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 "NC-Algorithms for Graphs with Small Treewidth"):
  Abstract: In this paper we give a parallel algorithm for recognizing graphs with treewidth ≤ k, for constant k, and building the corresponding tree-decomposition, that uses O(log n) time and O(n3k+4) processors on a CRCW PRAM. Also, we give a parallel algorithm that transforms a given tree-decomposition of a graph G with treewidth k to another tree-decomposition of G with treewidth ≤ 3k+2, such that the tree in this tree-decomposition is binary and has logarithmic depth. The algorithm uses a linear number of processors and O(log n) time. Many NP-complete graph problems are known to be solvable in polynomial time, when restricted to graphs with treewidth ≤ k, k constant. From the results in this paper, it follows that most of these problems are also in NC, when restricted to graphs with treewidth bounded by a constant.

Includes members:
  Member "Polynomial algorithms for graph isomorphism and chromatic index on partial k -trees":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "The Computational Structure of Monotone Monadic SNP and Constraint Satisfaction: A Study through Datalog and Group Theory")

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: Computer science