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We consider surfaces with parallel mean curvature vector field and finite total curvature in product spaces of type $\mathbb{M}^n(c)\times\mathbb{R}$, where $\mathbb{M}^n(c)$ is a space form, and characterize certain of these surfaces. When…

Differential Geometry · Mathematics 2016-06-22 Márcio Batista , Marcos P. Cavalcante , Dorel Fetcu

This article studies a large, general class of orthogonal polytopes which we may call "generic orthotopes". These objects emerged from a desire to represent a Coxeter complex by an orthogonal polytope that is particularly nice with respect…

Combinatorics · Mathematics 2022-10-24 David Richter

We give a complete classification of Riemannian and Lorentzian surfaces of arbitrary codimension in a pseudo-sphere whose pseudo-spherical Gauss maps are of 1-type or, in particular, harmonic. In some cases a concrete global classification…

Differential Geometry · Mathematics 2016-04-25 Burcu Bektaş , Joeri Van der Veken , Luc Vrancken

Quadratic points of a surface in the projective 3-space are the points which can be exceptionally well approximated by a quadric. They are also singularities of a 3-web in the elliptic part and of a line field in the hyperbolic part of the…

Differential Geometry · Mathematics 2017-11-30 Marcos Craizer , Ronaldo Alves Garcia

The mean width is a measure on three-dimensional convex bodies that enjoys equal status with volume and surface area [Rota]. As the phrase suggests, it is the mean of a probability density f. We verify formulas for mean widths of the…

Metric Geometry · Mathematics 2016-03-15 Steven R. Finch

The orbital dynamics of most planetary satellites is governed by the quadrupole moment from the equatorial bulge of the host planet and the tidal field from the Sun. On the Laplace surface, the long-term orbital evolution driven by the…

Astrophysics · Physics 2009-11-13 Scott Tremaine , Jihad Touma , Fathi Namouni

The ruled surfaces, i.e., surfaces generated by one parametric set of lines, are widely used in the~field of applied geometry. An~isophote on a surface is a curve consisting of surface points whose normals form a constant angle with some…

Algebraic Geometry · Mathematics 2016-09-27 Jan Vršek

Coronal loops reveal crucial information about the nature of both coronal magnetic fields and coronal heating. The shape of the corresponding flux tube cross section and how it varies with position are especially important properties. They…

Solar and Stellar Astrophysics · Physics 2020-07-31 James A. Klimchuk , Craig E. DeForest

Given a function $\mathcal{H} \in C^1(\mathbb{S}^2)$, an $\mathcal{H}$-surface $\Sigma$ is a surface in the Euclidean space $\mathbb{R}^3$ whose mean curvature $H_\Sigma$ satisfies $H_\Sigma = \mathcal{H} \circ \eta$, where $\eta$ is the…

Differential Geometry · Mathematics 2024-01-10 Aires Eduardo Menani Barbieri

This paper constructs a family of coordinate systems about a point on a quaternionic contact manifold, called quaternionic contact pseudohermitian normal coordinates. Once defined, conformal variations of the quaternionic contact structure…

Differential Geometry · Mathematics 2008-07-04 Christopher S. Kunkel

We consider the Laplace normal vector field of relatively normalized ruled surfaces with non-vanishing Gaussian curvature in the three-dimensional Euclidean space $\mathbb{R}^{3}$. We determine all ruled surfaces and all relative…

Differential Geometry · Mathematics 2016-03-16 Stylianos Stamatakis

Given $2n$ unit equilateral triangles, there are finitely many ways to glue each edge to a partner. We obtain a random sphere-homeomorphic surface by sampling uniformly from the gluings that produce a topological sphere. As $n$ tends to…

Probability · Mathematics 2022-03-07 Scott Sheffield

We prove that under some assumptions on the mean curvature the set of umbilical points of an immersed surface in a $3$-dimensional space form has positive measure. In case of an immersed sphere our result can be seen as a generalization of…

Differential Geometry · Mathematics 2021-01-21 Giovanni Catino , Alberto Roncoroni , Luigi Vezzoni

Various substances in the liquid state tend to form droplets. In this paper the shape of such droplets is investigated within the spherical model of a lattice gas. We show that in this case the droplet boundary is always diffusive, as…

Statistical Mechanics · Physics 2015-05-20 Anatoly E. Patrick

We study those Lagrangian surfaces in complex Euclidean space which are foliated by circles or by straight lines. The former, which we call cyclic, come in three types, each one being described by means of, respectively, a planar curve, a…

Differential Geometry · Mathematics 2009-09-18 Henri Anciaux , Pascal Romon

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

Consider the Euclidean space $\mathbb{R}^3$ endowed with a canonical semi-symmetric non-metric connection determined by a vector field $\mathsf{C}\in\mathfrak{X}(\mathbb{R}^3)$. We study surfaces when the sectional curvature with respect to…

Differential Geometry · Mathematics 2024-05-22 Muhittin Evren Aydin , Rafael López , Adela Mihai

In Euclidean space, we investigate surfaces whose mean curvature $H$ satisfies the equation $H=\alpha\langle N,\mathbf{x}\rangle+\lambda$, where $N$ is the Gauss map, $\mathbf{x}$ is the position vector and $\alpha$ and $\lambda$ are two…

Differential Geometry · Mathematics 2020-05-18 Rafael López

This paper presents results on the extent to which mean curvature data can be used to determine a surface in space or its shape. The emphasis is on Bonnet's problem: classify and study the surface immersions in $\R^3$ whose shape is not…

dg-ga · Mathematics 2007-05-23 George I. Kamberov

The cornea, as the outer element of the human eye, plays a pivotal role in vision. Any defects in its shape can result in visual impairments. Mechanical defect manifest as shape defects, as the cornea is under to pressure. Our study…

Medical Physics · Physics 2024-04-29 Chloé Giraudet , Qian Wu , Jean-Marc Allain