Localization Game for Random Geometric Graphs

Abstract

The localization game is a two player combinatorial game played on a graph G = (V, E). The cops choose a set of vertices S 1 ⊆ V with |S 1 | = k. The robber then chooses a vertex v ∈ V whose location is hidden from the cops, but the cops learn the graph distance between the current position of the robber and the vertices in S 1 . If this information is sufficient to locate the robber, the cops win immediately; otherwise the cops choose another set of vertices S 2 ⊆ V with |S 2 | = k, and the robber may move to a neighbouring vertex. The new distances are presented to the robber, and if the cops can deduce the new location of the robber based on all information they accumulated thus far, then they win; otherwise, a new round begins. If the robber has a strategy to avoid being captured, then she wins. The localization number is defined to be the smallest integer k so that the cops win the game. In this paper we determine the localization number (up to poly-logarithmic factors) of the random geometric graph G ∈ G(n, r) slightly above the connectivity threshold.

Edge and Pair Queries -- Random Graphs and Complexity

“…The bounds for dense graphs were consecutively improved in [19], and the arguments were extended to sparse graphs. The localization game was also recently studied for random geometric graphs [30]. We direct the reader to the book [7] for more graph searching games in the context of random graphs.…”