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: "Clique decompositions of multipartite graphs and completion of latin squares"
  Abstract: Abstract   Our main result essentially reduces the problem of finding an edge-decomposition of a balanced  r -partite graph of large minimum degree into  r -cliques to the problem of finding a fractional  r -clique decomposition or an approximate one. Together with very recent results of Bowditch and Dukes as well as Montgomery on fractional decompositions into triangles and cliques respectively, this gives the best known bounds on the minimum degree which ensures an edge-decomposition of an  r -partite graph into  r -cliques (subject to trivially necessary divisibility conditions). The case of triangles translates into the setting of partially completed Latin squares and more generally the case of  r -cliques translates into the setting of partially completed mutually orthogonal Latin squares.

Connected through hyperedge HE-1 (induced by source paper "Edge-decompositions of graphs with high minimum degree"):
  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