English
Related papers

Related papers: Convex polytopes in restricted point sets in $\mat…

200 papers

The general $d$-position number ${\rm gp}_d(G)$ of a graph $G$ is the cardinality of a largest set $S$ for which no three distinct vertices from $S$ lie on a common geodesic of length at most $d$. This new graph parameter generalizes the…

Combinatorics · Mathematics 2020-05-19 Sandi Klavzar , Douglas F. Rall , Ismael G. Yero

For a positive integer $d$, a set of points in $d$-dimensional Euclidean space is called almost-equidistant if for any three points from the set, some two are at unit distance. Let $f(d)$ denote the largest size of an almost-equidistant set…

Metric Geometry · Mathematics 2020-02-25 Martin Balko , Attila Pór , Manfred Scheucher , Konrad Swanepoel , Pavel Valtr

We investigate the asymptotic properties of random polytopes arising as convex hulls of $n$ independent random points sampled from a family of block-beta distributions. Notably, this family includes the uniform distribution on a product of…

Probability · Mathematics 2024-12-02 Florian Besau , Anna Gusakova , Christoph Thäle

We show that, for a constant-degree algebraic curve $\gamma$ in $\mathbb{R}^D$, every set of $n$ points on $\gamma$ spans at least $\Omega(n^{4/3})$ distinct distances, unless $\gamma$ is an {\it algebraic helix} (see Definition 1.1). This…

Metric Geometry · Mathematics 2020-09-16 Orit E. Raz

Symmetric edge polytopes, also called adjacency polytopes, are lattice polytopes determined by simple undirected graphs. We introduce the integer array \(\mathrm{maxf}(n,m)\) giving the maximum number of facets of a symmetric edge polytope…

Combinatorics · Mathematics 2023-07-07 Benjamin Braun , Kaitlin Bruegge

Our first contribution in this paper is to prove that three natural sum of squares (sos) based sufficient conditions for convexity of polynomials, via the definition of convexity, its first order characterization, and its second order…

Optimization and Control · Mathematics 2013-12-31 Amir Ali Ahmadi , Pablo A. Parrilo

In this note, we derive an asymptotically sharp upper bound on the number of lattice points in terms of the volume of centrally symmetric convex bodies. Our main tool is a generalization of a result of Davenport that bounds the number of…

Metric Geometry · Mathematics 2013-10-25 Matthias Henze

We obtain estimates for the number $p_d(n)$ of $(d-1)$-dimensional integer partitions of a number $n$. It is known that the two-sided inequality $C_1(d)n^{1-1/d}<\log p_d(n)< C_2(d)n^{1-1/d}$ is always true and that $C_1(d)>1$ whenever…

Combinatorics · Mathematics 2024-05-14 Kristina Oganesyan

Let $k,d,\lambda\geqslant1$ be integers with $d\geqslant\lambda $. Let $m(k,d,\lambda)$ be the maximum positive integer $n$ such that every set of $n$ points (not necessarily in general position) in $\mathbb{R}^{d}$ has the property that…

Let $P$ be a set of $n$ points in $\mathbb{R}^d$ and $\mathcal{F}$ be a family of geometric objects. We call a point $x \in P$ a strong centerpoint of $P$ w.r.t $\mathcal{F}$ if $x$ is contained in all $F \in \mathcal{F}$ that contains more…

Computational Geometry · Computer Science 2015-02-27 Pradeesha Ashok , Sathish Govindarajan

Let $\gamma: S^n\to \mathbb{R}_+$ be a convex integrand and $\mathcal{W}_\gamma$ be the Wulff shape of $ \gamma$. Apex point naturally arise in non-smooth Wulff shape, in particular, vertex of convex polytope. %Let $P\in S^n$. In this…

Metric Geometry · Mathematics 2023-10-17 Huhe Han

We address the problem of constructing elliptic polytopes in R^d, which are convex hulls of finitely many two-dimensional ellipses with a common center. Such sets arise in the study of spectral properties of matrices, asymptotics of long…

Numerical Analysis · Mathematics 2021-07-07 Thomas Mejstrik , Vladimir Yu. Protasov

We prove the following sparse approximation result for polytopes. Assume that $Q$ is a polytope in John's position. Then there exist at most $2d$ vertices of $Q$ whose convex hull $Q'$ satisfies $Q \subseteq - 2d^2 \, Q'$. As a consequence,…

Metric Geometry · Mathematics 2022-09-13 Víctor Hugo Almendra-Hernández , Gergely Ambrus , Matthew Kendall

We study random polytopes of the form $[X_1,\ldots,X_n]$ defined as convex hulls of independent and identically distributed random points $X_1,\ldots,X_n$ in $\mathbb{R}^d$ with one of the following densities: $$ f_{d,\beta} (x) =…

Probability · Mathematics 2020-02-04 Zakhar Kabluchko , Christoph Thaele , Dmitry Zaporozhets

Let $B(2d-1, d)$ be the subgraph of the hypercube $\mathcal{Q}_{2d-1}$ induced by its two largest layers. Duffus, Frankl and R\"odl proposed the problem of finding the asymptotics for the logarithm of the number of maximal independent sets…

Combinatorics · Mathematics 2025-05-02 József Balogh , Ce Chen , Ramon I. Garcia

An important theorem by Timofte states that nonnegativity of real $n$-variate symmetric polynomials of degree $d$ can be decided at test sets given by all points with at most $\lfloor\frac{d}{2}\rfloor$ distinct components. However, if the…

Algebraic Geometry · Mathematics 2013-03-19 Sadik Iliman , Timo de Wolff

The maximum volume $j$-simplex problem asks to compute the $j$-dimensional simplex of maximum volume inside the convex hull of a given set of $n$ points in $\mathbb{Q}^d$. We give a deterministic approximation algorithm for this problem…

Computational Geometry · Computer Science 2015-04-15 Aleksandar Nikolov

We present a simple proof to a fact recently established in [5]: let $\xi$ be a symmetric random variable that has variance $1$, let $\Gamma=(\xi_{ij})$ be an $N \times n$ random matrix whose entries are independent copies of $\xi$, and set…

Functional Analysis · Mathematics 2019-02-06 Shahar Mendelson

We describe a maximum entropy approach for computing volumes and counting integer points in polyhedra. To estimate the number of points from a particular set X in R^n in a polyhedron P in R^n, by solving a certain entropy maximization…

Combinatorics · Mathematics 2009-07-15 Alexander Barvinok , John Hartigan

We consider the discrepancy of the integer lattice with respect to the collection of all translated copies of a dilated convex body having a finite number of flat, possibly non-smooth, points in its boundary. We estimate the $L^{p}$ norm of…

Functional Analysis · Mathematics 2018-10-02 Luca Brandolini , Leonardo Colzani , Bianca Gariboldi , Giacomo Gigante , Giancarlo Travaglini