Linear Quadratic Mean Field Teams: Optimal and Approximately Optimal Decentralized Solutions

Understand

We consider team optimal control of decentralized systems with linear dynamics, quadratic costs, and arbitrary disturbance that consist of multiple sub-populations with exchangeable agents (i.e., exchanging two agents within the same sub-population does not affect the dynamics or the cost).

• Such a system is equivalent to one where the dynamics and costs are coupled across agents through the mean-field (or empirical mean) of the states and actions (even when the primitive random variables are non-exchangeable).
• Two information structures are investigated.
• In the first, all agents observe their local state and the mean-field of all sub-populations, in the second, all agents observe their local state but the mean-field of only a subset of the sub-populations.