Topological Complexity of Configuration Spaces of Fully Articulated Graphs and Banana Graphs

Abstract

We determine the topological complexity of configuration spaces of graphs that are not necessarily trees, which was a crucial assumption in previous results. We do this for two very different classes of graphs: fully articulated graphs and banana graphs. We also complete the computation in the case of trees to include configuration spaces with any number of points, extending a proof of Farber. At the end we show that an unordered configuration space on a graph does not always have the same topological complexity as the corresponding ordered configuration space (not even when they are both connected). Surprisingly, in our counterexamples the topological complexity of the unordered configuration space is in fact smaller than for the ordered one.