On September 10, 2024, Zhihan Jin (金之涵) from ETH Zürich gave a talk at the Discrete Math Seminar on the analog of Helly’s theorem inside the Hamming cube. The title of his talk was “The Helly number of Hamming balls and related problems“.

## Neal Bushaw gave a talk on the rainbow version of the saturation problem at the Discrete Math Seminar

On September 6, 2024, Neal Bushaw from Virginia Commonwealth University gave a talk at the Discrete Math Seminar on the rainbow version of the saturation problem. The title of his talk was “Edge-colored Extremal Problems“.

## Amadeus Reinald gave a talk on finding an oriented tree inside a digraph of large chromatic number at the Discrete Math Seminar

On September 3, 2024, Amadeus Reinald from LIRMM, Université de Montpellier gave a talk at the Discrete Math Seminar on the existence of every oriented tree of fixed size inside a digraph of large chromatic number. The title of his talk was “Oriented trees in $O(k\sqrt k)$-chromatic digraphs, a subquadratic bound for Burr’s conjecture“.

## Welcome Colin Geniet, a new member of the IBS Discrete Mathematics Group

The IBS discrete mathematics group welcomes Dr. **Colin Geniet**, a new research fellow at the IBS Discrete Mathematics Group from September 1, 2024. He received his Ph.D. from ENS de Lyon under the supervision of Prof. Stéphan Thomassé. He is interested in graphs in relation with logic and algorithmic, and more specifically structural graph theory, graph parameters, finite model theory, and parameterized complexity.

## Welcome Eng Keat Hng, a new member of the IBS Extremal Combinatorics and Probability Group

The IBS discrete mathematics group welcomes Dr. **Eng Keat Hng**, a new research fellow at the IBS Extremal Combinatorics and Probability Group from September 1, 2024. He received his Ph.D. from the London School of Economics and Political Science under the supervision of Prof. Julia Böttcher and Prof. Peter Allen. He is interested in extremal and probabilistic combinatorics.

## Welcome Gunwoo Kim (김건우), a new graduate student of the IBS Discrete Mathematics Group

The IBS Discrete Mathematics Group welcomes **Gunwoo Kim (김건우)**, a new graduate student of the Discrete Mathematics Group from September 1, 2024. She received her B.S. degree from the Technische Universität Berlin and entered the School of Computing at KAIST as a graduate student on September 2024. Her advisor is Eunjung Kim (김은정).

## “2024 Combinatorics Workshop” was held at Chungbuk National University on August 28-30

The 2024 Combinatorics Workshop (2024 조합론 학술대회) was held from August 28, 2024 to August 30, 2024 at Chungbuk National University, Cheongju. Combinatorics Workshop (조합론 학술대회) is an annual conference for researchers in combinatorics and related areas in Korea, started in 2004. There were five invited talks and ten contributed talks.

## Invited talks

## Contributed talks

## Organizing Committee

- Doowon Koh (고두원), Chungbuk National University
- Eunjeong Lee (이은정), Chungbuk National University
- Sang-il Oum (엄상일), IBS Discrete Mathematics Group
- Meesue Yoo (류미수), Chungbuk National University

## Hosts

## Dillon Mayhew gave a talk on the monadic second-order definability of gain-graphic matroids at the Discrete Math Seminar

On August 27, 2024, Dillon Mayhew from the University of Leeds gave a talk at the Discrete Math Seminar on the monadic second-order definability of gain-graphic matroids. The title of his talk was “Monadic second-order definability for gain-graphic matroids“.

## 2024 Workshop on (Mostly) Matroids was held at IBS on August 19-23, 2024

The 2024 Workshop on (Mostly) Matroids was held at the IBS Science Culture Center from August 19 to August 23, 2024. There were 41 talks. Videos are available.

## Organizers

- Spencer Backman (University of Vermont)
- Rutger Campbell (IBS Discrete Mathematics Group)
- Dillon Mayhew (University of Leeds)
- Sang-il Oum (IBS Discrete Mathematics Group)

## Speakers

### August 19

- Graham Denham (Western University)
- Geoff Whittle (Victoria University)
- Nick Brettell (Victoria University of Wellington)
- Koji Imamura (Kumamoto University)
- Dillon Mayhew (University of Leeds)
- Dániel Garamvölgyi (Alfréd Rényi Institute of Mathematics)
- Peter Nelson (University of Waterloo)
- José Samper (Pontifical Catholic University of Chile)

### August 20

- Felipe Rincón (Queen Mary University of London)
- Dmitry Mineev (Bar-Ilan University)
- Alex Fink (Queen Mary University of London)
- Kisun Lee (Clemson University)
- Donggyu Kim (KAIST & IBS Discrete Mathematics Group)
- Gianira Alfarano (University College Dublin)
- Sebastian Degen (Bielefeld University)
- Shinya Kawabuchi (Kumamoto University)
- Andrew Fulcher (University College Dublin)

### August 21

- CaroIyn Chun (University of Maryland)
- Iain Moffatt (Royal Holloway University of London)
- Fernanda Rivera Omaña (University of Waterloo)
- J. Dylan Douthitt (Louisiana State University)
- Jim Geelen (University of Waterloo)
- Matthew Kroeker (University of Waterloo)
- Rick Danner (University of Vermont)
- Jonathan Boretsky (MPI Leipzig)

### August 22

- Swee Hong Chan (Rutgers University)
- Hsin-Chieh Liao (University of Miami)
- Donggun Lee (IBS Center for Complex Geometry)
- Soohyun Park (Hebrew University of Jerusalem)
- Changxin Ding (Georgia Institute of Technology)
- Graham Farr (Monash University)
- Benjamin Schröter (KTH Royan Institute of Technology)
- Rudi Pendavingh (Eindhoven Technical University)
- Chi Ho Yuen (National Yang Ming Chiao Tung University)

### August 23

- Sam Bastida (Victoria University of Wellington)
- Charles Semple (University of Canterbury)
- James Davies (University of Cambridge)
- Tamás Schwarcz (Eötvös Loránd University)
- Nathan Bowler (University of Hamburg)
- O-joung Kwon (Hanyang University & IBS Discrete Mathematics Group)
- Meike Hatzel (IBS Discrete Mathematics Group)

## Welcome Felix Christian Clemen, a new member of the IBS Extremal Combinatorics and Probability Group

The IBS Discrete Mathematics Group welcomes Dr. Felix Christian Clemen, a new research fellow at the IBS Extremal Combinatorics and Probability Group, from August 16, 2024. He received his Ph.D. from the University of Illinois at Urbana-Champaign under the supervision of Prof. József Balogh. He is interested in extremal combinatorics, combinatorial geometry, and probabilistic combinatorics.