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

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Randomized iterative algorithms have attracted much attention in recent years because they can approximately solve large-scale linear systems of equations without accessing the entire coefficient matrix. In this paper, we propose two novel…

Numerical Analysis · Mathematics 2021-10-22 Kui Du , Xiao-Hui Sun

A cohomology for product systems of Hilbert bimodules is defined via the Ext functor. For the class of product systems corresponding to irreversible algebraic dynamics, relevant resolutions are found explicitly and it is shown how the…

Operator Algebras · Mathematics 2017-04-05 Jeong Hee Hong , Mi Jung Son , Wojciech Szymanski

Frame theory has been rapidly generalized and various generalizations have been developed. In this paper, we present a brief survey of the frames in Hilbert $C^{\ast}$-modules, including frames, $\ast$-frames, g-frames, $\ast$-g-frames,…

Functional Analysis · Mathematics 2022-12-20 M'hamed Ghiati , Mohammed Mouniane , Mohamed Rossafi

In the present paper the notion of a Hilbert module over a locally C*-algebra is discussed and some results are obtained on this matter. In particular, we give a detailed proof of the known result that the set of adjointable endomorphisms…

Operator Algebras · Mathematics 2007-05-23 Yu. I. Zhuraev , F. Sharipov

We give a new Banach module characterization of $W^*$-modules, also known as selfdual Hilbert $C^*$-modules over a von Neumann algebra. This leads to a generalization of the notion, and the theory, of W*-modules, to the setting where the…

Operator Algebras · Mathematics 2009-08-28 David P. Blecher , Upasana Kashyap

Phase retrieval has been an attractive but difficult problem rising from physical science, and there has been a gap between state-of-the-art theoretical convergence analyses and the corresponding efficient retrieval methods. Firstly, these…

Information Theory · Computer Science 2017-12-06 Gen Li , Yuchen Jiao , Yuantao Gu

Given a compact metric space X and a unital C*-algebra A, we introduce a family of seminorms on the C*-algebra of continuous functions from X to A, denoted C(X, A), induced by classical Lipschitz seminorms that produce compact quantum…

Operator Algebras · Mathematics 2018-03-28 Konrad Aguilar , Tristan Bice

The Kaczmarz method is an algorithm for finding the solution to an overdetermined consistent system of linear equations Ax=b by iteratively projecting onto the solution spaces. The randomized version put forth by Strohmer and Vershynin…

Numerical Analysis · Mathematics 2011-02-15 Yonina C. Eldar , Deanna Needell

This work concerns the use of the iterative algorithm (KMF algorithm) proposed by Kozlov, Mazya and Fomin to solve the Cauchy problem for Laplaces equation. This problem consists to recovering the lacking data on some part of the boundary…

Numerical Analysis · Computer Science 2014-05-14 Chakir Tajani , Jaafar Abouchabaka

A refined notion of curvature for a linear system of Hermitian vector spaces, in the sense of Grothendieck, leads to the unitary classification of a large class of analytic Hilbert modules. Specifically, we study Hilbert sub-modules, for…

Spectral Theory · Mathematics 2009-09-11 Shibananda Biswas , Gadadhar Misra , Mihai Putinar

We study Kaczmarz type methods to solve consistent linear matrix equations. We first present a block Kaczmarz (BK) method that employs a deterministic cyclic row selection strategy. Assuming that the associated coefficient matrix has full…

Numerical Analysis · Mathematics 2026-02-04 Wenli Wang , Duo Liu , Gangrong Qu , Michiel E. Hochstenbach

We propose a new deterministic Kaczmarz algorithm for solving consistent linear systems $A\mathbf{x}=\mathbf{b}$. Basically, the algorithm replaces orthogonal projections with reflections in the original scheme of Stefan Kaczmarz. Building…

Numerical Analysis · Mathematics 2023-05-17 Changpeng Shao

We prove that the C*-algebra of a minimal diffeomorphism satisfies Blackadar's Fundamental Comparability Property for positive elements. This leads to the classification, in terms of K-theory and traces, of the isomorphism classes of…

Operator Algebras · Mathematics 2015-05-13 Andrew S. Toms

In this article, we study tensor product of Hilbert $C^*$-modules and Hilbert spaces. We show that if $E$ is a Hilbert $A$-module and $F$ is a Hilbert $B$-module, then tensor product of frames (orthonormal bases) for $E$ and $F$ produce…

Operator Algebras · Mathematics 2007-05-23 Amir Khosravi , Behrooz Khosravi

This paper shows how data-driven deep generative models can be utilized to solve challenging phase retrieval problems, in which one wants to reconstruct a signal from only few intensity measurements. Classical iterative algorithms are known…

Image and Video Processing · Electrical Eng. & Systems 2020-07-17 Martin Reiche , Peter Jung

We define Schatten classes of adjointable operators on Hilbert modules over abelian $C^*$-algebras. Many key features carry over from the Hilbert space case. In particular, the Schatten classes form two-sided ideals of compact operators and…

Operator Algebras · Mathematics 2020-10-16 Abel B. Stern , Walter D. van Suijlekom

The Kaczmarz algorithm is a well known iterative method for solving overdetermined linear systems. Its randomized version yields provably exponential convergence in expectation. In this paper, we propose two new methods to speed up the…

Numerical Analysis · Computer Science 2016-08-02 Tengfei Ma

It is shown that the metric on the union of the sets $X$ and $Y$ defines a Hilbert $C^*$-module over the uniform Roe algebra of the space $X$ with a fixed metric $d_X$. A number of examples of such Hilbert $C^*$-modules are described.

Operator Algebras · Mathematics 2021-05-11 V. Manuilov

We introduce a localization concept for operator-valued frames, where the quality of localization is measured by the associated operator-valued Gram matrix belonging to some suitable Banach algebra. We prove that intrinsic localization of…

Functional Analysis · Mathematics 2025-05-29 Lukas Köhldorfer , Peter Balazs

We compute the C*-algebra generated by a group of composition operators acting on certain reproducing kernel Hilbert spaces over the disk, where the symbols belong to a non-elementary Fuchsian group. We show that such a C*-algebra contains…

Operator Algebras · Mathematics 2007-05-23 Michael T. Jury