Local h^*-polynomials of some weighted projective spaces

Abstract

There is currently a growing interest in understanding which lattice simplices have unimodal local h * -polynomials (sometimes called box polynomials); specifically in light of their potential applications to unimodality questions for Ehrhart h * -polynomials. In this note, we compute a general form for the local h * -polynomial of a well-studied family of lattice simplices whose associated toric varieties are weighted projective spaces. We then apply this formula to prove that certain such lattice simplices, whose combinatorics are naturally encoded using common systems of numeration, all have real-rooted, and thus unimodal, local h * -polynomials. As a consequence, we discover a new restricted Eulerian polynomial that is real-rooted, symmetric, and admits intriguing number theoretic properties.

Thin polytopes: Lattice polytopes with vanishing local $h^*$-polynomial

“…This polynomial l * P (t) of a lattice simplex P has sometimes also been called box polynomial, cf. [Sol19]. For instance, we have h * P (t) = 1 if and only if P is a unimodular simplex; in this case, l * P (t) = 0.…”