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Related papers: On the Edge-length Ratio of Outerplanar Graphs

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A graph drawn in the plane is called k-quasi-planar if it does not contain k pairwise crossing edges. It has been conjectured for a long time that for every fixed k, the maximum number of edges of a k-quasi-planar graph with n vertices is…

Combinatorics · Mathematics 2011-12-13 Jacob Fox , Janos Pach , Andrew Suk

In this paper, extending a result of Brooks et.al. [arXiv:2403.04110], we show that if an outerplanar graph $G$ with minimum degree at least $2$ has positive Lin-Lu-Yau curvature on every vertex pair, then $G$ has at most $10$ vertices, and…

Combinatorics · Mathematics 2024-09-23 Xiaonan Liu , Linyuan Lu , Zhiyu Wang

In this paper, we show that all simple outerplanar graphs $G$ with minimum degree at least $2$ and positive Lin-Lu-Yau Ricci curvature on every edge have maximum degree at most $9$. Furthermore, if $G$ is maximally outerplanar, then $G$ has…

Combinatorics · Mathematics 2025-10-01 George Brooks , Fadekemi Osaye , Anna Schenfisch , Zhiyu Wang , Jing Yu

Let $C_{s,t}$ be the complete bipartite geometric graph, with $s$ and $t$ vertices on two distinct parallel lines respectively, and all $s t$ straight-line edges drawn between them. In this paper, we show that every complete bipartite…

Combinatorics · Mathematics 2026-02-25 Balázs Keszegh , Andrew Suk , Gábor Tardos , Ji Zeng

It is shown that every 2-planar graph is quasiplanar, that is, if a simple graph admits a drawing in the plane such that every edge is crossed at most twice, then it also admits a drawing in which no three edges pairwise cross. We further…

Computational Geometry · Computer Science 2019-09-05 Michael Hoffmann , Csaba D. Tóth

We show that every outerplanar graph $G$ can be linearly embedded in the plane such that the number of distinct distances between pairs of adjacent vertices is at most thirteen and there is no intersection between the image of a vertex and…

Combinatorics · Mathematics 2021-04-20 Ziv Bakhajian , Ohad N. Feldheim

Tait and Tobin [J. Combin. Theory Ser. B 126 (2017) 137--161] determined the unique spectral extremal graph over all outerplanar graphs and the unique spectral extremal graph over all planar graphs when the number of vertices is…

Combinatorics · Mathematics 2024-10-02 Liangdong Fan , Liying Kang , Jiadong Wu

Let $G$ be a finite, connected graph and $v$ a vertex of $G$. The average distance and the eccentricity of $v$ in $G$ are defined as the arithmetic mean and the maximum, respectively, of the distances from $v$ to all other vertices of $G$.…

Combinatorics · Mathematics 2025-08-15 Peter Dankelmann , Sonwabile Mafunda , Sufiyan Mallu

Given a connected outerplanar graph G of pathwidth p, we give an algorithm to add edges to G to get a supergraph of G, which is 2-vertex-connected, outerplanar and of pathwidth O(p). This settles an open problem raised by Biedl, in the…

Discrete Mathematics · Computer Science 2014-01-03 Jasine Babu , Manu Basavaraju , L. Sunil Chandran , Deepak Rajendraprasad

The study of nonplanar drawings of graphs with restricted crossing configurations is a well-established topic in graph drawing, often referred to as beyond-planar graph drawing. One of the most studied types of drawings in this area are the…

In this paper, we investigate the ratio of the numbers of odd and even cycles in outerplanar graphs. We verify that the ratio generally diverges to infinity as the order of a graph diverges to infinity. We also give sharp estimations of the…

Combinatorics · Mathematics 2021-05-07 Akihiro Higashitani , Naoki Matsumoto

An outer-1-planar graph is a graph admitting a drawing in the plane so that all vertices appear in the outer region of the drawing and every edge crosses at most one other edge. This paper establishes the local structure of outer-1-planar…

Combinatorics · Mathematics 2023-06-22 Yan Li , Xin Zhang

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…

Data Structures and Algorithms · Computer Science 2017-02-07 Therese Biedl , Philippe Demontigny

While orthogonal drawings have a long history, smooth orthogonal drawings have been introduced only recently. So far, only planar drawings or drawings with an arbitrary number of crossings per edge have been studied. Recently, a lot of…

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…

Computational Geometry · Computer Science 2015-12-16 Michael A. Bekos , Michael Kaufmann , Robert Krug

We study straight-line drawings of planar graphs with few segments and few slopes. Optimal results are obtained for all trees. Tight bounds are obtained for outerplanar graphs, 2-trees, and planar 3-trees. We prove that every 3-connected…

Combinatorics · Mathematics 2008-09-09 Vida Dujmovic' , David Eppstein , Matthew Suderman , David R. Wood

We settle a problem of Dujmovi\'c, Eppstein, Suderman, and Wood by showing that there exists a function $f$ with the property that every planar graph $G$ with maximum degree $d$ admits a drawing with noncrossing straight-line edges, using…

Combinatorics · Mathematics 2010-11-13 Balázs Keszegh , János Pach , Dömötör Pálvölgyi

A graph is beyond-planar if it can be drawn in the plane with a specific restriction on crossings. Several types of beyond-planar graphs have been investigated, such as k-planar if every edge is crossed at most k times and RAC if edges can…

Discrete Mathematics · Computer Science 2022-01-04 Franz J. Brandenburg

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…

Combinatorics · Mathematics 2013-04-24 Xin Zhang

A graph $G=(V,E)$ is called 1-planar if it admits a drawing in the plane such that each edge is crossed at most once. In this paper, we study bipartite $1$-planar graphs with prescribed numbers of vertices in partite sets. Bipartite…

Combinatorics · Mathematics 2015-03-05 Július Czap , Jakub Przybyło , Erika Škrabuľáková