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Related papers: L-Graphs and Monotone L-Graphs

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We consider the graph class Grounded-L corresponding to graphs that admit an intersection representation by L-shaped curves, where additionally the topmost points of each curve are assumed to belong to a common horizontal line. We prove…

Combinatorics · Mathematics 2019-11-06 Vít Jelínek , Martin Töpfer

In a planar L-drawing of a directed graph (digraph) each edge e is represented as a polyline composed of a vertical segment starting at the tail of e and a horizontal segment ending at the head of e. Distinct edges may overlap, but not…

Computational Geometry · Computer Science 2020-08-19 Patrizio Angelini , Steven Chaplick , Sabine Cornelsen , Giordano Da Lozzo

An L-shape is the union of a horizontal and a vertical segment with a common endpoint. These come in four rotations: L, \Gamma, LE{} and \eeG. A $k$-bend path is a simple path in the plane, whose direction changes $k$ times from horizontal…

Combinatorics · Mathematics 2016-01-08 Stefan Felsner , Kolja Knauer , George B. Mertzios , Torsten Ueckerdt

Graph embeddings, wherein the nodes of the graph are represented by points in a continuous space, are used in a broad range of Graph ML applications. The quality of such embeddings crucially depends on whether the geometry of the space…

Machine Learning · Statistics 2022-02-03 Francesco Di Giovanni , Giulia Luise , Michael Bronstein

Any planar graph has a crossing-free straight-line drawing in the plane. A simultaneous geometric embedding of two n-vertex graphs is a straight-line drawing of both graphs on a common set of n points, such that the edges withing each…

Computational Geometry · Computer Science 2007-05-23 Martin Kutz

In a {\em grounded string representation} of a graph there is a horizontal line $\ell$ and each vertex is represented as a simple curve below $\ell$ with one end point on $\ell$ such that two curves intersect if and only if the respective…

Computational Geometry · Computer Science 2026-03-04 Sabine Cornelsen , Jan Kratochvíl , Miriam Münch , Giacomo Ortali , Alexandra Weinberger , Alexander Wolff

In this paper, we determine the computational complexity of recognizing two graph classes, \emph{grounded L}-graphs and \emph{stabbable grid intersection} graphs. An L-shape is made by joining the bottom end-point of a vertical ($\vert$)…

Discrete Mathematics · Computer Science 2023-03-14 Dibyayan Chakraborty , Kshitij Gajjar , Irena Rusu

An L-shaped embedding of a tree in a point set is a planar drawing of the tree where the vertices are mapped to distinct points and every edge is drawn as a sequence of two axis-aligned line segments. There has been considerable work on…

Computational Geometry · Computer Science 2020-05-01 Torsten Mütze , Manfred Scheucher

We announce results about flat (linkless) embeddings of graphs in 3-space. A piecewise-linear embedding of a graph in 3-space is called {\it flat} if every circuit of the graph bounds a disk disjoint from the rest of the graph. We have…

Combinatorics · Mathematics 2016-09-06 Neil Robertson , Paul Seymour , Robin Thomas

A crossing-free straight-line drawing of a graph is monotone if there is a monotone path between any pair of vertices with respect to some direction. We show how to construct a monotone drawing of a tree with $n$ vertices on an $O(n^{1.5})…

Computational Geometry · Computer Science 2016-04-26 Philipp Kindermann , André Schulz , Joachim Spoerhase , Alexander Wolff

An embedding of a graph into $\mathbb{R}^3$ is said to be linear, if any edge of the graph is sent to be a line segment. And we say that an embedding $f$ of a graph $G$ into $\mathbb{R}^3$ is free, if $\pi_1(\mathbb{R}^3-f(G))$ is a free…

Geometric Topology · Mathematics 2014-09-25 Youngsik Huh , Jung Hoon Lee

A few steps are made towards representation theory of embeddability among uncountable graphs. A monotone class of graphs is defined by forbidding countable subgraphs, related to the graph's end-structure. Using a combinatorial theorem of…

Logic · Mathematics 2016-09-06 Menachem Kojman

In this paper, we propose a new type of graph, denoted as "embedded-graph", and its theory, which employs a distributed representation to describe the relations on the graph edges. Embedded-graphs can express linguistic and complicated…

Discrete Mathematics · Computer Science 2017-09-15 Atsushi Yokoyama

This paper considers *-graphs in which all vertices have degree 4 or 6, and studies the question of calculating the genus of orientable 2-surfaces into which such graphs may be embedded. A *-graph is a graph endowed with a formal adjacency…

Combinatorics · Mathematics 2012-12-27 Tyler Friesen , Vassily Manturov

A graph drawing in the plane is called an almost embedding if the images of any two non-adjacent simplices (i.e. vertices or edges) are disjoint. Almost embeddings (more precisely, their higher-dimensional analogues) naturally appear in…

Geometric Topology · Mathematics 2026-03-10 E. Alkin , A. Miroshnikov , A. Skopenkov

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

A graph class is monotone if it is closed under taking subgraphs. It is known that a monotone class defined by finitely many obstructions has bounded treewidth if and only if one of the obstructions is a so-called tripod, that is, a…

We investigate the property of a spatial graph of having a leveled embedding and characterize the abstract graphs with this property. We show that all leveled embeddings are free and we compare leveled and paneled (also known as flat)…

Combinatorics · Mathematics 2025-09-22 Senja Barthel , Fabio Buccoliero

The L-intersection graphs are the graphs that have a representation as intersection graphs of axis parallel shapes in the plane. A subfamily of these graphs are {L, |, --}-contact graphs which are the contact graphs of axis parallel L, |,…

Computational Geometry · Computer Science 2017-07-31 Daniel Gonçalves , Lucas Isenmann , Claire Pennarun

An \emph{obstacle representation} of a graph consists of a set of polygonal obstacles and a distinct point for each vertex such that two points see each other if and only if the corresponding vertices are adjacent. Obstacle representations…

Computational Geometry · Computer Science 2013-06-14 Alexander Koch , Marcus Krug , Ignaz Rutter
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