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

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The randomized Kaczmarz method is an iterative algorithm that solves overdetermined systems of linear equations. Recently, the method was extended to systems of equalities and inequalities by Leventhal and Lewis. Even more recently, Needell…

Numerical Analysis · Mathematics 2014-09-04 Jonathan Briskman , Deanna Needell

The duality principle for Gabor frames is one of the pillars of Gabor analysis. We establish a far-reaching generalization to Morita equivalent $C^*$-algebras where the equivalence bimodule is a finitely generated projective Hilbert…

Operator Algebras · Mathematics 2019-05-07 Are Austad , Mads S. Jakobsen , Franz Luef

In this study, we consider a general time-space system, whose model operator and observation operator are locally Lipschitz continuous, over a finite time horizon and parameter identification by using Landweber-Kaczmarz regularization. The…

Analysis of PDEs · Mathematics 2019-02-20 Tram Thi Ngoc Nguyen

Phase retrieval in real or complex Hilbert spaces is the task of recovering a vector, up to an overall unimodular multiplicative constant, from magnitudes of linear measurements. In this paper, we assume that the vector is normalized, but…

Probability · Mathematics 2019-11-19 Dylan Domel-White , Bernhard G. Bodmann

We show that the unit ball of a full Hilbert $C^*$-module is sequentially compact in a certain weak topology if and only if the underlying $C^*$-algebra is finite dimensional. This provides an answer to the question posed in J.…

Operator Algebras · Mathematics 2010-05-31 Lj. Arambasic , D. Bakic , M. S. Moslehian

In this paper we present results concerning orthogonality in Hilbert $C^*$-modules. Moreover, for a $C^*$-algebra $\mathscr{A}$, we prove theorems concerning the multi-$\mathscr{A}$-linearity and its preservation by $\mathscr{A}$-linear…

Operator Algebras · Mathematics 2021-12-01 Pawel Wojcik , Ali Zamani

We develop a stochastic approximation version of the classical Kaczmarz algorithm that is incremental in nature and takes as input noisy real time data. Our analysis shows that with probability one it mimics the behavior of the original…

Optimization and Control · Mathematics 2014-04-29 Gugan Thoppe , Vivek S. Borkar , D. Manjunath

The backward-backward algorithm is a tool for finding minima of a regularization of the sum of two convex functions in Hilbert spaces. We generalize this setting to Hadamard spaces and prove the convergence of an error-tolerant version of…

Optimization and Control · Mathematics 2013-10-01 Sebastian Banert

The Kaczmarz algorithm is popular for iteratively solving an overdetermined system of linear equations. The traditional Kaczmarz algorithm can approximate the solution in few sweeps through the equations but a randomized version of the…

Numerical Analysis · Computer Science 2014-02-04 Hemant Kumar Aggarwal , Angshul Majumdar

The (abstract) Cuntz algebra is generated by non-unitary isometries and has therefore no intrinsic finiteness properties. To approximate the elements of the Cuntz algebra by finite-dimensional objects, we thus consider a spatial…

Operator Algebras · Mathematics 2008-11-20 Steffen Roch

In this paper, by regarding the two-subspace Kaczmarz method [20] as an alternated inertial randomized Kaczmarz algorithm we present a new convergence rate estimate which is shown to be better than that in [20] under a mild condition.…

Numerical Analysis · Mathematics 2023-06-16 Songnian He , Ziting Wang , Qiao-Li Dong

Frames in a Hilbert space that are generated by operator orbits are vastly studied because of the applications in dynamic sampling and signal recovery. We demonstrate in this paper a representation theory for frames generated by operator…

Functional Analysis · Mathematics 2024-09-24 Chad Berner , Eric S. Weber

The Kaczmarz method is an efficient iterative algorithm for large-scale linear systems. However, its linear convergence rate suffers from ill-conditioned problems and is highly sensitive to the smallest nonzero singular value. In this work,…

Numerical Analysis · Mathematics 2026-02-26 Yunying Ke , Hao Luo

Randomized regularized Kaczmarz algorithms have recently been proposed to solve tensor recovery models with {\it consistent} linear measurements. In this work, we propose a novel algorithm based on the randomized extended Kaczmarz algorithm…

Numerical Analysis · Mathematics 2021-12-17 Kui Du , Xiao-Hui Sun

The Landweber algorithm defined on complex/real Hilbert spaces is a gradient descent algorithm for linear inverse problems. Our contribution is to present a novel method for accelerating convergence of the Landweber algorithm. In this…

Information Theory · Computer Science 2020-01-20 Tadashi Wadayama , Satoshi Takabe

We initiate a study of Hilbert modules over the polynomial algebra A=C[z_1,...,z_d] that are obtained by completing A with respect to an inner product having certain natural properties. A standard Hilbert module is a finite multiplicity…

Operator Algebras · Mathematics 2007-05-23 William Arveson

In the first part of the paper we describe the dual \ell^2(A)^{\prime} of the standard Hilbert C*-module \ell^2(A) over an arbitrary (not necessarily unital) C*-algebra A. When A is a von Neumann algebra, this enables us to construct…

Operator Algebras · Mathematics 2019-12-19 Damir Bakic

The Kaczmarz method is an iterative method for solving large systems of equations that projects iterates orthogonally onto the solution space of each equation. In contrast to direct methods such as Gaussian elimination or QR-factorization,…

Numerical Analysis · Computer Science 2013-09-30 Noreen Jamil , Deanna Needell , Johannes Muller , Christof Lutteroth , Gerald Weber

The Kaczmarz method is an iterative algorithm for solving systems of linear equations Ax=b. Theoretical convergence rates for this algorithm were largely unknown until recently when work was done on a randomized version of the algorithm. It…

Numerical Analysis · Mathematics 2010-04-01 Deanna Needell

The Hildreth's algorithm is a row action method for solving large systems of inequalities. This algorithm is efficient for problems with sparse matrices, as opposed to direct methods such as Gaussian elimination or QR-factorization. We…

Numerical Analysis · Computer Science 2014-09-11 Noreen Jamil , Xuemei Chen , Alex Cloninger
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