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Given a tree $T$, its path polytope is the convex hull of the edge indicator vectors for the paths between any two distinct leaves in $T$. These polytopes arise naturally in polyhedral geometry and applications, such as phylogenetics,…

Combinatorics · Mathematics 2025-03-03 Amer Goel , Aida Maraj , Alvaro Ribot

We introduce tropical analogues of the notion of volume of polytopes, leading to a tropical version of the (discrete) classical isoperimetric inequality. The planar case is elementary, but a higher-dimensional generalization leads to an…

Combinatorics · Mathematics 2019-12-30 Jules Depersin , Stéphane Gaubert , Michael Joswig

We consider, for complete bipartite graphs, the convex hulls of characteristic vectors of all matchings, extended by a binary entry indicating whether the matching contains two specific edges. These polytopes are associated to the quadratic…

Discrete Mathematics · Computer Science 2019-04-09 Matthias Walter

A (convex) polytope $P$ is said to be $2$-level if for every direction of hyperplanes which is facet-defining for $P$, the vertices of $P$ can be covered with two hyperplanes of that direction. The study of these polytopes is motivated by…

In this paper we study general tropical linear spaces locally: For any basis B of the matroid underlying a tropical linear space L, we define the local tropical linear space L_B to be the subcomplex of L consisting of all vectors v that…

Combinatorics · Mathematics 2013-10-14 Felipe Rincón

We establish a characterization of the vertices of a tropical polyhedron defined as the intersection of finitely many half-spaces. We show that a point is a vertex if, and only if, a directed hypergraph, constructed from the…

Combinatorics · Mathematics 2013-02-13 Xavier Allamigeon , Stephane Gaubert , Eric Goubault

An equidistant polytope is a special equidistant set in the space $\mathbb{R}^n$ all of whose boundary points have equal distances from two finite systems of points. Since one of the finite systems of the given points is required to be in…

Metric Geometry · Mathematics 2021-12-16 Csaba Vincze , Márk Oláh , Letícia Lengyel

We consider the bipartite boolean quadric polytope (BQP) with multiple-choice constraints and analyse its combinatorial properties. The well-studied BQP is defined as the convex hull of all quadric incidence vectors over a bipartite graph.…

Optimization and Control · Mathematics 2020-09-25 Andreas Bärmann , Alexander Martin , Oskar Schneider

A cubical polytope is a polytope with all its facets being combinatorially equivalent to cubes. The paper is concerned with the linkedness of the graphs of cubical polytopes. A graph with at least $2k$ vertices is \textit{$k$-linked} if,…

Combinatorics · Mathematics 2023-10-13 Hoa T. Bui , Guillermo Pineda-Villavicencio , Julien Ugon

We describe an algorithm for computing the convex hull of a finite collection of points in the affine building of SL_d(K), for K a field with discrete valuation. These convex hulls describe the relations among a finite collection of…

Combinatorics · Mathematics 2018-11-22 Leon Zhang

A polycube is an orthogonal polyhedron composed of unit cubes glued together along entire faces, and homeomorphic to a sphere. A layer of a polycube refers to the portion lying between two horizontal cross-sections spaced one unit apart. We…

Computational Geometry · Computer Science 2025-07-15 Mirela Damian , Henk Meijer

We study the subgroup structure of the semigroup of finitary tropical matrices under multiplication. We show that every maximal subgroup is isomorphic to the full linear automorphism group of a related tropical polytope, and that each of…

Group Theory · Mathematics 2012-03-13 Zur Izhakian , Marianne Johnson , Mark Kambites

We characterize the polytopes in $\mathbb{R}^d$ (not necessarily convex or connected ones) which multi-tile the space by translations along a given lattice. We also give a necessary and sufficient condition for two polytopes in…

Combinatorics · Mathematics 2019-10-30 Nir Lev , Bochen Liu

We present a framework for modeling complex, high-dimensional distributions on convex polytopes by leveraging recent advances in discrete and continuous normalizing flows on Riemannian manifolds. We show that any full-dimensional polytope…

Machine Learning · Computer Science 2025-03-18 Tomek Diederen , Nicola Zamboni

Abstract polytopes are a combinatorial generalization of convex and skeletal polytopes. Counting how many flag orbits a polytope has under its automorphism group is a way of measuring how symmetric it is. Polytopes with one flag orbit are…

Combinatorics · Mathematics 2024-02-20 Elías Mochán

2-level polytopes naturally appear in several areas of pure and applied mathematics, including combinatorial optimization, polyhedral combinatorics, communication complexity, and statistics. In this paper, we present a study of some 2-level…

Combinatorics · Mathematics 2017-12-15 Manuel Aprile , Alfonso Cevallos , Yuri Faenza

An $S$-hypersimplex for $S \subseteq \{0,1, \dots,d\}$ is the convex hull of all $0/1$-vectors of length $d$ with coordinate sum in $S$. These polytopes generalize the classical hypersimplices as well as cubes, crosspolytopes, and…

Combinatorics · Mathematics 2019-12-02 Sebastian Manecke , Raman Sanyal , Jeonghoon So

This work provides two sufficient conditions in terms of sections or projections for a convex body to be a polytope. These conditions are necessary as well.

Metric Geometry · Mathematics 2021-10-05 Sergii Myroshnychenko

A permutation polytope is the convex hull of a group of permutation matrices. In this paper we investigate the combinatorics of permutation polytopes and their faces. As applications we completely classify permutation polytopes in…

Combinatorics · Mathematics 2010-02-14 Barbara Baumeister , Christian Haase , Benjamin Nill , Andreas Paffenholz

We define a family of convex polytopes called constrainahedra, which index collisions of horizontal and vertical lines. Our construction proceeds by first defining a poset $C(m,n)$ of good rectangular preorders, then proving that $C(m,n)$…

Combinatorics · Mathematics 2022-09-01 Nathaniel Bottman , Daria Poliakova