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 "Coloring intersection graphs of x-monotone curves in the plane"):
  Abstract: A class of graphs G is ?-bounded if the chromatic number of the graphs in G is bounded by some function of their clique number. We show that the class of intersection graphs of simple families of x-monotone curves in the plane intersecting a vertical line is ?-bounded. As a corollary, we show that the class of intersection graphs of rays in the plane is ?-bounded, and the class of intersection graphs of unit segments in the plane is ?-bounded.

Includes members:
  Member "Triangle-free intersection graphs of line segments with large chromatic number":
    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