English
Related papers

Related papers: Orthant polyhedra

200 papers

An edge-unfolding of a polyhedron is produced by cutting along edges and flattening the faces to a *net*, a connected planar piece with no overlaps. A *grid unfolding* allows additional cuts along grid edges induced by coordinate planes…

Computational Geometry · Computer Science 2007-05-23 Mirela Damian , Robin Flatland , Joseph O'Rourke

Partial permutohedra are lattice polytopes which were recently introduced and studied by Heuer and Striker. For positive integers $m$ and $n$, the partial permutohedron $\mathcal{P}(m,n)$ is the convex hull of all vectors in…

The diameter of the graph of a $d$-dimensional polyhedron with $n$ facets is at most $n^{\log d+2}$

Metric Geometry · Mathematics 2008-02-03 Gil Kalai , Daniel J. Kleitman

We present a simple algorithm for determining the extremal points in Euclidean space whose convex hull is the nth polytope in the sequence known as the multiplihedra. This answers the open question of whether the multiplihedra could be…

Algebraic Topology · Mathematics 2008-06-10 Stefan Forcey

We show the existence of families of periodic polyhedra in spaces of constant curvature whose fundamental domains can be obtained by attaching prisms and antiprisms to Archimedean solids. These polyhedra have constant discrete curvature and…

Differential Geometry · Mathematics 2024-01-09 Christina Duffield , Daniel Freese , William Holt , Matthias Weber , Ramazan Yol

We consider polynomials on the intersection of the closed positive orthant with the height-$1$ level hypersurface of certain polynomials with positive coefficients. We show that any polynomial strictly positive on such a semi-algebraic set…

Algebraic Geometry · Mathematics 2026-03-12 Colin Tan , Wing-Keung To

The Gauss-Bonnet theorem for a polyhedron (a union of finitely many compact convex polytopes) in $n$-dimensional Euclidean space expresses the Euler characteristic of the polyhedron as a sum of certain curvatures, which are different from…

Metric Geometry · Mathematics 2017-08-18 Rolf Schneider

In this paper, motivated by the work of Edelman and Strang, we show that for fixed integers $d\geq 2$ and $n\geq d+1$ the configuration space of all facet volume vectors of all $d$-polytopes in $\mathbb R^{d}$ with $n$ facets is a full…

Combinatorics · Mathematics 2021-12-17 Pavle V. M. Blagojević , Paul Breiding , Alexander Heaton

Dyadic rationals are rationals whose denominator is a power of 2. A dyadic n-dimensional convex set is defined as the intersection with n-dimensional dyadic space of an n-dimensional real convex set. Such a dyadic convex set is said to be a…

Rings and Algebras · Mathematics 2025-10-08 A. Mućka , A. Romanowska

We characterise Newton polytopes of nondegenerate quadratic forms and Newton polyhedra of Morse singularities.

Combinatorics · Mathematics 2019-10-15 Aliaksandr Yuran

Over a decade ago, it was shown that every edge unfolding of the Platonic solids was without self-overlap, yielding a valid net. We consider this property for regular polytopes in arbitrary dimensions, notably the simplex, cube, and…

Computational Geometry · Computer Science 2021-11-03 Satyan L. Devadoss , Matthew Harvey

We prove that octants are cover-decomposable into multiple coverings, i.e., for any k there is an m(k) such that any m(k)-fold covering of any subset of the space with a finite number of translates of a given octant can be decomposed into k…

Combinatorics · Mathematics 2012-07-04 Balázs Keszegh , Dömötör Pálvölgyi

The notion of a spiral unfolding of a convex polyhedron, resulting by flattening a special type of Hamiltonian cut-path, is explored. The Platonic and Archimedian solids all have nonoverlapping spiral unfoldings, although among generic…

Computational Geometry · Computer Science 2015-10-20 Joseph O'Rourke

Let $P_{\lambda\Sigma_n}$ be the Ehrhart polynomial associated to an intergal multiple $\lambda$ of the standard symplex $\Sigma_n \subset \mathbb{R}^n$. In this paper we prove that if $(M, L)$ is an $n$-dimensional polarized toric manifold…

Differential Geometry · Mathematics 2022-06-29 Andrea Loi , Fabio Zuddas

We study a class of mechanisms known as Kokotsakis polyhedra with a quadrangular base. These are $3\times3$ quadrilateral meshes whose faces are rigid bodies and joined by hinges at the common edges. In contrast to existing work, the…

Algebraic Geometry · Mathematics 2026-03-09 Yang Liu

We study two notions. One is that of spindle convexity. A set of circumradius not greater than one is spindle convex if, for any pair of its points, it contains every short circular arc of radius at least one, connecting them. The other…

Metric Geometry · Mathematics 2011-10-20 Karoly Bezdek , Zsolt Langi , Marton Naszodi , Peter Papez

We prove that every three-dimensional polyhedron is uniquely determined by its dihedral angles and edge lengths, even if nonconvex or self-intersecting, under two plausible sufficient conditions: (i) the polyhedron has only convex faces and…

Geometric Topology · Mathematics 2023-07-28 Yunhi Cho , Seonhwa Kim

In this work, we show the geometric properties of a family of polyhedra obtained by folding a regular tetrahedron along regular triangular grids. Each polyhedron is identified by a pair of nonnegative integers. The polyhedron can be cut…

Computational Geometry · Computer Science 2019-12-04 Seri Nishimoto , Takashi Horiyama , Tomohiro Tachi

This paper deals with triangulations of the 2-torus with the vertex labeled general octahedral graph $O_4$ which is isomorphic to the complete four-partite graph $K_{2,2,2,2}$; it is known that there exist precisely twelve such…

Combinatorics · Mathematics 2022-04-25 Serge Lawrencenko , Alex Lao

A beautiful result of Br\"ocker and Scheiderer on the stability index of basic closed semi-algebraic sets implies, as a very special case, that every $d$-dimensional polyhedron admits a representation as the set of solutions of at most…

Metric Geometry · Mathematics 2007-05-23 Martin Grötschel , Martin Henk
‹ Prev 1 4 5 6 7 8 10 Next ›