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Related papers: A note on alternating projections in Hilbert space

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In this paper, we show a mean convergence theorem for a mapping with an attractive point in a Hilbert space by using a quasinonexpansive extension of the mapping and a mean convergence theorem for a quasinonexpansive mapping.

Functional Analysis · Mathematics 2022-05-24 Koji Aoyama , Masashi Toyoda

We study the well-known methods of alternating and simultaneous projections when applied to two nonorthogonal linear subspaces of a real Euclidean space. Assuming that both of the methods have a common starting point chosen from either one…

Optimization and Control · Mathematics 2023-11-15 Simeon Reich , Rafał Zalas

We consider sequences $(B_k)_{k=0}^\infty$ of points obtained by projecting back and forth between two manifolds $\M_1$ and $\M_2$, and give conditions guaranteeing that the sequence converge to a limit $B_\infty\in\M_1\cap\M_2$. Our…

Numerical Analysis · Mathematics 2011-07-21 Fredrik Andersson , Marcus Carlsson

A non-Hermitian complex symmetric 2x2 matrix toy model is used to study projective Hilbert space structures in the vicinity of exceptional points (EPs). The bi-orthogonal eigenvectors of a diagonalizable matrix are Puiseux-expanded in terms…

Mathematical Physics · Physics 2018-11-13 Uwe Guenther , Ingrid Rotter , Boris F. Samsonov

This work is devoted to establish the strong convergence results of an iterative algorithm generated by the shrinking projection method in Hilbert spaces. The proposed approximation sequence is used to find a common element in the set of…

Functional Analysis · Mathematics 2018-03-07 Abdul Ghaffar , Zafar Ullah , Muhammad Aqeel Ahmad Khan , Faisal Mumtaz

Given two nonempty and disjoint intersections of closed and convex subsets, we look for a best approximation pair relative to them, i.e., a pair of points, one in each intersection, attaining the minimum distance between the disjoint…

Optimization and Control · Mathematics 2024-06-06 Yair Censor , Rafiq Mansour , Daniel Reem

We present an extension of our earlier work [Ritt operators and convergence in the method of alternating projections, J. Approx. Theory, 205:133-148, 2016] by proving a general asymptotic result for orbits of an operator acting on a…

Functional Analysis · Mathematics 2019-02-14 Catalin Badea , David Seifert

In this paper, we give a simple proof and some generalizations of results in Falset, Llorens-Fuster, Marino, and Rugiano (2016).

Functional Analysis · Mathematics 2020-12-29 Koji Aoyama

This paper seeks to advance the theory of nonexpansive mappings by introducing and exploring a novel class of nonexpansive type mappings, which we aptly designate as perimetric nonexpansive mappings. We establish that the collection of…

Functional Analysis · Mathematics 2025-08-12 Anish Banerjee , Hiranmoy Garai , Pratikshan Mondal , Lakshmi Kanta Dey

Suppose that $A$ and $B$ are closed subsets of a Euclidean space such that $A\cap B\neq\varnothing$, and we aim to find a point in this intersection with the help of the sequences $(a_n)_\nnn$ and $(b_n)_\nnn$ generated by the \emph{method…

Optimization and Control · Mathematics 2013-07-11 Heinz H. Bauschke , Dominikus Noll

Let $A$ be a closed affine subspace and let $B$ be a hyperplane in a Hilbert space. Suppose we are given their associated nearest point mappings $P_A$ and $P_B$, respectively. We present a formula for the projection onto their intersection…

Optimization and Control · Mathematics 2022-06-24 Heinz H. Bauschke , Dayou Mao , Walaa M. Moursi

We provide formulas for projectors onto a polyhedral set, i.e. the intersection of a finite number of halfspaces. To this aim we formulate the problem of finding the projection as a convex optimization problem and we solve explicitly…

Optimization and Control · Mathematics 2017-04-20 Krzysztof E. Rutkowski

Let $H$ be a Hilbert space. We investigate the properties of weak limit points of iterates of random projections onto $K\geq 2$ closed convex sets in $H$ and the parallel properties of weak limit points of residuals of random greedy…

Functional Analysis · Mathematics 2021-12-10 Petr A. Borodin , Eva Kopecka

This note discusses some aspects of the asymptotic behaviour of nonexpansive maps. Using metric functionals, we make a connection to the invariant subspace problem and prove a new result for nonexpansive maps of $\ell^{1}$. We also point…

Functional Analysis · Mathematics 2022-06-01 Armando W. Gutiérrez , Anders Karlsson

We introduce an abstract algorithm that aims to find the Bregman projection onto a closed convex set. As an application, the asymptotic behaviour of an iterative method for finding a fixed point of a quasi Bregman nonexpansive mapping with…

Functional Analysis · Mathematics 2013-09-26 Heinz H. Bauschke , Jiawei Chen , Xianfu Wang

We provide new conditions under which the alternating projection sequence converges in norm for the convex feasibility problem where a linear subspace with finite codimension $N\geq 2$ and a lattice cone in a Hilbert space are considered.…

Optimization and Control · Mathematics 2024-12-16 Francesco Battistoni , Enrico Miglierina

In this note we point out that results on the asymptotic behaviour of an alternative iterative method are corollaries of corresponding results on the well-known Halpern iteration.

Functional Analysis · Mathematics 2015-04-09 Laurentiu Leustean , Adriana Nicolae

We establish the asymptotic regularity and the $\Delta$-convergence of the sequence constructed by the alternating projections to closed convex sets in a CAT($\kappa$) space with $\kappa > 0$. Furthermore, the strong convergence of the…

Metric Geometry · Mathematics 2016-11-08 Byoung Jin Choi , Un Cig Ji , Yongdo Lim

We investigate convergence of alternating Bregman projections between non-convex sets and prove convergence to a point in the intersection, or to points realizing a gap between the two sets. The speed of convergence is generally sub-linear,…

Statistics Theory · Mathematics 2025-07-30 Dominikus Noll

We give a short, elementary and explicit proof of the existence of Hilbert schemes of points on affine schemes. As a direct consequence we obtain the existence of the Hilbert scheme of points on any projective scheme, not necessarily of…

Algebraic Geometry · Mathematics 2007-05-23 Trond Gustavsen , Dan Laksov , Roy Skjelnes