ZixiangXu

For a graph $F$, the Turán number is the maximum number of edges in an $n$-vertex simple graph not containing $F$. The celebrated Erdős-Stone-Simonovits Theorem gives that \ where $\chi (F)$ is the chromatic number of $H$. This theorem asymptotically solves the problem when $\chi (F)⩾3$. In case of bipartite graphs $F$, not even the order of magnitude …