2 problems

A convex semialgebraic set is a convex subset of Euclidean space describable by polynomial equalities and inequalities. A spectrahedral shadow is a linear image of a spectrahedron.…

Let $M$ be a matrix represented as a slack matrix $M=S_{P,Q}$ of nested polytopes $P\subseteq Q\subseteq\mathbb R^{r-1}$. A spectrahedral shadow $C$ of size $k$ between $P$ and $Q$…