Quantitative asymptotic regularity and -asymptotic regularity for the inexact generalized Halpern iteration
Nicoleta Dumitru
University of Bucharest, RomaniaLaurenţiu Leuştean
University of Bucharest, Romania; Simion Stoilow Institute of Mathematics of the Romanian Academy, Bucharest, Romania; Institute for Logic and Data Science, Bucharest, Romania

Abstract
We apply proof mining techniques to obtain quantitative and qualitative results on asymptotic and -asymptotic regularity for the inexact generalized Halpern iteration, a viscosity-type extension of an iteration recently studied by Kanzow and Shehu. Specializing our results to the Kanzow–Shehu iteration and the sequential averaging method (SAM) yields analogous results for these iterations. Furthermore, we compute rates of (-)asymptotic regularity for particular choices of the parameter sequences, and for one of them, we obtain linear rates as an application of a lemma due to Sabach and Shtern.
Cite this article
Nicoleta Dumitru, Laurenţiu Leuştean, Quantitative asymptotic regularity and -asymptotic regularity for the inexact generalized Halpern iteration. Port. Math. (2026), published online first
DOI 10.4171/PM/2169