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수학자 그래프이론 전공 기초과학연구원 이산수학그룹
Seonghun Park (박성훈) gave a talk on formalizing the flag algebra in the lean theorem prover

On February 10, 2026, Seonghun Park (박성훈) from KAIST gave a talk on formalizing the flag algebra introduced by Alexander Razborov in the lean theorem…

https://dimag.ibs.re.kr/2026/seonghun-park-flag-algebra/
February 11, 2026 at 2:34 AM
#New_accepted_conference_paper
*Colin Geniet*, *Gunwoo Kim*, and Lucas Meijer,
First-Order Logic and Twin-Width for Some Geometric Graphs,
In the Proceedings of the 42nd International Symposium on Computational Geometry (SoCG 2026), accepted, 2026.
arxiv.org/abs/2512.21896
First-Order Logic and Twin-Width for Some Geometric Graphs
For some geometric graph classes, tractability of testing first-order formulas is precisely characterised by the graph parameter twin-width. This was first proved for interval graphs among others in [...
arxiv.org
February 10, 2026 at 11:56 AM
#New_arXiv_paper
*Maximilian Gorsky* and Clemens Kuske,
On non-planar, cycle-conformal graphs, 2026.
arxiv.org/abs/2602.07331
On non-planar, cycle-conformal graphs
A graph $G$ is called matching covered if all of its edges are contained in some perfect matching of $G$. Furthermore, a cycle $C \subseteq G$ is called conformal if $G - V(C)$ has a perfect matching ...
arxiv.org
February 10, 2026 at 7:25 AM
Xiaofan Yuan gave a talk on the minimum color-degree condition for having a rainbow path at the Discrete Math Seminar

On February 3, 2026, Xiaofan Yuan from the IBS Extremal Combinatorics and Probability Group gave a talk at the Discrete Math…

https://dimag.ibs.re.kr/2026/xiaofan-yuan-rainbow/
February 3, 2026 at 1:30 PM
#New_arXiv_paper
*Maximilian Gorsky*, Michał T. Seweryn, and Sebastian Wiederrecht,
The price of homogeneity is polynomial,
2026.
arxiv.org/abs/2602.01882
The price of homogeneity is polynomial
We provide explicit and polynomial bounds for the Homogeneous Wall Lemma which occurred for the first time implicitly in the $13$th entry of Robertson and Seymour's Graph Minors Series [JCTB 1990] and...
arxiv.org
February 3, 2026 at 5:42 AM
#New_accepted_paper
*Jungho Ahn*, *Jinha Kim*, and *O-joung Kwon*,
Unified almost linear kernels for generalized covering and packing problems on nowhere dense classes,
J. Comput. System Sci., accepted, 2026.
arxiv.org/abs/2207.06660
Unified almost linear kernels for generalized covering and packing problems on nowhere dense classes
Let $\mathcal{F}$ be a family of graphs, and let $p,r$ be nonnegative integers. The \textsc{$(p,r,\mathcal{F})$-Covering} problem asks whether for a graph $G$ and an integer $k$, there exists a set $D...
arxiv.org
February 1, 2026 at 4:17 AM
Welcome Hyunsung Choi (최현성), a new graduate student of the IBS Discrete Mathematics Group

The IBS Discrete Mathematics Group welcomes Hyunsung Choi (최현성), a new graduate student of the Discrete Mathematics Group from February 1, 2026. He received…

http://dimag.ibs.re.kr/2026/welcome-hyunsung-choi/
February 1, 2026 at 12:01 AM
#New_arXiv_paper
Jiangdong Ai, Ming Chen, *Seokbeom Kim*, and Hyunwoo Lee,
On a weaker notion of cross t-intersecting families, 2025.
arxiv.org/abs/2601.20516
On a weaker notion of cross $t$-intersecting families
We prove that if two families $\mathcal{F} \subseteq \binom{[n]}{k}$ and $\mathcal{F}' \subseteq \binom{[n]}{k'}$ satisfy $\sum_{1 \leq i, j \leq \ell} \lvert F_i \cap F_j' \rvert \geq \ell^2t - \ell ...
arxiv.org
January 29, 2026 at 8:17 AM
Daniel Dadush gave a talk on a strongly polynomial-time algorithm to solve linear programming problems with at most two non-zero entries per each row or each column at the Discrete Math Seminar

On January 27, 2025, Daniel Dadush from CWI gave a…

https://dimag.ibs.re.kr/2026/daniel-dadush-seminar/
January 29, 2026 at 1:51 AM
#New_arXiv_paper
Hyunwoo Lee, Chi Hoi Yip, and *Semin Yoo*,
Product representations of polynomials over finite fields, 2025.
arxiv.org/abs/2601.16657
Product representations of polynomials over finite fields
Erdős, Sárközy, and Sós studied the asymptotics of the maximum size of a subset of $\{1,2,\ldots, N\}$ such that it does not contain $k$ distinct elements whose product is a perfect square. More gener...
arxiv.org
January 26, 2026 at 8:20 AM
“KAIST 학생이 직접 쓰려고 만든 AI 강의 필기앱
# 10,000시간을 써도 무료⏤ 서버, API 비용이 안들기 때문에 가능합니다. 결제도 안 붙였어요.
# 로컬 AI⏤ 서버가 없기 때문에 인터넷이 필요없어요.
# 철저한 보안⏤모든 내용은 사용자 PC에만 저장됩니다.
# 실시간 번역“
www.altalt.io/ko
Alt - AI Lecture Notetaker
Transform your lectures into organized, searchable notes with AI. Join the waitlist for early access.
www.altalt.io
January 22, 2026 at 8:32 PM
#New_arXiv_paper
Chi Hoi Yip and *Semin Yoo*,
Paley-type matrices and 1-factorizations of complete graphs, 2026.
arxiv.org/abs/2601.12250
Paley-type matrices and $1$-factorizations of complete graphs
Ball, Ortega--Moreno, and Prodromou asked whether, for every odd prime $p$, one can find a $1$-factor of the complete graph $K_{p+1}$ with some arithmetic restrictions related to quadratic residues. T...
arxiv.org
January 21, 2026 at 7:35 AM
Tomáš Masařík gave a talk at the Discrete Math Seminar on finding a balanced separator in an H-minor-free graph in linear time

On January 20, 2026, Tomáš Masařík from the University of Warsaw, Poland, gave a talk on a linear-time algorithm to…

https://dimag.ibs.re.kr/2026/tomas-masarik-seminar/
January 20, 2026 at 1:21 PM
#New_accepted_paper
*O-joung Kwon* and Youngho Yoo,
Erdős-Pósa property of A-paths in unoriented group-labelled graphs,
Combinatorica, accepted, 2026.
arxiv.org/abs/2411.05372
Erdős-Pósa property of $A$-paths in unoriented group-labelled graphs
We characterize the obstructions to the Erdős-Pósa property of $A$-paths in unoriented group-labelled graphs. As a result, we prove that for every finite abelian group $Γ$ and for every subset $Λ$ of ...
arxiv.org
January 19, 2026 at 11:57 PM
Ferdinand Ihringer gave a talk at the Discrete Math Seminar on low-degree Boolean functions and applications of vector space Ramsey numbers

On January 13, 2026, Ferdinand Ihringer from the Southern University of Science and Technology, China gave a…

https://dimag.ibs.re.kr/2026/ferdinand-ihringer/
January 14, 2026 at 4:19 PM
#New_accepted_paper
P. S. Ardra, R. Krithika, Saket Saurabh, and *Roohani Sharma*,
Balanced Substructures in Bicolored Graphs,
Theoret. Comput. Sci., accepted, 2026.
doi.org/10.1016/j.tc...
Redirecting
doi.org
January 12, 2026 at 1:48 AM
#New_arXiv_paper
*Colin Geniet* and Ugo Giocanti,
Basis Number of Graphs Excluding Minors, 2026.
arxiv.org/abs/2601.05195
Basis Number of Graphs Excluding Minors
The basis number of a graph $G$ is the minimum $k$ such that the cycle space of $G$ is generated by a family of cycles using each edge at most $k$ times. A classical result of Mac Lane states that pla...
arxiv.org
January 9, 2026 at 10:06 AM
#New_arXiv_paper
Tuukka Korhonen and *Sang-il Oum*,
Branch-width of connectivity functions is fixed-parameter tractable, 2026.
arxiv.org/abs/2601.04756
Branch-width of connectivity functions is fixed-parameter tractable
A connectivity function on a finite set $V$ is a symmetric submodular function $f \colon 2^V \to \mathbb{Z}$ with $f(\emptyset)=0$. We prove that finding a branch-decomposition of width at most $k$ fo...
arxiv.org
January 9, 2026 at 3:04 AM
Daniel Mock gave a talk at the Discrete Math Seminar on an algorithmic framework for showing the fixed-parameter tractability of the dominating set problem and its generalizations

On January 6, 2026, Daniel Mock from RWTH Aachen gave a talk on an…

https://dimag.ibs.re.kr/2026/daniel-mock/
January 7, 2026 at 2:52 PM
#New_arXiv_paper
*Colin Geniet*, Fatemeh Ghasemi, and Mamadou Moustapha Kanté,
Transducing Linear Decompositions of Tournaments, 2025.
arxiv.org/abs/2601.02999
Transducing Linear Decompositions of Tournaments
Bojańczyk, Pilipczuk, and Grohe [LICS '18] proved that for graphs of bounded linear clique-width, clique-decompositions of bounded width can be produced by a CMSO transduction. We show that in the cas...
arxiv.org
January 7, 2026 at 4:32 AM
IBS에서 열리는 겨울학교:
Recent Advances in Cut-Problems on Graphs.
2026년 1월 19일-23일 오전 10시-11시 30분.
www.ibs.re.kr/ecopro/winte...
January 6, 2026 at 1:25 PM
Welcome Eero Räty, Xiaofan Yuan, and Xin Wei, new members of IBS ECOPRO

The IBS Discrete Mathematics Group welcomes Dr. Eero Räty, Dr. Xiaofan Yuan, and Dr. Xin Wei, new research fellows at the IBS Extremal Combinatorics and Probability Group,…

https://dimag.ibs.re.kr/2026/welcome-raty-yuan-wei/
January 2, 2026 at 2:36 AM
Yunbum Kook (국윤범) gave a talk on a faster randomized algorithm for sampling points in a convex body at the Discrete Math Seminar

On December 30, 2025, Yunbum Kook (국윤범) from the Georgia Institute of Technology gave a talk at the Discrete Math Seminar on a…

https://dimag.ibs.re.kr/2025/sampling/
December 31, 2025 at 5:12 AM
#New_arXiv_paper
*Colin Geniet*, *Gunwoo Kim*, and Lucas Meijer,
First-Order Logic and Twin-Width for Some Geometric Graphs, 2025.
arxiv.org/abs/2512.21896
First-Order Logic and Twin-Width for Some Geometric Graphs
For some geometric graph classes, tractability of testing first-order formulas is precisely characterised by the graph parameter twin-width. This was first proved for interval graphs among others in [...
arxiv.org
December 29, 2025 at 12:49 PM
#New_accepted_paper
Doowon Koh, Ben Lund, Chuandong Xu, and *Semin Yoo*,
Sphere intersections and incidences over finite fields,
Proc. Amer. Math. Soc., accepted, 2025.
arxiv.org/abs/2509.25997
Sphere intersections and incidences over finite fields
We bound the number of incidences between points and spheres in finite vector spaces by bounding the sum of the number of points in the pairwise intersections of the spheres. We obtain new incidence b...
arxiv.org
December 29, 2025 at 12:38 AM