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We derive integral and sup-estimates for the curvature of stably marginally outer trapped surfaces in a sliced space-time. The estimates bound the shear of a marginally outer trapped surface in terms of the intrinsic and extrinsic curvature…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Lars Andersson , Jan Metzger

We carry out a systematic investigation on floating bodies in real space forms. A new unifying approach not only allows us to treat the important classical case of Euclidean space as well as the recent extension to the Euclidean unit…

Differential Geometry · Mathematics 2016-06-27 Florian Besau , Elisabeth M. Werner

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

The algorithms given in Karney, J. Geodesy 87, 43-55 (2013), to compute geodesics on terrestrial ellipsoids are extended to apply to ellipsoids of revolution with arbitrary eccentricity. For the direct and inverse geodesic problems, this…

Geophysics · Physics 2025-10-28 Charles F. F. Karney

We construct a sequence of compact, oriented, embedded, two-dimensional surfaces of genus one into Euclidean 3-space with prescribed, almost constant, mean curvature of the form $H(X)=1+{A}{|X|^{-\gamma}}$ for $|X|$ large, when $A<0$ and…

Analysis of PDEs · Mathematics 2018-10-16 Paolo Caldiroli , Monica Musso

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

In this study, we define the generalized normal ruled surface of a curve in the Euclidean 3-space $E^3$. We study the geometry of such surfaces by calculating the Gaussian and mean curvatures to determine when the surface is flat or minimal…

Differential Geometry · Mathematics 2020-06-02 Onur Kaya , Mehmet Önder

Visual insights into a wide variety of statistical methods, for both didactic and data analytic purposes, can often be achieved through geometric diagrams and geometrically based statistical graphs. This paper extols and illustrates the…

Methodology · Statistics 2013-02-21 Michael Friendly , Georges Monette , John Fox

In this paper, we characterize round spheres in the Euclidean space under some suitable conditions on the r-mean curvature.

Differential Geometry · Mathematics 2020-12-18 Wagner Oliveira Costa-Filho

We use the solution space of a pair of ODEs of at least second order to construct a smooth surface in Euclidean space. We describe when this surface is a proper embedding which is geodesically complete with finite total Gauss curvature. If…

Differential Geometry · Mathematics 2014-11-04 P. Gilkey , C. Y. Kim , J. H. Park

We consider a rational elliptic surface with a relatively minimal fibration. We compute the number of integral sections in the above rational elliptic surface. As an application, we obtain an estimate of polynomial solutions of some…

Algebraic Geometry · Mathematics 2024-01-02 Jia-Li Mo

In this paper we consider Hugelschaffer cubic curves which are generated using appropriate geometric constructions. The main result of this work is the mode of explicitly calculating the area of the egg-shaped part of the cubic curve using…

Algebraic Geometry · Mathematics 2024-03-11 Maja Petrovic , Branko Malesevic

At any point of a surface in the four-dimensional Euclidean space we consider the geometric configuration consisting of two figures: the tangent indicatrix, which is a conic in the tangent plane, and the normal curvature ellipse. We show…

Differential Geometry · Mathematics 2009-05-28 Georgi Ganchev , Velichka Milousheva

We consider the pointwise in space Lp-type regularity for elliptic and parabolic equations of order m in Rn. We provide pointwise Schauder estimates for the general range of Lp exponents, extending previous results from p > n/m to 1 < p <…

Analysis of PDEs · Mathematics 2023-02-08 Igor Kukavica , Quinn Le

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

We mainly investigate some properties of quasiconformal mappings between smooth 2-dimensional surfaces with boundary in the Euclidean space, satisfying certain partial differential equations (inequalities) concerning Laplacian, and in…

Complex Variables · Mathematics 2012-02-21 David Kalaj , Miodrag Mateljevic

Algorithms for the computation of the forward and inverse geodesic problems for an ellipsoid of revolution are derived. These are accurate to better than 15 nm when applied to the terrestrial ellipsoids. The solutions of other problems…

Geophysics · Physics 2015-03-18 Charles F. F. Karney

Measures of erythrocytes volume and surface are helpful in several physiological studies, both for zoologists and veterinarians. Whilst diameter and volume are assessed with ease from observations of blood smears and complete blood count,…

Quantitative Methods · Quantitative Biology 2024-06-10 Ion Udroiu

We give a relationship that yields an effective geometric way of evaluating mean curvature of surfaces. The approach is reminiscent of the Gauss's contour based evaluation of intrinsic curvature. The presented formula may have a number of…

Numerical Analysis · Mathematics 2011-08-10 Pavel Grinfeld