6.S890 | Fall 2024 | Graduate

Topics in Multiagent Learning

Calendar

Part I: Normal-Form Games

Session 1: Introduction

Topics: Introduction to the course and logistics.

Session 2: Setting and Equilibria: The Nash Equilibrium

Topics: Definition of normal-form games. Solution concepts and Nash equilibrium. Nash equilibrium existence theorem.

Session 3: Setting and Equilibria: The Correlated Equilibrium

Topics: Topological and computational properties of the set of Nash equilibria in normal-form games. Connections with linear programming. Definition of correlated and coarse correlated equilibria; relationships with Nash equilibria.

Session 4: Learning in Games: Foundations

Key Date: Problem set 1 out.

Topics: Regret and hindsight rationality. Definition of regret minimization and relationships with equilibrium concepts.

Session 5: Learning in Games: Algorithms (part I)

Topics: General principles in the design of learning algorithms. Follow-the-leader, regret matching, multiplicative weights update, online mirror descent.

Session 6: Learning in Games: Algorithms (part II)

Topics: Optimistic mirror descent and optimistic follow-the-regularized-leader. Accelerated computation of approximate equilibria.

Session 7: Learning in Games: Bandit Feedback

Topics: From multiplicative weights to Exp3. General principles. Obtaining high-probability bounds.

Session 8: Learning in Games: Φ-Regret Minimization

Topics: Gordon, Greenwald, and Marks (2008); Blum and Mansour; Stolz-Lugosi.

Part II: Extensive-Form Games

Session 9: Foundations of Extensive-Form Games

Topics: Complete versus imperfect information. Kuhn’s theorem. Normal-form and sequence-form strategies. Similarities and differences with normal-form games.

Session 10: Learning in Extensive-Form Games

Key Date: Problem set 2 out.

Topics: No-regret algorithms for extensive-form games. Counterfactual utilities and counterfactual regret minimization (CFR).

Session 11: Equilibrium Refinements

Topics: Sequential irrationality. Extensive-form perfect equilibria and quasi-perfect equilibrium.

Session 12: No class (student holiday)

Session 13: Project ideas and brainstorming

Session 14: Project break

Coincides with INFORMS 2024 Annual Meeting.

Session 15: Project break

Coincides with INFORMS 2024 Annual Meeting.

Session 16: Deep Reinforcement Learning for Large-Scale Games (part I)

Topics: Rough taxonomy of deep RL methods for games. Decision-time planning in imperfect-information games, construction of superhuman agents for no-limit hold’em poker. Public belief states techniques (ReBeL).

Session 17: Deep Reinforcement Learning for Large-Scale Games (part II)

Topics: PPO and magnetic mirror descent.

Part III: Other Structured Games

Session 18: Combinatorial Games and Kernelized MWU (Part I)

Topics: Example of combinatorial games. Kernelized multiplicative weights update algorithm.

Session 19: Combinatorial Games and Kernelized MWU (Part II)

Topics: Example of combinatorial games. Kernelized multiplicative weights update algorithm.

Session 20: Computation of Exact Equilibria

Key Date: Problem set 3 out.

Topics: A second look at the minimax theorem. Hart and Schmeidler’s proof of existence of correlated equilibria. Ellipsoid against hope algorithm.

Session 21: Stochastic Games

Topics: Minimax theorem, and existence of equilibrium. Stationary Markov Nash equilibria. Coarse correlated and correlated equilibria in stochastic games.

Part IV: Complexity of Equilibrium Computation

Session 22: PPAD-Completeness of Nash Equilibria (part I)

Topics: Sperner’s lemma. The PPAD complexity class. Nash ∈ PPAD.

Session 23: PPAD-Completeness of Nash Equilibria (part II)

Topics: Arithmetic circuit SAT. PPAD-hardness of Nash equilibria. Project break and presentations.

Session 24: Project break

Session 25: No class (Thanksgiving)

Session 26: Project presentations

Session 27: Project presentations

Course Info

As Taught In
Fall 2024
Level
Learning Resource Types
Lecture Notes
Problem Set Solutions
Problem Sets
Projects
Readings