On January 20, 2022, Ken-ichi Kawarabayashi from the National Institute of Informatics, Japan gave an online talk at the Virtual Discrete Math Colloquium on the recent progress towards the directed graph minor theory. The title of his talk was “Toward Directed Graph Minor Theory“.

## Jaehyeon Seo (서재현) gave a talk on the rainbow Turán problem for color-critical graphs at the Discrete Math Seminar

On January 18, 2022, Jaehyeon Seo (서재현) from KAIST gave a talk at the Discrete Math Seminar on the rainbow Turán problem for color-critical graphs. The title of his talk was “A rainbow Turán problem for color-critical graphs“.

## Ron Aharoni gave an online talk at the Virtual Discrete Math Colloquium about a stronger version of the Caccetta-Haggkvist conjecture

On January 13, 2022, Ron Aharoni from the Technion gave an online talk at the Virtual Discrete Math Colloquium on a stronger version of the Caccetta-Haggkvist conjecture and recent results. The title of his talk was “A strong version of the Caccetta-Haggkvist conjecture“.

## Andreas Holmsen gave a talk about a counterexample to the Bárány-Kalai conjecture on line transversals of a finite family of convex sets at the Discrete Math Seminar

On January 11, 2022, Andreas Holmsen from KAIST gave a talk at the Discrete Math Seminar about the counterexample to the Bárány-Kalai conjecture on line transversals of a finite family of convex sets. The title of his talk was “Some recent results on geometric transversals“.

## Seunghun Lee (이승훈) gave a talk on the transversal number and the chromatic number of hypergraphs consisting of facets of a simplicial sphere at the Discrete Math Seminar

On January 4, 2022, Seunghun Lee (이승훈) from the Binghamton University gave a talk at the Discrete Math Seminar on the transversal number and the chromatic number of hypergraphs whose edges are facets of a simplicial sphere. The title of his talk was “Transversals and colorings of simplicial spheres“.

## Tuan Tran gave a talk on the volume of the intersection of two balls in a metric space with applications at the Discrete Math Seminar

On December 14, 2021, Tuan Tran from the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on sufficient conditions for balls in a metric space to have small intersection and their applications. The title of his talk was “Exponential decay of intersection volume with applications on list-decodability and sphere-covering bounds“.

## David Munhá Correia gave an online talk on the existence of rainbow matchings at the Virtual Discrete Math Colloquium

On December 9, 2021, David Munhá Correia from ETH Zürich gave an online talk at the Virtual Discrete Math Colloquium on the existence of rainbow matchings. The title of his talk was “Rainbow matchings“.

## Eun-Kyung Cho (조은경) gave a talk on the minimum independent dominating set at the Discrete Math Seminar

On December 7, 2021, Eun-Kyung Cho (조은경) from the Hankuk University of Foreign Studies gave a talk at the Discrete Math Seminar on various upper bounds for the minimum independent dominating set (or, the minimum maximal independent set) in a graph. The title of her talk was “Independent domination of graphs with bounded maximum degree“.

## Seonghyuk Im (임성혁) gave a talk on the existence of a large complete topological minor in a graph without small dense subgraphs at the Discrete Math Seminar

On November 30, 2021, Seonghyuk Im (임성혁) from KAIST gave a talk at the Discrete Math Seminar on the existence of a large complete topological minor in a graph of bounded average degree when the graph has no small dense subgraphs. The title of his talk was “Large clique subdivisions in graphs without small dense subgraphs“.

## Tuukka Korhonen gave an online talk on a faster FPT-approximation algorithm for rank-width at the Virtual Discrete Math Colloquium

On November 25, 2021, Tuukka Korhonen from the University of Bergen gave an online talk on a faster FPT-approximation algorithm for rank-width at the Virtual Discrete Math Colloquium. The title of his talk was “Fast FPT-Approximation of Branchwidth“.