On a theorem of Erdős and Simonovits on graphs not containing the cube

Abstract

The cube Q is the usual 8-vertex graph with 12 edges. Here we give a new proof for a theorem of Erdős and Simonovits concerning the Turán number of the cube. Namely, it is shown that e(G) < n^{8/5}+(2n)^{3/2} holds for any n-vertex cube-free graph G. Our aim is to give a self-contained exposition. We also point out the best known results and supply bipartite versions.

arXiv comment15 pages. This is the preliminary version of my article in the Turan memorial volume