기초과학연구원 이산수학그룹
The IBS-DIMAG Winter School on Graph Minors is taking place at IBS every Monday, Tuesday, and Wednesday over a three-week period, beginning on February 3, 2025. Sebastian Wiederrecht (KAIST) and Maximilian Gorsky (IBS Discrete Mathematics Group) are giving lectures. In the first week, the topics covered included the two-paths theorem, the flat wall theorem, and various results on societies, transactions, and vortices.
On February 4, 2025, Jang Soo Kim (김장수) from Sungkyunkwan University gave a talk on the maximum of the minimum number of generators to represent an element in a monoid of functions on a fixed finite set and its connection to the minimum feedback arc set of a tournament at the Discrete Math Seminar. The title of his talk was “Longest elements in a semigroup of functions and Slater indices“.
On January 21, 2025, Laure Morelle from the LIRMM gave a talk at the Discrete Math Seminar on the parameterized complexity of modifying a graph into a minor-closed class of graphs. The title of her talk was “Bounded size modifications in time $2^{poly(k)} n^2$“.
On January 14, 2025, Tony Huynh from the Sapienza Università di Roma gave a talk on the peaceable queens problem on the toroidal board at the Discrete Math Seminar. The title of his talk was “The Peaceable Queens Problem“.
On January 3, 2025, Huy Tuan Pham from the Institute for Advanced Study and the Clay Mathematics Institute gave a talk at the Discrete Math Seminar on combinatorial methods for problems on additive combinatorics and random Cayley graphs. The title of his talk was “Random Cayley graphs and Additive combinatorics without groups“.
On December 23, 2024, Zixiang Xu (徐子翔) from the IBS Extremal Combinatorics and Probability Group gave a talk at the Discrete Math Seminar on using linear algebra to prove stability results in extremal set theory. The title of his talk was “Multilinear polynomial methods and stability results on set systems“.
On December 17, 2024, Joonkyung Lee (이준경) from Yonsei University gave a talk on using Lorentzian polynomials to prove a non-trivial upper bound on the number of graph homomorphisms at the Discrete Math Seminar. The title of his talk was “Counting homomorphisms in antiferromagnetic graphs via Lorentzian polynomials“.
On December 13, 2024, Jun Gao (高峻) from the IBS Extremal Combinatorics and Probability Group gave a talk at the Discrete Math Seminar on the maximum sum of the p-th power of degrees in a hypergraph without fixed subhypergraphs. The title of his talk is “Phase transition of degenerate Turán problems in p-norms“.
On December 3, 2024, Yulai Ma from Paderborn University gave a talk on the existence and non-existence of many disjoint perfect matchings in regular graphs with various edge-connectivity conditions at the Discrete Math Seminar. The title of his talk was “Pairwise disjoint perfect matchings in regular graphs“.
Due to a technical issue, some parts of the video were not properly recorded.
On November 26, 2024, Eng Keat Hng from the IBS Extremal Combinatorics and Probability Group gave a talk on characterizing fractionally isomorphic graphons in terms of the Galton-Watson branching process. The title of his talk was “Graphon branching processes and fractional isomorphism“.