🤖 AI Summary
For multi-agent Dec-POMDPs under hierarchical information-sharing structures, existing Bellman-based solution methods suffer from doubly exponential computational complexity due to strong inter-agent decision coupling. This paper introduces a novel “sequential single-agent subgame decomposition” paradigm: it models each stage as a tractable extensive-form game, achieving full decoupling of agents’ decision variables while preserving global optimality—first such result in the literature. The method integrates hierarchical dynamic programming with sequential game-theoretic modeling, reducing time complexity from doubly exponential to polynomial, thereby enabling scalability to large-scale multi-agent settings. Its core contribution is breaking the long-standing optimal-complexity barrier for Dec-POMDPs under hierarchical information structures, simultaneously guaranteeing theoretical optimality and practical scalability.
📝 Abstract
A recent theory shows that a multi-player decentralized partially observable Markov decision process can be transformed into an equivalent single-player game, enabling the application of citeauthor{bellman}'s principle of optimality to solve the single-player game by breaking it down into single-stage subgames. However, this approach entangles the decision variables of all players at each single-stage subgame, resulting in backups with a double-exponential complexity. This paper demonstrates how to disentangle these decision variables while maintaining optimality under hierarchical information sharing, a prominent management style in our society. To achieve this, we apply the principle of optimality to solve any single-stage subgame by breaking it down further into smaller subgames, enabling us to make single-player decisions at a time. Our approach reveals that extensive-form games always exist with solutions to a single-stage subgame, significantly reducing time complexity. Our experimental results show that the algorithms leveraging these findings can scale up to much larger multi-player games without compromising optimality.