기초과학연구원 이산수학그룹
On September 16, 2025, Mujin Choi (최무진) from KAIST and the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on unavoidable induced minors in graphs of large tree-independence number without a fixed induced star. The title of his talk was “Excluding ladder and wheel as induced minor in graphs without induced stars“.
We prove that for all positive integers $k$ and $d$, the class of $K_{1,d}$-free graphs not containing the $k$-ladder or the $k$-wheel as an induced minor has a bounded tree-independence number. Our proof uses a generalization of the concept of brambles to tree-independence number. This is based on joint work with Claire Hilaire, Martin Milanič, and Sebastian Wiederrecht.
The IBS Discrete Mathematics Group welcomes Mujin Choi (최무진) and Dohyeon Lee (이도현), new graduate students of the Discrete Mathematics Group from January 2024.
Mujin Choi entered the Seoul National University in 2016, received his B.S. degree from the Department of Mathematical Sciences of Seoul National University in 2023, and entered the Department of Mathematical Sciences of KAIST as a graduate student in September 2023. His advisor is Sang-il Oum.
Dohyeon Lee entered KAIST as an undergraduate student in 2018 and became a graduate student of the Department of Mathematical Sciences of KAIST in September 2023. His advisor is Andreas Holmsen.