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: "Computing the Stability Number of a Graph Via Linear and Semidefinite Programming"
  Abstract: We study certain linear and semidefinite programming lifting approximation schemes for computing the stability number of a graph. Our work is based on and refines de Klerk and Pasechnik’s approach to approximating the stability number via copositive programming [SIAM J. Optim., 12 (2002), pp. 875-892]. We provide a closed-form expression for the values computed by the linear programming approximations. We also show that the exact value of the stability number $\alpha(G)$ is attained by the semidefinite approximation of order $\alpha(G)-1$ as long as $\alpha(G) \leq 6$. Our results reveal some sharp differences between the linear and the semidefinite approximations. For instance, the value of the linear programming approximation of any order is strictly larger than $\alpha(G)$ whenever $\alpha(G) > 1$.

Connected through hyperedge HE-1 (induced by source paper "Semidefinite bounds for the stability number of a graph via sums of squares of polynomials"):
  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