Igor Araujo

activity

20242026

collaborators

3 papers

math.CO2026

Monochromatic triangles with empty intersection and Kneser Ramsey numbers

Igor Araujo

Recently, Heath, McCourt, Parker, Schwieder, and Zerbib initiated the systematic study of the $r$ -Kneser Ramsey number $R_{r}^{K G} (s, t)$ and investigated related Ramsey-type problems…

math.CO2025

A note on the maximum ratio between chromatic number and clique number

Igor Araujo, Rafael Filipe, Rafael Miyazaki

Let $f (n)$ be the maximum, over all graphs $G$ on $n$ vertices, of the ratio $\frac{χ ( G )}{ω ( G )}$ , where $χ (G)$ denotes the chromatic number of $G$ and $ω (G)$ the clique number of $…

math.CO2024

On the off-diagonal unordered Erdős-Rado numbers

Igor Araujo, Dadong Peng

Erdős and Rado [P. Erdős, R. Rado, A combinatorial theorem, Journal of the London Mathematical Society 25 (4) (1950) 249-255] introduced the Canonical Ramsey numbers $er (t)$ …