Bounded-Degree Graphs have Arbitrarily Large Queue-Number

It is proved that there exist graphs of bounded degree with arbitrarily large queue-number. In particular, for all Δ ≥ 3 and for all sufficiently large n, there is a simple Δ-regular n-vertex graph with queue-number at least c √ Δ n 1/2-1/Δ for some absolute constant c.