Completeness and related properties of the graph topology on function spaces

Abstract

The graph topology $\tau_{\Gamma}$ is the topology on the space $C(X)$ of all continuous functions defined on a Tychonoff space $X$ inherited from the Vietoris topology on $X\times \mathbb R$ after identifying continuous functions with their graphs. It is shown that all completeness properties between complete metrizability and hereditary Baireness coincide for the graph topology if and only if $X$ is countably compact; however, the graph topology is $\alpha$-favorable in the strong Choquet game, regardless of $X$. Analogous results are obtained for the fine topology on $C(X)$. Pseudocompleteness, along with properties related to 1st and 2nd countability of $(C(X),\tau_{\Gamma})$ are also investigated.