The extreme rays of the 5×5 copositive cone

We give an explicit characterization of all extreme rays of the cone of 5×5 copositive matrices. The results are based on the work of Baumert [L. D. Baumert, “Extreme copositive quadratic forms”, PhD thesis, 1965], where an implicit characterization was given. We show that the class of extreme rays found by Baumert forms a 10-dimensional … Read more