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Related papers: On the Carath\'eodory number for strong convexity

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The Rolling Ball Theorem asserts that given a convex body K in Euclidean space and having a smooth surface bd(K) with all principal curvatures not exceeding c>0 at all boundary points, K necessarily has the property that to each boundary…

Differential Geometry · Mathematics 2009-03-30 Sz. Gy. Re've'sz

A new intrinsic volume metric is introduced for the class of convex bodies in $\mathbb{R}^n$. As an application, an inequality is proved for the asymptotic best approximation of the Euclidean unit ball by arbitrarily positioned polytopes…

Metric Geometry · Mathematics 2023-03-15 Florian Besau , Steven Hoehner

Let us define, for a compact set $A \subset \mathbb{R}^n$, the Minkowski averages of $A$: $$ A(k) = \left\{\frac{a_1+\cdots +a_k}{k} : a_1, \ldots, a_k\in A\right\}=\frac{1}{k}\Big(\underset{k\ {\rm times}}{\underbrace{A + \cdots +…

Metric Geometry · Mathematics 2016-02-09 Matthieu Fradelizi , Mokshay Madiman , Arnaud Marsiglietti , Artem Zvavitch

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 consider the family of constant width bodies in $\mathbb{R}^3$ which is convex under Minkowski addition. Extreme shapes cannot be expressed as a nontrivial convex combination of other constant width bodies. We show that each Meissner…

Metric Geometry · Mathematics 2025-01-29 Ryan Hynd

The Carath\'eodory's Extension Theorem is a powerful tool that allows us to generate a measure, over a sigma-algebra, from a pre-measure defined over an algebra of sets. However, although this result reduces our work to define a measure by…

Probability · Mathematics 2024-07-08 Patrick Oliveira

We obtain a sharp characterization of the Euclidean ball among all convex bodies K whose boundary has a pointwise k-th mean curvature not smaller than a geometric constant at almost all normal points. This geometric constant depends only on…

Differential Geometry · Mathematics 2020-10-30 Mario Santilli

If a convex body $K \subset \mathbb{R}^n$ is covered by the union of convex bodies $C_1, \ldots, C_N$, multiple subadditivity questions can be asked. Two classical results regard the subadditivity of the width (the smallest distance between…

Metric Geometry · Mathematics 2020-09-16 Alexey Balitskiy

The covariogram g_K(x) of a convex body K \subseteq E^d is the function which associates to each x \in E^d the volume of the intersection of K with K+x. Matheron asked whether g_K determines K, up to translations and reflections in a point.…

Metric Geometry · Mathematics 2007-05-23 Gennadiy Averkov , Gabriele Bianchi

In this paper, we generalize Minkowski's theorem. This theorem is usually stated for a centrally symmetric convex body and a lattice both included in $\mathbb{R}^n$. In some situations, one may replace the lattice by a more general set for…

Metric Geometry · Mathematics 2016-04-15 Pierre-Antoine Guihéneuf , Emilien Joly

In this note we consider two topics involving the relationship between the symplectic capacity and the mean width of convex bodies in $\mathbb{R}^{2n}$. We first describe an alternative path from the symplectic Brunn-Minkowski inequality of…

Symplectic Geometry · Mathematics 2026-02-10 Jonghyeon Ahn , Ely Kerman

A quadratic point on a surface in $RP^3$ is a point at which the surface can be approximated by a quadric abnormally well (up to order 3). We conjecture that the least number of quadratic points on a generic compact non-degenerate…

Differential Geometry · Mathematics 2007-05-23 Valentin Ovsienko , Serge Tabachnikov

I prove a scalar curvature rigidity theorem for spheres. In particular, I prove that geodesic balls of radii strictly less than $\frac{\pi}{2}$ in $n+1~(n\geq 2)$ dimensional unit sphere can be rigid under smooth deformations that increase…

Differential Geometry · Mathematics 2025-12-30 Puskar Mondal

Carath\'eodory's, Helly's and Radon's theorems are three basic results in discrete geometry. Their max-plus counterparts have been proved by various authors. In this paper, more advanced results in discrete geometry are shown to have also…

Combinatorics · Mathematics 2008-04-10 Stéphane Gaubert , Frédéric Meunier

We give the sharp lower bound of the volume product of $n$-dimensional convex bodies which are invariant under a discrete subgroup $SO(K)=\{ g \in SO(n); g(K)=K \}$, where $K$ is an $n$-cube or $n$-simplex. This provides new partial results…

Metric Geometry · Mathematics 2022-03-29 Hiroshi Iriyeh , Masataka Shibata

We prove that an arbitrary convex body $C \subseteq \mathbf{R}^{n+1} $, whose $ k $-th anisotropic curvature measure (for $ k =0, \ldots , n-1 $) is a multiple constant of the anisotropic perimeter of C, must be a rescaled and translated…

Metric Geometry · Mathematics 2022-04-15 Mario Santilli

Given a graph $G$, a set is $\Delta$-convex if there is no vertex $u\in V(G)\setminus S$ forming a triangle with two vertices of $S$. The $\Delta$-convex hull of $S$ is the minimum $\Delta$-convex set containing $S$. This article is an…

Combinatorics · Mathematics 2025-04-09 Bijo S. Anand , Arun Anil , Manoj Changat , Prasanth G. Narasimha-Shenoi , Sabeer S. Ramla

Determining the minimum density of a covering of $\mathbb{R}^{n}$ by Euclidean unit balls as $n\to\infty$ is a major open problem, with the best known results being the lower bound of $\left(\mathrm{e}^{-3/2}+o(1)\right)n$ by Coxeter, Few…

Combinatorics · Mathematics 2025-10-30 Boris Bukh , Jun Gao , Xizhi Liu , Oleg Pikhurko , Shumin Sun

This article derives closed-form parametric formulas for the Minkowski sums of convex bodies in d-dimensional Euclidean space with boundaries that are smooth and have all positive sectional curvatures at every point. Under these conditions,…

Metric Geometry · Mathematics 2021-11-04 Sipu Ruan , Gregory S. Chirikjian

We study Carath\'eodory convergence for open, simply connected surfaces spread over the sphere and, in particular, provide examples demonstrating that in the Speiser class the conformal type can change when two singular values collide.

Complex Variables · Mathematics 2024-12-10 Alexandre Eremenko , Sergei Merenkov