On February 16, 2021, Martin Ziegler from KAIST gave a talk at the Discrete Math Seminar on the encoding problem of metric spaces from the perspective of the complexity theory. The title of his talk was “Quantitative Coding and Complexity Theory of Continuous Data“.

## Jie Ma (马杰) gave an online talk on the maximum number of edges in a 2-connected graph with no two cycles of the same length at the Virtual Discrete Math Colloquium

On February 10, 2021, Jie Ma (马杰) from the University of Science and Technology of China gave an online talk at the Virtual Discrete Math Colloquium about the resolution of a conjecture of Boros, Caro, Füredi, and Yuster on the maximum number of edges in a 2-connected graph without two cycles of the same length. The title of his talk was “Non-repeated cycle lengths and Sidon sequences“.

## Doowon Koh (고두원) gave a talk on the approach to an upper bound of the point-sphere incidences over the finite field from the restriction estimates for cones at the Discrete Math Seminar

On February 9, 2021, Doowon Koh (고두원) from Chungbuk National University gave a talk at the Discrete Math Seminar on the restriction conjecture for the cone in four dimensions and its applications to the upper bound on the point-sphere incidences in the field field setting. The title of his talk was “On the cone restriction conjecture in four dimensions and applications in incidence geometry“.

## Ron Aharoni gave an online talk on the colorful version of the KKM theorem and a method of dividing multiple cakes at the Virtual Discrete Math Colloquium

On February 3, 2021, Ron Aharoni from the Technion gave an online talk at the Virtual Discrete Math Colloquium about the colorful version of the KKM theorem on topology and the problem of fairly partitioning multiple cakes. The title of his talk was “Colorful KKM and multiple cakes division“.

Photo by Marcus Quigmire from Wikipedia. CC BY-SA 2.0

## Dong Yeap Kang (강동엽) gave an online talk on the proof of the Erdős-Faber-Lovász conjecture (1972) at the Virtual Discrete Math Colloquium

On January 27, 2021 at the Virtual Discrete Math Colloquium, Dong Yeap Kang (강동엽) from the University of Birmingham presented his recent breakthrough on the Erdős-Faber-Lovász conjecture, jointly with Tom Kelly, Daniela Kühn, Abhishek Methuku, and Deryk Osthus. The title of his talk is “A proof of the Erdős-Faber-Lovász conjecture“.

## Tuan Tran gave a talk on the minimum saturated families of sets at the Discrete Math Seminar

On January 26, 2021, Tuan Tran from the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on a result towards the conjecture of Erdős and Kleitman on the size of an s-saturated family of subsets of {1,2,…,n}. The title of his talk was “Minimum saturated families of sets“.

## Yusuke Kobayashi gave an online talk on his algorithm for finding a large subgraph keeping the distance function differs by at most a constant at the Virtual Discrete Math Colloquium

On January 20, 2021, Yusuke Kobayashi (小林 佑輔) from RIMS, Kyoto University gave an online talk at the Virtual Discrete Math Colloquium on the fixed-parameter tractability of the problem of finding a small set X of edges such that for every pair v, w of vertices the distance from v to w in G is at most a constant plus the distance from v to w in G-X. The title of his talk was “An FPT Algorithm for Minimum Additive Spanner Problem“.

## Ben Lund gave a talk on an interesting property of perfect matchings in a bipartite graphs at the Discrete Math Seminar

On January 19, 2021, Ben Lund from the IBS Discrete Mathematics Group presented his result with Matija Bucic, Pat Devlin, Mo Hendon, and Dru Horne showing that each perfect matching in a bipartite graph intersects at least half of all perfect matchings. The title of his talk was “Perfect matchings and derangements on graphs“.

## Rose McCarty presented a result on flooding immersions of Eulerian group-labelled graphs motivated by vertex-minors of graphs at the Virtual Discrete Math Colloquium

At the Virtual Discrete Math Colloquium on January 13, 2021, Rose McCarty from University of Waterloo gave a talk presenting her work with Jim Geelen and Paul Wollan on flooding immersions of Eulerian group-labelled graphs, related to vertex-minors of graphs. The title of her talk was “Vertex-minors and flooding immersions“.

## Andreas Holmsen gave a talk on combinatorial geometry in convexity spaces at the Discrete Math Seminar

On January 12, 2021, Andreas Holmsen from KAIST gave a talk on the combinatorial geometry in convexity spaces. The title of his talk was “Discrete geometry in convexity spaces“.

This seminar talk was in honor of Helge Tverberg, who passed away in December 28, 2020 and was the Ph.D. advisor of Andreas Holmsen.