On February 15, 2023, Robert Hickingbotham from Monash University gave an online talk at the Virtual Discrete Math Colloquium on the relation between the tree-width and the Hadwiger number of circle graphs. The title of his talk was “Treewidth, Circle Graphs and Circular Drawings“.
Raphael Steiner gave a talk on a stronger version of Hadwiger’s conjecture at the Discrete Math Seminar
On February 14, 2023, Raphael Steiner from ETH Zürich gave a talk at the Discrete Math Seminar on a stronger version of Hadwiger’s conjecture, which finds a clique minor in which one of its branch set is a singleton. The title of his talk was “Strengthening Hadwiger’s conjecture for 4- and 5-chromatic graphs“. He is currently visiting the IBS discrete mathematics group for 2 weeks.
Will Perkins gave a lecture for 5 days at the winter school “Statistical Physics and Combinatorics”
On February 6-10, 2023, Will Perkins from Georgia Institute of Technology visited the IBS and gave a lecture for 5 days at the winter school “Statistical Physics and Combinatorics.” This winter school was organized by the IBS Extremal Combinatorics and Probability Group and Shandong University.
Benjamin Bergougnoux gave an online talk on proving tight lower bounds for the running time of various problems parameterized by rank-width at the Virtual Discrete Math Colloquium
On February 1, 2023, Benjamin Bergougnoux from the University of Warsaw gave an online talk at the Virtual Discrete Math Colloquium about proving tight lower bounds for the running time of various problems parameterized by rank-width. The title of his talk was “Tight Lower Bounds for Problems Parameterized by Rank-width“.
Abhishek Methuku gave a talk on the resolution of the Erdős-Faber-Lovász conjecture at the Discrete Math Seminar
On January 31, 2023, Abhishek Methuku from ETH Zürich gave a talk at the Discrete Math Seminar on the resolution of the Erdős-Faber-Lovász conjecture for all large instances. The title of his talk was “A proof of the Erdős–Faber–Lovász conjecture“. Abhishek Methuku was a former member of the IBS Discrete Mathematics Group in 2019-2020.
Pedro Montealegre gave an online talk on a proof labeling scheme certifying that the graph has tree-width at most k and satisfies a monadic second-order property with certificates of small size at each vertex at the Virtual Discrete Math Colloquium
On January 19, 2023, Pedro Montealegre from Universidad Adolfo Ibáñez gave an online talk at the Virtual Discrete Math Colloquium on a proof labeling scheme certifying that a graph has tree-width at most k and satisfies a monadic second-order property with a certificate of small size at each vertex. The title of his talk was “A Meta-Theorem for Distributed Certification“.
Noleen Köhler gave a talk on classes of graphs on which the parameterized complexity of the FO model checking on their subclasses can be explained by the twin-width at the Discrete Math Seminar
On January 17, 2023, Noleen Köhler from the LAMSADE, CNRS gave a talk at the Discrete Math Seminar on classes of graphs on which the first order model checking is FPT on its subclass if and only if the twin-width is bounded. The title of her talk was “Twin-Width VIII: Delineation and Win-Wins“.
Mamadou Moustapha Kanté gave a talk on the recognizability and the MSO definability of a class of matroids having the strongly pigeonhole property at the Discrete Math Seminar
On January 10, 2023, Mamadou Moustapha Kanté from the Université Clermont Auvergne gave a talk at the Discrete Math Seminar on the recognizability and the MSO definability for classes of matroids of bounded path-width having the strongly pigeonhole property. The title of his talk was “MSOL-Definable decompositions“.
Youngho Yoo gave a talk on the approximation algorithm for the traveling salesman problem on cubic graphs at the Discrete Math Seminar
On January 3, 2023, Youngho Yoo from Texas A&M University gave a talk at the Discrete Math Seminar on the approximation algorithm for the traveling salesman problem on cubic graphs by showing an upper bound on the length of a shortest closed spanning walk in a simple 2-connected subcubic graph. The title of his talk was “Approximating TSP walks in subcubic graphs“.
Debsoumya Chakraborti received the Outstanding Researcher Award and Mia Oh received the Outstanding Staff Award
On January 2, 2023, Debsoumya Chakraborti from the IBS Discrete Mathematics Group received the 2022 Outstanding Researcher Award (우수연구원상) from the IBS president. In addition, Mia Oh (오미아), one of our staff, received the 2022 Outstanding Staff Award (우수직원상) from the IBS president. Congratulations!