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Related papers: Level Planarity: Transitivity vs. Even Crossings

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An edge-coloring of a graph $G$ with colors $1,\ldots,t$ is called an \emph{interval $t$-coloring} if all colors are used and the colors of edges incident to each vertex of $G$ are distinct and form an interval of integers. In 1990,…

Discrete Mathematics · Computer Science 2023-03-22 Arsen Hambardzumyan , Levon Muradyan

This paper presents an empirical study of the relationship between the density of small-medium sized random graphs and their planarity. It is well known that, when the number of vertices tends to infinite, there is a sharp transition…

Discrete Mathematics · Computer Science 2020-08-27 Emanuele Balloni , Giuseppe Di Battista , Maurizio Patrignani

A simple topological graph T = (V(T), E(T)) is a drawing of a graph in the plane where every two edges have at most one common point (an endpoint or a crossing) and no three edges pass through a single crossing. Topological graphs G and H…

Combinatorics · Mathematics 2022-12-13 Jan Kynčl

A graph is $2$-planar if it has local crossing number two, that is, it can be drawn in the plane such that every edge has at most two crossings. A graph is maximal $2$-planar if no edge can be added such that the resulting graph remains…

Combinatorics · Mathematics 2023-03-16 Michael Hoffmann , Meghana M. Reddy

We show that if a planar graph $G$ has a plane straight-line drawing in which a subset $S$ of its vertices are collinear, then for any set of points, $X$, in the plane with $|X|=|S|$, there is a plane straight-line drawing of $G$ in which…

Combinatorics · Mathematics 2021-05-11 Vida Dujmović , Fabrizio Frati , Daniel Gonçalves , Pat Morin , Günter Rote

In this paper, we introduce the notion of 2-boundary planar graphs. A graph is 2-boundary planar if it has an embedding in the plane so that all vertices lie on the boundary of at most two faces and no edges are crossed. A proper coloring…

Combinatorics · Mathematics 2025-04-07 Weichan Liu , Mengke Qi , Xin Zhang

The $2$-layer drawing model is a well-established paradigm to visualize bipartite graphs. Several beyond-planar graph classes have been studied under this model. Surprisingly, however, the fundamental class of $k$-planar graphs has been…

Discrete Mathematics · Computer Science 2020-08-24 Patrizio Angelini , Giordano Da Lozzo , Henry Förster , Thomas Schneck

A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this note we give examples of class two 1-planar graphs with maximum degree six or seven.

Combinatorics · Mathematics 2011-04-26 Xin Zhang

This paper is an exploration of simple four-regular graphs in the plane (i.e. loopless and with no more than one edge between any two nodes). Such graphs are fundamental to the theory of knots and links in three dimensional space, and their…

Combinatorics · Mathematics 2021-08-19 Shalom Eliahou , Frank Harary , Louis H. Kauffman

We study a family of positive weighted well-covered graphs, which we call levelable graphs, that are related to a construction of level artinian rings in commutative algebra. A graph $G$ is levelable if there exists a weight function with…

Combinatorics · Mathematics 2025-10-28 Kieran Bhaskara , Michael Y. C. Chong , Takayuki Hibi , Naveena Ragunathan , Adam Van Tuyl

Graph packing and partitioning problems have been studied in many contexts, including from the algorithmic complexity perspective. Consider the packing problem of determining whether a graph contains a spanning tree and a cycle that do not…

Combinatorics · Mathematics 2014-09-09 Jed Yang

We study the long-standing open problem of efficiently testing rectilinear planarity of series-parallel graphs (SP-graphs) in the variable embedding setting. A key ingredient behind the design of a linear-time testing algorithm for…

Data Structures and Algorithms · Computer Science 2021-10-04 Walter Didimo , Michael Kaufmann , Giuseppe Liotta , Giacomo Ortali

Graph drawing beyond planarity focuses on drawings of high visual quality for non-planar graphs which are characterized by certain forbidden edge configurations. A natural criterion for the quality of a drawing is the number of edge…

Computational Geometry · Computer Science 2021-05-27 Nathan van Beusekom , Irene Parada , Bettina Speckmann

The 2-blowup of a graph is obtained by replacing each vertex with two non-adjacent copies; a graph is biplanar if it is the union of two planar graphs. We disprove a conjecture of Gethner that 2-blowups of planar graphs are biplanar:…

Combinatorics · Mathematics 2024-10-29 David Eppstein

A graph is regularizable if it is possible to assign weights to its edges so that all nodes have the same degree. Weights can be positive, nonnegative or arbitrary as soon as the regularization degree is not null. Positive and nonnegative…

Social and Information Networks · Computer Science 2017-07-03 Massimo Franceschet , Enrico Bozzo

In this paper we introduce a notion of planarity for graphs that are presented in a streaming fashion. A $\textit{streamed graph}$ is a stream of edges $e_1,e_2,...,e_m$ on a vertex set $V$. A streamed graph is $\omega$-$\textit{stream…

Data Structures and Algorithms · Computer Science 2015-01-29 Giordano Da Lozzo , Ignaz Rutter

A temporal graph is a graph whose edges appear at certain points in time. These graphs are temporally connected (in class TC) if all vertices can reach each other by temporal paths (traversing the edges in chronological order). Reachability…

Discrete Mathematics · Computer Science 2026-04-21 Arnaud Casteigts , Timothée Corsini , Nils Morawietz

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

Testing a graph on 2-vertex- and 2-edge-connectivity are two fundamental algorithmic graph problems. For both problems, different linear-time algorithms with simple implementations are known. Here, an even simpler linear-time algorithm is…

Data Structures and Algorithms · Computer Science 2012-09-05 Jens M. Schmidt

A level graph is the data of a pair $(G,\pi)$ consisting of a finite graph $G$ and an ordered partition $\pi$ on the set of vertices of $G$. To each level graph on $n$ vertices we associate a polytope in $\mathbb R^n$ called its residue…

Combinatorics · Mathematics 2024-10-18 Omid Amini , Eduardo Esteves , Eduardo Garcez
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