  The boxicity of a graph G is defined as the minimum integer k such that G is
an intersection graph of axis-parallel k-dimensional boxes. Chordal bipartite
graphs are bipartite graphs that do not contain an induced cycle of length
greater than 4. It was conjectured by Otachi, Okamoto and Yamazaki that chordal
bipartite graphs have boxicity at most 2. We disprove this conjecture by
exhibiting an infinite family of chordal bipartite graphs that have unbounded
boxicity.
