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In this paper we present a new technique to construct neighborly polytopes, and use it to prove a lower bound of ((r+d)^((r/2+d/2)^2))/(r^((r/2)^2)d^((d/2)^2)e^(3rd/4)) for the number of combinatorial types of vertex-labeled neighborly…

Metric Geometry · Mathematics 2013-08-29 Arnau Padrol

We describe a provably complete algorithm for the generation of a tight, possibly exact superset of all combinatorially distinct simple n-facet polytopes in R^d, along with their graphs, f-vectors, and face lattices. The technique applies…

Combinatorics · Mathematics 2009-08-13 Sandeep Koranne , Anand Kulkarni

In this note, we prove that every open primary basic semialgebraic set is stably equivalent to the realization space of an even-dimensional neighborly polytope. This in particular provides the final step for Mn\"ev's proof of the…

Metric Geometry · Mathematics 2014-10-01 Karim A. Adiprasito , Arnau Padrol

A stacking operation adds a $d$-simplex on top of a facet of a simplicial $d$-polytope while maintaining the convexity of the polytope. A stacked $d$-polytope is a polytope that is obtained from a $d$-simplex and a series of stacking…

Computational Geometry · Computer Science 2017-03-03 Erik D. Demaine , Andre Schulz

We show that there exist k-neighborly centrally symmetric d-dimensional polytopes with 2(n+d) vertices, where k(d,n)=Theta(d/(1+log ((d+n)/d))). We also show that this bound is tight.

Combinatorics · Mathematics 2007-05-23 Nathan Linial , Isabella Novik

We obtain computational hardness results for f-vectors of polytopes by exhibiting reductions of the problems DIVISOR and SEMI-PRIME TESTABILITY to problems on f-vectors of polytopes. Further, we show that the corresponding problems for…

Combinatorics · Mathematics 2021-09-20 Eran Nevo

The edge-of-the-wedge theorem in several complex variables gives the analytic continuation of functions defined on the poly upper half plane and the poly lower half plane, the set of points in $\mathbb{C}^d$ with all coordinates in the…

Complex Variables · Mathematics 2017-09-19 J. E. Pascoe

This paper is a survey of recent advances as well as open problems in the study of face numbers of centrally symmetric simplicial polytopes and spheres. The topics discussed range from neighborliness of centrally symmetric polytopes and the…

Combinatorics · Mathematics 2017-11-28 Isabella Novik

Let $f_i(P)$ denote the number of $i$-dimensional faces of a convex polytope $P$. Furthermore, let $S(n,d)$ and $C(n,d)$ denote, respectively, the stacked and the cyclic $d$-dimensional polytopes on $n$ vertices. Our main result is that for…

Combinatorics · Mathematics 2007-05-23 Anders Björner

In a nutshell, we show that polynomials and nested polytopes are topological, algebraic and algorithmically equivalent. Given two polytops $A\subseteq B$ and a number $k$, the Nested Polytope Problem (NPP) asks, if there exists a polytope…

Computational Geometry · Computer Science 2019-08-07 Michael G. Dobbins , Andreas Holmsen , Tillmann Miltzow

We take a unifying and new approach toward polynomial and trigonometric approximation in an arbitrary number of variables, resulting in a precise and general ready-to-use tool that anyone can easily apply in new situations of interest. The…

Classical Analysis and ODEs · Mathematics 2023-05-31 Marcel de Jeu

Starting from any finite simple graph, one can build a reflexive polytope known as a symmetric edge polytope. The first goal of this paper is to show that symmetric edge polytopes are intrinsically matroidal objects: more precisely, we…

Combinatorics · Mathematics 2023-07-12 Alessio D'Alì , Martina Juhnke-Kubitzke , Melissa Koch

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

We show that for fixed $d>3$ and $n$ growing to infinity there are at least $(n!)^{d-2 \pm o(1)}$ different labeled combinatorial types of $d$-polytopes with $n$ vertices. This is about the square of the previous best lower bounds. As an…

Combinatorics · Mathematics 2024-04-24 Arnau Padrol , Eva Philippe , Francisco Santos

An efficient algorithm to enumerate the vertices of a two-dimensional (2D) projection of a polytope, is presented in this paper. The proposed algorithm uses the support function of the polytope to be projected and enumerated for vertices.…

Computational Geometry · Computer Science 2016-12-01 Amit Gurung , Rajarshi Ray

We present a method for learning an embedding that places images of humans in similar poses nearby. This embedding can be used as a direct method of comparing images based on human pose, avoiding potential challenges of estimating body…

Computer Vision and Pattern Recognition · Computer Science 2015-07-02 Greg Mori , Caroline Pantofaru , Nisarg Kothari , Thomas Leung , George Toderici , Alexander Toshev , Weilong Yang

We prove that every polytope described by algebraic coordinates is the face of a projectively unique polytope. This provides a universality property for projectively unique polytopes. Using a closely related result of Below, we construct a…

Metric Geometry · Mathematics 2013-06-14 Karim Alexander Adiprasito , Arnau Padrol

The leading idea of the paper is to treat the theorem of Wigner with methods inspired by geometry. The exercise mentionned in the title has two functions: On the one hand it can serve as a pedagogical text in order to make the reader…

Mathematical Physics · Physics 2011-07-04 Manfred Buth

We investigate a novel setting for polytope rigidity, where a flex must preserve edge lengths and the planarity of faces, but is allowed to change the shapes of faces. For instance, the regular cube is flexible in this notion. We present…

Combinatorics · Mathematics 2026-03-11 Matthias Himmelmann , Bernd Schulze , Martin Winter

Neighborly polytopes are those that maximize the number of faces in each dimension among all polytopes with the same number of vertices. Despite their extremal properties they form a surprisingly rich class of polytopes, which has been…

Combinatorics · Mathematics 2015-01-30 Hiroyuki Miyata , Arnau Padrol
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