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Related papers: Infinite curvature on typical convex surfaces

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We develop the calculus of superforms as a tool for convex geometry. The formalism is applied to valuations on convex bodies, the Alexandrov-Fenchel inequalities and Monge- Amp\`ere equations on the boundary of convex bodies.

Metric Geometry · Mathematics 2025-01-30 Bo Berndtsson

We consider a compact, star-shaped, mean convex hypersurface $\Sigma^2\subset \mathbb{R}^3$. We prove that in some cases the flow exists until it shrinks to a point in a spherical manner, which is very typical for convex surfaces as well…

Differential Geometry · Mathematics 2008-09-03 Panagiota Daskalopoulos , Natasa Sesum

We prove that for every metric on the torus with curvature bounded from below by -1 in the sense of Alexandrov there exists a hyperbolic cusp with convex boundary such that the induced metric on the boundary is the given metric. The proof…

Metric Geometry · Mathematics 2015-12-15 François Fillastre , Ivan Izmestiev , Giona Veronelli

In this paper, we consider the mean curvature flow of convex hypersurfaces in Euclidean spaces with a general forcing term. We show that the flow may shrink to a point in finite time if the forcing term is small, or exist for all times and…

Differential Geometry · Mathematics 2008-06-17 Guanghan Li , Isabel Salavessa

We discuss various phenomena of tangency in projective and convex geometry.

Algebraic Geometry · Mathematics 2011-03-07 Roland Abuaf

It is proved the generalization of Toponogov theorem about the length of the curve in two-dimensional Riemannian manifolds in the case of two-dimensional Alexandrov spaces.

Differential Geometry · Mathematics 2020-07-06 Alexander A. Borisenko

A nonlocal curvature flow is introduced to evolve locally convex curves in the plane. It is proved that this flow with any initial locally convex curve has a global solution, keeping the local convexity and the elastic energy of the…

Differential Geometry · Mathematics 2024-04-09 Laiyuan Gao , Horst Martini , Deyan Zhang

The $c$-curvature of a complete surface with Gauss curvature close to 1 in $C^2$ norm is almost-positive (in the sense of Kim--McCann). Our proof goes by a careful case by case analysis combined with perturbation arguments from the constant…

Differential Geometry · Mathematics 2012-03-26 Philippe Delanoë , Yuxin Ge

We give a metric characterization of the scalar curvature of a smooth Riemannian manifold, analyzing the maximal distance between $(n+1)$ points in infinitesimally small neighborhoods of a point. Since this characterization is purely in…

Differential Geometry · Mathematics 2022-12-19 Giona Veronelli

An old theorem, due to Graustein, asserts that the average curvature of a plane oval is attained at least at four points. We present a proof by way of wave propagation and extend this result to the spherical and hyperbolic geometries - in…

Differential Geometry · Mathematics 2024-09-20 Serge Tabachnikov

This paper concerns the evolution of a closed convex hypersurface in ${\mathbb{R}}^{n+1}$, in direction of its inner unit normal vector, where the speed is given by a smooth function depending only on the mean curvature, and satisfies some…

Differential Geometry · Mathematics 2016-10-27 Shunzi Guo

We study surfaces in $\R^4$ whose tangent spaces have constant principal angles with respect to a plane. Using a PDE we prove the existence of surfaces with arbitrary constant principal angles. The existence of such surfaces turns out to be…

Differential Geometry · Mathematics 2011-05-11 Pierre Bayard , Antonio J. Di Scala , Osvaldo Osuna-Castro , Gabriel Ruiz-Hernandez

We construct the infinite sequence of invariants for curves in surfaces by using word theory that V. Turaev introduced. For plane closed curves, we add some extra terms, e.g. the rotation number. From these modified invariants, we get the…

Geometric Topology · Mathematics 2007-05-23 Noboru Ito

This survey article is about discrete constant mean curvature surfaces defined by an approach related to integrable systems techniques. We introduce the notion of discrete constant mean curvature surfaces by first introducing properties of…

Differential Geometry · Mathematics 2010-10-12 Wayne Rossman

A classical theorem of A.D. Alexandrov says that a connected compact smooth hypersurface in Euclidean space with constant mean curvature must be a sphere. We give exposition to some results on symmetry properties of hypersurfaces with…

Analysis of PDEs · Mathematics 2022-05-11 YanYan Li

On one hand, we study the class of graphs on surfaces, satisfying tessellation properties, with positive Forman curvature on each edge. Via medial graphs, we provide a new proof for the finiteness of the class, and give a complete…

Combinatorics · Mathematics 2020-02-11 Yohji Akama , Bobo Hua , Yanhui Su , Haohang Zhang

We study mean curvature flows in a warped product manifold defined by a closed Riemannian manifold and $\mathbb{R}$. In such a warped product manifold, we can define the notion of a graph, called a geodesic graph. We prove that the curve…

Differential Geometry · Mathematics 2023-12-21 Naotoshi Fujihara

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

We algebraically compute all possible sectional curvature values for canonical algebraic curvature tensors, and use this result to give a method for constructing general sectional curvature bounds. We use a well-known method to…

Differential Geometry · Mathematics 2020-07-15 Maxine Calle , Corey Dunn

We introduce an estimator for the curvature of curves and surfaces by using finite sample points drawn from sampling a probability distribution that has support on the curve or surface. First we give an algorithm for estimation of the…

Differential Geometry · Mathematics 2025-07-03 R. Mirzaie