Sample Complexity Characterization for Linear Contextual MDPs

التفاصيل البيبلوغرافية
العنوان: Sample Complexity Characterization for Linear Contextual MDPs
المؤلفون: Deng, Junze, Cheng, Yuan, Zou, Shaofeng, Liang, Yingbin
سنة النشر: 2024
المجموعة: Computer Science
Statistics
مصطلحات موضوعية: Computer Science - Machine Learning, Statistics - Machine Learning
الوصف: Contextual Markov decision processes (CMDPs) describe a class of reinforcement learning problems in which the transition kernels and reward functions can change over time with different MDPs indexed by a context variable. While CMDPs serve as an important framework to model many real-world applications with time-varying environments, they are largely unexplored from theoretical perspective. In this paper, we study CMDPs under two linear function approximation models: Model I with context-varying representations and common linear weights for all contexts; and Model II with common representations for all contexts and context-varying linear weights. For both models, we propose novel model-based algorithms and show that they enjoy guaranteed $\epsilon$-suboptimality gap with desired polynomial sample complexity. In particular, instantiating our result for the first model to the tabular CMDP improves the existing result by removing the reachability assumption. Our result for the second model is the first-known result for such a type of function approximation models. Comparison between our results for the two models further indicates that having context-varying features leads to much better sample efficiency than having common representations for all contexts under linear CMDPs.
Comment: accepted to AIstats2024
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2402.02700
رقم الأكسشن: edsarx.2402.02700
قاعدة البيانات: arXiv