Preprints

• Rui Zheng, Ryann Sim and Antonios Varvitsiotis
  Solving Imperfect-Recall Games via Sum-of-Squares Optimization.
  Submitted to ICLR 2026.
  

Journal Publications

• Wayne Lin, Georgios Piliouras, Ryann Sim, and Antonios Varvitsiotis.
  Learning in Quantum Common‑Interest Games and the Separability Problem.
  Quantum 9 (2025): 1689.
  Arxiv

• Wayne Lin, Georgios Piliouras, Ryann Sim, and Antonios Varvitsiotis.
  No‑Regret Learning and Equilibrium Computation in Quantum Games.
  Quantum 8 (2024): 1569.
  Arxiv

Conference Publications

• Vincent Leon, Iosif Sakos, Ryann Sim, and Antonios Varvitsiotis.
  Certifying Concavity and Monotonicity in Games via Sum‑of‑Squares Hierarchies.
  Advances in Neural Information Processing Systems, 38, 2025.
  Arxiv

• John Lazarsfeld, Georgios Piliouras, Ryann Sim, and Stratis Skoulakis.
  Optimism Without Regularization: Constant Regret in Zero‑Sum Games.
  Advances in Neural Information Processing Systems, 38, 2025.
  Arxiv

• John Lazarsfeld, Georgios Piliouras, Ryann Sim, and Andre Wibisono.
  Fast and Furious Symmetric Learning in Zero‑Sum Games: Gradient Descent as Fictitious Play.
  Conference on Learning Theory, 2025.
  Arxiv

• Volkan Cevher, Georgios Piliouras, Ryann Sim, and Stratis Skoulakis.
  Min‑Max Optimization Made Simple: Approximating the Proximal Point Method via Contraction Maps.
  SIAM Symposium on Simplicity in Algorithms, 2023.
  Arxiv

• Rahul Jain, Georgios Piliouras, and Ryann Sim.
  Matrix Multiplicative Weights Updates in Quantum Zero‑Sum Games: Conservation Laws & Recurrence.
  Advances in Neural Information Processing Systems, 35, 2022.
  Arxiv

• Georgios Piliouras, Ryann Sim, and Stratis Skoulakis.
  Beyond Time‑Average Convergence: Near‑Optimal Uncoupled Online Learning via Clairvoyant Multiplicative Weights Update.
  Advances in Neural Information Processing Systems, 35, 2022.
  Arxiv

• Ryann Sim, Stratis Skoulakis, Lillian J Ratliff, and Georgios Piliouras.
  Fast Convergence of Optimistic Gradient Ascent in Network Zero‑Sum Extensive Form Games
  International Symposium on Algorithmic Game Theory. Springer, 2022.
  Arxiv

• Tanner Fiez, Ryann Sim, Stratis Skoulakis, Georgios Piliouras, and Lillian Ratliff.
  Online Learning in Periodic Zero‑Sum Games.
  Advances in Neural Information Processing Systems, 34, 2021.
  Arxiv

• Stratis Skoulakis, Tanner Fiez, Ryann Sim, Georgios Piliouras, and Lillian Ratliff.
  Evolutionary Game Theory Squared: Evolving Agents in Endogenously Evolving Zero‑Sum Games.
  AAAI Conference on Artificial Intelligence, 2021.
  Arxiv