English
Related papers

Related papers: Nearly Planar Graphs and {\lambda}-flat Graphs

200 papers

The smallest nonzero eigenvalue of the normalized Laplacian matrix of a graph has been extensively studied and shown to have many connections to properties of the graph. We here study a generalization of this eigenvalue, denoted $\lambda(G,…

Combinatorics · Mathematics 2015-03-02 Mary Radcliffe , Chris Williamson

It is known that families of graphs with a semialgebraic edge relation of bounded complexity satisfy much stronger regularity properties than arbitrary graphs, and that they can be decomposed into very homogeneous semialgebraic pieces up to…

Logic · Mathematics 2016-02-25 Artem Chernikov , Sergei Starchenko

A minimally rigid graph, also called Laman graph, models a planar framework which is rigid for a general choice of distances between its vertices. In other words, there are finitely many ways, up to isometries, to realize such a graph in…

Computational Geometry · Computer Science 2022-01-04 Christoph Koutschan

In this paper, we give polynomial-time algorithms that can take a graph G with a given combinatorial embedding on an orientable surface S of genus g and produce a planar drawing of G in R^2, with a bounding face defined by a polygonal…

Computational Geometry · Computer Science 2009-08-13 Christian A. Duncan , Michael T. Goodrich , Stephen G. Kobourov

A $t$-nearly platonic graph is a finite, connected, regular, simple and planar graph in which all but exactly $t$ numbers of its faces have the same length. It is proved that there is no 2-connected $1$-nearly platonic graph. In this paper,…

Combinatorics · Mathematics 2020-03-10 Mahdi Reza Khorsandi , Seyed Reza Musawi

A plane graph is called a rectangular graph if each of its edges can be oriented either horizontally or vertically, each of its interior regions is a four-sided region and all interior regions can be fitted in a rectangular enclosure. Only…

Combinatorics · Mathematics 2021-02-11 Vinod Kumar , Krishnendra Shekhawat

We present an infinite family of finite planar graphs $\{X_n\}$ with degree at most five and such that for some constant $c > 0$, $$ \lambda_1(X_n) \geq c(\frac{\log \diam(X_n)}{\diam(X_n)})^2\,, $$ where $\lambda_1$ denotes the smallest…

Probability · Mathematics 2012-05-18 James R. Lee , Teng Qin

Let $G$ be a graph that is topologically embedded in the plane and let $\mathcal{A}$ be an arrangement of pseudolines intersecting the drawing of $G$. An aligned drawing of $G$ and $\mathcal{A}$ is a planar polyline drawing $\Gamma$ of $G$…

Data Structures and Algorithms · Computer Science 2018-10-24 Tamara Mchedlidze , Marcel Radermacher , Ignaz Rutter

We define the crossing graph of a given embedded graph (such as a road network) to be a graph with a vertex for each edge of the embedding, with two crossing graph vertices adjacent when the corresponding two edges of the embedding cross…

Data Structures and Algorithms · Computer Science 2017-09-20 David Eppstein , Siddharth Gupta

The comparison of graphs is a vitally important, yet difficult task which arises across a number of diverse research areas including biological and social networks. There have been a number of approaches to define graph distance however…

Social and Information Networks · Computer Science 2019-05-29 Andrew Mellor , Angelica Grusovin

In modern mathematics, graphs figure as one of the better-investigated class of mathematical objects. Various properties of graphs, as well as graph-processing algorithms, can be useful if graphs of a certain kind are used as denotations…

Logic in Computer Science · Computer Science 2007-05-23 Alex Shkotin

A graph $G$ is a non-separating planar graph if there is a drawing $D$ of $G$ on the plane such that (1) no two edges cross each other in $D$ and (2) for any cycle $C$ in $D$, any two vertices not in $C$ are on the same side of $C$ in $D$.…

Combinatorics · Mathematics 2019-07-24 Hooman R. Dehkordi , Graham Farr

A matrix-weighted graph is an undirected graph with a $k\times k$ positive semidefinite matrix assigned to each edge. There are natural generalizations of the Laplacian and adjacency matrices for such graphs. These matrices can be used to…

Combinatorics · Mathematics 2020-09-28 Jakob Hansen

A key concept for many graph layout algorithms is planarity, a graph property that allows to draw vertices and edges crossing-free in the plane. Important is the generalization to $k$-planar graphs, which can be drawn in the plane with at…

Discrete Mathematics · Computer Science 2026-05-18 Aaron Büngener , Jakob Franz , Michael Kaufmann , Maximilian Pfister

Graphs that are squares under the gluing algebra arise in the study of homomorphism density inequalities such as Sidorenko's conjecture. Recent work has focused on these homomorphism density applications. This paper takes a new perspective…

Combinatorics · Mathematics 2025-10-08 Karen L. Collins , David Galvin , Christine A. Kelley , Emily McMillon , Amanda Redlich

Beyond planarity concepts (prominent examples include k-planarity or fan-planarity) apply certain restrictions on the allowed patterns of crossings in drawings. It is natural to ask, how much the number of crossings may increase over the…

Computational Geometry · Computer Science 2024-09-05 Markus Chimani , Torben Donzelmann , Nick Kloster , Melissa Koch , Jan-Jakob Völlering , Mirko H. Wagner

A monotone drawing of a planar graph $G$ is a planar straight-line drawing of $G$ where a monotone path exists between every pair of vertices of $G$ in some direction. Recently monotone drawings of planar graphs have been proposed as a new…

Computational Geometry · Computer Science 2013-10-24 Md. Iqbal Hossain , Md. Saidur Rahman

We consider embeddings of 3-regular graphs into 3-dimensional Cartesian coordinates, in such a way that two vertices are adjacent if and only if two of their three coordinates are equal (that is, if they lie on an axis-parallel line) and…

Computational Geometry · Computer Science 2015-07-16 David Eppstein

This work studies certain aspects of graphs embedded on surfaces. Initially, a colored graph model for a map of a graph on a surface is developed. Then, a concept analogous to (and extending) planar graph is introduced in the same spirit as…

Combinatorics · Mathematics 2007-05-23 Sostenes Lins

Two graph parameters are said to be coarsely equivalent if they are within constant factors from each other for every graph $G$. Recently, several graph parameters were shown to be coarsely equivalent to tree-length. Recall that the length…

Combinatorics · Mathematics 2025-02-04 Feodor F. Dragan