Multi-Objective Discounted Continuous-Time Markov Decision Processes
摘要
This paper studies multi-objective infinite-horizon discounted continuous-time Markov decision processes (CTMDPs) with distinct discount rates across the objectives. We start the analysis through the weighted sum method. A counterexample demonstrates the absence of Pareto-optimal stationary policies, contrasting with the classic discounted CTMDP results. Inspired by the idea for finite-horizon scenarios, we derive the Hamilton-Jacobi-Bellman equation with time as the differential variable for the infinite-horizon weighted sum optimization. To solve the new equation, we introduce a novel dynamic programming operator along with a carefully constructed initial function. Our value iteration method establishes the existence of weighted-optimal Markov deterministic policies, thereby ensuring the existence of Pareto-optimal policies. Moreover, we prove weak Pareto sufficiency of weighted-optimal policies by the occupation measure technique. Finally, we characterize the structure of