Improving the Hk-bound on the price of stability in undirected Shapley network design games
Improving the Hk-bound on the price of stability in undirected Shapley network design games
复制标题
提高无向 Shapley 网络设计博弈稳定性价格的 Hk-bound
DOI:
10.1016/j.tcs.2014.10.037
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发表时间:
2012
期刊:
影响因子:
--
通讯作者:
Matús Mihalák
中科院分区:
文献类型:
--
作者:
Y. Disser;A. Feldmann;Max Klimm;Matús Mihalák
In this article 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 (2011)[3] 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.