Improvement on the Decay of Crossing Numbers

We prove that the crossing number of a graph decays in a "continuous fashion" in the following sense. For any varepsilon>0 there is a delta>0 such that for n sufficiently large, every graph G with n vertices and mge n^1+varepsilon edges has a subgraph G' of at most (1-delta)m edges and crossing number at least (1-varepsilon)cro(G). This generalizes the result of J. Fox and Cs. Tóth