On December 26, Thursday, Jaiung Jun (전재웅) from SUNY New Paltz gave a talk at the discrete math seminar held at KAIST. The title of his talk was “The Hall algebra of the category of matroids“.

## Attila Joó gave a talk on the partition of a set into bases of finitary matroids and cofinitary matroids at the discrete math seminar

On December 19, 2019, Attila Joó from University of Hamburg presented a talk on the partitioning of the ground set into bases of finitary and cofinitary matroids at the discrete math seminar. The title of his talk was “Base partition for finitary-cofinitary matroid families”.

## Hong Liu gave a talk on the conjecture of Mader about the topological minors in C4-free graphs at the discrete math seminar

On December 12, 2019, Hong Liu from University of Warwick gave a talk on the resolution of the conjecture of Mader on the existence of a complete topological minor under the condition of average degree for C4-free graphs at the discrete math seminar held at KAIST. The title of his talk was “A proof of Mader’s conjecture on large clique subdivisions in $C_4$-free graphs“.

## Jakub Gajarský gave a talk on the class of graphs of structurally bounded expansion at the discrete math seminar

On December 10, 2019, Jakub Gajarský from Technische Universität Berlin presented a talk on the class of graphs of structurally bounded expansion and its relationship to the low shrubdepth covers. The title of his talk was “First-order interpretations of bounded expansion classes“.