On Cartwright-Littlewood Fixed Point Theorem

Przemysław Kucharski

Published 2021-08-05Version 1

We prove the following generalization of the Cartwright-Littlewood fixed point theorem. Suppose $ h\colon~{\mathbb R}^{2}\to{\mathbb R}^{2} $ is an orientation preserving planar homeomorphism, and $ X $ is an acyclic continuum. Let $ C $ be a component of $ X \cap h(X) $. If there is a $ c \in C $ such that $ {\mathcal O}_{+} (c) \subseteq C $ or $ {\mathcal O}_{-} (c) \subseteq C $ then $ C $ also contains a fixed point of $ h$. Our result also generalizes earlier results of Ostrovski and Boro\'nski, and answers the Question from Boro\'nski's work in 2017. The proof is inspired by a short proof of the result of Cartwright and Littlewood due to Hamilton.