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“.
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“.
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“.
On January 5, 2021, O-joung Kwon (권오정) from Incheon National University and IBS Discrete Mathematics Group presented his recent work with Archontia C. Giannopoulou, Ken-ichi Kawarabayashi, Stephan Kreutzer, and Qiqin Xie on generalizing tangles and tangle-tree decompositions to directed graphs at the Discrete Math Seminar. The title of his talk was “Directed tangles and applications“.
On January 4, 2021, Pascal Gollin from the IBS Discrete Mathematics Group received the “Research of the Year” award from the president of IBS. Congratulations!