Understanding agent heterogeneity can inform the design of shared and agent-specific policy representations, however existing criteria provide no unified structural test. We study finite-horizon POSGs and define a type-compatible transformation as a policy-evaluation symmetry when complete policy evaluation commutes with it for every decentralized behavioral policy. Policy-evaluation symmetries form a group for which agent orbits define structural agent types. This classification does not depend on the particular policy chosen or the distribution of initial states. We prove that every componentwise environment automorphism is a policy-evaluation symmetry, but that the converse does not hold. Applying the framework to cooperative Dec-POMDPs shows that agents can belong to different structural types even when they share a common reward. For prescribed weighted reward aggregation, we derive an exact value identity and sufficient conditions for the resulting Dec-POMDP to inherit the policy-evaluation symmetries of the source POSG. Finally, we give sufficient conditions under which repeated model factorizations induce policy-evaluation symmetry, and show that preserving an optimal Boltzmann policy set neither implies nor follows from this symmetry in general.
Heterogeneity in Multi-Agent Reinforcement Learning
Institute of Automation, Chinese Academy of Sciences（中国科学院自动化研究所）；National Key Laboratory of Cognition and Decision Intelligence for Complex Systems（复杂系统认知与决策智能国家重点实验室）；School of Artificial Intelligence, University of Chinese Academy of Sciences（中国科学院大学人工智能学院）
Regret Minimization in Population Network Games: Vanishing Heterogeneity and Convergence to Equilibria
School of Mechanical Engineering, Northwestern Polytechnical University（西北工业大学机械工程学院）；Department of Computing, Hong Kong Polytechnic University（香港理工大学计算机学院）；Shanghai Artificial Intelligence Laboratory（上海人工智能实验室）；School of Statistics and Mathematics, Yunnan University of Finance and Economics（云南财经大学统计与数学学院）；School of Artificial Intelligence, Optics and Electronics (iOPEN), Northwestern Polytechnical University（西北工业大学人工智能、光学与电子学院（iOPEN））；School of Cybersecurity, Northwestern Polytechnical University（西北工业大学网络安全学院）
Heterogeneity-Aware Belief Synchronization for Semantic Communication in AI-Native 6G Networks
School of Electrical Engineering and Computer Science (SEECS), National University of Sciences and Technology (NUST)（国家科学技术大学 电气工程与计算机科学学院）；Kyung Hee University（庆熙大学）；Munster Technological University（芒斯特理工大学）
