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Related papers: Effective metastability of Halpern iterates in CAT…

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We study a convergence criterion which generalises the notion of being monotonically decreasing, and introduce a quantitative version of this criterion, a so called metastable rate of asymptotic decreasingness. We then present a concrete…

Functional Analysis · Mathematics 2020-04-27 Thomas Powell

In this paper we apply methods of proof mining to obtain a highly uniform effective rate of asymptotic regularity for the Ishikawa iteration associated to nonexpansive self-mappings of convex subsets of a class of uniformly convex geodesic…

Logic · Mathematics 2014-03-06 Laurentiu Leustean

We apply proof mining methods to analyse a result of Boikanyo and Moro\c{s}anu on the strong convergence of a Halpern-type proximal point algorithm. As a consequence, we obtain quantitative versions of this result, providing uniform…

Optimization and Control · Mathematics 2021-03-01 Laurentiu Leustean , Pedro Pinto

In a recent paper~\cite{paper2}, we proposed the concept of optimal error bounds for an iterative process, which allows us to obtain the convergence result of the iterative sequence to the common fixed point of the nonexpansive mappings in…

Numerical Analysis · Mathematics 2025-10-21 Tan-Phuc Nguyen , Thai-Hung Nguyen , Tien-Khai Nguyen , Cong-Duy-Nguyen Nguyen , Trung-Hieu Huynh

A generalized method of alternating resolvents was introduced by Boikanyo and Moro{\c s}anu as a way to approximate common zeros of two maximal monotone operators. In this paper we analyse the strong convergence of this algorithm under two…

Functional Analysis · Mathematics 2021-02-01 Bruno Dinis , Pedro Pinto

This paper is a close follow-up of Kaltenbacher and Tomba 2013 and Jin 2012, where Newton-Landweber iterations have been shown to converge either (unconditionally) without rates or (under an additional regularity assumption) with rates. The…

Numerical Analysis · Mathematics 2014-08-22 Barbara Kaltenbacher , Ivan Tomba

Let $E$ be a uniformly smooth and uniformly convex real Banach space and $E^*$ be its dual space. Suppose $A : E\rightarrow E^*$ is bounded, strongly monotone and satisfies the range condition such that $A^{-1}(0)\neq \emptyset$. Inspired…

Functional Analysis · Mathematics 2020-08-19 Mathew O. Aibinu , O. T. Mewomo

In this paper, we study $\Delta$- convergence of iterations for a sequence of strongly quasi-nonexpansive mappings as well as the strong convergence of the Halpern type regularization of them in Hadamard spaces. Then, we give some their…

Functional Analysis · Mathematics 2016-11-10 Hadi Khatibzadeh , Vahid Mohebbi

Let $X$ be a real Banach space with a normalized duality mapping uniformly norm-to-weak$^\star$ continuous on bounded sets or a reflexive Banach space which admits a weakly continuous duality mapping $J_{\Phi}$ with gauge $\phi$. Let $f$ be…

Optimization and Control · Mathematics 2007-12-10 Jean-Philippe Chancelier

We leverage the connections between nonexpansive maps, monotone Lipschitz operators, and proximal mappings to obtain near-optimal (i.e., optimal up to poly-log factors in terms of iteration complexity) and parameter-free methods for solving…

Optimization and Control · Mathematics 2020-04-14 Jelena Diakonikolas

The Halpern algorithm is a powerful fixed point approximation method for finding the closest point in the fixed point set of a nonexpansive mapping to the initial point. However, in practice, it is not necessarily true that this algorithm…

Optimization and Control · Mathematics 2026-04-24 Hideaki Iiduka

In this paper, we prove the strong convergence theorems for nearly nonexpansive mappings, using the modified Picard-Mann hybrid iteration process in the context of uniformly convex Banach space.

Functional Analysis · Mathematics 2021-01-15 Adrian Ghiura

In this paper, we study, in a nonlinear setting, the asymptotic behaviour of a generalized viscosity approximation method associated with a countable family of nonexpansive mappings satisfying resolvent-like conditions. We apply proof…

Optimization and Control · Mathematics 2025-12-12 Paulo Firmino , Laurentiu Leustean

We compute uniform rates of metastability for the Ishikawa iteration of a Lipschitz pseudo-contractive self-mapping of a compact convex subset of a Hilbert space. This extraction is an instance of the proof mining program that aims to apply…

Functional Analysis · Mathematics 2016-08-23 Laurentiu Leustean , Vlad Radu , Andrei Sipos

The Halpern iteration for solving monotone inclusion problems has gained increasing interests in recent years due to its simple form and appealing convergence properties. In this paper, we investigate the inexact variants of the scheme in…

Optimization and Control · Mathematics 2025-05-28 Ling Liang , Zusen Xu , Kim-Chuan Toh , Jia-Jie Zhu

We propose an adaptive way to choose the anchoring parameters for the Halpern iteration to find a fixed point of a nonexpansive mapping in a real Hilbert space. We prove strong convergence of this adaptive Halpern iteration and obtain the…

Optimization and Control · Mathematics 2025-05-19 Songnian He , Hong-Kun Xu , Qiao-Li Dong , Na Mei

In this paper, we unify all know iterative methods by introducing a new explicit iterative scheme for approximation of common fixed points of finite families of total asymptotically $I$-nonexpansive mappings. Note that such a scheme…

Functional Analysis · Mathematics 2012-04-10 Farrukh Mukhamedov , Mansoor Saburov

We show that the asymptotic regularity and the strong convergence of the modified Halpern iteration due to T.-H. Kim and H.-K. Xu and studied further by A. Cuntavenapit and B. Panyanak and the Tikhonov-Mann iteration introduced by H. Cheval…

Optimization and Control · Mathematics 2023-03-15 Horatiu Cheval , Ulrich Kohlenbach , Laurentiu Leustean

In this paper, we consider the Halpern iteration scheme for a finite family of quasinonexpansive mappings and then prove a strong convergence theorem to their common fixed point in a complete geodesic space with curvature bounded above by…

Functional Analysis · Mathematics 2019-11-19 Tatsuki Ezawa , Yasunori Kimura

In this paper, we study a new approach related to the convergence analysis of Ishikawa-type iterative models to a common fixed point of two non-expansive mappings in Banach spaces. The main novelty of our contribution lies in the so-called…