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Related papers: Surface area and other measures of ellipsoids

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We prove $\epsilon$-closeness of hypersurfaces to a sphere in Euclidean space under the assumption that the traceless second fundamental form is $\delta$-small compared to the mean curvature. We give the explicit dependence of $\delta$ on…

Differential Geometry · Mathematics 2015-07-08 Julian Scheuer

We characterize the standard $\mathbb{S}^3$ as the closed Ricci-positive 3-manifold with scalar curvature at least 6 having isoperimetric surfaces of largest area: $4\pi$. As a corollary we answer in the affirmative an interesting special…

Differential Geometry · Mathematics 2009-06-08 Michael Eichmair

We show that for elliptic parametric functionals whose Wulff shape is smooth and has strictly positive curvature, any surface with constant anisotropic mean curvature which is a topological sphere is a rescaling of the Wulff shape.

Differential Geometry · Mathematics 2009-09-14 Miyuki Koiso , Bennett Palmer

The volume charge density for a conducting ellipsoid is expressed in simple geometrical terms, and then used to obtain the known surface charge density as well as the uniform charge per length along any principal axis. Corresponding results…

Classical Physics · Physics 2020-06-24 T L Curtright , Z Cao , S Huang , J S Sarmiento , S Subedi , D A Tarrence , T R Thapaliya

This article is concerned with the problem of placing seven or eight points on the unit sphere $\mathbb{S}^2$ in $\mathbb{R}^3$ so that the surface area of the convex hull of the points is maximized. In each case, the solution is given for…

Metric Geometry · Mathematics 2024-05-22 Nicolas Freeman , Steven Hoehner , Jeff Ledford , David Pack , Brandon Walters

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

General results on convex bodies are reviewed and used to derive an exact closed-form parametric formula for the boundary of the geometric (Minkowski) sum of $k$ ellipsoids in $n$-dimensional Euclidean space. Previously this was done…

Metric Geometry · Mathematics 2021-07-20 Navid Hashemi , Justin Ruths

General results on convex bodies are reviewed and used to derive an exact closed-form parametric formula for the boundary of the geometric (Minkowski) sum of $k$ ellipsoids in $n$-dimensional Euclidean space. Previously this was done…

Systems and Control · Electrical Eng. & Systems 2021-07-07 Navid Hashemi , Justin Ruths

The indicatrix or curvature ellipse and the characteristic curve of a surface in $\mathbf R^4$ are presented, as well as the projective duality connecting them. The characterisation of points in the surfaces as elliptic, parabolic and…

Differential Geometry · Mathematics 2013-04-09 J. Basto-Gonçalves

We have derived an analytical formulation for estimating the volume of geometries enclosed by implicitly defined surfaces. The novelty of this work is due to two aspects. First we provide a general analytical formulation for all…

Numerical Analysis · Mathematics 2019-05-01 Shucheng Pan , Xiangyu Hu , Nikolaus. A. Adams

This article deals with quantitative error analysis resulting from ellipsometric data obtained from measurement on curved surfaces including the influence of non-collimated beams. Numerical model based on the combination of geometrical and…

Optics · Physics 2011-09-06 Jaromir Krepelka

We show some characterizations of hyperspheres in the $(n+1)$-dimensional Euclidean space ${\Bbb E}^{n+1}$ with intrinsic and extrinsic properties such as the $n$-dimensional area of the sections cut off by hyperplanes, the…

Differential Geometry · Mathematics 2012-08-28 Dong-Soo Kim , Young Ho Kim

In this study, we define a brief description of the hyperbolic and elliptic rotational surfaces using a curve and matrices in 4-dimensional semi Euclidean space. That is, we provide different types of rotational matrices, which are the…

Differential Geometry · Mathematics 2023-06-13 Fatma Almaz , Mihriban Alyamaç Külahcı

We present a model for computing the surface force density on a fluid ellipsoid in simple shear flow, which we derive by coupling existing models for the shape of a fluid droplet and the surface force density on a solid ellipsoid. The…

Fluid Dynamics · Physics 2016-10-13 E. P. Kightley , A. Pearson , J. A. Evans , D. M. Bortz

We give an explicit estimate of the area of a closed surface by the diameter and a lower bound of curvature. This is better than Calabi-Cao's estimate for a nonnegatively curved two-sphere.

Differential Geometry · Mathematics 2014-08-01 Takashi Shioya

We discuss infinitesimal isometries of the middle surfaces and present some characteristic conditions for a function to be the normal component of an infinitesimal isometry. Our results show that those characteristic conditions depend on…

Analysis of PDEs · Mathematics 2013-10-22 Peng-Fei Yao

We study necessary conditions on the geometry and the topology of domains in $\mathbb{R}^2$ that support a positive solution to a classical overdetermined elliptic problem. The ideas and tools we use come from constant mean curvature…

Analysis of PDEs · Mathematics 2013-10-15 Antonio Ros , Pieralberto Sicbaldi

We compute the area of a generic d-sphere in a Snyder geometry.

High Energy Physics - Theory · Physics 2021-02-09 P. Valtancoli

Our aim is to study invariant hypersurfaces immersed in the Euclidean space $\mathbb{R}^{n+1}$, whose mean curvature is given as a linear function in the unit sphere $\mathbb{S}^n$ depending on its Gauss map. These hypersurfaces are closely…

Differential Geometry · Mathematics 2019-08-21 Antonio Bueno , Irene Ortiz

See http://www.youtube.com/watch?v=izbGXdjvK_I for a YouTube video showing part of the results in this paper.We will consider surfaces whose mean curvature at a point is a linear function of the square of the distance from that point to the…

Differential Geometry · Mathematics 2014-04-14 Bennett Palmer , Oscar Perdomo