TY - GEN
T1 - Settling the complexity of Nash equilibrium in congestion games
AU - Babichenko, Yakov
AU - Rubinstein, Aviad
N1 - Publisher Copyright:
© 2021 ACM.
PY - 2021/6/15
Y1 - 2021/6/15
N2 - We consider (i) the problem of finding a (possibly mixed) Nash equilibrium in congestion games, and (ii) the problem of finding an (exponential precision) fixed point of the gradient descent dynamics of a smooth function f:[0,1]n ? R. We prove that these problems are equivalent. Our result holds for various explicit descriptions of f, ranging from (almost general) arithmetic circuits, to degree-5 polynomials. By a very recent result of [Fearnley et al., STOC 2021], this implies that these problems are PPAD PLS-complete. As a corollary, we also obtain the following equivalence of complexity classes: CCLS = PPAD PLS.
AB - We consider (i) the problem of finding a (possibly mixed) Nash equilibrium in congestion games, and (ii) the problem of finding an (exponential precision) fixed point of the gradient descent dynamics of a smooth function f:[0,1]n ? R. We prove that these problems are equivalent. Our result holds for various explicit descriptions of f, ranging from (almost general) arithmetic circuits, to degree-5 polynomials. By a very recent result of [Fearnley et al., STOC 2021], this implies that these problems are PPAD PLS-complete. As a corollary, we also obtain the following equivalence of complexity classes: CCLS = PPAD PLS.
KW - Equilibrium computation
KW - computational complexity
KW - congestion games
KW - gradient descent
KW - potential games
UR - http://www.scopus.com/inward/record.url?scp=85102664314&partnerID=8YFLogxK
U2 - 10.1145/3406325.3451039
DO - 10.1145/3406325.3451039
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AN - SCOPUS:85102664314
T3 - Proceedings of the Annual ACM Symposium on Theory of Computing
SP - 1426
EP - 1437
BT - STOC 2021 - Proceedings of the 53rd Annual ACM SIGACT Symposium on Theory of Computing
A2 - Khuller, Samir
A2 - Williams, Virginia Vassilevska
T2 - 53rd Annual ACM SIGACT Symposium on Theory of Computing, STOC 2021
Y2 - 21 June 2021 through 25 June 2021
ER -