Pursuit-evasion games and visibility
Broadly, there are two classical pursuit-evasion problems in graphs. One is cops and robbers, where cops move along vertices in pursuit of a robber that is slow, visible, and also moving on vertices. The other is edge-searching, or sweeping, where agents pursue a fast, invisible evader who moves on edges and vertices. This talk will talk about some of the history of these two problems, as they relate to Brian Alspach, and some recent results on zero-(and low-)visibility cops and robbers, which attempts to bridge the gaps between the two.