Rendezvous Search on Labelled Networks

Two players are independently placed on a commonly labelled network X: They cannot see each other but wish to meet in least expected time. We consider continuous and discrete versions, in which they may move at unit speed or between adjacent distinct nodes, respectively. There are two versions of the problem (asymmetric or symmetric) depending on whether or not we allow the players to use diierent strategies. After obtaining some optimality conditions for general networks, we specialize to the interval and circle networks. In the rst setting, we extend the work of J. V. Howard; in the second we prove a conjecture concerning the optimal symmetric strategy.