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We prove Nehari's theorem for integral Hankel and Toeplitz operators on simple convex polytopes in several variables. A special case of the theorem, generalizing the boundedness criterion of the Hankel and Toeplitz operators on the…

Functional Analysis · Mathematics 2017-10-10 Marcus Carlsson , Karl-Mikael Perfekt

This paper is about the operators defined between K\"othe spaces whose associated matrix is a Hankel matrix. After demonstrating how these operators are defined, the conditions for continuity and compactness of these operators are…

Functional Analysis · Mathematics 2024-10-01 Nazlı Doğan

In this paper, we study operator-theoretic properties (boundedness and compactness) of Hankel operators on the Fock-sobolev spaces $ \mathscr{F}^{p,m} $ in terms of $ \mathcal{BMO}_r^p $ and $ \mathcal{VMO}_r^p $ spaces, respectively, for a…

Functional Analysis · Mathematics 2018-06-08 Anuradha Gupta , Bhawna Gupta

We introduce and study a natural non-commutative generalization of \(\mu\)-Hankel operators originally defined on Hardy spaces over compact abelian groups. Within the framework of Peter-Weyl theory, we define matrix-valued Hankel operators…

Functional Analysis · Mathematics 2025-05-21 Emma Sulaver

In the first half of this text we explore the interrelationships between the abstract theory of limit operators (see e.g. the recent monographs of Rabinovich, Roch & Silbermann and Lindner) and the concepts and results of the generalised…

Spectral Theory · Mathematics 2010-11-05 Simon N. Chandler-Wilde , Marko Lindner

The main aim of this paper is to generalize the classical concept of positive operator, and to develop a general extension theory, which overcomes not only the lack of a Hilbert space structure, but also the lack of a normable topology. The…

Functional Analysis · Mathematics 2018-10-08 Zsigmond Tarcsay , Tamás Titkos

We extend to multilinear Hankel operators the fact that truncation of bounded Hankel operators is bounded. We prove and use a continuity property of a kind of bilinear Hilbert transforms on product of Lipschitz spaces and Hardy spaces.

Functional Analysis · Mathematics 2007-05-23 Sandrine Grellier , Mohammad Kacim

We determine the boundedness and compactness of a large class of operators, mapping from general Banach spaces of holomorphic functions into a particular type of spaces of functions determined by the growth of the functions, or the growth…

Functional Analysis · Mathematics 2017-03-16 Nina Zorboska

We prove that the notions of compactness and weak compactness for a Hankel operator on BMOA are identical.

Complex Variables · Mathematics 2011-08-16 Michael Papadimitrakis

One approach to multivariate operator theory involves concepts and techniques from algebraic and complex geometry and is formulated in terms of Hilbert modules. In these notes we provide an introduction to this approach including many…

Functional Analysis · Mathematics 2007-11-28 Ronald G. Douglas

Let $\Omega$ be a bounded convex domain in $\mathbb{C}^{n}$. We show that if $\varphi \in C^{1}(\overline{\Omega})$ is holomorphic along analytic varieties in $b\Omega$, then $H^{q}_{\varphi}$, the Hankel operator with symbol $\varphi$, is…

Complex Variables · Mathematics 2023-08-02 Mehmet Celik , Sonmez Sahutoglu , Emil J. Straube

This paper is devoted to self-adjoint cyclically compact operators on Hilbert--Kaplansky module over a ring of bounded measurable functions. The spectral theorem for such a class of operators are given. We apply this result to partial…

Operator Algebras · Mathematics 2015-02-10 Farrukh Mukhamedov , Karimbergen Kudaybergenov

In this paper we examine the general theory of continuous frame multipliers in Hilbert space. These operators are a generalization of the widely used notion of (discrete) frame multipliers. Well-known examples include Anti-Wick operators,…

Functional Analysis · Mathematics 2015-06-03 Peter Balazs , Dominik Bayer , Asghar Rahimi

Let $\Omega$ be a bounded convex Reinhardt domain in $\mathbb{C}^2$ and $\phi\in C(\bar{\Omega})$. We show that the Hankel operator $H_{\phi}$ is compact if and only if $\phi$ is holomorphic along every non-trivial analytic disc in the…

Complex Variables · Mathematics 2021-03-08 Timothy Clos , Sonmez Sahutoglu

Let X be a Hermitian complex space of pure dimension n. We show that the d-bar-Neumann operator on (p,q)-forms is compact at isolated singularities of X if q>0 and p+q is not equal to n-1 or n. The main step is the construction of compact…

Complex Variables · Mathematics 2010-07-27 Jean Ruppenthal

In this paper, we apply the Hausdorff measure of noncompactness to obtain the necessary and sufficient conditions for certain matrix operators on the Fibonacci difference sequence spaces l_{p}(F) and l_{infinite}(F) to be compact, where…

Functional Analysis · Mathematics 2013-09-03 E. E. Kara , M. Başarır , M. Mursaleen

This paper offers a unified approach to determining when two generalized Toeplitz operators on L^2 are equivalent. This will be done through multipliers between closed subspaces of L^2. Our discussion will include Toeplitz operators (and…

Functional Analysis · Mathematics 2023-07-12 Cristina Camara , Carlos Carteiro. William T. Ross

For a wide class of unbounded integral Hankel operators on the positive half-line, we prove essential self-adjointness on the set of smooth compactly supported functions.

Spectral Theory · Mathematics 2025-02-07 Alexander Pushnitski , Sergei Treil

Given an n-tuple of multiplication operators on the Bergman space of a bounded pseudoconvex domain in C^n, we study the algebra of their commutants. In particular, we give a geometric description of the maximal C*-subalgebra of this…

Functional Analysis · Mathematics 2016-07-05 Akaki Tikaradze

On a bounded smooth pseudoconvex domain in $\mathbb{C}^n$ with $n >2$, inspired by the compactness condition introduced by Yue Zhang, we present the new sufficient condition for the exact regularity of the $\overline\partial$-Neumann…

Complex Variables · Mathematics 2026-01-21 Qianyun Wang , Yuan Yuan , Xu Zhang