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Related papers: Cut Locus Realizations on Convex Polyhedra

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On a convex polyhedron P, the cut locus C(x) with respect to a point x is a tree of geodesic segments (shortest paths) on P that includes every vertex. We say that P has a skeletal cut locus if there is some x in P such that C(x) subset…

Computational Geometry · Computer Science 2025-06-25 Joseph O'Rourke , Costin Vilcu

We extend the notion of a source unfolding of a convex polyhedron P to be based on a closed polygonal curve Q in a particular class rather than based on a point. The class requires that Q "lives on a cone" to both sides; it includes simple,…

Computational Geometry · Computer Science 2012-05-07 Jin-ichi Itoh , Joseph O'Rourke , Costin Vilcu

Ghomi proved that every convex polyhedron could be stretched via an affine transformation so that it has an edge-unfolding to a net [Gho14]. A net is a simple planar polygon; in particular, it does not self-overlap. One can view his result…

Computational Geometry · Computer Science 2023-02-17 Joseph O'Rourke

We prove that every connected graph can be realized as the cut locus of some point on some Riemannian surface $S$ which, in some cases, has constant curvature. We study the stability of such realizations, and their generic behavior.

Differential Geometry · Mathematics 2016-08-14 Jin-ichi Itoh , Costin Vîlcu

We proved in another paper that every connected graph can be realized as the cut locus of some point on some riemannian surface. Here we give upper bounds on the number of such realizations.

Combinatorics · Mathematics 2016-08-14 Jin-ichi Itoh , Costin Vîlcu

A notion of "radially monotone" cut paths is introduced as an effective choice for finding a non-overlapping edge-unfolding of a convex polyhedron. These paths have the property that the two sides of the cut avoid overlap locally as the cut…

Computational Geometry · Computer Science 2016-08-01 Joseph O'Rourke

We prove two results about transforming any convex polyhedron, modeled as a linkage L of its edges. First, if we subdivide each edge of L in half, then L can be continuously flattened into a plane. Second, if L is equilateral and we again…

Computational Geometry · Computer Science 2024-12-20 Erik D. Demaine , Martin L. Demaine , Markus Hecher , Rebecca Lin , Victor H. Luo , Chie Nara

Given a finite collection P of convex n-polytopes in RP^n (n>1), we consider a real projective manifold M which is obtained by gluing together the polytopes in P along their facets in such a way that the union of any two adjacent polytopes…

Geometric Topology · Mathematics 2007-05-29 Jaejeong Lee

Given a convex polyhedral surface P, we define a tailoring as excising from P a simple polygonal domain that contains one vertex v, and whose boundary can be sutured closed to a new convex polyhedron via Alexandrov's Gluing Theorem. In…

Metric Geometry · Mathematics 2022-05-24 Joseph O'Rourke , Costin Vilcu

The geodesic complexity of a length space $X$ quantifies the required number of case distinctions to continuously choose a shortest path connecting any given start and end point. We prove a local lower bound for the geodesic complexity of…

Metric Geometry · Mathematics 2025-09-12 Florian Frick , Pranav Rajbhandari

Let C be a simple, closed, directed curve on the surface of a convex polyhedron P. We identify several classes of curves C that "live on a cone," in the sense that C and a neighborhood to one side may be isometrically embedded on the…

Discrete Mathematics · Computer Science 2011-02-15 Joseph O'Rourke , Costin Vilcu

It is a classical result that any finite tree with positively weighted edges, and without vertices of degree 2, is uniquely determined by the weighted path distance between each pair of leaves. Moreover, it is possible for a (small) strict…

Combinatorics · Mathematics 2012-09-12 Katharina T. Huber , Mike Steel

This paper is a study of the interaction between the combinatorics of boundaries of convex polytopes in arbitrary dimension and their metric geometry. Let S be the boundary of a convex polytope of dimension d+1, or more generally let S be a…

Metric Geometry · Mathematics 2007-05-23 Ezra Miller , Igor Pak

Let $ES_{\ell}(n)$ be the minimum $N$ such that every $N$-element point set in the plane contains either $\ell$ collinear members or $n$ points in convex position. We prove that there is a constant $C>0$ such that, for each $\ell, n \ge 3$,…

Combinatorics · Mathematics 2024-05-07 David Conlon , Jacob Fox , Xiaoyu He , Dhruv Mubayi , Andrew Suk , Jacques Verstraete

We give a complete description of all convex polyhedra whose surface can be constructed from several congruent regular pentagons by folding and gluing them edge to edge. Our method of determining the graph structure of the polyhedra from a…

Computational Geometry · Computer Science 2020-07-06 Elena Arseneva , Stefan Langerman , Boris Zolotov

We prove that every tree on $n$ edges decomposes $K_{nx,nx}$ and $K_{2nx + 1}$ for all positive integers $x$. The said decompositions are obtained by proving that every tree admits a $\vec{\beta}$-labeling (oriented beta-labeling). Our…

Combinatorics · Mathematics 2024-12-06 Parikshit Chalise , Antwan Clark , Edinah K. Gnang

Given any two convex polyhedra P and Q, we prove as one of our main results that the surface of P can be reshaped to a homothet of Q by a finite sequence of "tailoring" steps. Each tailoring excises a digon surrounding a single vertex and…

Metric Geometry · Mathematics 2020-08-06 Joseph O'Rourke , Costin Vilcu

A proper vertex of a rooted tree with totally ordered vertices is a vertex that is less than all its proper descendants. We count several kinds of labeled rooted trees and forests by the number of proper vertices. Our results are all…

Combinatorics · Mathematics 2013-04-02 Ira M. Gessel , Seunghyun Seo

We study lattice polytopes which arise as the convex hull of chip vectors for \textit{self-reachable} chip configurations on a tree $T$. We show that these polytopes always have the integer decomposition property and characterize the vertex…

Combinatorics · Mathematics 2024-09-13 Benjamin Lyons , McCabe Olsen

We showed in another paper [arXiv:1103.1759] that every connected graph can be realized as the cut locus of some point on some riemannian surface $S$. Here, criteria for the orientability of $S$ are given, and are applied to classify the…

Differential Geometry · Mathematics 2016-08-14 Jin-ichi Itoh , Costin Vîlcu
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