Oliver Janzer

collaborators

2 papers

math.CO2026

Hamiltonicity of regular sublinear expanders

Domagoj BradaÄ, Oliver Janzer

We say that a $d$ -regular graph is a $I^^{3}$ -expander if for every not too large set of vertices $S$ , there are at least $I^^{3} d ∣ S ∣$ edges leaving $S$ , and we say that a graph $G$ is $Î…

math.CO2025

An improved upper bound for the multicolour Ramsey number of odd cycles

Maria Axenovich, Wouter Cames van Batenburg, Oliver Janzer +2

We show that the $k$ -colour Ramsey number of an odd cycle of length $2 ℓ + 1$ is at most $(4 ℓ)^{k} \cdot k^{k / ℓ}$ . This proves a conjecture of Fox and is the first improvem…