### Hong Liu (刘鸿), A solution to Erdős and Hajnal’s odd cycle problem

Room B232 IBS (기초과학연구원)I will go over the history on the study of the set of cycle lengths of graphs with large average degree or chromatic number, and discuss recent work with Richard Montgomery on this topic. In particular, we will see the divergence of harmonic sum of odd cycle lengths in graphs with large chromatic number and …