기초과학연구원 이산수학그룹
On November 3, 2020, Jaeseong Oh (오재성) from Seoul National University presented his work with Iain Moffatt on the characterization of ribbon graphs having the same delta-matroid. The title of his talk is “A 2-isomorphism theorem for delta-matroids“.
On October 27, 2020, Jeong Ok Choi (최정옥) from IBS Discrete Mathematics Group / GIST gave a talk on some game-theoretic problems on graphs, more specifically on the contagion game and the network creation game. The title of her talk was “Various game-theoretic models on graphs“.
On October 22, 2020, Chun-Hung Liu (劉俊宏) from Texas A&M University gave a talk on his recent work answering several open problems on the asymptotic dimension of several graph classes at the Virtual Discrete Math Colloquium. The title of his talk was “Asymptotic dimension of minor-closed families and beyond“.
On October 21, 2020, Joonkyung Lee (이준경) from University College London gave a talk at the Discrete Math Seminar on norms defined from graphs motivated by Sidorenko’s conjecture and Gowers norms on extremal combinatorics, unifying two seemingly different concepts of real-norming graphs and complex-norming graphs. The title of his talk was “On graph norms for complex-valued functions“. Joonkyung Lee will stay at the IBS discrete mathematics group for several weeks from October 19.
On September 29, 2020, Minki Kim (김민기) from the IBS Discrete Mathematics Group presented his work on the collapsibility of the complex $I_n(G)$ of vertex sets of a graph $G$ not containing any $n$-vertex independent set at the Discrete Math Seminar. The title of his talk was “Complexes of graphs with bounded independence number“.
On September 24, 2020, Zihan Tan from University of Chicago gave an online talk about his recent work with Julia Chuzhoy on an improved bound for the grid minor theorem of Robertson and Seymour. They prove that every graph with no $g\times g$ grid minor has tree-width at most $O(g^{9}\operatorname{poly log}(g))$. The title of his talk was “Towards Tight(er) Bounds for the Excluded Grid Theorem“.
On September 22, 2020, Jinha Kim (김진하) from the IBS Discrete Mathematics Group presented her recent work on the collapsibility of the non-cover complexes of graphs at the Discrete Math Seminar. The non-cover complex of a graph is a simplicial complex consisting of subsets of vertices not covering all edges. The title of her talk was “Collapsibility of Non-Cover Complexes of Graphs“.
On September 17, 2020, Luke Postle from the University of Waterloo gave an online talk about his recent (another) breakthrough towards Hadwiger’s conjecture. The title of his talk was “Further progress towards Hadwiger’s conjecture“.
On September 15, 2020, Debsoumya Chakraborti from the IBS Discrete Mathematics Group presented a talk on the extremal problem on the number of cliques in a graph of small maximum degree with a fixed number of edges. The title of his talk was “Maximum number of cliques in a graph with bounded maximum degree“.
On September 10, 2020, Sebastian Siebertz from University of Bremen gave an online talk about recent attempts to combine the model theory to the theory of dense graphs at the Virtual Discrete Math Colloquium. The title of his talk was “Rank-width meets stability“.