Last-iterate convergence: Zero-sum games and constrained min-max optimization

© Constantinos Daskalakis and Ioannis Panageas. Motivated by applications in Game Theory, Optimization, and Generative Adversarial Networks, recent work of Daskalakis et al [Daskalakis et al., ICLR, 2018] and follow-up work of Liang and Stokes [Liang and Stokes, 2018] have established that a variant...

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Main Authors: Daskalakis, C, Panageas, I
Other Authors: Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory
Format: Article
Language:English
Published: 2022
Online Access:https://hdl.handle.net/1721.1/143460
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author Daskalakis, C
Panageas, I
author2 Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory
author_facet Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory
Daskalakis, C
Panageas, I
author_sort Daskalakis, C
collection MIT
description © Constantinos Daskalakis and Ioannis Panageas. Motivated by applications in Game Theory, Optimization, and Generative Adversarial Networks, recent work of Daskalakis et al [Daskalakis et al., ICLR, 2018] and follow-up work of Liang and Stokes [Liang and Stokes, 2018] have established that a variant of the widely used Gradient Descent/Ascent procedure, called “Optimistic Gradient Descent/Ascent (OGDA)”, exhibits last-iterate convergence to saddle points in unconstrained convex-concave min-max optimization problems. We show that the same holds true in the more general problem of constrained min-max optimization under a variant of the no-regret Multiplicative-Weights-Update method called “Optimistic Multiplicative-Weights Update (OMWU)”. This answers an open question of Syrgkanis et al [Syrgkanis et al., NIPS, 2015]. The proof of our result requires fundamentally different techniques from those that exist in no-regret learning literature and the aforementioned papers. We show that OMWU monotonically improves the Kullback-Leibler divergence of the current iterate to the (appropriately normalized) min-max solution until it enters a neighborhood of the solution. Inside that neighborhood we show that OMWU becomes a contracting map converging to the exact solution. We believe that our techniques will be useful in the analysis of the last iterate of other learning algorithms.
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spelling mit-1721.1/1434602023-02-13T21:35:00Z Last-iterate convergence: Zero-sum games and constrained min-max optimization Daskalakis, C Panageas, I Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory © Constantinos Daskalakis and Ioannis Panageas. Motivated by applications in Game Theory, Optimization, and Generative Adversarial Networks, recent work of Daskalakis et al [Daskalakis et al., ICLR, 2018] and follow-up work of Liang and Stokes [Liang and Stokes, 2018] have established that a variant of the widely used Gradient Descent/Ascent procedure, called “Optimistic Gradient Descent/Ascent (OGDA)”, exhibits last-iterate convergence to saddle points in unconstrained convex-concave min-max optimization problems. We show that the same holds true in the more general problem of constrained min-max optimization under a variant of the no-regret Multiplicative-Weights-Update method called “Optimistic Multiplicative-Weights Update (OMWU)”. This answers an open question of Syrgkanis et al [Syrgkanis et al., NIPS, 2015]. The proof of our result requires fundamentally different techniques from those that exist in no-regret learning literature and the aforementioned papers. We show that OMWU monotonically improves the Kullback-Leibler divergence of the current iterate to the (appropriately normalized) min-max solution until it enters a neighborhood of the solution. Inside that neighborhood we show that OMWU becomes a contracting map converging to the exact solution. We believe that our techniques will be useful in the analysis of the last iterate of other learning algorithms. 2022-06-17T14:24:41Z 2022-06-17T14:24:41Z 2019-01-01 2022-06-17T14:20:15Z Article http://purl.org/eprint/type/ConferencePaper https://hdl.handle.net/1721.1/143460 Daskalakis, C and Panageas, I. 2019. "Last-iterate convergence: Zero-sum games and constrained min-max optimization." Leibniz International Proceedings in Informatics, LIPIcs, 124. en 10.4230/LIPIcs.ITCS.2019.27 Leibniz International Proceedings in Informatics, LIPIcs Creative Commons Attribution 3.0 unported license https://creativecommons.org/licenses/by/3.0/ application/pdf DROPS
spellingShingle Daskalakis, C
Panageas, I
Last-iterate convergence: Zero-sum games and constrained min-max optimization
title Last-iterate convergence: Zero-sum games and constrained min-max optimization
title_full Last-iterate convergence: Zero-sum games and constrained min-max optimization
title_fullStr Last-iterate convergence: Zero-sum games and constrained min-max optimization
title_full_unstemmed Last-iterate convergence: Zero-sum games and constrained min-max optimization
title_short Last-iterate convergence: Zero-sum games and constrained min-max optimization
title_sort last iterate convergence zero sum games and constrained min max optimization
url https://hdl.handle.net/1721.1/143460
work_keys_str_mv AT daskalakisc lastiterateconvergencezerosumgamesandconstrainedminmaxoptimization
AT panageasi lastiterateconvergencezerosumgamesandconstrainedminmaxoptimization