activity
20242026
collaborators

9 papers

math.CO2026

A directed flat wall theorem excluding a crossrow grid

Meike Hatzel, Ken-ichi Kawarabayashi, Stephan Kreutzer +1

The graph minor project contains the most influential results in recent undirected graph theory research. There has been progress in recent years in generalising some of their resu…

math.CO2026

Optimal Bounds for the k-Disjoint Paths Problem

Dario Cavallaro, Maximilian Gorsky, Stephan Kreutzer +2

The Graph Minors Series of Robertson and Seymour forms the foundation of algorithmic structural graph theory, yielding fixed-parameter algorithms for problems such as Disjoint Path…

cs.DM2026

Well-Quasi-Ordering Eulerian Digraphs: Bounded Carving Width

Dario Cavallaro, Ken-ichi Kawarabayashi, Stephan Kreutzer

We prove that every class of Eulerian directed graphs of bounded carving width (equivalently of bounded degree and treewidth) is well-quasi-ordered by strong immersion. In fact, we…

cs.DM2026

Cycles of Well-Linked Sets I: an Elementary Bound for Directed Cycle Packing

Meike Hatzel, Stephan Kreutzer, Marcelo Garlet Milani +1

In 1996, Reed, Robertson, Seymour and Thomas [Combinatorica 1996] proved Younger's Conjecture, which states that, for all directed graphs , there exists a function such that…

cs.DM2026

Cycles of Well-Linked Sets II: an Elementary Bound for the Directed Grid Theorem

Meike Hatzel, Stephan Kreutzer, Marcelo Garlet Milani +1

In 2015, Kawarabayashi and Kreutzer proved the Directed Grid Theorem - the generalisation of the well-known Excluded Grid Theorem to directed graphs - confirming a conjecture by Re…

cs.DM2025

Well-Quasi-Ordering Eulerian Digraphs Embeddable in Surfaces by Strong Immersion

Dario Cavallaro, Ken-ichi Kawarabayashi, Stephan Kreutzer

We prove that for every surface , the class of Eulerian directed graphs that are Eulerian embeddable into (in particular they have degree at most ) is well-quasi-ordere…