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Related papers: Integral $K$-Operator Frames for $\mathcal{B}(H)$

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For finding the numerical solution of operator equations in many applications a decomposition in subspaces is needed. Therefore, it is necessary to extend the known method of matrix representation to the utilization of fusion frames. In…

Functional Analysis · Mathematics 2020-07-14 Peter Balazs , Mitra Shamsabadi , Ali Akbar Arefijamaal , Chilles Gardon

Finite rank perturbations $T=N+K$ of a bounded normal operator $N$ on a separable Hilbert space are studied thanks to a natural functional model of $T$; in its turn the functional model solely relies on a perturbation matrix/ characteristic…

Functional Analysis · Mathematics 2020-08-03 Mihai Putinar , Dmitry Yakubovich

We characterize weak* closed unital vector spaces of operators on a Hilbert space $H$. More precisely, we first show that an operator system, which is the dual of an operator space, can be represented completely isometrically and weak*…

Operator Algebras · Mathematics 2014-02-26 David P. Blecher , Bojan Magajna

In this paper, we introduce and study a new class of bounded linear operators on complex Hilbert spaces, which we call 2-C-normal operators. This class is inspired by and closely related to the notion of 2-normal operators, with additional…

Functional Analysis · Mathematics 2025-10-09 Messaoud Guesba , Ismail Lakehal , Sid Ahmed Ould Ahmed Mahmoud

We introduce the notion of continuous controlled g-fusion frame in Hilbert space which is the generalization of discrete controlled g-fusion frame and give an example. Some characterizations of continuous controlled g-fusion frame have been…

Functional Analysis · Mathematics 2021-10-22 Prasenjit Ghosh , T. K. Samanta

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

Frames play significant role in signal and image processing, which leads to many applications in differents fields. In this paper we define the dual of $\ast$-operator frames and we show their propreties obtained in Hilbert…

Operator Algebras · Mathematics 2019-01-15 A. Bourouihiya , M. Rossafi H. Labrigui , A. Touri

We develop elements of a general dilation theory for operator-valued measures and bounded linear maps between operator algebras that are not necessarily completely-bounded. We prove our main results by extending and generalizing some known…

Operator Algebras · Mathematics 2012-07-23 Deguang Han , David R. Larson , Bei Liu , Rui Liu

Frames play significant role in various areas of science and engineering. In this paper, we introduce the concepts of frames for $End_{\mathcal{A}}^{\ast}(\mathcal{H, K})$ and their generalizations. Moreover, we obtain some new results for…

Operator Algebras · Mathematics 2019-07-05 Mohamed Rossafi , Samir Kabbaj

For H a separable infinite dimensional complex Hilbert space, we prove that every B(H) operator has a basis with respect to which its matrix representation has a universal block tridiagonal form with block sizes given by a simple…

Functional Analysis · Mathematics 2019-11-05 Sasmita Patnaik , Srdjan Petrovic , Gary Weiss

Multipliers have been recently introduced by P. Balazs as operators for Bessel sequences and frames in Hilbert spaces. These are operators that combine (frame-like) analysis, a multiplication with a fixed sequence (called the symbol) and…

Functional Analysis · Mathematics 2012-04-09 Asghar Rahimi , Abolhassan Fereydooni

In this paper, we study one of the fundamental notions in dynamical systems, the shadowing of invertible (bounded and linear) operators on a Hilbert space. Although the problem of finding a spectral characterization for shadowing has been…

Dynamical Systems · Mathematics 2025-11-20 Mihály Pituk

We consider conditions on a given system $\mathcal{F}$ of vectors in Hilbert space $\mathcal{H}$, forming a frame, which turn $\mathcal{H}$ into a reproducing kernel Hilbert space. It is assumed that the vectors in $\mathcal{F}$ are…

Functional Analysis · Mathematics 2016-06-16 Palle E. T. Jorgensen , Myung-Sin Song

We say that an operator $T \in B(H)$ is complex symmetric if there exists a conjugate-linear, isometric involution $C:H\to H$ so that $T = CT^*C$. We prove that binormal operators, operators that are algebraic of degree two (including all…

Functional Analysis · Mathematics 2009-07-23 Stephan Ramon Garcia , Warren R. Wogen

In this paper, structural properties of lower semi-frames in separable Hilbert spaces are explored with a focus on transformations under linear operators (may be unbounded). Also, the direct sum of lower semi-frames, providing necessary and…

Functional Analysis · Mathematics 2025-04-18 Hemalatha M , P. Sam Johnson , Harikrishnan P. K

In this paper we study the completely bounded anti-isomorphisms on operator algebras, that work similarly to the involutions with the exception for the property of being completely isometric. We elaborate the Blecher's characterization…

Operator Algebras · Mathematics 2011-04-15 Nikolay P. Ivankov

Let $\mathcal{H}$ be a Hilbert space, and let $K(\mathcal{H})$ be the $C^*$-algebra of compact operators on $\mathcal{H}$. In this paper, we present some characterizations of the norm-parallelism for elements of a Hilbert…

Functional Analysis · Mathematics 2018-12-04 M. Mohammadi Gohari , M. Amyari

In this note we study the generalized Hilbert series operator $H_{\mu}$, induced by a positive Bore measure $\mu$ on $[0, 1)$, between weighted sequence spaces. We characterize the measures $\mu$ for which $H_{\mu}$ is bounded between…

Classical Analysis and ODEs · Mathematics 2022-05-12 Jianjun Jin , Shuan Tang

Frames in a separable quaternionic Hilbert space were introduced and studied in [17] to have more applications. In this paper, we extend the study of frames in quaternionic Hilbert spaces and introduce different types of duals of a frame in…

Functional Analysis · Mathematics 2018-03-16 S. K. Sharma , Ghanshyam Singh , Soniya Sahu

In this work, we consider some relationships between a closed range operator $T$ and a fusion frame $\mathcal{W}=(W_i,w_i)_{i\in I}$ for a Hilbert space $\mathcal{H}$ that provides that the sequence $(\overline{T(W_i)},v_i)_{i\in I}$ is a…

Functional Analysis · Mathematics 2022-03-10 M. Ruiz , P. Calderón