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In this note we examine the volume of the convex hull of two congruent copies of a convex body in Euclidean $n$-space, under some subsets of the isometry group of the space. We prove inequalities for this volume if the two bodies are…

Metric Geometry · Mathematics 2013-06-19 Ákos G. Horváth , Z. Lángi

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

We conjecture that for every dimension n not equal 3 there exists a noncompact hyperbolic n-manifold whose volume is smaller than the volume of any compact hyperbolic n-manifold. For dimensions n at most 4 and n=6 this conjecture follows…

Metric Geometry · Mathematics 2015-04-09 Mikhail Belolipetsky , Vincent Emery

We prove that the (n-2)-dimensional surface area (perimeter) of central hyperplane sections of the n-dimensional unit cube is maximal for the hyperplane perpendicular to the vector (1,1,0,...,0). This gives a positive answer to a question…

Metric Geometry · Mathematics 2018-06-25 Hermann Koenig , Alexander Koldobsky

We show that if $d\ge 4$ is even, then one can find two essentially different convex bodies such that the volumes of their maximal sections, central sections, and projections coincide for all directions.

Classical Analysis and ODEs · Mathematics 2014-01-14 Fedor Nazarov , Dmitry Ryabogin , Artem Zvavitch

The $N$-body problem with a $1/r^2$ potential has, in addition to translation and rotational symmetry, an effective scale symmetry which allows its zero energy flow to be reduced to a geodesic flow on complex projective $N-2$-space, minus a…

Dynamical Systems · Mathematics 2015-02-03 Connor Jackman , Richard Montgomery

The main goal of this paper is to present a series of inequalities connecting the surface area measure of a convex body and surface area measure of its projections and sections. We present a solution of a question from S. Campi, P.…

Metric Geometry · Mathematics 2017-08-29 Alexander Koldobsky , Christos Saroglou , Artem Zvavitch

The aim of this note is to survey the results in some geometric problems related to the centroids and the static equilibrium points of convex bodies. In particular, we collect results related to Gr\"unbaum's inequality and the…

Metric Geometry · Mathematics 2025-01-15 Zsolt Lángi , Péter L. Várkonyi

The purpose of this paper is twofold. First, we describe one (presumably) new case, in which Busemann--Hausdorff densities are convex. We apply the corresponding result to prove the existence of minimizing rectifiable chains of codimension…

Functional Analysis · Mathematics 2024-12-09 Ioann Vasilyev

The Nontrivial Projection Problem asks whether every finite-dimensional normed space of dimension greater than one admits a well-bounded projection of non-trivial rank and corank or, equivalently, whether every centrally symmetric convex…

Functional Analysis · Mathematics 2010-09-14 Stanislaw J. Szarek , Nicole Tomczak-Jaegermann

Given $L$ a convex body, the $L_p$-Busemann Random Simplex Inequality is closely related to the centroid body $\Gamma_p L$ for $p=1$ and $2$, and only in these cases it can be proved using the $L_p$-Busemann-Petty centroid inequality. We…

Metric Geometry · Mathematics 2025-01-24 Julián Eduardo Haddad

We classify the full set of convex central configurations in the Newtonian four-body problem. Particular attention is given to configurations possessing some type of symmetry or defining geometric property. Special cases considered include…

Dynamical Systems · Mathematics 2019-07-24 Montserrat Corbera , Josep M. Cors , Gareth E. Roberts

A translation body of a convex body is the convex hull of two of its translates intersecting each other. In the 1950s, Rogers and Shephard found the extremal values, over the family of $n$-dimensional convex bodies, of the maximal volume of…

Metric Geometry · Mathematics 2014-11-21 Zsolt Lángi

We consider Newton's problem of minimal resistance, in particular we address the problem arising in the limit if the height goes to infinity. We establish existence of solutions and lack radial symmetry of solutions. Moreover, we show that…

Optimization and Control · Mathematics 2021-05-12 Lev Lokutsievskiy , Gerd Wachsmuth , Mikhail Zelikin

For convex partitions of a convex body $B$ we prove that we can put a homothetic copy of $B$ into each set of the partition so that the sum of homothety coefficients is $\ge 1$. In the plane the partition may be arbitrary, while in higher…

Combinatorics · Mathematics 2012-12-27 Arseniy Akopyan , Roman Karasev

In this paper, we consider the isoperimetric problem in the space $\mathbb{R}^N$ with density. Our result states that, if the density f is l.s.c. and converges to a positive limit at infinity, being smaller than this limit far from the…

Analysis of PDEs · Mathematics 2014-11-20 Guido De Philippis , Giovanni Franzina , Aldo Pratelli

Given a symmetric convex body $C$ and $n$ hyperplanes in an Euclidean space, there is a translate of a multiple of $C$, at least ${1\over n+1}$ times as large, inside $C$, whose interior does not meet any of the hyperplanes. The result…

Metric Geometry · Mathematics 2009-10-22 Keith Ball

We give the sharp lower bound of the volume product of three dimensional convex bodies which are invariant under two kinds of discrete subgroups of $O(3)$ of order four. We also characterize the convex bodies with the minimal volume product…

Metric Geometry · Mathematics 2024-10-02 Hiroshi Iriyeh , Masataka Shibata

In this paper we analyze theoretical properties of bi-objective convex-quadratic problems. We give a complete description of their Pareto set and prove the convexity of their Pareto front. We show that the Pareto set is a line segment when…

Optimization and Control · Mathematics 2018-12-04 Cheikh Toure , Anne Auger , Dimo Brockhoff , Nikolaus Hansen

In this paper, we prove Mahler's conjecture concerning the volume product of centrally symmetric convex bodies in $\mathbb{R}^n$ in the case where $n=3$. Furthermore, we determine the equality condition.

Metric Geometry · Mathematics 2020-12-16 Hiroshi Iriyeh , Masataka Shibata