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相关论文: Adjacency posets of outerplanar graphs

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We show that every 1-planar graph with minimum degree at least 4 has girth at most $8$, and every 1-planar graph with minimum degree at least 3 has girth at most $198$.

离散数学 · 计算机科学 2020-01-17 François Dross

A subset $S$ of vertices in a graph $G$ is a secure dominating set of $G$ if $S$ is a dominating set of $G$ and, for each vertex $u \not\in S$, there is a vertex $v \in S$ such that $uv$ is an edge and $(S \setminus \{v\}) \cup \{u\}$ is…

组合数学 · 数学 2024-03-14 Toru Araki

We determine upper and lower bounds on the zero forcing number of 2-connected outerplanar graphs in terms of the structure of the weak dual. We show that the upper bound is always at most half the number of vertices of the graph. This work…

组合数学 · 数学 2023-08-23 Nolan Ison , Mark Kempton , Franklin Kenter

We consider embeddings of maximal outerplanar graphs whose vertices all lie on a cycle $\mathcal{C}$ bounding a face. Each edge of the graph that is not in $\mathcal{C}$, a chord, is assigned a length equal to the length of the shortest…

组合数学 · 数学 2024-04-18 Haley Broadus , Elena Pavelescu

An octilinear drawing of a planar graph is one in which each edge is drawn as a sequence of horizontal, vertical and diagonal at 45 degrees line-segments. For such drawings to be readable, special care is needed in order to keep the number…

计算几何 · 计算机科学 2015-12-16 Michael A. Bekos , Michael Kaufmann , Robert Krug

A feedback vertex set of a graph is a subset of vertices intersecting all cycles. We provide tight upper bounds on the size of a minimum feedback vertex set in planar graphs of girth at least five. We prove that if $G$ is a connected planar…

组合数学 · 数学 2016-11-29 Tom Kelly , Chun-Hung Liu

A graph is pseudo-outerplanar if each of its blocks has an embedding in the plane so that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another. It is proved that…

组合数学 · 数学 2013-04-24 Xin Zhang

We show that intersection graphs of compact convex sets in R^n of bounded aspect ratio have asymptotic dimension at most 2n+1. More generally, we show this is the case for intersection graphs of systems of subsets of any metric space of…

组合数学 · 数学 2022-10-05 Zdeněk Dvořák , Sergey Norin

We prove that every planar poset $P$ of height $h$ has dimension at most $192h + 96$. This improves on previous exponential bounds and is best possible up to a constant factor. We complement this result with a construction of planar posets…

组合数学 · 数学 2018-01-11 Gwenaël Joret , Piotr Micek , Veit Wiechert

In 1989, Ne\v{s}et\v{r}il and Pudl\'ak posed the following challenging question: Do planar posets have bounded Boolean dimension? We show that every poset with a planar cover graph and a unique minimal element has Boolean dimension at most…

组合数学 · 数学 2022-12-20 Heather Smith Blake , Piotr Micek , William T. Trotter

A graph is outerplanar if it can be embedded in a plane such that all vertices lie on its outer face. The outerplanar Tur\'{a}n number of a given graph $H$, denoted by ${\rm ex}_{\mathcal{OP}}(n,H)$, is the maximum number of edges over all…

组合数学 · 数学 2021-10-22 Longfei Fang , Mingqing Zhai

Recently, the problem of establishing bounds on the edge density of 1-planar graphs, including their subclass IC-planar graphs, has received considerable attention. In 2018, Angelini et al. showed that any n-vertex bipartite IC-planar graph…

组合数学 · 数学 2025-06-03 Guiping Wang , Yuanqiu Huang , Zhangdong Ouyang , Licheng Zhang

A graph is outerplanar if it has a planar drawing for which all vertices belong to the outer face of the drawing. Let $H$ be a graph. The outerplanar Tur\'an number of $H$, denoted by $ex_\mathcal{OP}(n,H)$, is the maximum number of edges…

组合数学 · 数学 2023-10-03 Ervin Győri , Guilherme Zeus Dantas e Moura , Runtian Zhou

We show that there exists an adjacency labelling scheme for planar graphs where each vertex of an $n$-vertex planar graph $G$ is assigned a $(1+o(1))\log_2 n$-bit label and the labels of two vertices $u$ and $v$ are sufficient to determine…

数据结构与算法 · 计算机科学 2021-12-03 Vida Dujmović , Louis Esperet , Gwenaël Joret , Cyril Gavoille , Piotr Micek , Pat Morin

We introduce and study a new graph representation where vertices are embedded in three or more dimensions, and in which the edges are drawn on the projections onto the axis-parallel planes. We show that the complete graph on $n$ vertices…

离散数学 · 计算机科学 2020-10-06 N. R. Aravind , Udit Maniyar

We show that the asymptotic dimension of a geodesic space that is homeomorphic to a subset in the plane is at most three. In particular, the asymptotic dimension of the plane and any planar graph is at most three.

度量几何 · 数学 2021-07-09 Koji Fujiwara , Panos Papasoglu

A matchstick graph is a plane graph with edges drawn as unit distance line segments. This class of graphs was introduced by Harborth who conjectured that a matchstick graph on $n$ vertices can have at most $\lfloor 3n - \sqrt{12n -…

组合数学 · 数学 2025-06-04 Panna Gehér , Géza Tóth

A subset $R\subseteq V(G)$ of a graph $G$ is a general position set if any triple set $R_0$ of $R$ is non-geodesic in $G$, that is, no vertex of $R_0$ lies on any geodesic between the other two vertices of $R_0$ in $G$. Let $\mathcal{R}$ be…

组合数学 · 数学 2022-09-30 Jing Tian , Kexiang Xu , Daikun Chao

In this paper, we study planar drawings of maximal outerplanar graphs with the objective of achieving small height. A recent paper gave an algorithm for such drawings that is within a factor of 4 of the optimum height. In this paper, we…

数据结构与算法 · 计算机科学 2017-02-07 Therese Biedl , Philippe Demontigny

A graph on $n \ge 3$ vertices drawn in the plane such that each edge is crossed at most four times has at most $6(n-2)$ edges -- this result proven by Ackerman is outstanding in the literature of beyond-planar graphs with regard to its…

组合数学 · 数学 2025-10-03 Aaron Büngener