Jonathan Rollin

activity

20122020

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7 papers · 1 filter

math.CO2020

Augmenting Geometric Graphs with Matchings

Alexander Pilz, Jonathan Rollin, Lena Schlipf +1

We study noncrossing geometric graphs and their disjoint compatible geometric matchings. Given a cycle (a polygon) P we want to draw a set of pairwise disjoint straight-line edges…

math.CO2018

The interval number of a planar graph is at most three

Guillaume Guégan, Kolja Knauer, Jonathan Rollin +1

The interval number of a graph $G$ is the minimum $k$ such that one can assign to each vertex of $G$ a union of $k$ intervals on the real line, such that $G$ is the intersection gr…

math.CO2018

Induced and Weak Induced Arboricities

Maria Axenovich, Philip Dörr, Jonathan Rollin +1

We define the induced arboricity of a graph $G$ , denoted by $ia (G)$ , as the smallest $k$ such that the edges of $G$ can be covered with $k$ induced forests in $G$ . This notio…

math.CO2017

Minimal Ordered Ramsey Graphs

Jonathan Rollin

An ordered graph is a graph equipped with a linear ordering of its vertex set. A pair of ordered graphs is Ramsey finite if it has only finitely many minimal ordered Ramsey graphs…

math.CO2016

Regular colorings and factors of regular graphs

Anton Bernshteyn, Omid Khormali, Ryan R. Martin +4

An $(r - 1, 1)$ -coloring of an $r$ -regular graph $G$ is an edge coloring such that each vertex is incident to $r - 1$ edges of one color and $1$ edge of a different color. In this paper…

math.CO2016

Chromatic number of ordered graphs with forbidden ordered subgraphs

Maria Axenovich, Jonathan Rollin, Torsten Ueckerdt

It is well-known that the graphs not containing a given graph H as a subgraph have bounded chromatic number if and only if H is acyclic. Here we consider ordered graphs, i.e., grap…