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Related papers: The Mid-sphere Cousin of the Medial Axis Transform

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The midpoint set M(S) of a set S of points is the set of all midpoints of pairs of points in S. We study the largest cardinality of a midpoint set M(S) in a finite-dimensional normed space, such that M(S) is contained in the unit sphere,…

Metric Geometry · Mathematics 2011-08-26 Konrad J. Swanepoel

Let M be a smooth strictly convex closed surface in space and denote by H the set of points x in the exterior of M such that all the tangent segments from x to M have equal lengths. In this note we prove that if H is either a closed surface…

Metric Geometry · Mathematics 2012-05-07 J. Jeronimo-Castro , G. Ruiz-Hernandez , S. Tabachnikov

We show that for every complete Riemannian surface $M$ diffeomorphic to a sphere with $k \geq 0$ holes there exists a Morse function $f:M \rightarrow \mathbb{R}$, which is constant on each connected component of the boundary of $M$ and has…

Differential Geometry · Mathematics 2014-07-01 Yevgeny Liokumovich

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

We study metric spheres Z obtained by gluing two hemispheres of the Euclidean sphere along an orientation-preserving homeomorphism mapping the equator onto itself, where the distance on Z is the canonical distance that is locally isometric…

Complex Variables · Mathematics 2021-06-03 Toni Ikonen

This paper investigates which smooth manifolds arise as quotients (orbit spaces) of flows of vector fields. Such quotient maps were already known to be surjective on fundamental groups, but this paper shows that every epimorphism of…

Dynamical Systems · Mathematics 2017-03-14 Robert E. Gompf

Let $Y\subseteq \mathbb{R}^n$ be a closed definable subset and $X\subseteq \mathbb{R}^n$ be a smooth manifold. We construct a version of Morse theory for the restriction to $X$ of the Euclidean distance function from $Y$. This is done using…

Algebraic Geometry · Mathematics 2026-05-12 Andrea Guidolin , Antonio Lerario , Isaac Ren , Martina Scolamiero

We study the Riemannian distance function from a fixed point (a point-wise target) of Euclidean space in the presence of a compact obstacle bounded by a smooth hypersurface. First, we show that such a function is locally semiconcave with a…

Optimization and Control · Mathematics 2021-10-25 Paolo Albano , Vincenzo Basco , Piermarco Cannarsa

The aim of this paper is to give a survey of the known results concerning centrally symmetric polytopes, spheres, and manifolds. We further enumerate nearly neighborly centrally symmetric spheres and centrally symmetric products of spheres…

Metric Geometry · Mathematics 2007-05-23 Frank H. Lutz

Using the Lawson's existence theorem of minimal surfaces and the symmetries of the Hopf fibration, we will construct symmetric embedded closed minimal surfaces in the three dimensional sphere. These surfaces contain the Clifford torus, the…

Geometric Topology · Mathematics 2018-07-06 Sheng Bai , Chao Wang , Shicheng Wang

Natural objects can be subject to various transformations yet still preserve properties that we refer to as invariants. Here, we use definitions of affine invariant arclength for surfaces in R^3 in order to extend the set of existing…

Computer Vision and Pattern Recognition · Computer Science 2010-12-30 Dan Raviv , Alexander M. Bronstein , Michael M. Bronstein , Ron Kimmel , Nir Sochen

A multibranched surface is a 2-dimensional polyhedron without vertices. We introduce moves for multibranched surfaces embedded in a 3-manifold, which connect any two multibranched surfaces with the same regular neighborhoods in finitely…

Geometric Topology · Mathematics 2018-06-26 Kai Ishihara , Yuya Koda , Makoto Ozawa , Koya Shimokawa

A framed surface is a smooth surface in the Euclidean space with a moving frame. By using the moving frame, we can define Bertrand framed surfaces as the same idea as Bertrand framed curves. Then we find the caustics and involutes as…

Differential Geometry · Mathematics 2025-05-08 Nozomi Nakatsuyama , Masatomo Takahashi

A method is presented for constructing closed surfaces out of Euclidean polygons with infinitely many segment identifications along the boundary. The metric on the quotient is identified. A sufficient condition is presented which guarantees…

Dynamical Systems · Mathematics 2014-11-11 André de Carvalho , Toby Hall

The quantitative characterization of the microstructure of random heterogeneous media in $d$-dimensional Euclidean space $\mathbb{R}^d$ via a variety of $n$-point correlation functions is of great importance, since the respective infinite…

Soft Condensed Matter · Physics 2018-08-07 Zheng Ma , Salvatore Torquato

It was shown by E. Gluskin and V.D. Milman in [GAFA Lecture Notes in Math. 1807, 2003] that the classical arithmetic-geometric mean inequality can be reversed (up to a multiplicative constant) with high probability, when applied to…

Classical Analysis and ODEs · Mathematics 2018-10-16 Zakhar Kabluchko , Joscha Prochno , Vladislav Vysotsky

Let $\Sigma$ be a compact immersed stable capillary hypersurface in a wedge bounded by two hyperplanes in $\mathbb R^{n+1}$. Suppose that $\Sigma$ meets those two hyperplanes in constant contact angles and is disjoint from the edge of the…

Differential Geometry · Mathematics 2014-05-22 Jaigyoung Choe , Miyuki Koiso

The edge-to-edge tilings of the sphere by congruent quadrilaterals of Type $a^2bc$ are classified as $3$ classes: a sequence of two-parameter families of $2$-layer earth map tilings with $2n$ $(n\ge3)$ tiles, a one-parameter family of…

Combinatorics · Mathematics 2022-07-26 Yixi Liao , Pinren Qian , Erxiao Wang , Yingyun Xu

In 3-dimensional Euclidean space, Scherk second surfaces are singly periodic embedded minimal surfaces with four planar ends. In this paper, we obtain a natural generalization of these minimal surfaces in any higher dimensional Euclidean…

Differential Geometry · Mathematics 2007-05-23 Frank Pacard

Let $X$ denote a metric Lie group diffeomorphic to $\mathbb{R}^3$ that admits an algebraic open book decomposition. In this paper we prove that if $\Sigma$ is an immersed surface in $X$ whose left invariant Gauss map is a diffeomorphism…

Differential Geometry · Mathematics 2016-01-26 William H. Meeks , Pablo Mira , Joaquín Pérez