The minimum number of triangular edges and a symmetrization method for multiple graphs
arXiv:1411.0771
Abstract
We give an asymptotic formula for the minimum number of edges contained in triangles in a graph having n vertices and e edges. Our main tool is a generalization of Zykov's symmetrization method that can be applied for several graphs simultaneously.
Same paper, better presentation. Now it has 10 pages with 7 figures