11 papers
Sharp Bounds on the Independence Number of Simplicial Spheres
Jesús A. De Loera, Ethan X. Fang, Junwei Lu +2
We study the maximum size of an independent set in the graph of a simplicial sphere. Let denote this maximum over all simplicial -spheres on vertices, and let $…
Ehrhart Theory over Abelian Group Rings
Robert Davis, Jesús A. De Loera, Alexey Garber +3
We introduce a unified framework for Ehrhart theory in which lattice point enumerators take coefficients in an Abelian group ring, encoding substantially richer algebraic data than…
From Ham-Sandwich to Centerpoints: Semialgebraic Algorithms for Cutting Polytopal Measures
Marie-Charlotte Brandenburg, Jesús A. De Loera, Chiara Meroni
We design exact algorithms for the ham-sandwich and centerpoint theorems for polytopal measures. Our key observation is that the cap-volume function of such a measure, i.e., the vo…
Critical moments of slices and slabs of the cube (and other polyhedral norms)
Marie-Charlotte Brandenburg, Jesús A. De Loera, Yu Luo +1
In this article, we present a unified algebraic-combinatorial framework for computing explicit, piecewise rational, and combinatorially indexed parametric formulas for volumes and…
Persistent Subdivisions of Coxeter Permutahedra
Timothy Blanton, Jesús A. De Loera, Melissa Sherman-Bennett
We investigate the realizations of Coxeter permutahedra which are also Coxeter matroid polytopes; these are polytopes of the form where is a…
There are matroid toric ideals without quadratic Gröbner bases
Jesús A. De Loera, Luis Ferroni, Santiago Morales +1
Our paper shows that if a matroid contains the Fano plane or its dual as a minor, then its toric ideal does not have any quadratic Gröbner basis. More than 25 years ago, Hibi, Her…