3 papers
math.CO2025
A characterization of locally ordered ternary relations in terms of digraphs
Guillermo Gamboa Quintero, Martín Matamala, Juan Pablo Peña
In 1917, Huntington and Kline, followed by Huntington in 1924, studied systems of axioms for ternary relations aiming to capture the concepts of linear order (called betwenness) an…
math.CO2025
Strong odd coloring in minor-closed classes
Miriam Goetze, Fabian Klute, Kolja Knauer +3
We show that the strong odd chromatic number on any proper minor-closed graph class is bounded by a constant. We almost determine the smallest such constant for outerplanar graphs.
math.CO2024
Lines on digraphs of low diameter
Gabriela Araujo-Pardo, Martín Matamala, Juan P. Peña +1
A set of n non-collinear points in the Euclidean plane defines at least n different lines. Chen and Chvtal in 2008 conjectured that the same results is true in metric spaces for an…