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 "Geodesic Spanners on Polyhedral Surfaces"):
  Abstract: In this paper we consider the problem of efficiently constructing geodesic t-spanners. We consider finding sparse spanners on the surface of a 3 dimensional polyhedron allowing for steiner vertices. If Steiner vertices are not allowed, then we establish lower bounds on the maximum node degree, depending on the spanning ratio t and also the total number of vertices of the polyhedron surface. We also consider the case of the surface of a convex polytope $\mathcal P $ with V vertices. Using its vertex set P and Steiner points, we can construct a t-spanner with a constant degree and weight O(MST(U)), where MST(U) is the minimum spanning tree on the set U of vertices on convex polytope.

Includes members:
  Member "On the hardness of approximating spanners":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "A fast parametric maximum flow algorithm and applications")

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