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Related papers: Direct Sum of Lower Semi-Frames in Hilbert Spaces

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The aim of this paper is to study $K$-frames for quaternionic Hilbert spaces. First, we present the quaternionic version of Douglas's theorem and then investigate $K$-frames for a quaternionic Hilbert space $\mathcal{H}$, where $K \in…

Functional Analysis · Mathematics 2024-11-08 Najib Khachiaa

In the present paper, we investigate some properties of duals of continuous frames in Hilbert C*-modules. In particular, we give requirements so that by removing some elements of a continuous frame, it does not remain a continuous frame and…

Functional Analysis · Mathematics 2023-04-25 Hadi Ghasemi , Tayebe Lal Shateri

This paper presents a bicomplex version of the Spectral Decomposition Theorem on infinite dimensional bicomplex Hilbert spaces. In the process, the ideas of bounded linear operators, orthogonal complements and compact operators on bicomplex…

Functional Analysis · Mathematics 2013-01-25 Kuldeep Singh Charak , Ravinder Kumar , Dominic Rochon

Operator-valued frames are natural generalization of frames that have been used in quantum computing, packets encoding, etc. In this paper, we focus on developing the theory about operator-valued frames for finite Hilbert spaces. Some…

Functional Analysis · Mathematics 2010-09-28 Bin Meng

This work presents problems of constructing finite-difference formulas in the Hilbert space, i.e., setting problems of constructing finite-difference formulas using functional methods. The work presents a functional statement of the problem…

Numerical Analysis · Mathematics 2026-02-11 Kh. M. Shadimetov , R. S. Karimov

In this paper we present the construction of an exact dual frame under specific structural assumptions posed on the dual frame. When given a frame $F$ for a finite dimensional Hilbert space, and a set of vectors $H$ that is assumed to be a…

Functional Analysis · Mathematics 2025-01-16 Roza Aceska , Yeon Hyang Kim , Sivaram K. Narayan

We apply Lax-Milgram theorem to characterize scalable and piecewise scalable frame in finite and infinite-dimensional Hilbert spaces. We also introduce a method for approximating the inverse frame operator using finite-dimensional linear…

Functional Analysis · Mathematics 2022-12-05 Laura De Carli , Pierluigi Vellucci

In this work, we introduce the concept of the direct integral of locally Hilbert spaces. This notion is formulated such that the direct integral of locally Hilbert spaces forms a locally Hilbert space. We then define two classes of locally…

Functional Analysis · Mathematics 2025-08-06 Chaitanya J. Kulkarni , Santhosh Kumar Pamula

In this short article we show an orthogonal decomposition of a Hilbert space as a sum of null solutions of the first derivative and the first derivative of a traceless higher order Hilbert/Sobolev space. We define orthogonal projections and…

Functional Analysis · Mathematics 2015-03-05 Dejenie A. Lakew

We study the existence and approximate controllability of a class of fractional nonlocal delay semilinear differential systems in a Hilbert space. The results are obtained by using semigroup theory, fractional calculus, and Schauder's fixed…

Optimization and Control · Mathematics 2013-11-26 Amar Debbouche , Delfim F. M. Torres

Let $H_1$ and $H_2$ be two Hilbert spaces, $K$ and $L$ be bounded operatrors on $H_1$ and $H_2$ respectively. In this paper we study the relationship between $K$-frames for $H_1$ and $L$-frames for $H_2$ and $K\oplus L$-frames for…

Functional Analysis · Mathematics 2025-01-09 Najib Khachiaa

In this note, we verify that the bounded shadowing property and quasi-hyperbolicity of bounded linear operators on Hilbert spaces are preserved under Aluthge transforms.

Functional Analysis · Mathematics 2022-09-19 Linh Tran

The purpose of this paper is to propose a definition of continuous frames of rank n for Krein spaces and to study their basic properties. Similarly to the Hilbert space case, continuous frames are characterized by the analysis, the…

Functional Analysis · Mathematics 2021-03-24 Diego Carrillo , Kevin Esmeral , Elmar Wagner

The aim of this article is to explore in all remaining aspects the spectral theory of locally normal operators. In a previous article we proved the spectral theorem in terms of locally spectral measures. Here we prove the spectral theorem…

Functional Analysis · Mathematics 2025-11-04 Aurelian Gheondea

Several new properties of weighted Hilbert transform are obtained. If mu is zero, two Plancherel-like equations and the isotropic properties are derived. For mu is real number, a coerciveness is derived and two iterative sequences are…

Machine Learning · Computer Science 2020-02-12 Jason You

We study approximations of compact linear multivariate operators defined over Hilbert spaces. We provide necessary and sufficient conditions on various notions of tractability. These conditions are mainly given in terms of sums of certain…

Numerical Analysis · Mathematics 2018-07-10 Peter Kritzer , Henryk Wozniakowski

The paper is aimed to establish the interdependence between linear expand-contract plasticity of an ellipsoid in a separable Hilbert spaces and properties of the set of its semi-axes.

Functional Analysis · Mathematics 2018-11-02 Olesia Zavarzina

We propose an algorithm for computing the proximity operator of a sum of composite convex functions in Hilbert spaces and investigate its asymptotic behavior. Applications to best approximation and image recovery are described.

Optimization and Control · Mathematics 2010-07-22 Patrick L. Combettes , Dinh Dung , Bang Cong Vu

The existence of a rigged Hilbert space whose extreme spaces are, respectively, the projective and the inductive limit of a directed contractive family of Hilbert spaces is investigated. It is proved that, when it exists, this rigged…

Functional Analysis · Mathematics 2013-12-06 Giorgia Bellomonte , Camillo Trapani

Finite frames, or spanning sets for finite-dimensional Hilbert spaces, are a ubiquitous tool in signal processing. There has been much recent work on understanding the global structure of collections of finite frames with prescribed…

Functional Analysis · Mathematics 2023-09-14 Tom Needham , Clayton Shonkwiler