human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge groups authors who co-authored the same paper.

Details of the hypergraph:
Center hyperedge (induced by source paper "Transformations affines agissant sur un simplexe"):
  Abstract: Dans ce travail nous montrons l'equivalence entre le polytope de transport symetrique T(@l) (un objet ''physique''), le polytope de Revesz P(@l) (un object ''algebrique'') et le polytope A(x"0) des transformations affines agissant sur un simplexe en laissant x"0 fixe (un objet ''geometrique'') et nous utilisons ce fait pour determiner certaines proprietes des elements extremaux de A(x"0). Une description du contenu de cet article est donnee a la Section 2.

Includes members:
  Member "Polytopes de transport symetriques":
    also connected through other hyperedges:
      (none)

Question: Please tell me which research area the co-authored paper (i.e., the source paper of the center hyperedge) belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Mathematics