**Abstract:** The chromatic number of \(G \times H\) can be smaller than the minimum of the chromatic numbers of finite simple graphs \(G\) and \(H\).

2

a/graphtheory
posted by
smh
6 months ago

Counterexamples to Hedetniemi's conjecture
(arxiv.org/abs/1905.02167)

**Abstract:** The chromatic number of \(G \times H\) can be smaller than the minimum of the chromatic numbers of finite simple graphs \(G\) and \(H\).