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: "On minimum spanning tree-like metric spaces☆"
  Abstract: Abstract   We attempt to shed new light on the notion of ‘tree-like’ metric spaces by focusing on an approach that does not use the four-point condition. Our key question is: Given metric space    M    on    n    points, when does a fully labelled positive-weighted tree    T    exist on the same    n    vertices that precisely realises    M    using its shortest path metric? We prove that if a spanning tree representation,    T   , of    M    exists, then it is isomorphic to the unique minimum spanning tree in the weighted complete graph associated with    M   , and we introduce a  fourth-point condition  that is necessary and sufficient to ensure the existence of    T    whenever each distance in    M    is unique. In other words, a finite median graph, in which each geodesic distance is distinct, is simply a tree. Provided that the tie-breaking assumption holds, the fourth-point condition serves as a criterion for measuring the goodness-of-fit of the minimum spanning tree to    M   , i.e., the spanning tree-likeness of    M   . It is also possible to evaluate the spanning path-likeness of    M   . These quantities can be measured in    O   (    n    4    )     and    O   (    n    3    )     time, respectively.

Connected through hyperedge HE-1 (induced by source paper "A Characterization of Minimum Spanning Tree-Like Metric Spaces"):
  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