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Related papers: Localization of operator-valued frames

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A finite-dimensional Hilbert space is usually described in terms of an orthonormal basis, but in certain approaches or applications a description in terms of a finite overcomplete system of vectors, called a finite tight frame, may offer…

Mathematical Physics · Physics 2010-04-22 Nicolae Cotfas , Jean Pierre Gazeau

We study finite systems of vectors whose frame operator matrices are unitarily equivalent, via explicit and computationally efficient unitary transformations, to block-diagonal matrices. We call such systems block-equivalent. We show that a…

Functional Analysis · Mathematics 2026-05-18 Oleg Asipchuk , Laura De Carli , Luis Rodriguez

In this paper, we introduce and study frame of operators in quaternionic Hilbert spaces as a generalization of g frames which in turn generalized various notions like Pseduo frames, bounded quasi-projectors and frame of subspaces (fusion…

Functional Analysis · Mathematics 2020-03-03 S. K. Sharma , A. M. Jarrah , S. K. Kaushik

G-frames are generalized frames which include ordinary frames, bounded invertible linear operators, as well as many recent generalizations of frames, e.g., bounded quasi-projectors and frames of subspaces. G-frames are natural…

Functional Analysis · Mathematics 2007-05-23 Wenchang Sun

Using the notions of frame transform and of square integrable projective representation of a locally compact group $G$, we introduce a class of isometries (tight frame transforms) from the space of Hilbert-Schmidt operators in the carrier…

Quantum Physics · Physics 2008-11-26 P. Aniello , V. I. Man'ko , G. Marmo

We study a notion analogous to the $p$-Approximation Property ($p$-AP) for Banach spaces, within the noncommutative context of operator spaces. Referred to as the $p$-Operator Approximation Property ($p$-OAP), this concept is linked to the…

Functional Analysis · Mathematics 2025-06-09 Javier Alejandro Chávez-Domínguez , Verónica Dimant , Daniel Galicer

Frames for operators or k-frames were recently considered by Gavruta (2012) in connection with atomic systems. Also generalized frames are important frames in the Hilbert space of bounded linear operators. Fusion frames, which are a special…

Functional Analysis · Mathematics 2018-06-12 Vahid Sadri , Reza Ahmadi , Asghar Rahimi

We study families of time-frequency localization operators and derive a new characterization of modulation spaces. This characterization relates the size of the localization operators to the global time-frequency distribution. As a…

Functional Analysis · Mathematics 2009-12-11 Monika Doerfler , Karlheinz Groechenig

We study strongly measurable random bounded operators on separable Hilbert spaces and analyze two simple iterations driven by independent random positive contractions. The first, a Kaczmarz-like iteration, converges in mean square and…

Functional Analysis · Mathematics 2025-11-18 James Tian

We investigate some subtle and interesting phenomena in the duality theory of operator spaces and operator algebras. In particular, we give several applications of operator space theory, based on the surprising fact that certain maps are…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Bojan Magajna

We characterize geometric properties of Banach spaces in terms of boundedness of square functions associated to general Schrodinger operators of the form $L=-\Delta+V$, where the nonnegative potential $V$ satisfies a reverse Holder…

Classical Analysis and ODEs · Mathematics 2011-02-08 I. Abu-Falahah , P. R. Stinga , J. L. Torrea

Motivated by the famous Blanco-Koldobsky-Turn\v{s}ek characterization of isometries, we study the \textit{approximate preservation of Birkhoff-James orthogonality by a linear operator between Banach spaces}. In particular, we investigate…

Functional Analysis · Mathematics 2025-01-22 Kalidas Mandal , Jayanta Manna , Kallol Paul , Debmalya Sain

We answer, by counterexample, several open questions concerning algebras of operators on a Hilbert space. The answers add further weight to the thesis that, for many purposes, such algebras ought to be studied in the framework of operator…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Bojan Magajna

We study random iterations of averaged operators in Hilbert spaces and prove that the associated residuals converge exponentially fast, both in expectation and almost surely. Our results provide quantitative bounds in terms of a single…

Functional Analysis · Mathematics 2025-09-15 James Tian

This paper treats parabolic final value problems generated by coercive Lax--Milgram operators, and well-posedness is proved for this large class. The result is obtained by means of an isomorphism between Hilbert spaces containing the data…

Analysis of PDEs · Mathematics 2019-10-31 Jon Johnsen

The paper is largely concerned with the possibility of obtaining a series representation for a compact linear map $T$ acting between Banach spaces. It is known that, using the notions of $j-$eigenfunctions and $j-$% eigenvalues, such a…

Functional Analysis · Mathematics 2021-05-17 D. E. Edmunds , J. Lang

In this paper it is investigated how to find a matrix representation of operators on a Hilbert space with Bessel sequences, frames and Riesz bases. In many applications these sequences are often preferable to orthonormal bases (ONBs).…

Functional Analysis · Mathematics 2008-04-09 Peter Balazs

This note is a survey and collection of results, as well as presenting some original research. For Bessel sequences and frames, the analysis, synthesis and frame operators as well as the Gram matrix are well-known, bounded operators. We…

Functional Analysis · Mathematics 2012-05-31 Peter Balazs , Diana T. Stoeva , Jean-Pierre Antoine

In this Work, We introduce the concept of $\ast$-operator frame, which is a generalization of $\ast$-frames in Hilbert pro-$C^{\ast}$-modules, and we establish some results, we also study the tensor product of $\ast$-operator frame for…

Functional Analysis · Mathematics 2021-11-19 Roumaissae Eljazzar , Mohamed Rossafi

We investigate a limiting procedure for extending local integral operator equalities to the global ones and to applying it to obtaining generalizations of the Newton-Leibnitz formula for operator-valued maps for a wide class of unbounded…

Functional Analysis · Mathematics 2012-02-03 Benedetto Silvestri