English
Related papers

Related papers: Note on illuminating constant width bodies

200 papers

We show that there exist convex bodies of constant width in $\mathbb{E}^n$ with illumination number at least $(\cos(\pi/14)+o(1))^{-n}$, answering a question by G. Kalai. Furthermore, we prove the existence of finite sets of diameter $1$ in…

Metric Geometry · Mathematics 2024-06-27 Andrii Arman , Andriy Bondarenko , Andriy Prymak

K. Bezdek and Gy. Kiss showed that existence of origin-symmetric coverings of unit sphere in $\mathbb{E}^n$ by at most $2^n$ congruent spherical caps with radius not exceeding $\arccos\sqrt{\frac{n-1}{2n}}$ implies the $X$-ray conjecture…

Metric Geometry · Mathematics 2025-04-15 A. Bondarenko , A. Prymak , D. Radchenko

The illumination conjecture asserts that any convex body in $n$-dimensional Euclidean space can be illuminated by at most $2^n$ external light sources or parallel beams of light. Despite recent progress on the illumination conjecture, it…

Metric Geometry · Mathematics 2026-02-05 Andrii Arman , Jaskaran Singh Kaire , Andriy Prymak

The X-ray numbers of some classes of convex bodies are investigated. In particular, we give a proof of the X-ray Conjecture as well as of the Illumination Conjecture for almost smooth convex bodies of any dimension and for convex bodies of…

Metric Geometry · Mathematics 2011-09-29 Karoly Bezdek , Gyorgy Kiss

For every large enough $n$, we explicitly construct a body of constant width $2$ that has volume less than $0.9^n \text{Vol}(\mathbb{B}^{n}$), where $\mathbb{B}^{n}$ is the unit ball in $\mathbb{R}^{n}$. This answers a question of…

Metric Geometry · Mathematics 2025-03-21 Andrii Arman , Andriy Bondarenko , Fedor Nazarov , Andriy Prymak , Danylo Radchenko

It was conjectured by Levi, Hadwiger, Gohberg and Markus that the boundary of any convex body in ${\mathbb R}^n$ can be illuminated by at most $2^n$ light sources, and, moreover, $2^n-1$ light sources suffice unless the body is a…

Metric Geometry · Mathematics 2017-10-17 Galyna Livshyts , Konstantin Tikhomirov

The illumination conjecture is a classical open problem in convex and discrete geometry, asserting that every compact convex body~$K$ in $\mathbb R^n$ can be illuminated by a set of no more than $2^n$ points. If $K$ has smooth boundary, it…

Metric Geometry · Mathematics 2025-03-31 Lenny Fukshansky

We settle the Hadwiger-Boltyanski Illumination Conjecture for all 1-unconditional convex bodies in ${\mathbb R}^3$ and in ${\mathbb R}^4$. Moreover, we settle the conjecture for those higher-dimensional 1-unconditional convex bodies which…

Metric Geometry · Mathematics 2025-08-06 Wen Rui Sun , Beatrice-Helen Vritsiou

In the recent paper "On a formula for sets of constant width in 2D", Comm. Pure Appl. Anal. 18 (2019), 2117-2131, we gave a constructive formula for all 2d sets of constant width. Based on this result we derive here a formula for the…

Metric Geometry · Mathematics 2023-10-31 Bernd Kawohl , Guido Sweers

A variant of the flatness problem from integer programming is studied, in which one considers convex bodies in $\mathbb{R}^d$ with at most $k$ interior lattice points. The maximum lattice width of such a body is denoted by Flt(d,k) and it…

Metric Geometry · Mathematics 2026-05-01 Gennadiy Averkov , Giulia Codenotti , Ansgar Freyer , Kyle Huang

We extend the notion of illumination bodies to Riemannian spaces of constant curvature and to projective Finsler geometries. We prove that the derivative of their volume defines a notion of surface area for convex bodies in these settings,…

Metric Geometry · Mathematics 2026-05-26 Rotem Assouline , Florian Besau , Elisabeth M. Werner

In ["Illumination of convex bodies with many symmetries", Mathematika 63 (2017)], Tikhomirov verified the Hadwiger-Boltyanski Illumination Conjecture for the class of 1-symmetric convex bodies of sufficiently large dimension. We propose an…

Metric Geometry · Mathematics 2024-07-16 Wen Rui Sun , Beatrice-Helen Vritsiou

Let $n\geq C$ for a large universal constant $C>0$, and let $B$ be a convex body in $R^n$ such that for any $(x_1,x_2,\dots,x_n)\in B$, any choice of signs $\varepsilon_1,\varepsilon_2,\dots,\varepsilon_n\in\{-1,1\}$ and for any permutation…

Metric Geometry · Mathematics 2019-02-20 Konstantin Tikhomirov

In this paper, we introduce an $m$-fold illumination number $I^m(K)$ of a convex body $K$ in Euclidean space $\mathbb{E}^d$, which is the smallest number of directions required to $m$-fold illuminate $K$, i.e., each point on the boundary of…

Metric Geometry · Mathematics 2023-06-26 Kirati Sriamorn

We discuss basic properties of several different width functions in the $n$-dimensional hyperbolic space such as continuity, and we also define a new hyperbolic width as the extension of Leichtweiss' width function. Then we prove a…

Metric Geometry · Mathematics 2024-01-22 Károly J. Böröczky , András Csépai , Ádám Sagmeister

We present a probabilistic model of illuminating a convex body by independently distributed light sources. In addition to recovering C.A. Rogers' upper bounds for the illumination number, we improve previous estimates of J. Januszewski and…

Metric Geometry · Mathematics 2016-06-30 Galyna Livshyts , Konstantin Tikhomirov

It is known that an $n$-dimensional convex body which is typical in the sense of Baire category, shows a simple, but highly non-intuitive curvature behaviour: at almost all of its boundary points, in the sense of measure, all curvatures are…

Metric Geometry · Mathematics 2014-04-29 Imre Barany , rolf Schneider

The Illumination Problem may be phrased as the problem of covering a convex body in Euclidean $n$-space by a minimum number of translates of its interior. By a probabilistic argument, we show that, arbitrarily close to the Euclidean ball,…

Metric Geometry · Mathematics 2016-02-24 Márton Naszódi

In this paper we show that a spherical convex body $C$ is of constant diameter $\tau$ if and only if $C$ is of constant width $\tau$, for $0<\tau<\pi$. Moreover, some applications to Wulff shapes are given.

Metric Geometry · Mathematics 2019-12-18 Huhe Han , Denghui Wu

We prove that the Cram\'er transform of the uniform measure on a convex body in $\mathbb{R}^n$ is a $(1+o(1)) n$-self-concordant barrier, improving a seminal result of Nesterov and Nemirovski. This gives the first explicit construction of a…

Optimization and Control · Mathematics 2015-04-14 Sébastien Bubeck , Ronen Eldan
‹ Prev 1 2 3 10 Next ›