English
Related papers

Related papers: Convex Pentagons with Positive Heesch Number

200 papers

This is a survey on cohomogeneity one manifolds with positive curvature. We discuss the known examples of this type and their geometry and the functions that describe the metric. We also describe the classification of cohomogeneity one…

Differential Geometry · Mathematics 2007-07-24 Wolfgang Ziller

We introduce the property of convex normality of rational polytopes and give a dimensionally uniform lower bound for the edge lattice lengths, guaranteeing the property. As an application, we show that if every edge of a lattice d-polytope…

Combinatorics · Mathematics 2011-12-14 Joseph Gubeladze

We propose a new approach to the study of compact Riemannian manifolds with nonnegative Ricci curvature and strictly convex boundary or positive Ricci curvature and convex boundary. Several conjectures are formulated. Some partial results…

Differential Geometry · Mathematics 2020-05-27 Xiaodong Wang

A convexity point of a convex body is a point with the property that the union of the body and its reflection in the point is convex. It is proved that in the plane a typical convex body (in the sense of Baire category) has infinitely many…

Metric Geometry · Mathematics 2016-07-12 Rolf Schneider

Let $E$ be a $(\mathrm{IV})$-polyhedral Banach space. We show that, for each $\epsilon>0$, $E$ admits an $\epsilon$-equivalent $\mathrm{(V)}$-polyhedral norm such that the corresponding closed unit ball is the closed convex hull of its…

Functional Analysis · Mathematics 2023-03-20 Carlo Alberto De Bernardi

We give new bounds on the Erdos-Szekeres theorems for convex bodies of Bisztriczky and Fejes Toth and of Pach and Toth. We derive them from a combinatorial characterization of convex position of a family of planar convex bodies. This…

Combinatorics · Mathematics 2010-10-25 Alfredo Hubard , Luis Montejano , Emiliano Mora , Andrew Suk

A topological condition is given, characterizing which closed manifolds in dimensions < 8 (and conjecturally in general) admit symplectic structures. The condition is the existence of a certain fibration-like structure called a hyperpencil.…

Symplectic Geometry · Mathematics 2007-05-23 Robert E. Gompf

This addendum to [O'R17] establishes that a nearly flat acutely triangulated convex cap in the sense of that paper can be edge-unfolded even if closed to a polyhedron by adding the convex polygonal base under the cap.

Computational Geometry · Computer Science 2017-09-11 Joseph O'Rourke

In this paper we consider planar polygons with parallel opposite sides. This type of polygons can be regarded as discretizations of closed convex planar curves by taking tangent lines at samples with pairwise parallel tangents. For this…

Differential Geometry · Mathematics 2013-07-09 Marcos Craizer , Ralph C. Teixeira , Moacyr A. H. B. da Silva

''Positive geometries'' are a class of semi-algebraic domains which admit a unique ''canonical form'': a logarithmic form whose residues match the boundary structure of the domain. The study of such geometries is motivated by recent…

Algebraic Geometry · Mathematics 2025-09-11 Francis Brown , Clément Dupont

We consider the sequence of independent centered Gaussian random elements of a separable Banach space and their consecutive closed convex hulls. If inicial elements converge weakly to some limite, then, as shown in Davydov- Paulauskas…

Probability · Mathematics 2026-04-13 Youri Davydov

We introduce the notion of a Tits arrangement on a convex open cone as a special case of (infinite) simplicial arrangements. Such an object carries a simplicial structure similar to the geometric representation of Coxeter groups. The…

Combinatorics · Mathematics 2015-06-01 Michael Cuntz , Bernhard Mühlherr , Christian J. Weigel

We introduce and study a new class of $\eps$-convex bodies (extending the class of convex bodies) in metric and normed linear spaces. We analyze relations between characteristic properties of convex bodies, demonstrate how $\eps$-convex…

Differential Geometry · Mathematics 2016-02-03 Vladimir Golubyatnikov , Vladimir Rovenski

The Upper Bound Theorem for convex polytopes implies that the $p$-th Betti number of the \v{C}ech complex of any set of $N$ points in $\mathbb R^d$ and any radius satisfies $\beta_{p} = O(N^{m})$, with $m = \min \{ p+1, \lceil d/2 \rceil…

Combinatorics · Mathematics 2023-10-24 Herbert Edelsbrunner , János Pach

We study kernel quadrature rules with convex weights. Our approach combines the spectral properties of the kernel with recombination results about point measures. This results in effective algorithms that construct convex quadrature rules…

Numerical Analysis · Mathematics 2022-10-12 Satoshi Hayakawa , Harald Oberhauser , Terry Lyons

In this paper, we study the topological properties of the subpower Higson corona of proper metric spaces and show that the subpower Higson corona of the half open interval with the usual metric is an indecomposable continuum. Some…

General Topology · Mathematics 2019-09-10 Yutaka Iwamoto

The aperture angle alpha(x, Q) of a point x not in Q in the plane with respect to a convex polygon Q is the angle of the smallest cone with apex x that contains Q. The aperture angle approximation error of a compact convex set C in the…

Computational Geometry · Computer Science 2010-08-26 Hee-Kap Ahn , Sang Won Bae , Otfried Cheong , Joachim Gudmundsson

Various characterizations of finite convex geometries are well known. This note provides similar characterizations for possibly infinite convex geometries whose lattice of closed sets is strongly coatomic and lower continuous. Some classes…

Combinatorics · Mathematics 2017-01-27 Kira Adaricheva , J. B. Nation

Motivated by recent work of Bukh and Nivasch on one-sided $\varepsilon$-approximants, we introduce the notion of \emph{weighted $\varepsilon$-nets}. It is a geometric notion of approximation for point sets in $\mathbb{R}^d$ similar to…

Computational Geometry · Computer Science 2020-02-21 Daniel Bertschinger , Patrick Schnider

We show that the ordered rings naturally associated to compact convex polyhedra with interior satisfy a positivity property known as order unit cancellation, and obtain other general positivity results as well.

Algebraic Geometry · Mathematics 2010-09-30 David Handelman