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Related papers: Sections and projections of nested convex bodies

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We study touching cones of a (not necessarily closed) convex set in a finitedimensional real Euclidean vector space and we draw relationships to other concepts in Convex Geometry. Exposed faces correspond to normal cones by an antitone…

Metric Geometry · Mathematics 2016-05-17 Stephan Weis

We study the surface area of an ellipsoid in n-dimensional Euclidean space as the function of the lengths of their major semi-axes. We write down an explicit formula as an integral over the unit sphere, use the formula to derive convexity…

Metric Geometry · Mathematics 2007-05-23 Igor Rivin

We begin by studying the surface area of an ellipsoid in n-dimensional Euclidean space as the function of the lengths of the semi-axes. We write down an explicit formula as an integral over the unit sphere in n-dimensions and use this…

Metric Geometry · Mathematics 2007-05-23 Igor Rivin

We consider here a generalization of a well known discrete dynamical system produced by the bisection of reflection angles that are constructed recursively between two lines in the Euclidean plane. It is shown that similar properties of…

Dynamical Systems · Mathematics 2009-02-03 Nikolai A. Krylov , Edwin L. Rogers

An infinitely smooth symmetric convex body $K\subset\mathbb R^d$ is called $k$-separably integrable, $1\leq k<d$, if its $k$-dimensional isotropic volume function $V_{K,H}(t)=\mathcal H^d(\{\boldsymbol x\in K:\mathrm{dist}(\boldsymbol…

Metric Geometry · Mathematics 2023-06-30 Vladyslav Yaskin , Bartłomiej Zawalski

We discuss how well a given convex body B in a real d-dimensional vector space V can be approximated by a set X for which the membership question: ``given an x in V, does x belong to X?'' can be answered efficiently (in time polynomial in…

Metric Geometry · Mathematics 2007-05-23 Alexander Barvinok , Ellen Veomett

In this manuscript, we study the inequalities between measures of convex bodies implied by comparison of their projections and sections. Recently, Giannopoulos and Koldobsky proved that if convex bodies $K, L$ satisfy $|K|\theta^{\perp}|…

Metric Geometry · Mathematics 2018-11-16 Johannes Hosle

Projective geometry provides the preferred framework for most implementations of Euclidean space in graphics applications. Translations and rotations are both linear transformations in projective geometry, which helps when it comes to…

Computational Geometry · Computer Science 2007-05-23 Chris Doran , Anthony Lasenby , Joan Lasenby

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

Closed form expressions are given for computing the parameters and vectors that identify and define the $n-1$ dimensional conic section that results from the intersection of a hyperplane with an $n$-dimensional conic section: cone,…

General Mathematics · Mathematics 2020-01-15 P. M. Dearing

Variational analysis presents a unified theory encompassing in particular both smoothness and convexity. In a Euclidean space, convex sets and smooth manifolds both have straightforward local geometry. However, in the most basic hybrid case…

Optimization and Control · Mathematics 2025-01-29 Adrian S. Lewis , Adriana Nicolae , Tonghua Tian

We characterize all possible relative positions between a hyperboloid of one sheet and a sphere through the roots of a characteristic polynomial associated to these quadrics. The classification is also suitable for a hyperboloid and a…

Metric Geometry · Mathematics 2016-05-05 M. Brozos-Vázquez , M. J. Pereira-Sáez , M. J. Souto-Salorio , Ana D. Tarrío-Tobar

The Gauss curvature measure of a pointed Euclidean convex body is a measure on the unit sphere which extends the notion of Gauss curvature to non-smooth bodies. Alexandrov's problem consists in finding a convex body with given curvature…

Metric Geometry · Mathematics 2019-03-18 Jérôme Bertrand , Philippe Castillon

Given an Euclidean space, this paper elucidates the topological link between the partial derivatives of the Minkowski functional associated to a set (assumed to be compact, convex, with a differentiable boundary and a non-empty interior)…

Differential Geometry · Mathematics 2024-07-18 Gustave Bainier , Benoit Marx , Jean-Christophe Ponsart

In this note we characterize isoperimetric regions inside almost-convex cones. More precisely, as in the case of convex cones, we show that isoperimetric sets are given by intersecting the cone with a ball centered at the origin.

Analysis of PDEs · Mathematics 2016-05-04 Eric Baer , Alessio Figalli

In computer vision, camera pose estimation from correspondences between 3D geometric entities and their projections into the image has been a widely investigated problem. Although most state-of-the-art methods exploit low-level primitives…

Computer Vision and Pattern Recognition · Computer Science 2023-06-16 Vincent Gaudillière , Gilles Simon , Marie-Odile Berger

Let $K$ and $L$ be two convex bodies in ${\mathbb R^4}$, such that their projections onto all $3$-dimensional subspaces are directly congruent. We prove that if the set of diameters of the bodies satisfy an additional condition and some…

Metric Geometry · Mathematics 2015-09-30 M. Angeles Alfonseca , Michelle Cordier , Dmitry Ryabogin

Let $K$ and $L$ be two convex bodies in $\mathbb R^n$, $n\geq 2$, with $L\subset \text{int}\, K$. We say that $L$ is an equichordal body for $K$ if every chord of $K$ tangent to $L$ has length equal to a given fixed value $\lambda$. J.…

Metric Geometry · Mathematics 2026-02-03 Jesús Jerónimo-Castro , Francisco G. Jimenez-Lopez , Efrén Morales-Amaya

We propose a statistical framework to identify topological differences in two populations of random geometric objects. The proposed framework involves first associating a topological signature with random geometric objects and then…

Methodology · Statistics 2026-03-17 Satish Kumar , Subhra Sankar Dhar

The consideration of the so-called rotation minimizing frames allows for a simple and elegant characterization of plane and spherical curves in Euclidean space via a linear equation relating the coefficients that dictate the frame motion.…

Differential Geometry · Mathematics 2018-03-28 Luiz C. B. da Silva , José Deibsom da Silva