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Related papers: The Kaczmarz Algorithm in Hilbert $C^{*}$-modules

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To conduct a more in-depth investigation of randomized solvers for solving linear systems, we adopt a unified randomized batch-sampling Kaczmarz framework with per-iteration costs as low as cyclic block methods, and develop a general…

Numerical Analysis · Mathematics 2026-04-21 Dong-Yue Xie , Xi Yang

Frame Theory has a great revolution in recent years. This Theory have been extended from Hilbert spaces to Hilbert $C^{\ast}$-modules. In this paper we consider the stability of continuous operator frame and continuous $K$-operator frames…

Functional Analysis · Mathematics 2021-01-13 A. Touri

The most important purpose of this article is to investigate perfect reconstruction underlying range space of operators in finite dimensional Hilbert spaces by matrix methods. To this end, first we obtain more structures of the canonical…

Functional Analysis · Mathematics 2020-08-12 Fahimeh Arabyani Neyshaburi , Rajab Ali Kamyabi-Gol

In the present paper the notion of continuous frames is introduced and some results of these frames are proved. Next, we give the concept of duals of continuous frames in Hilbert C*-modules and investigate some properties of them.

Functional Analysis · Mathematics 2023-01-24 Hadi Ghasemi , Tayebe Lal Shateri

Solving linear systems of equations is a fundamental problem in mathematics. When the linear system is so large that it cannot be loaded into memory at once, iterative methods such as the randomized Kaczmarz method excel. Here, we extend…

Numerical Analysis · Mathematics 2020-06-03 Anna Ma , Denali Molitor

Randomized Kaczmarz methods form a family of linear system solvers which converge by repeatedly projecting their iterates onto randomly sampled equations. While effective in some contexts, such as highly over-determined least squares,…

Numerical Analysis · Mathematics 2025-07-30 Michał Dereziński , Deanna Needell , Elizaveta Rebrova , Jiaming Yang

The randomized Kaczmarz method and its accelerated variants are a powerful class of iterative methods for solving large-scale linear systems, offering guaranteed convergence with low per-iteration cost. However, their numerical stability…

Numerical Analysis · Mathematics 2026-05-19 Michał Dereziński , Ethan N. Epperly , Deanna Needell , Alexander Xue

In this paper we introduce the concepts of atomic systems for operators and K-frames in Hilbert C*-modules and we establish some results.

Operator Algebras · Mathematics 2014-03-04 Abbas Najati , M. Mohammadi Saem , P. Gavruta

We investigate orthonormality-preserving, C*-conformal and conformal module mappings on Hilbert C*-modules to obtain their general structure. Orthogonality-preserving bounded module maps T act as a multiplication by an element \lambda of…

Operator Algebras · Mathematics 2025-04-29 Michael Frank , Alexander S. Mishchenko , Alexander A. Pavlov

The Kaczmarz algorithm is an iterative method that solves linear systems of equations. It stands out among iterative algorithms when dealing with large systems for two reasons. First, at each iteration, the Kaczmarz algorithm uses a single…

Numerical Analysis · Mathematics 2024-04-10 Inês A. Ferreira , Juan A. Acebrón , José Monteiro

We investigate the generalized derivations and show that every generalized derivation on a simple Hilbert $C^*$-module either is closable or has a dense range. We also describe dynamical systems on a full Hilbert $C^*$-module ${\mathcal M}$…

Operator Algebras · Mathematics 2021-07-23 Gh. Abbaspour , M. S. Moslehian , A. Niknam

We establish several operator extensions of the Chebyshev inequality. The main version deals with the Hadamard product of Hilbert space operators. More precisely, we prove that if $\mathscr{A}$ is a $C^*$-algebra, $T$ is a compact Hausdorff…

Functional Analysis · Mathematics 2014-05-30 Mohammad Sal Moslehian , Mojtaba Bakherad

We investigate the orthogonality preserving property for pairs of mappings on inner product $C^*$-modules extending existing results for a single orthogonality-preserving mapping. Guided by the point of view that the $C^*$-valued inner…

Operator Algebras · Mathematics 2025-04-29 Michael Frank , M. S. Moslehian , Ali Zamani

The randomized Kaczmarz algorithm is one of the most popular approaches for solving large-scale linear systems due to its simplicity and efficiency. In this paper, we propose two classes of global randomized Kaczmarz methods for solving…

Numerical Analysis · Mathematics 2025-12-23 Yu-Qi Niu , Bing Zheng

In this paper, we will introduce the concept of a continuous biframe for Hilbert $ C^{\ast}- $modules. Then, we examine some characterizations of this biframe with the help of an invertible and adjointable operator is given. Moreover, we…

Functional Analysis · Mathematics 2025-03-24 Abdellatif Lfounoune , Abdelilah Karara , Mohamed Rossafi

The Kaczmarz method is a way to iteratively solve a linear system of equations $Ax = b$. One interprets the solution $x$ as the point where hyperplanes intersect and then iteratively projects an approximate solution onto these hyperplanes…

Numerical Analysis · Mathematics 2024-11-12 Stefan Steinerberger

The paper is devoted to continuous frames and Riesz bases in Hilbert C*-modules. we define a continuous Riesz basis for Hilbert C*-modules and give some results about them.

Functional Analysis · Mathematics 2022-09-20 Hadi Ghasemi , Tayebe Lal Shateri

Phase retrieval using a frame for a finite-dimensional Hilbert space is known to always be Lipschitz stable. However, phase retrieval using a frame or a continuous frame for an infinite-dimensional Hilbert space is always unstable. In order…

Functional Analysis · Mathematics 2025-12-10 Daniel Freeman , Mitchell A. Taylor

We establish necessary and sufficient conditions for the stability of the finite section method for operators belonging to a certain $C^*$-algebra of operators acting on the Hilbert space $l^2_H(\mathbb{Z})$ of $H$-valued sequences where…

Functional Analysis · Mathematics 2019-06-20 Torsten Ehrhardt , Zheng Zhou

We investigate complexes of Hilbert C*-modules, which are cochain complexes with (unbounded) regular operators between Hilbert C*-modules as differential maps. In particular, we provide various equivalent characterizations of the Fredholm…

Operator Algebras · Mathematics 2025-05-13 Brian Villegas-Villalpando , Koen van den Dungen