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Let $K$ be a $d$ dimensional convex body with a twice continuously differentiable boundary and everywhere positive Gauss-Kronecker curvature. Denote by $K_n$ the convex hull of $n$ points chosen randomly and independently from $K$ according…

Metric Geometry · Mathematics 2015-02-25 Imre Bárány , Ferenc Fodor , Viktor Vígh

Let $K$ be a convex body in $\mathbb{R}^{3}$. We denote the volume of $K$ by $Vol(K)$ and the diameter of $K$ by $Diam(K).$ In this paper we prove that there exists a linear bijection $T:\mathbb{R}^{3}\to \mathbb{R}^{3}$ such that…

Metric Geometry · Mathematics 2023-08-25 Arkadiy Aliev

In this paper we discuss three distance functions on the set of convex bodies. In particular we study the convergence of Delzant polytopes, which are fundamental objects in symplectic toric geometry. By using these observations, we derive…

Metric Geometry · Mathematics 2026-01-14 Hajime Fujita , Yu Kitabeppu , Ayato Mitsuishi

We consider two inverse problems related to the tokamak \textsl{Tore Supra} through the study of the magnetostatic equation for the poloidal flux. The first one deals with the Cauchy issue of recovering in a two dimensional annular domain…

Analysis of PDEs · Mathematics 2012-04-09 Yannick Fischer , Benjamin Marteau , Yannick Privat

We consider orthogonal polynomials on the unit circle with respect to a weight which is a quotient of $q$-gamma functions. We show that the Verblunsky coefficients of these polynomials satisfy discrete Painlev\'e equations, in a Lax form,…

Classical Analysis and ODEs · Mathematics 2010-07-06 Philippe Biane

For every convex body $K \subset \mathbb R^n$ and $\delta \in (0,1)$, the $\delta$-convolution body of $K$ is the set of $x \in \mathbb R^n$ for which $\left|K \cap (K+x)\right|_n \geq \delta \left|K\right|_n$. We show that for $n=2$ and…

Metric Geometry · Mathematics 2024-10-22 J. Haddad

Since the answer to the complex Busemann-Petty problem is negative in most dimensions, it is natural to ask what conditions on the (n-1)-dimensional volumes of the central sections of complex convex bodies with complex hyperplanes allow to…

Functional Analysis · Mathematics 2008-07-08 Marisa Zymonopoulou

In this paper we establish the coefficient bodies for a wide class of families of inverse functions. We also completely describe those functions that provide boundary points of that bodies in small dimensions. As an application we get sharp…

Complex Variables · Mathematics 2020-12-15 Mark Elin , Fiana Jacobzon

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

We show that in all dimensions d>2, there exists an asymmetric convex body of revolution all of whose maximal hyperplane sections have the same volume. This gives the negative answer to the question posed by V. Klee in 1969.

Metric Geometry · Mathematics 2012-01-04 Fedor Nazarov , Dmitry Ryabogin , Artem Zvavitch

This paper deals with the regularization of the sum of functions defined on a locally convex spaces through their closed-convex hulls in the bidual space. Different conditions guaranteeing that the closed-convex hull of the sum is the sum…

Optimization and Control · Mathematics 2024-10-11 Rafael Correa , Abderrahim Hantoute , Marco A. López

The classical Busemann-Petty problem (1956) asks, whether origin-symmetric convex bodies in $\mathbb {R}^n$ with smaller hyperplane central sections necessarily have smaller volumes. It is known, that the answer is affirmative if $n\le 4$…

Functional Analysis · Mathematics 2009-03-30 Boris Rubin

The authors gave an affine isoperimetric inequality \cite{LYZ2010} that gives a lower bound for the volume of a polar body and the equality holds if and only if the body is a simplex. In this paper, we give a functional isoperimetric…

Metric Geometry · Mathematics 2023-10-20 Zengle Zhang , Jiazu Zhou

We give the sharp lower bound of the volume product of three dimensional convex bodies which are invariant under a discrete subgroup of $O(3)$ in several cases. We also characterize the convex bodies with the minimal volume product in each…

Metric Geometry · Mathematics 2020-10-09 Hiroshi Iriyeh , Masataka Shibata

For a d-dimensional convex lattice polytope P, a formula for the boundary volume is derived in terms of the number of boundary lattice points on the first $\floor{d/2}$ dilations of P. As an application we give a necessary and sufficient…

Combinatorics · Mathematics 2012-12-21 Gábor Hegedüs , Alexander M. Kasprzyk

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

An antinorm is a concave analogue of a norm. In contrast to norms, antinorms are not defined on the entire space $R^d$ but on a cone $K\subset R^d$. They are applied in the matrix analysis, optimal control, and dynamical systems. Their…

Metric Geometry · Mathematics 2024-07-08 Maxim Makarov , Vladimir Yu. Protasov

The inequality of Berwald is a reverse-H\"older like inequality for the $p$th average, $p\in (-1,\infty),$ of a non-negative, concave function over a convex body in $\mathbb{R}^n.$ We prove Berwald's inequality for averages of functions…

Metric Geometry · Mathematics 2025-06-04 Dylan Langharst , Eli Putterman

We show that the generating series of traces of reciprocal singular moduli is a mixed mock modular form of weight $3/2$ whose shadow is given by a linear combination of products of unary and binary theta functions. To prove these results,…

Number Theory · Mathematics 2020-06-19 Claudia Alfes-Neumann , Markus Schwagenscheidt

In a work by Artstein-Avidan and Milman the concept of polarity is generalized from the class of convex bodies to the larger class of convex functions. While the only self-polar convex body is the Euclidean ball, it turns out that there are…

Metric Geometry · Mathematics 2012-10-17 Liran Rotem