Bottleneck congestion games properly model the properties of many real-world network routing applications. They are known to possess strong equilibria -a strengthening of Nash equilibrium to resilience against coalitional deviations. In this paper, we study the computational complexity of pure Nash and strong equilibria in these games. We provide a generic centralized algorithm to compute strong equilibria, which has polynomial running time for many interesting classes of games such as, e.g., matroid or single-commodity bottleneck congestion games. In addition, we examine the more demanding goal to reach equilibria in polynomial time using natural improvement dynamics. Using unilateral improvement dynamics in matroid games pure Nash equilibria can be reached efficiently. In contrast, computing even a single coalitional improvement move in matroid and singlecommodity games is strongly NP-hard. In addition, we establish a variety of hardness results and lower bounds regarding the duration of unilateral and coalitional improvement dynamics. They continue to hold even for convergence to approximate equilibria.
The complexity of computing PNE and strong equilibria in these games was further investigated in REF .
Computing pure Nash and strong equilibria in bottleneck congestion games
IN PROC. 18TH EUROPEAN SYMPOSIUM ON ALGORITHMS (ESA
Mathematics Computer Science