TY - GEN
T1 - Improving the H_k Bound on the Price of Stability in Undirected Shapley Network Design Games
AU - Disser, Yann
AU - Feldmann, Andreas Emil
AU - Klimm, Max
AU - Mihalak, Matus
PY - 2013
Y1 - 2013
N2 - In this paper we show that the price of stability of Shapley network design games on undirected graphs with k players is at most k
3(k+1)/2- k
2/1+k
3(k+1)/2-k
2 H
k = (1-Θ(1/k
4))H
k, where H
k denotes the k-th harmonic number. This improves on the known upper bound of H
k, which is also valid for directed graphs but for these, in contrast, is tight. Hence, we give the first non-trivial upper bound on the price of stability for undirected Shapley network design games that is valid for an arbitrary number of players. Our bound is proved by analyzing the price of stability restricted to Nash equilibria that minimize the potential function of the game. We also present a game with k = 3 players in which such a restricted price of stability is 1.634. This shows that the analysis of Bilò and Bove (Journal of Interconnection Networks, Volume 12, 2011) is tight. In addition, we give an example for three players that improves the lower bound on the (unrestricted) price of stability to 1.571.
AB - In this paper we show that the price of stability of Shapley network design games on undirected graphs with k players is at most k
3(k+1)/2- k
2/1+k
3(k+1)/2-k
2 H
k = (1-Θ(1/k
4))H
k, where H
k denotes the k-th harmonic number. This improves on the known upper bound of H
k, which is also valid for directed graphs but for these, in contrast, is tight. Hence, we give the first non-trivial upper bound on the price of stability for undirected Shapley network design games that is valid for an arbitrary number of players. Our bound is proved by analyzing the price of stability restricted to Nash equilibria that minimize the potential function of the game. We also present a game with k = 3 players in which such a restricted price of stability is 1.634. This shows that the analysis of Bilò and Bove (Journal of Interconnection Networks, Volume 12, 2011) is tight. In addition, we give an example for three players that improves the lower bound on the (unrestricted) price of stability to 1.571.
U2 - 10.1007/978-3-642-38233-8_14
DO - 10.1007/978-3-642-38233-8_14
M3 - Conference article in proceeding
SN - 9783642382321
T3 - Lecture Notes in Computer Science
SP - 158
EP - 169
BT - Algorithms and Complexity - 8th International Conference, CIAC 2013, Proceedings
PB - Springer Verlag
ER -