KAIST Math Graduate Student Seminar (KMGS)

We uploaded photos from the 48th KMGS on Sep 11, 2025.
Thanks, Mujin Choi and all the participants!

The 48th KMGS will be held on September 11, Thursday, at the Natural Science Building (E6-1) Room 1410. We invite a speaker Mujin Choi from the Dept. of Mathematical Sciences, KAIST.
The abstract of the talk is as follows.

[Speaker] 최무진 (Mujin Choi) from Dept. of Mathematical Sciences, KAIST, supervised by Prof. 엄상일, Sang-il Oum
[Title] Toward an induced grid minor theorem
[Discipline] Combinatorics
[Abstract]
The Grid Minor Theorem by Robertson and Seymour is one of the most important results in structural graph theory. In recent years, there has been growing interest in exploring an induced analogue of this theorem. In this talk, 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. These two graphs can be considered as strong evidence for existence of a grid as an induced minor. Our proof uses a generalization of the concept of brambles for tree-independence number. This is based on joint work with Claire Hilaire, Martin Milanič, and Sebastian Wiederrecht.
[Language] Korean but English if it is requested

We are informing you of the schedule of the KAIST Math Graduate Student Seminar(KMGS) 2025 Fall. We look forward to your attention and participation!

In this seminar, 6 talks will be held on Thursday from 11:50 to 12:40 in Room 1401 on the first floor of the Natural Science Building(E6-1).

Lunch will be provided after each talk.
Please apply through the QR code on the poster.

We are informing you of the schedule of the KAIST Math Graduate student Seminar(KMGS) 2025 Spring. We look forward to your attention and participation!

In this seminar, 6 talks will be held on Thursday from 11:50 to 12:40 in Room 1501 on the first floor of the Natural Science Building(E6-1).

Lunch will be provided after each talk.
Please apply through the QR code on the poster.

The 41th KMGS will be held on December 05, Thursday, at the Natural Science Building (E6-1) Room 3438. We invite a speaker Woojoo Lee from the Dept. of Mathematical Sciences, KAIST.
The abstract of the talk is as follows.

[Speaker] 이우주 (Woojoo Lee) from Dept. of Mathematical Sciences, KAIST, supervised by Prof. 임미경, Mikyoung Lim
[Title] Inverse scattering problems for moving targets: tracking of location and orientation
[Discipline] Inverse problems (Applied mathematics)
[Abstract]
Inverse scattering problems aim to identify geometric and material properties of scatterers from measurements. For moving targets, the problems extend to estimating their trajectories; these problems are inherently nonlinear, ill-posed, and further complicated by the unpredictable motion of the targets. In this talk, I address the inverse scattering problem for moving targets using far-field data. Specifically, I focus on identifying both the location and orientation of targets from a single incident field, assuming the target’s movement is modeled as a rigid motion. We derive the translation and rotation formulas for far-field data and establish their local Lipschitz property with respect to the rotation angle. By integrating these results with Bayesian optimization and machine learning, we recover the trajectory of the moving target and estimate its shape with accurate orientation at each time point. Numerical simulations with randomly generated targets and trajectories demonstrate the robustness and effectiveness of the proposed method.
[Language] Korean but English if it is requested

The 40th KMGS will be held on November 21, Thursday, at the Natural Science Building (E6-1) Room 3438. We invite a speaker Minseong Kwon from the Dept. of Mathematical Sciences, KAIST.
The abstract of the talk is as follows.

[Speaker] 권민성 (Minseong Kwon) from Dept. of Mathematical Sciences, KAIST, supervised by Prof. 황준묵, Jun-Muk Hwang from IBS CCG
[Title] Isotropy Irreducible Varieties and Complex Contact Geometry
[Discipline] Geometry
[Abstract]
Isotropy irreducible spaces are first introduced by Riemannian geometers, as homogeneous real manifolds carrying a canonical invariant metric. Such spaces are classified by Manturov (1960s), Wolf (1968) and Krämer (1975), and their classification provides a number of interesting new examples, for example satisfying the Einstein condition. In this talk, I will introduce a complexified version of isotropy irreducible space, which is called isotropy irreducible variety. In the first half, I will explain geometric properties of isotropy irreducible varieties, and give several non-classical examples belonging to algebraic geometry. Next, I will present a connection between isotropy irreducible varieties and complex contact geometry, which has not been observed in the real setting.
[Language] Korean but English if it is requested

The 39th KMGS will be held on November 7, Thursday, at the Natural Science Building (E6-1) Room 3438.We invite a speaker Junseok Kim from the Dept. of Mathematical Sciences, KAIST.
The abstract of the talk is as follows.

[Speaker] 김준석 (Junseok Kim) from Dept. of Mathematical Sciences, KAIST, supervised by Prof. 백형렬, Hyungryul Baik
[Title] Right-angled Artin groups and their automorphism groups
[Discipline] Group Theory
[Abstract]Right-angled Artin groups are fascinating objects in geometric topology and geometric group theory. They play a central role in Ian Agol’s proof of Thurston’s virtual fibering and virtual Haken conjectures, providing numerous examples in the field of geometric group theory. In this talk, we will focus on their automorphism groups and outer automorphism groups. I will introduce these groups from a group-theoretic perspective, covering aspects such as finite generation and the standard representation. If time permits, we will also explore the relationship between Gromov-hyperbolicity and the outer automorphism groups.
[Language] Korean but English if it is requested

The 38th KMGS will be held on October 31, Thursday, at the Natural Science Building (E6-1) Room 3438.We invite a speaker Yun Min Song from the Dept. of Mathematical Sciences, KAIST.
The abstract of the talk is as follows.

[Speaker] 송윤민 (Yun Min Song) from Dept. of Mathematical Sciences, KAIST, supervised by Prof. 김재경, Jae Kyoung Kim
[Title] Personalized Digital Medicine for Mood & Sleep disorders using mathematical models
[Discipline] Mathematical Biology
[Abstract]
Mood and sleep disorders are common in today’s society, often linked to irregular sleep patterns and disrupted circadian rhythms. However, it is difficult to measure circadian rhythms directly, making the relationship between these factors unclear. In this talk, we show how mathematical models, applied to data from wearable devices, can help predict changes in circadian rhythms and clarify the connection between sleep patterns and mood. We also discuss the potential for using these models to develop personalized digital treatments for mood and sleep disorders.
[Language] Korean but English if it is requested

The 37th KMGS will be held on October 10, Thursday, at the Natural Science Building (E6-1) Room 3438.We invite a speaker Dohyeon Lee from the Dept. of Mathematical Sciences, KAIST.
The abstract of the talk is as follows.

[Speaker] 이도현 (Dohyeon Lee) from Dept. of Mathematical Sciences, KAIST, supervised by Prof. Andreas Holmsen
[Title] Colorful intersecting patterns of convex sets
[Discipline] Combinatorics
[Abstract]
In d-dimensional Euclidean space R^d, any set of d+1 points is linearly dependent, meaning they can be partitioned into two parts, say A and B, such that the subspace spanned by A and B intersect nontrivially. Similarly, d+2 points in R^d have affine dependency, and Radon’s theorem asserts that this dependency gives a partition that their convex hull intersect. In this talk, we will see fundamental results in combinatorial geometry including Tverberg’s, Caratheodory’s, and Helly’s theorem in a linear algebraic point of view. We will also discuss various generalizations of these theorems, including colorful and fractional versions.
[Language] Korean but English if it is requested

The 36th KMGS will be held on September 26th, Thursday, at the Natural Science Building (E6-1) Room 3438.
We invite a speaker Namhyun Eun from the Dept. of Mathematical Sciences, KAIST.
The abstract of the talk is as follows.

[Speaker] 은남현 (Namhyun Eun) from Dept. of Mathematical Sciences, KAIST, supervised by Prof. 강문진, Moon-Jin Kang
[Title] Uniqueness and Stability of Riemann shocks to compressible Euler system in a class of inviscid limits
[Discipline] Analysis (of PDEs)
[Abstract]
In this talk, we will discuss the uniqueness and stability of a Riemann shock solution to the compressible Euler system, which is a self-similar entropy solution connecting two different constant states, in a physical vanishing viscosity limits. We focus on the one dimensional compressible full Euler system and consider the Brenner-Navier-Stokes-Fourier system, which is an amendment of the Navier-Stokes-Fourier system, to describe the physical perturbation class. (This is a joint work with Moon-Jin Kang (KAIST) and Saehoon Eo (Stanford University).
[Language] Korean