collaborators

5 papers

math.CO2025

Reduced bandwidth: a qualitative strengthening of twin-width in minor-closed classes (and beyond)

Édouard Bonnet, O-joung Kwon, David R. Wood

In a reduction sequence of a graph, vertices are successively identified until the graph has one vertex. At each step, when identifying and , each edge incident to exactly o…

cs.DS2025

A new width parameter of graphs based on edge cuts: -edge-crossing width

Yeonsu Chang, O-joung Kwon, Myounghwan Lee

We introduce graph width parameters, called -edge-crossing width and edge-crossing width. These are defined in terms of the number of edges crossing a bag of a tree-cut decompo…

math.CO2025

A unified Erdős-Pósa theorem for cycles in graphs labelled by multiple abelian groups

J. Pascal Gollin, Kevin Hendrey, O-joung Kwon +2

In 1965, Erdős and Pósa proved that there is an (approximate) duality between the maximum size of a packing of cycles and the minimum size of a vertex set hitting all cycles. Suc…

math.CO2024

A half-integral Erdős-Pósa theorem for directed odd cycles

Ken-ichi Kawarabayashi, Stephan Kreutzer, O-joung Kwon +1

We prove that there exists a function such that every directed graph contains either directed odd cycles where every vertex of is c…

math.CO2024

A characterization of graphs of radius- flip-width at most

Yeonsu Chang, Sejin Ko, O-joung Kwon +1

The -flip-width of a graph, for , is a graph parameter defined in terms of a variant of the cops and robber game, called the flipper game, and it…