Computer-generated holograms written on a liquid-crystal display can be used to generate dynamic light fields of arbitrary shape. This method was used to simultaneously trap polystyrene particles laterally and to displace them independently of one another.

In this paper we study the concurrent cops and robber (CCCR) game. CCCR follows the same rules as the classical, turn-based game, except for the fact that the players move simultaneously. The cops' goal is to capture the robber and the concurrent cop number of a graph is defined the minimum number of cops which guarantees capture. For the variant in which it it required to capture the robber in...