Approximation of a common fixed point for a countable family of mappings in complete geodesic spaces with curvature bounded above



	Approximation of a common fixed point for a countable family of mappings in complete geodesic spaces with curvature bounded above


	Fixed Point Theory, Volume 27, No. 2, 2026, 579-598, June 1st, 2026 DOI: 10.24193/fpt-ro.2026.2.06 Authors: Yasunori Kimura, Tomoya Ogihara Abstract: In this paper, we introduce a Halpern iteration of a countable family of strongly quasinonexpansive and delta-demiclosed mappings and prove convergence to a common fixed point. Further, we prove its convergence theorem with the combining projection method of balanced type. Key Words and Phrases: CAT\((1)\) space, fixed point, balanced mapping, Halpern iteration, metric projection, projection method, strongly quasinonexpansive, delta-demiclosed mapping 2020 Mathematics Subject Classification: 47H09, 47H10. Published on-line: June 1st, 2026. Fulltext pdf Back to volume's table of contents