collaborators

7 papers

cs.GT2026

Equilibrium Computation in Extensive-Form Games with Stochastic Action Sets

Thomas Schwarz, Ryann Sim, Chun Kai Ling

Extensive-form games (EFGs) are a standard model for sequential decision-making in games. A fundamental and typically implicit assumption in EFGs is that players always have access…

cs.GT2026

Solving Imperfect-Recall Games via Sum-of-Squares Optimization

Rui Zheng, Ryann Sim, Antonios Varvitsiotis

Extensive-form games (EFGs) provide a powerful framework for modeling sequential decision making, capturing strategic interaction under imperfect information, chance events, and te…

cs.GT2026

Computing Equilibria in Games with Stochastic Action Sets

Thomas Schwarz, Jiaru Li, Ryann Sim +1

The study of learning in games typically assumes that each player always has access to all of their actions. However, in many practical scenarios, players' available actions might…

cs.LG2026

Optimism Without Regularization: Constant Regret in Zero-Sum Games

John Lazarsfeld, Georgios Piliouras, Ryann Sim +1

This paper studies the optimistic variant of Fictitious Play for learning in two-player zero-sum games. While it is known that Optimistic FTRL -- a regularized algorithm with a bou…

cs.GT2025

Certifying Concavity and Monotonicity in Games via Sum-of-Squares Hierarchies

Vincent Leon, Iosif Sakos, Ryann Sim +1

Concavity and its refinements underpin tractability in multiplayer games, where players independently choose actions to maximize their own payoffs which depend on other players' ac…

cs.LG2025

Fast and Furious Symmetric Learning in Zero-Sum Games: Gradient Descent as Fictitious Play

John Lazarsfeld, Georgios Piliouras, Ryann Sim +1

This paper investigates the sublinear regret guarantees of two non-no-regret algorithms in zero-sum games: Fictitious Play, and Online Gradient Descent with constant stepsizes. In…