Caristi-Kirk and Oettli-Th��ra Ball Spaces and applications

Autor: B��aszkiewicz, Piotr, ��miel, Hanna, Linzi, Alessandro, Szewczyk, Piotr
Rok vydání: 2019
Předmět:
DOI: 10.48550/arxiv.1901.03853
Popis: Based on the theory of ball spaces introduced by Kuhlmann and Kuhlmann we introduce and study Caristi-Kirk and Oettli-Th��ra ball spaces. We show that if the underlying metric space is complete, then these have a very strong property: every ball contains a singleton ball. This fact provides quick proofs for several results which are equivalent to the Caristi-Kirk Fixed Point Theorem, namely Ekeland's Variational Principles, the Oettli-Th��ra Theorem, Takahashi's Theorem and the Flower Petal Theorem.
15 pages, submitted to Journal of Fixed Point Theory and Applications
Databáze: OpenAIRE