Showing 2026Show all
2 papers · 1 filter
math.CO2026
Countable Graphs with Finite Path-width: Characterisation and Universality
Tony Huynh, Freddie Illingworth, Nikolai Karol +4
We study path-width and the closely related parameter line-width in countably infinite graphs. Our first result characterises the graphs of finite path-width: they are the graphs t…
math.CO2026
Sparse String Graphs and Region Intersection Graphs over Minor-Closed Classes have Linear Expansion
Nikolai Karol, David R. Wood
We prove that sparse string graphs in a fixed surface have linear expansion. We extend this result to the more general setting of sparse region intersection graphs over any proper…