous works we have constructed operator equalities which transform scalar singular integral operators with shift
to matrix characteristic singular integral operators without shift and found some of their applications to problems with shift.
In this article the operator equalities are used for the study of matrix characteristic singular integral operators.
Conditions for the invertibility of the singular integral operators with orientation preserving shift and coefficients with
a special structure generated by piecewise constant functions, t, t
−1, were found.
Conditions for the invertibility of the matrix characteristic singular integral operators with four-valued piecewise constant
coefficients of a special structure were likewise obtained.
Submitted: June 15, 2007. Revised: October 25, 2007. Accepted: November 5, 2007. 相似文献
6.
We continue the study of algebras generated by the Cauchy singular integral operator and integral operators with fixed singularities on the unit interval, started in R.Duduchava, E.Shargorodsky, 1990. Such algebras emerge when one considers singular integral operators with complex conjugation on curves with cusps. As one of possible applications of the obtained results we find an explicit formula for the local norms of the Cauchy singular integral operator on the Lebesgue spaceL
2
(, ), where is a curve with cusps of arbitrary order and is a power weight. For curves with angles and cusps of order 1 the formula was already known (see R.Avedanio, N.Krupnik, 1988 and R.Duduchava, N.Krupnik, 1995).
Dedicated to Professor
Israel Gohberg
on the occasion of his 70-th birthday
Supported by EPSRC grant GR/K01001 相似文献
7.
Ariyadasa Aluthge 《Integral Equations and Operator Theory》2007,59(3):299-307
It is known that for a semi-hyponormal operator, the spectrum of the operator is equal to the union of the spectra of the
general polar symbols of the operator. The original proof of this theorem involves the so-called singular integral model.
The purpose of this paper is to give a different proof of the same theorem for the case of invertible semi-hyponormal operators
without using the singular integral model.
相似文献
8.
Applying the results on singular integral operators with the complex conjugation on curves with cusps (see R. Duduchava, T. Latsabidze, A. Saginashvili, 1992, 1994) the explicit formula for the local norm of the Cauchy singular integral operator on a curve with cusps in a Lebesgue space with an exponential weightL
2 (, ) is obtained. For curves with angles the formula was already known (see R. Avedanio, N. Krupnik, 1988). 相似文献
9.
《Mathematische Nachrichten》2018,291(1):178-186
The main object of this investigation is to study weak Morrey spaces. Block spaces, which are preduals of weak Morrey spaces, are characterized. Besides, the Fatou property of block spaces is proved. Finally, as an application, we study the boundedness of singular integral operators in weak Morrey spaces. 相似文献
10.
The existence of multiple positive solutions of systems of singular Hammerstein integral equations is studied, where the nonlinearities involved are allowed to have singularities in their second variables and satisfy weaker conditions involving the first eigenvalues of the corresponding linear Hammerstein integral operators. Such systems contain some mathematical models arising in science and engineering. Applications are given to the existence of multiple positive radial solutions of systems of semilinear singular elliptic equations in annuli on which, to the best of our knowledge, there has been little study. 相似文献
11.
目前对奇异积分算子的研究基本上都要求核满足标准型条件,现把标准型条件减弱成Dini条件,证明了核满足Dini条件的奇异积分算子关于任意权函数的几个加权赋范不等式,扩大了奇异积分算子的研究范围. 相似文献
12.
Marek Niezgoda 《Linear algebra and its applications》2009,431(8):1192-142
In this paper, singular values of commutators of Hilbert space operators are estimated. To this aim the accretivity of a transform of the operators is applied. Some recent results of Kittaneh [F. Kittaneh, Singular value inequalities for commutators of Hilbert space operators, Linear Algebra Appl. 430 (2009) 2362-2367] are extended. 相似文献
13.
Andrej Zlatoš 《Journal of Functional Analysis》2004,207(1):216-252
We construct non-random bounded discrete half-line Schrödinger operators which have purely singular continuous spectral measures with fractional Hausdorff dimension (in some interval of energies). To do this we use suitable sparse potentials. Our results also apply to whole line operators, as well as to certain random operators. In the latter case we prove and compute an exact dimension of the spectral measures. 相似文献
14.
In this paper we study the Banach algebra of singular integral operators with piecewise continuous coefficients and a Carleman orientation-reversing slowly oscillating shift on the Lebesgue space with a power weight on the unit circle. The slow oscillation of the shift derivative, in contrast to the classic assumption on its piecewise continuity, leads to the appearance of massive local spectra for the considered operators. Applying localization techniques and the theory of Mellin pseudodifferential and associated limit operators, we construct a symbol calculus for the above-mentioned operator algebra and find a Fredholm criterion and an index formula for the operators in this algebra in terms of their symbols.Partially supported by CONaCYT grant, Cátedra Patrimonial, No. 990017-EX and by CONACYT project 32726-E, México.Partially supported by F. C. T. grant Praxis XXI/2/2.1/MAT/441/94, Portugal. 相似文献
15.
We revisit the computation of (2-modified) Fredholm determinants
for operators with matrix-valued semi-separable integral kernels. The latter
occur, for instance, in the form of Greens functions associated with closed
ordinary differential operators on arbitrary intervals on the real line. Our
approach determines the (2-modified) Fredholm determinants in terms of solutions
of closely associated Volterra integral equations, and as a result offers
a natural way to compute such determinants.We illustrate our approach by identifying classical objects such as the
Jost function for half-line Schrödinger operators and the inverse transmission
coe.cient for Schrödinger operators on the real line as Fredholm determinants,
and rederiving the well-known expressions for them in due course.
We also apply our formalism to Floquet theory of Schrödinger operators, and
upon identifying the connection between the Floquet discriminant and underlying
Fredholm determinants, we derive new representations of the Floquet
discriminant.Finally, we rederive the explicit formula for the 2-modified Fredholm
determinant corresponding to a convolution integral operator, whose kernel
is associated with a symbol given by a rational function, in a straghtforward
manner. This determinant formula represents a Wiener-Hopf analog of Days
formula for the determinant associated with finite Toeplitz matrices generated
by the Laurent expansion of a rational function. 相似文献
16.
SINGULAR INTEGRAL OPERATORS ANDSINGULAR QUADRATURE OPERATORSASSOCIATED WITH SINGULAR INTEGRAL EQUATIONS 总被引:1,自引:1,他引:0
杜金元 《数学物理学报(B辑英文版)》1998,(2)
1IntroductionSingUlarlintegralequations(SIEs)withCauchytypekernelsoftheformappearfrequelltlyinproblemsOfthetheoriesofelasticity.Heretheinputfunctionsa)b,f,l,aretheH5lder-continuousfunctionsfortheirvariables,Aisagivenconstant,anditisrequiredtofindthesolutionWintheclassho[1,2].Theclassicaltheoryoftheseequationsisrathercomplete[1,2].Inthepasttwentyyearsagreatdealofinteresthasarisenintheirnumericalsolution.VariouscollocationmethodsforSIEshaveappeared,forwhichsomereferencescanbefoundinthesurv… 相似文献
17.
Multilinear singular integral operators with generalized kernels and their multilinear commutators
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In this paper, the authors study a class of multilinear singular integral operators with generalized kernels and their multilinear commutators with BMO functions. By establishing the sharp maximal estimates, the boundedness on product of weighted Lebesgue spaces and product of variable exponent Lebesgue spaces is obtained, respectively. Moreover, the endpoint estimate of this class of mutilinear singular integral operators is also established. These results can improve the corresponding known results of classical multilinear Calderón–Zygmund operators and multilinear Calder′on–Zygmund operators with Dini type kernels. 相似文献
18.
We prove the boundedness for a class of multi-sublinear singular integral operators on the product of central Morrey spaces with variable exponents. Based on this result, we obtain the boundedness for the multilinear singular integral operators and two kinds of multilinear singular integral commutators on the above spaces. 相似文献
19.
20.
J. Elschner 《Numerische Mathematik》1984,43(2):265-281
Summary In this paper a convergence analysis of Galerkin methods with splines for strongly elliptic singular integral equations over the interval (0, 1) is given. As trial functions we utilize smoothest polynomial splines on arbitrary meshes and continuous splines on special nonuniform partitions, multiplied by a weight function. Using inequalities of Gårding type for singular integral operators in weightedL
2 spaces and the complete asymptotics of solutions at the endpoints, we provide error estimates in certain Sobolev norms. 相似文献