Title
Inapproximability results for constrained approximate Nash equilibria.
Abstract
We study the problem of finding approximate Nash equilibria that satisfy certain conditions, such as providing good social welfare. In particular, we study the problem ϵ-NE δ-SW: find an ϵ-approximate Nash equilibrium (ϵ-NE) that is within δ of the best social welfare achievable by an ϵ-NE. Our main result is that, if the exponential-time hypothesis (ETH) is true, then solving (18−O(δ))-NE O(δ)-SW for an n×n bimatrix game requires nΩ˜(log⁡n) time. Building on this result, we show similar conditional running time lower bounds for a number of other decision problems for ϵ-NE, where, for example, the payoffs or supports of players are constrained. We show quasi-polynomial lower bounds for these problems assuming ETH, where these lower bounds apply to ϵ-Nash equilibria for all ϵ<18. The hardness of these other decision problems has so far only been studied in the context of exact equilibria.
Year
DOI
Venue
2018
10.1016/j.ic.2018.06.001
Information and Computation
Keywords
Field
DocType
Approximate Nash equilibrium,Constrained equilibrium,Quasi-polynomial time,Lower bound,Exponential time hypothesis
Discrete mathematics,Decision problem,Combinatorics,Bimatrix game,Nash equilibrium,Mathematics
Journal
Volume
Issue
ISSN
262
Part
0890-5401
Citations 
PageRank 
References 
1
0.36
19
Authors
3
Name
Order
Citations
PageRank
Argyrios Deligkas1197.43
John Fearnley281.15
Rahul Savani324330.09