The positive semi-definite cone and sum-of-squares cone of Hankel form
arXiv:1505.03201
Abstract
In this paper, the geometry properties of Hankel form are studied, including their positive semi-definite (PSD) cone and sum-of-squares (SOS) cone. We denote them by and , respectively. We show that both and are closed convex cones. The dual cone of is the convex hull of all -times convolutions of real vectors. Besides, we derive the dual cone of SOS tensors. By reformulation, it follows that the dual cone of can also be written explicitly. These results may lead further research on the Hilbert-Hankel problem.