A computational approach to Conwayʼs thrackle conjecture

R Fulek, J Pach - Computational Geometry, 2011 - Elsevier
A drawing of a graph in the plane is called a thrackle if every pair of edges meets precisely
once, either at a common vertex or at a proper crossing. Let t (n) denote the maximum …

Hanani-Tutte and related results

M Schaefer - Geometry—Intuitive, Discrete, and Convex: A Tribute to …, 2013 - Springer
We investigate under what conditions crossings of adjacent edges and pairs of edges
crossing an even number of times are unnecessary when drawing graphs. This leads us to …

Conway's conjecture for monotone thrackles

J Pach, E Sterling - The American Mathematical Monthly, 2011 - Taylor & Francis
A drawing of a graph in the plane is called a thrackle if every pair of edges meet precisely
once, either at a common vertex or at a proper crossing. According to Conway's conjecture …

[HTML][HTML] Removing even crossings on surfaces

MJ Pelsmajer, M Schaefer, D Štefankovič - European Journal of …, 2009 - Elsevier
In this paper we investigate how certain results related to the Hanani–Tutte theorem can be
extended from the plane to surfaces. We give a simple topological proof that the weak …

Outerplanar thrackles

G Cairns, Y Nikolayevsky - Graphs and Combinatorics, 2012 - Springer
We show that a graph drawing is an outerplanar thrackle if and only if, up to an inversion in
the plane, it is Reidemeister equivalent to an odd musquash. This establishes Conway's …

On the bounds of Conway's thrackles

L Goddyn, Y Xu - Discrete & Computational Geometry, 2017 - Springer
A thrackle on a surface X is a graph of size e and order n drawn on X such that every two
distinct edges of G meet exactly once either at their common endpoint, or at a proper …

[HTML][HTML] Thrackles: An improved upper bound

R Fulek, J Pach - Discrete Applied Mathematics, 2019 - Elsevier
A thrackle is a graph drawn in the plane so that every pair of its edges meet exactly once:
either at a common end vertex or in a proper crossing. We prove that any thrackle of n …

[HTML][HTML] Great-circle spherical thrackles

G Cairns, TJ Koussas, Y Nikolayevsky - Discrete Mathematics, 2015 - Elsevier
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The chromatic number of the convex segment disjointness graph

R Fabila-Monroy, DR Wood - Spanish Meeting on Computational …, 2011 - Springer
Let P be a set of n points in general and convex position in the plane. Let D n be the graph
whose vertex set is the set of all line segments with endpoints in P, where disjoint segments …

Generalized Thrackles and Geometric Graphs in with No Pair of Strongly Avoiding Edges

A Perlstein, R Pinchasi - Graphs and Combinatorics, 2008 - Springer
We define the notion of a geometric graph in R^ 3. This is a graph drawn in R^ 3 with its
vertices drawn as points and its edges as straight line segments connecting corresponding …