4 problems

Let $P$ and $Q$ be lattice polytopes in $\mathbb R^n$. For lattice polytopes, write … A lattice polytope is smooth if it is simple and the primitive facet normal vectors around eve…

Postnikov–Stanley polynomials are a class of polynomials associated with permutations. A polynomial is M-convex when the set of exponent vectors of its monomials satisfies the disc…

Let ${\mit\Gamma}$ be a modular graph. For an orbit $Q$ of ${\mit\Gamma}$, let ${\mit\Gamma}/Q$ be the corresponding quotient graph, and let $\tau({\mit\Gamma},h;V,c)$ denote the o…

Let ${\mit\Gamma}$ be an undirected graph, and let ${\bf 0\text{-}Ext}[{\mit\Gamma}]$ denote the corresponding minimum $0$-extension problem. An orientable modular graph is an orie…