K_4-free graphs have sparse halves

Abstract

Every $K_4$-free graph on $n$ vertices has a set of $\lfloor n/2\rfloor$ vertices spanning at most $n^2/18$ edges.

Second version addresses referee report

References in corpus (1)

• On the Ramsey-Turán density of triangles

Cited by in corpus (1)

• 10 Problems for Partitions of Triangle-free Graphs