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Related papers: A note on the operator window of modulation spaces

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This paper investigates composition operators and weighted composition operators on semi-Hilbert spaces induced by positive multiplication operators on \( L^2(\mu) \). Within the framework of \( A \)-adjoint operators, we characterize…

Functional Analysis · Mathematics 2025-08-08 Y. Estaremi , M. S. Al Ghafri

We give the sharp conditions for boundedness of Hausdorff operators on certain modulation and Wiener amalgam spaces.

Classical Analysis and ODEs · Mathematics 2018-11-14 Guoping Zhao , Dashan Fan , Weichao Guo

We consider an integral operator $\mathcal{I}$, special instances of which was studied in various contexts. Using an appropriate transformation we write this operator in terms of weighted composition operators. Then, we provide a…

Complex Variables · Mathematics 2012-04-16 Epaminondas Diamantopoulos

We investigate the category of ``matricial order operator spaces,'' which generalize operator systems, being equipped with both matricial norms and matricial order. For these objects, we develop duality theory. Taking a cue from the theory…

Functional Analysis · Mathematics 2026-05-22 Roy Araiza , Timur Oikhberg

Time-frequency analysis have played a crucial role in the development of localization operators in the last twenty years. We present its applications to the study of boundedness and Schatten Class property for such operators. In particular,…

Functional Analysis · Mathematics 2020-02-11 Elena Cordero

We study the bounded operators on weighted spaces Lw^2 on R^+ commuting either with the right translations St or left translations and we establish the existence of a symbol for these operators. We characterize completely the spectrum of…

Functional Analysis · Mathematics 2012-09-26 Violeta Petkova

In this paper, we consider composition operators on weighted Hilbert spaces of analytic functions and observe that a formula for the essential norm, give a Hilbert-Schmidt characterization and characterize the membership in Schatten-class…

Functional Analysis · Mathematics 2013-08-08 Mostafa Hassanlou

The central topic of this work is the categories of modules over unital quantales. The main categorical properties are established and a special class of operators, called Q-module transforms, is defined. Such operators - that turn out to…

Logic · Mathematics 2015-09-01 Ciro Russo

We demonstrate that a class of modulation spaces are examples of a smooth structure on the noncommutative 2-torus in the sense of recent developments in KK-theory. In addition, we prove that this class of modulation spaces can be…

Operator Algebras · Mathematics 2019-06-06 Are Austad , Franz Luef

Orthonormal systems in commutative $L_2$ spaces can be used to classify Banach spaces. When the system is complete and satisfies certain norm condition the unconditionality with respect to the system characterizes Hilbert spaces. As a…

Functional Analysis · Mathematics 2007-05-23 Hun Hee Lee

We develop a natural generalization of vector-valued frame theory, we term operator-valued frame theory, using operator-algebraic methods. This extends work of the second author and D. Han which can be viewed as the multiplicity one case…

Functional Analysis · Mathematics 2007-07-24 Victor Kaftal , David Larson , Shuang Zhang

Well-bounded operators are linear operators on a Banach space $X$ that have an $AC[a,b]$ functional calculus for some interval $[a,b]$. A well-bounded operator is of type (B) if it can be written as an integral against a spectral family of…

Functional Analysis · Mathematics 2022-08-19 Alan Stoneham

Generalizing Pisier's idea, we introduce a Hilbertian matrix cross normed space associated with a pair of symmetric normed ideals. When the two ideals coincide, we show that our construction gives an operator space if and only if the ideal…

Operator Algebras · Mathematics 2007-05-23 Takahiro Ohta

We discuss some of the analytic properties of lens space indices for 4d N=2 theories of class S. The S-duality properties of these theories highly constrain the lens space indices, and imply in particular that they are naturally acted upon…

High Energy Physics - Theory · Physics 2013-11-06 Shlomo S. Razamat , Masahito Yamazaki

Normal elements (or multipliers) of the C* algebra of a certain class of locally compact groupoids admit a natural faithful representation as normal operators on the $L^2$-space of a dense orbit of the groupoid. We prove norm estimates on…

Operator Algebras · Mathematics 2018-09-05 M. Mantoiu

Derivatives and integration operators are well-studied examples of linear operators that commute with scaling up to a fixed multiplicative factor; i.e., they are scale-invariant. Fractional order derivatives (integration operators) also…

Functional Analysis · Mathematics 2022-06-23 Arash Amini , Julien Fageot , Michael Unser

We establish necessary and sufficient conditions for boundedness of composition operators on the most general class of Hilbert spaces of entire Dirichlet series with real frequencies. Depending on whether or not the space contains any…

Complex Variables · Mathematics 2017-10-11 Minh Luan Doan , Le Hai Khoi

We shall say that a densely defined closed operator $T$ on a Hilbert space is balanced if $\cD(T)=\cD(T^*)$. Balanced operators are described in terms of their phase operators abnd their moduli. Examples of balanced operators are developed.…

Functional Analysis · Mathematics 2021-03-15 Konrad Schmüdgen

We consider Fourier integral operators with symbols in modulation spaces and non-smooth phase functions whose second orders of derivatives belong to certain types of modulation space. We establish continuity and Schatten-von Neumann…

Analysis of PDEs · Mathematics 2008-02-19 Joachim Toft , Francesco Concetti , Gianluca Garello

Marginal operators in a d-dimensional conformal field theory (CFT), those with conformal dimension $\Delta=d$, give us information about the space of related theories. This can be incredibly useful when trying to develop an intrinsic…

High Energy Physics - Theory · Physics 2025-07-22 Sruthi A. Narayanan