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For a given $\lambda >0$, a convex body in $\mathbb R^n$ is $\lambda$-convex if it is the intersection of (finitely or infinitely many) balls of radius $1/\lambda$. In this note, we show that among all $\lambda$-convex bodies in $\mathbb…

Metric Geometry · Mathematics 2025-11-18 Kostiantyn Drach , Kateryna Tatarko

This article gives estimates on covering numbers and diameters of random proportional sections and projections of symmetric quasi-convex bodies in $\mathbb R$. These results were known for the convex case and played an essential role in…

Metric Geometry · Mathematics 2008-02-03 A. E. Litvak , V. D. Milman , A. Pajor

We survey results concerning sharp estimates on volumes of sections and projections of certain convex bodies, mainly $\ell_p$ balls, by and onto lower dimensional subspaces. This subject emerged from geometry of numbers several decades ago…

Functional Analysis · Mathematics 2025-01-28 Piotr Nayar , Tomasz Tkocz

We introduce the notion of domains with uniform squeezing property, study various analytic and geometric properties of such domains and show that they cover many interesting examples, including Teichmuller spaces and Hermitian symmetric…

Complex Variables · Mathematics 2009-06-26 Sai-Kee Yeung

We prove rigidity for hypersurfaces with boundary in the unit $(n+1)$-sphere with scalar curvature bounded below by $n(n-1)$. Under appropriate boundary conditions, the hypersurfaces are shown to be part of the equatorial spheres. The lower…

Differential Geometry · Mathematics 2016-12-28 Lan-Hsuan Huang , Damin Wu

In the first part of this paper, we develop the theory of anisotropic curvature measures for convex bodies in the Euclidean space. It is proved that any convex body whose boundary anisotropic curvature measure equals a linear combination of…

Differential Geometry · Mathematics 2021-08-05 Ben Andrews , Yitao Lei , Yong Wei , Changwei Xiong

Properties of two classes of generally convex sets in the n-dimentional real Euclidean space, called m-semiconvex and weakly m-semiconvex, 1<=m<n, are investigated in the present work. In particular, it is established that an open set with…

Geometric Topology · Mathematics 2017-11-15 Tetiana Osipchuk

Starting from the geometrical concept of a 4-dimensional de-Sitter configuration of spheres in Euclidean 3-space and modelling voids in the Universe as spheres, we show that a uniform distribution over this configuration space implies a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Gary W. Gibbons , Marcus C. Werner , Naoki Yoshida , Sunmyon Chon

We use the intrinsic area to define a distance on the space of homothety classes of convex bodies in the $n$-dimensional Euclidean space, which makes it isometric to a convex subset of the infinite dimensional hyperbolic space. The ambient…

Differential Geometry · Mathematics 2021-09-02 Clément Debin , François Fillastre

Cone spherical surfaces are orientable Riemannian surfaces with constant curvature one and a finite set of conical singularities. A subset of these surfaces, referred to as dihedral surfaces, is characterized by their monodromy groups,…

Geometric Topology · Mathematics 2024-04-04 Sicheng Lu , Bin Xu

A centrally symmetric convex body is a convex compact set with non-empty interior that is symmetric about the origin. Of particular interest are those that are both smooth and strictly convex -- known here as regular symmetric bodies --…

Metric Geometry · Mathematics 2024-01-18 Sean Dewar

Using combinatorial methods, we derive several formulas for the volume of convex bodies obtained by intersecting a unit hypercube with a halfspace, or with a hyperplane of codimension 1, or with a flat defined by two parallel hyperplanes.…

Metric Geometry · Mathematics 2008-02-12 Jean-Luc Marichal , Michael J. Mossinghoff

As the most common representation for 3D shapes, mesh is often stored discretely with arrays of vertices and faces. However, 3D shapes in the real world are presented continuously. In this paper, we propose to learn a continuous…

Computer Vision and Pattern Recognition · Computer Science 2023-01-13 Zhongpai Gao

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

Surface area and mean width of a cylinder (the convex hull of two parallel disks) in R^3 are computed. It is more difficult to obtain analogous results for a cone (the convex hull of a disk D and a point p). Oblique formulas for mean width,…

Metric Geometry · Mathematics 2013-01-01 Steven R. Finch

We study the motion of smooth, strictly convex bodies in $\mathbb{R}^n$ expanding in the direction of their normal vector field with speed depending on Gauss curvature and support function.

Differential Geometry · Mathematics 2025-06-30 Mohammad N. Ivaki

We prove an existence and uniqueness theorem about spherical helicoidal (in particular, rotational) surfaces with prescribed mean or Gaussian curvature in terms of a continuous function depending on the distance to its axis. As an…

Differential Geometry · Mathematics 2024-03-04 Ildefonso Castro , Ildefonso Castro-Infantes , Jesús Castro-Infantes

We study symmetrization procedures within the class $\mathcal S_n$ of \emph{ball-bodies}, i.e.\ intersections of unit Euclidean balls (equivalently, summands of the Euclidean unit ball, or $c$-convex sets via the $c$-duality $A\mapsto…

Metric Geometry · Mathematics 2026-02-17 Shiri Artstein-Avidan , Dan I. Florentin

We develop a Morse-Lusternik-Schnirelmann theory for the distance between two points of a smoothly embedded circle in a complete Riemannian manifold. This theory suggests very naturally a definition of width that generalises the classical…

Differential Geometry · Mathematics 2025-03-27 Lucas Ambrozio , Rafael Montezuma , Roney Santos

Many classical geometric inequalities on functionals of convex bodies depend on the dimension of the ambient space. We show that this dimension dependence may often be replaced (totally or partially) by different symmetry measures of the…

Metric Geometry · Mathematics 2014-12-11 René Brandenberg , Stefan König