Note on a helicopter search problem on graphs Original Research Article

We consider a search game on a graph in which one cop in a helicopter flying from vertex to vertex tries to catch the invisible robber. The existence of the winning program for the cop in this problem depends only on the robberʹs speed. We investigate the problem of finding the minimal robberʹs speed which prevents the cop from winning. For this parameter we give tight bounds in terms of the linkage and the pathwidth of a graph.