Timezone: »

 
Poster
Tight last-iterate convergence rates for no-regret learning in multi-player games
Noah Golowich · Sarath Pattathil · Constantinos Daskalakis

Thu Dec 10 09:00 PM -- 11:00 PM (PST) @ Poster Session 6 #1858

We study the question of obtaining last-iterate convergence rates for no-regret learning algorithms in multi-player games. We show that the optimistic gradient (OG) algorithm with a constant step-size, which is no-regret, achieves a last-iterate rate of O(1/√T) with respect to the gap function in smooth monotone games. This result addresses a question of Mertikopoulos & Zhou (2018), who asked whether extra-gradient approaches (such as OG) can be applied to achieve improved guarantees in the multi-agent learning setting. The proof of our upper bound uses a new technique centered around an adaptive choice of potential function at each iteration. We also show that the O(1/√T) rate is tight for all p-SCLI algorithms, which includes OG as a special case. As a byproduct of our lower bound analysis we additionally present a proof of a conjecture of Arjevani et al. (2015) which is more direct than previous approaches.

Author Information

Noah Golowich (Massachusetts Institute of Technology)
Sarath Pattathil (Massachusetts Institute of Technology)
Constantinos Daskalakis (MIT)

More from the Same Authors