English
Related papers

Related papers: Laplacian polytopes of simplicial complexes

200 papers

There are many different algebraic, geometric and combinatorial objects that one can attach to a complex polynomial with distinct roots. In this article we introduce a new object that encodes many of the existing objects that have…

Geometric Topology · Mathematics 2021-04-16 Michael Dougherty , Jon McCammond

If we fix the angles at the vertices of a convex planar $n$-gon, the lengths of its edges must satisfy two linear constraints in order for it to close up. If we also require unit perimeter, our vectors of $n$ edge lengths form a convex…

Metric Geometry · Mathematics 2020-02-20 Lyle Ramshaw , James B. Saxe

Consider a random set of points on the unit sphere in $\mathbb{R}^d$, which can be either uniformly sampled or a Poisson point process. Its convex hull is a random inscribed polytope, whose boundary approximates the sphere. We focus on the…

Metric Geometry · Mathematics 2020-07-16 Arseniy Akopyan , Herbert Edelsbrunner , Anton Nikitenko

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

Bisztriczky defines a multiplex as a generalization of a simplex, and an ordinary polytope as a generalization of a cyclic polytope. This paper presents results concerning the combinatorics of multiplexes and ordinary polytopes. The flag…

Combinatorics · Mathematics 2007-05-23 Margaret M. Bayer , Aaron M. Bruening , Joshua Stewart

Stanley proved that for any centrally symmetric simplicial $d$-polytope $P$ with $d\geq 3$, $g_2(P) \geq {d \choose 2}-d$. We provide a characterization of centrally symmetric $d$-polytopes with $d\geq 4$ that satisfy this inequality as…

Combinatorics · Mathematics 2018-11-13 Steven Klee , Eran Nevo , Isabella Novik , Hailun Zheng

Self-polar polytopes are convex polytopes that are equal to an orthogonal transformation of their polar sets. These polytopes were first studied by Lov\'{a}sz as a means of establishing the chromatic number of distance graphs on spheres,…

Combinatorics · Mathematics 2019-02-05 Alathea Jensen

The aim of this paper is to prove isoperimetric inequalities for simplices and polytopes with $d+2$ vertices in Euclidean, spherical and hyperbolic $d$-space. In particular, we find the minimal volume $d$-dimensional hyperbolic simplices…

Metric Geometry · Mathematics 2022-06-22 Bushra Basit , Zsolt Langi

This is an introduction to graph theory, from a geometric and analytic viewpoint. A finite graph $X$ is described by its adjacency matrix $d\in M_N(0,1)$, which can be thought of as being a kind of discrete Laplacian, and we first discuss…

Quantum Algebra · Mathematics 2024-10-23 Teo Banica

The degree partition of a simple graph is its degree sequence rearranged in weakly decreasing order. The polytope of degree partitions (respectively, degree sequences) is the convex hull of all degree partitions (respectively, degree…

Combinatorics · Mathematics 2007-05-23 Amitava Bhattacharya , S. Sivasubramanian , Murali K. Srinivasan

A simplicial complex of dimension $d-1$ is said to be balanced if its graph is $d$-colorable. Juhnke-Kubitzke and Murai proved an analogue of the generalized lower bound theorem for balanced simplicial polytopes. We establish a…

Combinatorics · Mathematics 2016-08-30 Martina Juhnke-Kubitzke , Satoshi Murai , Isabella Novik , Connor Sawaske

In this note we prove that the number of combinatorial types of $d$-polytopes with $d+1+\alpha$ vertices and $d+1+\beta$ facets is bounded by a constant independent of $d$.

Combinatorics · Mathematics 2015-03-16 Arnau Padrol

Suppose we choose $N$ points uniformly randomly from a convex body in $d$ dimensions. How large must $N$ be, asymptotically with respect to $d$, so that the convex hull of the points is nearly as large as the convex body itself? It was…

Probability · Mathematics 2020-09-22 Alan Frieze , Wesley Pegden , Tomasz Tkocz

Polytope complexes are the generalisation of polygon meshes in geo-information systems (GIS) to arbitrary dimension, and a natural concept for accessing spatio-temporal information. Complexes of each dimension have a straight-forward…

Computational Geometry · Computer Science 2012-05-28 Norbert Paul

We show that the graph of a simplicial polytope of dimension $d \ge 3$ has no nontrivial minimum edge cut with fewer than $d(d+1)/2$ edges, hence the graph is $\min\{\delta, d(d+1)/2\}$-edge-connected where $\delta$ denotes the minimum…

Combinatorics · Mathematics 2023-11-14 Vincent Pilaud , Guillermo Pineda-Villavicencio , Julien Ugon

Marginal polytopes are important geometric objects that arise in statistics as the polytopes underlying hierarchical log-linear models. These polytopes can be used to answer geometric questions about these models, such as determining the…

Combinatorics · Mathematics 2023-12-06 Jane Ivy Coons , Joseph Cummings , Benjamin Hollering , Aida Maraj

Let $X$ be a simplicial complex on vertex set $V$. We say that $X$ is $d$-representable if it is isomorphic to the nerve of a family of convex sets in $\mathbb{R}^d$. We define the $d$-boxicity of $X$ as the minimal $k$ such that $X$ can be…

Combinatorics · Mathematics 2020-08-25 Alan Lew

For positive integers $n,d$, let $\lambda(n,d)$ be the minimal number of vertices of a triangulation of $n$-sphere which admits a degree $d$ simplicial map to the boundary of $(n+1)$-simplex. We show that…

Combinatorics · Mathematics 2025-12-02 Andrey Ryabichev

Given a polytope $\mathcal{P}$ in $\mathbb{R}^d$ and a subset $U$ of its vertices, is there a triangulation of $\mathcal{P}$ using $d$-simplices that all contain $U$? We answer this question by proving an equivalent and easy-to-check…

Metric Geometry · Mathematics 2018-03-09 Michael Kerber , Robert Tichy , Mario Weitzer

We study the harmonic polytope, which arose in Ardila, Denham, and Huh's work on the Lagrangian geometry of matroids. We describe its combinatorial structure, showing that it is a $(2n-2)$-dimensional polytope with…

Combinatorics · Mathematics 2021-07-05 Federico Ardila , Laura Escobar