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相关论文: Belt diameter of $\Pi$-zonotopes

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For every d-dimensional polytope P with centrally symmetric facets we can associate a "subway map" such that every line of this "subway" corresponds to set of facets parallel to one of ridges P. The belt diameter of P is the maximal number…

组合数学 · 数学 2013-06-19 Alexey Garber

We show that the edge graph of a 6-dimensional polytope with 12 facets has diameter at most 6, thus verifying the d-step conjecture of Klee and Walkup in the case of d=6. This implies that for all pairs (d,n) with n-d \leq 6 the diameter of…

组合数学 · 数学 2011-08-24 David Bremner , Lars Schewe

We establish sharp asymptotic estimates for the diameter of primitive zonotopes when their dimension is fixed. We also prove that, for infinitely many integers $k$, the largest possible diameter of a lattice zonotope contained in the…

组合数学 · 数学 2020-06-17 Antoine Deza , Lionel Pournin , Noriyoshi Sukegawa

We prove upper bounds on the graph diameters of polytopes in two settings. The first is a worst-case bound for polytopes defined by integer constraints in terms of the height of the integers and certain subdeterminants of the constraint…

组合数学 · 数学 2022-09-16 Hariharan Narayanan , Rikhav Shah , Nikhil Srivastava

We show that the largest possible diameter $\delta(d,k)$ of a $d$-dimensional polytope whose vertices have integer coordinates ranging between $0$ and $k$ is at most $kd-\lceil2d/3\rceil$ when $k\geq3$. In addition, we show that…

度量几何 · 数学 2018-03-22 Antoine Deza , Lionel Pournin

There are d-dimensional zonotopes with n zones for which a 2-dimensional central section has \Omega(n^{d-1}) vertices. For d=3 this was known, with examples provided by the "Ukrainian easter eggs'' by Eppstein et al. Our result is…

度量几何 · 数学 2008-06-03 Thilo Rörig , Nikolaus Witte , Günter M. Ziegler

In this paper we show that the diameter of a d-dimensional lattice polytope in [0,k]^n is at most (k - 1/2) d. This result implies that the diameter of a d-dimensional half-integral polytope is at most 3/2 d. We also show that for…

计算几何 · 计算机科学 2015-12-25 Alberto Del Pia , Carla Michini

It is proven here that the diameter of the d-dimensional associahedron is 2d-4 when d is greater than 9. Two maximally distant vertices of this polytope are explicitly described as triangulations of a convex polygon, and their distance is…

组合数学 · 数学 2014-03-31 Lionel Pournin

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

度量几何 · 数学 2008-02-03 Gil Kalai , Daniel J. Kleitman

It is known that polytopes with at most two nonsimple vertices are reconstructible from their graphs, and that $d$-polytopes with at most $d-2$ nonsimple vertices are reconstructible from their 2-skeletons. Here we close the gap between 2…

组合数学 · 数学 2018-11-28 Guillermo Pineda-Villavicencio , Julien Ugon , David Yost

It is shown here that the diameter of the $d$-dimensional cyclohedron is not greater than $\lceil 5d/2\rceil-2$. It is also shown that the $5/2$ coefficient in this upper bound is asymptotically sharp. More precisely, the $d$-dimensional…

组合数学 · 数学 2017-05-12 Lionel Pournin

The degree-diameter problem consists of finding the maximum number of vertices $n$ of a graph with diameter $d$ and maximum degree $\Delta$. This problem is well studied, and has been solved for plane graphs of low diameter in which every…

组合数学 · 数学 2024-01-23 Brandon Du Preez

A polytope in a finite-dimensional normed space is subequilateral if the length in the norm of each of its edges equals its diameter. Subequilateral polytopes occur in the study of two unrelated subjects: surface energy minimizing cones and…

度量几何 · 数学 2007-05-23 Konrad J Swanepoel

We determine $\pi_*(BDiff_\partial(D^{2n})) \otimes \mathbb{Q}$ for $2n \geq 6$ completely in degrees $* \leq 4n-10$, far beyond the pseudoisotopy stable range. Furthermore, above these degrees we discover a systematic structure in these…

代数拓扑 · 数学 2023-10-17 Alexander Kupers , Oscar Randal-Williams

The orbital diameter of a primitive permutation group is the maximal diameter of its orbital graphs. There has been a lot of interest in bounds for the orbital diameter. In this paper we provide explicit bounds on the diameters of groups of…

群论 · 数学 2021-03-10 Kamilla Rekvényi

The diameter of a strongly connected $d$-dimensional simplicial complex is the diameter of its dual graph. We provide a probabilistic proof of the existence of $d$-dimensional simplicial complexes with diameter $ (\frac{1}{d \cdot d!} -…

组合数学 · 数学 2022-04-27 Tom Bohman , Andrew Newman

We provide a sharp estimate for the asymptotic number of lattice zonotopes, inscribed in $[0,n ]^d$ when $n$ tends to infinity. Our estimate refines the logarithmic equivalent established by Barany, Bureaux, and Lund when the sum of the…

组合数学 · 数学 2023-02-14 Théophile Buffière

We introduce and study a family of polytopes which can be seen as a generalization of the permutahedron of type $B_d$. We highlight connections with the largest possible diameter of the convex hull of a set of points in dimension $d$ whose…

最优化与控制 · 数学 2017-02-07 Antoine Deza , George Manoussakis , Shmuel Onn

We prove that for 2-bridge knots, the diameter, D, of the set of boundary slopes is twice the crossing number, c. This constitutes partial verification of a conjecture that, for all knots in S^3, D is at most 2c.

几何拓扑 · 数学 2007-05-23 Thomas W. Mattman , Gabriel Maybrun , Kristin Robinson

The Hirsch conjecture, posed in 1957, stated that the graph of a $d$-dimensional polytope or polyhedron with $n$ facets cannot have diameter greater than $n - d$. The conjecture itself has been disproved, but what we know about the…

组合数学 · 数学 2013-10-29 Francisco Santos
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