Stable cooperation in graph-restricted games

In the paper we study stable coalition structures in the games with restrictions on players' cooperation and communication. Restriction on cooperation among players is given by a coalition structure, whereas restriction on their communication is described by a graph. Having both a coalition structure and a graph fixed, a payoff distribution can be calculated based on worth of each coalition of players. We use the concept of stability for a coalition structure similar to Nash stability, assuming that the graph structure is fixed. The results are illustrated with examples.