The previous lecture in this series is here. The next lecture in this series is here.
Among all graphs with a given edge density, which graph has the maximum/minimum triangle density? Prof. Zhao explains extremal problems on subgraph densities using the framework of graph limits.
These videos are of a lecture course by Yufei Zhao at the Massachusetts Institute of Technology in 2019, and made available as part of its OpenCourseWare initiative. The website for the course may be found here.