Hyperbolicity cones of elementary symmetric polynomials are spectrahedral
arXiv:1204.2997
Abstract
We prove that the hyperbolicity cones of elementary symmetric polynomials are spectrahedral, i.e., they are slices of the cone of positive semidefinite matrices. The proof uses the matrix--tree theorem, an idea already present in Choe et al.
9 pages. Some typos corrected. Details added. To appear in Optimization Letters