human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Vector-space analysis of belief-state approximation for POMDPs"
  Abstract: We propose a new approach to value-directed belief state approximation for POMDPs. The value directed model allows one to choose approximation methods for belief state monitoring that have a small impact on decision quality. Using a vector space analysis of the problem, we devise two new search procedures for selecting an approximation scheme that have much better computational properties than existing methods, Though these provide looser error bounds, we show empirically that they have a similar impact on decision quality in practice, and run up to two orders of magnitude more quickly.

Connected through hyperedge HE-1 (induced by source paper "Reinforcement Learning with Factored States and Actions"):
  with members:
    - "Exploiting structure and utilizing agent-centric rewards to promote coordination in large multiagent systems"
    - "Reinforcement learning and function approximation"

Connected through hyperedge HE-2 (induced by source paper "Value-Directed Sampling Methods for POMDPs"):
  with members:
    (none)

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Mathematics