TY - JOUR AU - Shi, Jie PY - 2026 TI - A fixed-point theorem for generalized strictly nonexpansive mappings on bounded sets in complete metric spaces JO - AIMS Mathematics SP - 7143 EP - 7154 VL - 11 IS - 3 AB - This paper offers substantial advances in the theory of fixed points for generalized strictly nonexpansive mappings. We develop a novel proof technique based on nonstandard analysis to establish a new fixed-point theorem. The core result demonstrates that, in a complete metric space, every continuous generalized strictly nonexpansive mapping with a bounded orbit possesses a unique fixed point to which all iterative sequences converge. The significance of this theorem lies in its substantial relaxation of the classical framework: It entirely dispenses with compactness and convexity requirements, which are typically indispensable in the study of nonexpansive mappings (such as in the Browder–Göhde theorem), replacing them solely with a boundedness condition. UR - https://doi.org/10.3934/math.2026294 DO - 10.3934/math.2026294