On set-valued convex contractions
摘要
In this paper, we introduce and study a new class of multivalued mappings called set-valued convex contractions of order two. This notion extends the classical concept of Nadler contractions by incorporating two control parameters that jointly govern the contractive behavior of the mapping through both the Pompeiu–Hausdorff metric and the underlying metric of the space. We establish a fixed point theorem for such mappings in complete metric spaces under the assumption of upper semicontinuity. Our result properly generalizes Nadler’s fixed point theorem and provides a unified framework encompassing several existing types of multivalued contractions. Illustrative examples are provided to demonstrate that the new class of contractions is strictly broader than the classical one. Possible extensions and applications of the main result to more general metric-like spaces are also discussed.