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20242026
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7 papers · 1 filter

math.CO2026

Hereditary 2-WQO Graph Classes Have Bounded Clique-Width

Julien Duron, Nikolas Mählmann, Szymon Toruńczyk

A graph class is -WQO if its -labeled graphs are well-quasi-ordered under label-preserving induced subgraph embeddings. We show that every hereditary graph class that is -…

math.CO2026

Decomposing tournaments into comparability graphs

Pierre Aboulker, Logan Crew, Julien Duron +7

In this note, we introduce the \emph{partial order decomposition number} of a digraph , denoted , defined as the minimum integer such that $A(D)=A(P_1)\cup\cdots\cup…

math.CO2025

On the minimum number of inversions to make a digraph -(arc-)strong

Julien Duron, Frédéric Havet, Florian Hörsch +1

The {\it inversion} of a set of vertices in a digraph consists of reversing the direction of all arcs of . We study (resp. ) whic…

math.CO2025

Counterexamples to statements on isometric graph coverings

Paul Bastide, Julien Duron, Jędrzej Hodor +2

A connected subgraph of a graph is isometric if it preserves distances. In this short note, we provide counterexamples to several variants of the following general question: When a…

math.CO2025

Planar induced paths via a decomposition into non-crossing ordered graphs

Julien Duron, Hugo Jacob

In any graph, the maximum size of an induced path is bounded by the maximum size of a path. However, in the general case, one cannot find a converse bound, even up to an arbitrary…

math.CO2024

Long induced paths in sparse graphs and graphs with forbidden patterns

Julien Duron, Louis Esperet, Jean-Florent Raymond

Consider a graph with a path of order . What conditions force to also have a long induced path? As complete bipartite graphs have long paths but no long induced path…