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!

## Stijn Cambie gave a talk on the number of maximal independent sets at the Discrete Math Seminar

On December 28, 2022, Stijn Cambie from the IBS Extremal Combinatorics and Probability Group gave a talk at the Discrete Math Seminar on various problems on the number of independent sets, including the problem of finding a graph with a given number of independent sets of fixed size. The title of his talk was “The 69-conjecture and more surprises on the number of independent sets“.