English
Related papers

Related papers: On some covering problems in geometry

200 papers

We consider the problem of lower bounding a generalized Minkowski measure of subsets of a convex body with a log-concave probability measure, conditioned on the set size. A bound is given in terms of diameter and set size, which is sharp…

Functional Analysis · Mathematics 2007-05-23 Ravi Montenegro

Inspired by the boolean discrepancy problem, we study the following optimization problem which we term \textsc{Spherical Discrepancy}: given $m$ unit vectors $v_1, \dots, v_m$, find another unit vector $x$ that minimizes $\max_i \langle x,…

Computational Complexity · Computer Science 2019-11-19 Chris Jones , Matt McPartlon

In 1974, Witsenhausen asked for the maximum possible density $\alpha_n$ of a measurable subset $A$ of the unit sphere $\mathbb{S}^{n-1}\subset \mathbb{R}^n$ such that $A$ contains no pair of orthogonal vectors. For $n=3$, the best known…

Combinatorics · Mathematics 2026-05-28 Domonkos Czifra , Ákos Dúcz , Máté Matolcsi , Dániel Varga , Pál Zsámboki

General results on convex bodies are reviewed and used to derive an exact closed-form parametric formula for the boundary of the geometric (Minkowski) sum of $k$ ellipsoids in $n$-dimensional Euclidean space. Previously this was done…

Metric Geometry · Mathematics 2021-07-20 Navid Hashemi , Justin Ruths

General results on convex bodies are reviewed and used to derive an exact closed-form parametric formula for the boundary of the geometric (Minkowski) sum of $k$ ellipsoids in $n$-dimensional Euclidean space. Previously this was done…

Systems and Control · Electrical Eng. & Systems 2021-07-07 Navid Hashemi , Justin Ruths

We prove rigidity for hypersurfaces with boundary in the unit $(n+1)$-sphere with scalar curvature bounded below by $n(n-1)$. Under appropriate boundary conditions, the hypersurfaces are shown to be part of the equatorial spheres. The lower…

Differential Geometry · Mathematics 2016-12-28 Lan-Hsuan Huang , Damin Wu

Thurston's circle packing approximation of the Riemann Mapping (proven to give the Riemann Mapping in the limit by Rodin-Sullivan) is largely based on the theorem that any topological disk with a circle packing metric can be deformed into a…

Geometric Topology · Mathematics 2017-06-21 David Glickenstein

This article is concerned with the approximation of unbounded convex sets by polyhedra. While there is an abundance of literature investigating this task for compact sets, results on the unbounded case are scarce. We first point out the…

Optimization and Control · Mathematics 2023-05-04 Daniel Dörfler

We study the approximability of general convex sets in $\mathbb{R}^n$ by intersections of halfspaces, where the approximation quality is measured with respect to the standard Gaussian distribution $N(0,I_n)$ and the complexity of an…

Computational Complexity · Computer Science 2023-11-16 Anindya De , Shivam Nadimpalli , Rocco A. Servedio

In this article we give a sharp upper bound on the possible values of the Euler characteristic for a minimal symplectic filling of a tight contact structure on a lens space. This estimate is obtained by looking at the topology of the spaces…

Geometric Topology · Mathematics 2020-03-31 Edoardo Fossati

We show that a closed piecewise-linear hypersurface immersed in $R^n$ ($n\ge 3$) is the boundary of a convex body if and only if every point in the interior of each $(n-3)$-face has a neighborhood that lies on the boundary of some convex…

Computational Geometry · Computer Science 2007-05-23 Konstantin Rybnikov

A \emph{covering array} is an $N \times k$ array of elements from a $v$-ary alphabet such that every $N \times t$ subarray contains all $v^t$ tuples from the alphabet of size $t$ at least $\lambda$ times; this is denoted as $\CA_\lambda(N;…

Combinatorics · Mathematics 2023-06-06 Mason R. Calbert , Ryan E. Dougherty

Cooper and Long generalised Epstein and Penner's Euclidean cell decomposition of cusped hyperbolic manifolds of finite volume to non-compact strictly convex projective manifolds of finite volume. We show that Weeks' algorithm to compute…

Geometric Topology · Mathematics 2015-12-08 Stephan Tillmann , Sampson Wong

Approximating convex bodies is a fundamental question in geometry, which has a wide variety of applications. Given a convex body $K$ in $\textbf{R}^d$ for fixed $d$, the objective is to minimize the number of facets of an approximating…

Computational Geometry · Computer Science 2026-01-26 Sunil Arya , David M. Mount

Johnson and Lov\'asz and Stein proved independently that any hypergraph satisfies $\tau\leq (1+\ln \Delta)\tau^{\ast}$, where $\tau$ is the transversal number, $\tau^{\ast}$ is its fractional version, and $\Delta$ denotes the maximum…

Combinatorics · Mathematics 2017-09-11 Márton Naszódi , Alexandr Polyanskii

In this paper, we study the problem of hyperball (hypersphere) packings in $n$-dimensional hyperbolic space ($n \ge 4$). We prove that to each $n$-dimensional congruent saturated hyperball packing, there is an algorithm to obtain a…

Metric Geometry · Mathematics 2025-06-16 Arnasli Yahya , Jenő Szirmai

We apply polynomial techniques (linear programming) to obtain lower and upper bounds on the covering radius of spherical designs as function of their dimension, strength, and cardinality. In terms of inner products we improve the lower…

Combinatorics · Mathematics 2020-07-14 Peter Boyvalenkov , Maya Stoyanova

In this paper we give a lower bound on the waist of the unit sphere of a uniformly convex normed space by using the localization technique in codimension greater than one and a strong version of the Borsuk-Ulam theorem. The tools used in…

Metric Geometry · Mathematics 2019-02-20 Yashar Memarian

The isoperimetric problem with a density or weighting seeks to enclose prescribed weighted area with minimum weighted perimeter. According to Chambers' recent proof of the Log Convex Density Conjecture, for many densities on $\mathbb{R}^n$…

Metric Geometry · Mathematics 2016-10-25 Leonardo Di Giosia , Jahangir Habib , Lea Kenigsberg , Dylanger Pittman , Weitao Zhu

Let $H_n$ be the minimal number of smaller homothetic copies of an $n$-dimensional convex body required to cover the whole body. Equivalently, $H_n$ can be defined via illumination of the boundary of a convex body by external light sources.…

Metric Geometry · Mathematics 2020-10-01 A. Prymak , V. Shepelska