Approximating nash equilibria in tree polymatrix games

Siddharth Barman*, Katrina Ligett, Georgios Piliouras

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

14 Scopus citations


We develop a quasi-polynomial time Las Vegas algorithm for approximating Nash equilibria in polymatrix games over trees, under a mild renormalizing assumption. Our result, in particular, leads to an expected polynomial-time algorithm for computing approximate Nash equilibria of tree polymatrix games in which the number of actions per player is a fixed constant. Further, for trees with constant degree, the running time of the algorithm matches the best known upper bound for approximating Nash equilibria in bimatrix games (Lipton, Markakis, and Mehta 2003). Notably, this work closely complements the hardness result of Rubinstein (2015), which establishes the inapproximability of Nash equilibria in polymatrix games over constant-degree bipartite graphs with two actions per player.

Original languageAmerican English
Title of host publicationAlgorithmic Game Theory - 8th International Symposium, SAGT 2015
EditorsMartin Hoefer, Martin Hoefer
PublisherSpringer Verlag
Number of pages12
ISBN (Print)9783662484326
StatePublished - 2015
Externally publishedYes
Event8th International Symposium on Algorithmic Game Theory, SAGT 2015 - Saarbrucken, Germany
Duration: 28 Sep 201530 Sep 2015

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference8th International Symposium on Algorithmic Game Theory, SAGT 2015

Bibliographical note

Funding Information:
This work was supported by NSF grants CNS-0846025, CCF-1101470, CNS-1254169, SUTD grant SRG ESD 2015 097, along with a Microsoft Research Faculty Fellowship, a Google Faculty Research Award, a Linde/ SISL Postdoctoral Fellowship and a CMI Wally Baer and Jeri Weiss postdoctoral fellowship. Katrina Ligett gratefully acknowledges the support of the Charles Lee Powell Foundation. The bulk of the work was conducted while Georgios Piliouras was a postdoctoral scholar at Caltech.

Publisher Copyright:
© Springer International Publishing Switzerland 2015.


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