English
Related papers

Related papers: Curve Closest to Sphere

200 papers

We revisit the well-known Curve Shortening Flow for immersed curves in the $d$-dimensional Euclidean space. We exploit a fundamental structure of the problem to derive a new global construction of a solution, that is, a construction that is…

Analysis of PDEs · Mathematics 2023-12-01 Patrick Guidotti

We construct a sequence $\{\Sigma_\ell\}_{\ell=1}^\infty$ of closed, axially symmetric surfaces $\Sigma_\ell\subset \mathbb{R}^3$ that converges to the unit sphere in $W^{2,p}\cap C^1$ for every $p\in[1,\infty)$ and such that, for every…

Differential Geometry · Mathematics 2023-06-07 Otis Chodosh , Michael Eichmair , Thomas Koerber

This paper is devoted to the prescribed scalar curvature under minimal boundary mean curvature on the standard four dimensional half sphere. Using topological methods from the theory of critical points at infinity, we prove some existence…

Analysis of PDEs · Mathematics 2007-05-23 Hichem Chtioui , Khalil El Mehdi

We propose a general framework for geometric approximation of circular arcs by parametric polynomial curves. The approach is based on constrained uniform approximation of an error function by scalar polynomials. The system of nonlinear…

Numerical Analysis · Mathematics 2018-08-07 Aleš Vavpetič , Emil Žagar

In 2012 Driemel et al. \cite{DBLP:journals/dcg/DriemelHW12} introduced the concept of $c$-packed curves as a realistic input model. In the case when $c$ is a constant they gave a near linear time $(1+\varepsilon)$-approximation algorithm…

Computational Geometry · Computer Science 2020-09-18 Joachim Gudmundsson , Yuan Sha , Sampson Wong

In this paper we deal with the task of uniformly approximating an $L$-biLipschitz curve by means of piecewise linear ones. This is rather simple if one is satisfied to have approximating functions which are $L'$-biLipschitz, for instance…

Classical Analysis and ODEs · Mathematics 2015-05-26 Aldo Pratelli , Emanuela Radici

A $\textit{spherical $t$-design curve}$ was defined by Ehler and Gr\"{o}chenig to be a continuous, piecewise smooth, closed curve on the sphere with finitely many self-intersections whose associated line integral applied to any polynomial…

Metric Geometry · Mathematics 2025-07-24 Ayodeji Lindblad

How efficiently can a closed curve of unit length in $\mathbb{R}^d$ be covered by $k$ closed curves so as to minimize the maximum length of the $k$ curves? We show that the maximum length is at most $2k^{-1} - \frac{1}{4} k^{-4}$ for all…

Metric Geometry · Mathematics 2025-09-16 Travis Dillon , Adrian Dumitrescu

If K' and K are convex bodies of the plane such that K' is a subset of K then the perimeter of K' is not greater than the perimeter of K. We obtain the following generalization of this fact. Let K be a convex compact body of the plane with…

Metric Geometry · Mathematics 2012-05-04 Don Coppersmith , Gyozo Nagy , Alex Ravsky

We prove that the least area of the non-contractible immersed spheres is no more than $4\pi$ in any oriented compact manifold with dimension $n+2\leq 7$ which satisfies $R\geq 2$ and admits a map to $\mathbf S^2\times T^n$ with nonzero…

Differential Geometry · Mathematics 2019-03-29 Jintian Zhu

The purpose of this article is to give an explicit formula for all curves of constant torsion $\tau$ in the unit two-sphere $S^2(1)$. These curves and their basic properties have been known since the 1890's, and some of these properties are…

Differential Geometry · Mathematics 2013-12-03 Demetre Kazaras , Ivan Sterling

Schwartz's solution to the Bj\"orling problem leads to an equivalence class of spatial strips S(t)=(c(t),n(t)) which produce equivalent minimal surfaces. For the particular case when the generating strip S(t) belongs to some plane E and…

Differential Geometry · Mathematics 2011-12-12 Hugo Jiménez-Pérez , Santiago López de Medrano

We present a general construction of embedded minimal and constant mean curvature surfaces in $\mathbb{S}^n$ and one-phase free boundaries joined by a smooth interpolation by capillary hypersurfaces. This framework recovers all known…

Differential Geometry · Mathematics 2026-04-07 Benjy Firester , Raphael Tsiamis

The problem of the optimal approximation of circular arcs by parametric polynomial curves is considered. The optimality relates to the curvature error. Parametric polynomial curves of low degree are used and a geometric continuity is…

Numerical Analysis · Mathematics 2025-09-03 Ema Češek , Aleš Vavpetič

We study the lengths of curves passing through a fixed number of points on the boundary of a convex shape in the plane. We show that for any convex shape $K$, there exist four points on the boundary of $K$ such that the length of any curve…

Metric Geometry · Mathematics 2016-09-07 Arseniy Akopyan , Vladislav Vysotsky

The average distance of a vertex $v$ of a connected graph $G$ is the arithmetic mean of the distances from $v$ to all other vertices of $G$. The proximity $\pi(G)$ and the remoteness $\rho(G)$ of $G$ are the minimum and the maximum of the…

Combinatorics · Mathematics 2021-06-07 Peter Dankelmann , Sonwabile Mafunda

This expository paper provides a unified and pedagogical introduction to optimal quantization for probability measures supported on spherical curves and discrete subsets of the sphere, emphasizing both continuous and discrete settings. We…

Optimization and Control · Mathematics 2025-12-25 Mrinal Kanti Roychowdhury

We define a manifold $M$ where objects $c\in M$ are curves, which we parameterize as $c:S^1\to R^n$ ($n\ge 2$, $S^1$ is the circle). Given a curve $c$, we define the tangent space $T_cM$ of $M$ at $c$ including in it all deformations…

Differential Geometry · Mathematics 2013-06-05 A. C. G. Mennucci , A. Yezzi , G. Sundaramoorthi

In this paper, we show that the $C^1$-differentiability of the norm of a two-dimensional normed space depends only on distances between points of the unit sphere in two different ways. As a consequence, we see that any isometry between the…

Metric Geometry · Mathematics 2021-02-23 Javier Cabello Sánchez

In a recent paper by Giuliani and Rothman \cite{GR}, the problem of finding a lower bound on the radius $R$ of a charged sphere with mass M and charge Q<M is addressed. Such a bound is referred to as the critical stability radius.…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Hakan Andreasson