Topological and uniform structures on universal covering spaces

Abstract

We discuss various uniform structures and topologies on the universal covering space $\widetilde X$ and on the fundamental group $π_1(X,x_0)$. We introduce a canonical uniform structure $CU(X)$ on a topological space $X$ and use it to relate topologies on $\widetilde X$ and uniform structures on $\widetilde{CU(X)}$. Using our concept of universal Peano space we show connections between the topology introduced by Spanier and a uniform structure of Berestovskii and Plaut. We give a sufficient and necessary condition for Berestovskii-Plaut structure to be identical with the one generated by the uniform convergence structure on the space of paths in $X$. We also describe when the topology of Spanier is identical with the quotient of the compact-open topology on the space of paths.