Well-Supported vs. Approximate Nash Equilibria: Query Complexity of Large Games

@article{Chen2017WellSupportedVA,
  title={Well-Supported vs. Approximate Nash Equilibria: Query Complexity of Large Games},
  author={Xi Chen and Y. Cheng and Bo Tang},
  journal={ArXiv},
  year={2017},
  volume={abs/1511.00785}
}
We study the randomized query complexity of approximate Nash equilibria (ANE) in large games. We prove that, for some constant $\epsilon>0$, any randomized oracle algorithm that computes an $\epsilon$-ANE in a binary-action, $n$-player game must make $2^{\Omega(n/\log n)}$ payoff queries. For the stronger solution concept of well-supported Nash equilibria (WSNE), Babichenko previously gave an exponential $2^{\Omega(n)}$ lower bound for the randomized query complexity of $\epsilon$-WSNE, for… 
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