상일 (Sang-il)

arxiv.orgConstructions for Nearly Diagonal Book Ramsey NumbersThe Ramsey number $R(G_1,G_2)$ is the smallest positive integer $n$ such that for every graph $H$ on $n$ vertices, either $H$ contains a copy of $G_1$ or the complement $\overline H$ contains a copy o...

#New_arXiv_paper Stephen Chung and *William J. Wesley*, Constructions for Nearly Diagonal Book Ramsey Numbers, 2026 arxiv.org/abs/2610.36522

dimag.ibs.re.krXiying Du gave a talk on the characterization of graphs admitting, for any pair (X,Y) of vertex sets of size 2 and 3, two disjoint connected subgraphs containing X and Y, respectively, at the Discrete Math SeminarOn October 27, 2026, Xiying Du from the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on the characterization of graphs admitting two disjoint connected subgraphs containing X and Y, respectively, for any pair (X,Y) of vertex sets of size 2 and 3. The title of her talk was "Characterizing (2,3)-linked graphs".

16h

On October 27, 2026, Xiying Du from the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on the characterization of graphs admitting two disjoint connected subgraphs containing X and Y, respectively, for any pair (X,Y) of… https://dimag.ibs.re.kr/2026/xiying-du-seminar/

상일 (Sang-il) reposted

Ryan Williams

@rrwilliams.bsky.social

An internal model at OpenAI has produced a claimed refutation of ETH! Russell Impagliazzo, Mohan Paturi, and I have been asked to help organize an open and independent examination of this claim. 1/4

상일 (Sang-il) reposted

Ryan Williams

@rrwilliams.bsky.social

Here's a direct link to the PDF claiming a faster 3SAT algorithm: github.com/openai/math/...

github.commath/preprints/The-Exponential-Time-Hypothesis-is-False-October-25-2026/paper.pdf at main · openai/mathContribute to openai/math development by creating an account on GitHub.

dimag.ibs.re.kr2026 Combinatorics Workshop was held at Gonjiam Resort on October 20-22, 2026The 2026 Combinatorics Workshop (2026 조합론 학술대회) was held from October 20, 2026 to October 22, 2026 at Gonjiam Resort, Gwangju. Combinatorics Workshop (조합론 학술대회) is an annual conference for researchers in combinatorics and related areas in Korea, started in 2004. There were 1 plenary talk, 5 invited talks, and 14 contributed talks. Plenary talk Alexandr V. Kostochka

The 2026 Combinatorics Workshop (2026 조합론 학술대회) was held from October 20, 2026 to October 22, 2026 at Gonjiam Resort, Gwangju.... https://dimag.ibs.re.kr/2026/2026-combinatorics-workshop/

상일 (Sang-il) reposted

American Mathematical Society

@amermathsoc.bsky.social

The American Mathematical Society (AMS) has launched AI and Mathematics: Selected Resources, a curated collection to help mathematicians explore the opportunities, questions, and evolving discussions surrounding AI and mathematical discovery.

상일 (Sang-il) reposted

arXiv math.CO Combinatorics

@mathco-bot.bsky.social

Suyoung Choi, Ringi Kim: Small covers and the Four Color Theorem https://arxiv.org/abs/2610.29131 https://arxiv.org/pdf/2610.29131 https://arxiv.org/html/2610.29131

arxiv.orgEvery tournament of dichromatic number $10 k^2$ has a vertex whose out-neighborhood has dichromatic number more than $k$The dichromatic number of a tournament is the minimum number of colors needed to color the vertices so that no directed cycle is monochromatic. Nguyen, Scott, and Seymour (2025) asked whether every to...

#new_arXiv_paper *Seokbeom Kim* and *Sang-il Oum*, Every tournament of dichromatic number 10k^2 has a vertex whose out-neighborhood has dichromatic number more than k, 2026. arxiv.org/abs/2610.29043

arxiv.orgProof of the Erdős-Szemerédi sunflower conjectureIn the 1970s, Erdős and Szemerédi conjectured that for any $n \ge k-1\ge 2$, any collection of subsets of $[n]$ not containing a $k$-sunflower has size at most $c_k^n$ for some $c_k<2$. In the $k=3$ c...

Hyunwoo Lee, a Ph.D. student at KAIST and a research student of IBS ECOPRO, is currently visiting Vienna for a few weeks and he managed to solve the Erdős-Szemerédi sunflower conjecture with Matija Bucić and Fankang He! arxiv.org/abs/2610.26686

youtube.com6.5. Erdős-Szemerédi sunflower conjectureYouTube video by Sang-il Oum

I gave a lecture on the Erdős-Szemerédi sunflower conjecture in my graduate course on combinatorics at KAIST 5 years ago. Hyunwoo emailed me that he learned sunflowers, polynomial methods, and slice rank from this YouTube lecture, all useful for the proof. www.youtube.com/watch?v=o4Dg...

arxiv.orgErdős-Hajnal for excluding pathsWe prove the Erdős-Hajnal conjecture for excluding an arbitrary path. A major step in our proof is a novel Gyárfás path argument based on the ideas of bookkeeping blockades and splitting paths, which ...

The Erdős-Hajnal conjecture for excluding paths has been proved independently by at least 2 groups, 1. Tung Nguyen at Oxford 2. Google DeepMind Also claimed by Yuwen Zhou at UBC... (But according to Junehyuk, the lean formalization is not complete) arxiv.org/abs/2610.24887 github.com/google-deepm...

상일 (Sang-il) reposted

Hung Le

@hunglv.bsky.social

I spent 40+ hours, and now I understand the mechanics of the proof of the L1 embedding conjecture by Open AI. I do not think I’ve internalized the proof yet, since I can’t explain how someone could have come up with it. Need more time to consolidate my understanding. minorfree.github.io/OpenAIDump/

minorfree.github.ioOpenAI Math Dump Hits My Home | Rambling on Graphs

상일 (Sang-il) reposted

Dave Richeson

@divbyzero.bsky.social

My mom asked how I was feeling about math, AI, and the big theorem dump. I told her she should listen to @stevenstrogatz.com's interview on The Daily. He does a great job of capturing the complicated emotions of today's mathematicians. www.nytimes.com/2026/10/13/p...

nytimes.comWhen A.I. Comes for Your Purpose in LifeIn the span of just a few months, A.I. systems have solved some of the biggest outstanding problems in math — adding mathematicians to the list of those terrified of losing their job to the technology...

arxiv.orgAn Erdős-Pósa theorem for induced packings of even cyclesWe show that for every graph $G$ and every positive integer $k$, $G$ contains either $k$ vertex-disjoint even cycles with no edges between distinct cycles, or a set of $O(k^2\log k)$ vertices whose cl...

#New_arXiv_paper Jungho Ahn, Lars Jaffke, *O-joung Kwon*, Paloma T. de Lima, and Hyemi Park, An Erdős-Pósa theorem for induced packings of even cycles, 2026 arxiv.org/abs/2610.22967

arxiv.orgSolving SAT via Treewidth Backdoors in Linear Time: Beyond SparsityThe Boolean Satisfiability (SAT) problem is a remarkably expressive computational problem, serving both as a cornerstone of complexity theory and as a unifying language for a wide range of search and ...

#New_arXiv_paper Jan Dreier, Robert Ganian, Marlene Gründel, *Roohani Sharma*, and Simon Wietheger, Solving SAT via Treewidth Backdoors in Linear Time: Beyond Sparsity, 2026. arxiv.org/abs/2610.18540

arxiv.orgHitting Minors: Stronger Lower BoundsFor a fixed finite collection of graphs $\mathcal{F}$, the $\mathcal{F}$-Minor-Free Deletion problem asks, given a graph $G$ and an integer $k$, whether there is a set $S\subseteq V(G)$ with $|S|\leq ...

#New_arXiv_paper Jongseo Lee, *Roohani Sharma*, and Sebastian Wiederrecht, Hitting Minors: Stronger Lower Bounds, 2026. arxiv.org/abs/2610.17664

arxiv.orgTractability of Hard Digraph Cut Problems on Eulerian Instances: Treewidth Reduction and Reducing CMSO to Unbreakable Eulerian InstancesEulerian digraphs retain the directional structure of general digraphs while exhibiting a symmetry of cuts reminiscent of undirected graphs. We show that this symmetry extends beyond individual cuts t...

#New_arXiv_paper Esther Galby, *Roohani Sharma*, and Bart van der Steenhoven, Tractability of Hard Digraph Cut Problems on Eulerian Instances: Treewidth Reduction and Reducing CMSO to Unbreakable Eulerian Instances, 2026. arxiv.org/abs/2610.16869

dimag.ibs.re.krJulien Codsi gave a talk at the Discrete Math Seminar on the tree-independence number of graphsOn October 13, 2026, Julien Codsi from the Princeton University gave a talk on various results on the tree-independence number of graphs. The title of his talk was "Recent progress in the tree-⍺ world".

On October 13, 2026, Julien Codsi from the Princeton University gave a talk on various results on the tree-independence number of graphs. The title of his talk was "Recent progress in the tree-⍺ world". https://www.youtube.com/watch?v=X1wm82tVRN4 https://dimag.ibs.re.kr/2026/julien-codsi-seminar/

doi.orgBounds on Treewidth via Excluding Disjoint Unions of Cycles | The Electronic Journal of CombinatoricsOne of the fundamental results in graph minor theory is that for every planar graph $H$, there is a minimum integer $f(H)$ such that graphs with no minor isomorphic to~$H$ have treewidth at most $f(H)$. The best bound known for an arbitrary planar $H$ is ${O(|V(H)|^9\operatorname{poly~log}|V(H)|)}$. We show that if $H$ is the disjoint union of cycles, then $f(H)$ is $O(|V(H)|\log^2 |V(H)|)$, which is a $\log|V(H)|$ factor away from being optimal.

#New_published_paper *Meike Hatzel*, Chun-Hung Liu, Bruce Reed, and Sebastian Wiederrecht, Bounds on treewidth via excluding disjoint unions of cycles, Electron. J. Combin., 33(4), #P4.8, October 2026. doi.org/10.37236/13735

상일 (Sang-il) reposted

Hung Le

@hunglv.bsky.social

OpenAI Math Dump Hits My Home Recent OpenAI math dump have solutions to many long standing probems in Math and TCS. Two problems that I and my friends, notably Arnold Filtser, have studied for more than a decade: L1 embedding conjectures. minorfree.github.io/OpenAIDump/

minorfree.github.ioOpenAI Math Dump Hits My Home | Rambling on Graphs

dimag.ibs.re.krDaniel McGinnis gave a talk at the Discrete Math Seminar on a commutative-algebraic approach to regularity that yields an optimal colorful fractional Helly theorem for d-Leray simplicial complexes.On October 6, 2026, Daniel McGinnis from the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on a commutative-algebraic approach to regularity that yields an optimal colorful fractional Helly theorem for d-Leray simplicial complexes. The title of his talk was "Multi-generic initial ideals, regularity, and the optimal colorful fractional Helly theorem for d-Leray complexes".

On October 6, 2026, Daniel McGinnis from the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on a commutative-algebraic approach to regularity that yields an optimal colorful fractional Helly theorem for d-Leray… https://dimag.ibs.re.kr/2026/daniel-mcginnis-seminar-2/

ChatGPT dot에다가 개인홈페이지 연구그룹 홈페이지 cv 오류를 찾아서 고쳐보라고 했더니 매우 편리하네요.

github.comLinearHadwiger/paper/LinearHadwiger.pdf at master · snorin239/LinearHadwigerLean 4 formalization of the main result of the paper "A proof of the Linear Hadwiger conjecture" by Sergey Norin and Raphael Steiner - snorin239/LinearHadwiger

"A proof of the Linear Hadwiger Conjecture " by Norine and Steiner. github.com/snorin239/Li...

arxiv.orgAn elementary proof of the 2-regularity of Pythagorean triplesWe give a new proof of the fact that every 2-coloring of the positive integers contains a monochromatic Pythagorean triple. This result was originally proven by Heule, Kullmann, and Marek with SAT sol...

#New_arXiv_paper *William J. Wesley*, An elementary proof of the 2-regularity of Pythagorean triples, 2026 arxiv.org/abs/2609.39063

arxiv.orgA double-logarithmic upper bound on the chromatic number of the associahedronWe show that the associahedron $\mathcal{A}_n$ has chromatic number $O(\log\log n)$, improving on the previously best known upper bound of $O(\log n)$.

#New_arXiv_paper *Sang-il Oum* and David R. Wood, A double-logarithmic upper bound on the chromatic number of the associahedron, 2026. arxiv.org/abs/2609.39015

arxiv.orgTowers and Bratteli-Vershik systems in Fibonacci-like unimodal mapsFor a class of Fibonacci-like unimodal maps, the restriction to the $ω$-limit set of the unique turning point defines a minimal Cantor system. We construct these Cantor sets geometrically using a nest...

#New_accepted_paper Jorge Olivares-Vinales and *Semin Yoo*, Towers and Bratteli-Vershik systems in Fibonacci-like unimodal maps, Int. Math. Res. Not. IMRN, accepted, 2026. arxiv.org/abs/2602.21623

#New_accepted_conference_paper Jan Drier, Robert Ganian, Marlene Gründel, *Roohani Sharma*, and Simon Wietheger, Solving SAT via Treewidth Backdoors in Linear Time: Beyond Sparsity, In the Proceedings of SODA 2027 (January 24-27, 2027, Philadelphia, USA), accepted, 2026.

arxiv.orgThe Fibonacci numbers are not 3-accessibleA $D$-diffsequence is a sequence of integers $x_1 < \dots < x_k$ such that $x_{i+1} -x_i \in D$ for $1 \le i \le k-1$. The set $D$ is called $r$-accessible if every $r$-coloring of the positive intege...

#New_arXiv_paper *William J. Wesley*, The Fibonacci numbers are not 3-accessible, 2026. arxiv.org/abs/2609.33744

arxiv.orgBranch-width of represented matroids in matrix multiplication timeFor an $n$-element matroid $M$ given by an $n \times n$ matrix representation over a finite field $\mathbb F$ and an integer $k$, we present an algorithm with running time $O_{k,\mathbb F}(n^2)+O(n^ω)...

#New_accepted_conference_paper *Mujin Choi*, Tuukka Korhonen, and *Sang-il Oum*, Branch-width of represented matroids in matrix multiplication time, SODA 2027, Philadelphia, USA, January 24-27, 2027), accepted, 2026. arxiv.org/abs/2605.14428

dimag.ibs.re.krDavid R. Wood gave a talk on a weakening of Hadwiger’s conjecture in terms of the clustered chromatic number at the Discrete Math SeminarOn September 22, 2026, David R. Wood from Monash University gave a talk on coloring graphs without K_t minor with t colors while avoiding large monochromatic components at the Discrete Math Seminar. The title of his talk was "Proof of the Clustered Hadwiger Conjecture".

On September 22, 2026, David R. Wood from Monash University gave a talk on coloring graphs without K_t minor with t colors while avoiding large monochromatic components at the Discrete Math Seminar. The title of his talk was "Proof of the Clustered… https://dimag.ibs.re.kr/2026/clustered-hadwiger/

dimag.ibs.re.krDavid R. Wood gave a talk explaining the proof of the Erdős-Sós conjecture by GPT Astra at the Discrete Math SeminarOn September 18, 2026, David R. Wood from Monash University gave a talk showing the proof of the Erdős-Sós conjecture found by GPT Astra at the Discrete Math Seminar. The title of his talk was "The Erdős-Sós Theorem".

18 Sept

On September 18, 2026, David R. Wood from Monash University gave a talk showing the proof of the Erdős-Sós conjecture found by GPT Astra at the Discrete Math Seminar. The title of his talk was "The Erdős-Sós Theorem".… https://dimag.ibs.re.kr/2026/erdos-sos/

dimag.ibs.re.krGabriëlle Zwaneveld gave a talk on oriented graphs with the same number of the neighbors and second neighbors at each vertex at the Discrete Math Seminar - Discrete Mathematics GroupOn September 15, 2026, Gabriëlle Zwaneveld from University of Amsterdam gave a talk on oriented graphs with the same number of neighbors and second neighbors at each vertex movited by … Continue readi...

16 Sept

On Sep 15, 2026, Gabriëlle Zwaneveld from University of Amsterdam gave a talk on oriented graphs with the same number of neighbors and second neighbors at each vertex, motivated by Seymour's second neighborhood conjecture, at the Discrete Math Seminar. dimag.ibs.re.kr/2026/gabriel...

dimag.ibs.re.krResearch Positions at the IBS Discrete Mathematics Group (DIMAG) (Due: November 30, 2026)The IBS Discrete Mathematics Group (DIMAG) in Daejeon, Korea invites applications for four research fellowship positions (senior researcher positions). DIMAG is a research group that was established on December 1, 2018 at the Institute for Basic Science (IBS), led by its Chief Investigator (CI) Sang-il Oum. DIMAG is located at the headquarters of IBS in Daejeon, South Korea, a city of 1.5 million people.

15 Sept

Research Positions at the IBS Discrete Mathematics Group (DIMAG) (Due: November 30, 2026) The IBS Discrete Mathematics Group (DIMAG) in Daejeon, Korea invites applications for four research fellowship positions (senior researcher positions)....

dimag.ibs.re.krThe 2026 DIMAG Internal Workshop was held in Namwon on September 9-13, 2026The IBS Discrete Mathematics Group held the "2026 DIMAG Internal Workshop" at the Kensington Resort in Namwon on September 9-13, 2026. Participants included all but one of DIMAG's current members, as well as Sebastian Wiederrecht (KAIST), Minki Kim (GIST), Seonghyuk Im (KIAS), and Hojin Chu (KIAS). Every participant presented open problems, and there were active discussions throughout, leading to several progress reports.

14 Sept

The IBS Discrete Mathematics Group held the "2026 DIMAG Internal Workshop" at the Kensington Resort in Namwon on September 9-13, 2026.... https://dimag.ibs.re.kr/2026/2026-dimag-internal-workshop/

상일 (Sang-il) reposted

Terence Tao

@teorth.bsky.social

11 Sept

A group of 25 Fields Medalists, including myself, have made a joint declaration on Math and AI: mathandai.org . We welcome additional signatories. See also this article in the Economist announcing the declaration: www.economist.com/science-and-...

mathandai.orgDeclaration — Math and AIRead the declaration and add your name.

arxiv.orgColoring graphs with no long induced pathLet $P_t$ denote the induced path on $t$ vertices. Let $ω(G)$ denote the maximum number of vertices in a clique of a graph $G$. Gyárfás (1987) proved that every $P_t$-free graph $G$ satisfies $χ(G)\le...

11 Sept

My arXiv paper of this week has been updated! New bound: "We prove that for t≥5,every Pt-free graph G satisfies χ(G)< 3 (t-3)^{ ω(G)+4}." arxiv.org/abs/2609.08847

dimag.ibs.re.krBen Lund gave a talk on the number of incidences between points and n-dimensional projective subspaces at the Discrete Math SeminarOn September 1, 2026, Ben Lund from Xidian University, China gave a talk at the Discrete Math Seminar on an upper bound of the number of incidences between points and n-dimensional projective subspaces in PG(n+d,q). The title of his talk was "Incidences between points and n-flats in PG(n+d,q)".

On September 1, 2026, Ben Lund from Xidian University, China gave a talk at the Discrete Math Seminar on an upper bound of the number of incidences between points and n-dimensional projective subspaces in PG(n+d,q). The title of his talk was… https://dimag.ibs.re.kr/2026/ben-lund-seminar-3/

arxiv.orgComplexity lower bounds for succinct binary structures of bounded clique-width with restrictionsWe present a Rice-like complexity lower bound for any MSO-definable problem on binary structures succinctly encoded by circuits. This work extends the framework recently developed as a counterpoint to...

#New_conference_paper *Colin Geniet*, Aliénor Goubault-Larrecq, and Kévin Perrot, Complexity lower bounds for succinct binary structures of bounded clique-width with restrictions, 11th Conference on Machines, Computations and Universality (MCU 2026), accepted, 2026. arxiv.org/abs/2602.18240

dimag.ibs.re.krOlga Medrano Martín del Campo gave a talk on ε-saturation of classes of graphs of bounded Littlestone dimension and VC dimension at the Discrete Math SeminarOn September 8, 2026, Olga Medrano Martín del Campo from the IBS Discrete Mathematics Group gave a talk on -saturation of classes of graphs of bounded Littlestone dimension and VC dimension at the Discrete Math Seminar. The title of her talk was "Epsilon-saturation for Littlestone classes and stable graphs".

On September 8, 2026, Olga Medrano Martín del Campo from the IBS Discrete Mathematics Group gave a talk on -saturation of classes of graphs of bounded Littlestone dimension and VC dimension at the Discrete Math Seminar. The title of her talk was… https://dimag.ibs.re.kr/2026/olga-seminar/

arxiv.orgOverlap-Helly theoremsIn this paper we introduce a generalization of Helly's theorem closely connected to Bárány-Gromov overlap theorems (also called selection lemmas). Our main result implies both the topological colorful...

#New_arXiv_paper *Andreas F. Holmsen* and Alfredo Hubard, Overlap-Helly theorems, 2026. arxiv.org/abs/2609.10023

arxiv.orgColoring graphs with no long induced pathLet $P_t$ denote the induced path on $t$ vertices. Let $ω(G)$ denote the maximum number of vertices in a clique of a graph $G$. Previously Gyárfás (1987) proved that every $P_t$-free graph $G$ satisfi...

9 Sept

#New_arXiv_paper *Sang-il Oum*, Coloring graphs with no long induced path, 2026. arxiv.org/abs/2609.08847

arxiv.orgAn FPT algorithm for cycle rank on semi-complete digraphsCycle rank is a depth parameter for digraphs introduced by Eggan in 1963. Gruber (DMTCS 2012) and Giannopoulou, Hunter, and Thilikos (DAM 2012) asked whether the problem of determining if a given digr...

7 Sept

#New_accepted_conference_paper *Seokbeom Kim*, *O-joung Kwon*, and Myounghwan Lee, An FPT algorithm for cycle rank on semi-complete digraphs, In the Proceedings of ISAAC 2026 (Hangzhou, China, December 6-9, 2026), accepted, 2026. arxiv.org/abs/2606.29336

상일 (Sang-il) reposted

Wes Pegden

@wespegden.bsky.social

2 Sept

Trellis has formalized the Strong Perfect Graph Theorem of Chudnovsky, Robertson, Seymour, Thomas. It ran autonomously for 6 weeks; the proof is 540k LOC, the largest Lean autoformalization. OG paper here: annals.math.princeton.edu/2006/164-1/p02 Viewer, git here: math.cmu.edu/~wes/trellis...

sites.google.comDebsoumya ChakrabortiDebsoumya Chakraborti (দেবসৌম্য চক্রবর্তী) Assistant ProfessorIIT Bombay I am an assistant professor in the Department of Mathematics at IIT Bombay, India. My research interest broadly lies in Combi...

3 Sept

IBS 이산수학그룹 선임연구원이었던 Debsoumya Chakraborti 박사가 8월 31일 IIT Bombay 수학과 교수가 되었습니다. Debsoumya Chakraborti, a former member of the IBS Discrete Mathematics Group, joined the Indian Institute of Technology Bombay as an assistant professor on August 31, 2026. Congratulations! sites.google.com/view/debsoumya

donggyu-math.github.ioDonggyu KimDonggyu Kim is a postdoctoral fellow at Georgia Tech working on matroid theory and algebraic combinatorics.

3 Sept

KAIST 수리과학과에서 제 박사 지도학생이었으며 IBS 이산수학그룹에서 학생연구원으로 지냈던 김동규 (Donggyu Kim) 박사가 2026년 9월부로 한양대학교 수학과 조교수로 부임하였습니다. Congratulations! donggyu-math.github.io

dimag.ibs.re.krWelcome Xiying Du, a new member of the IBS Discrete Mathematics GroupThe IBS Discrete Mathematics Group welcomes Dr. Xiying Du, a new research fellow at the IBS Discrete Mathematics Group, starting on September 1, 2026. She received her Ph.D. from the Georgia Institute of Technology under the supervision of Prof. Rose McCarty and Prof. Xingxing Yu. She is interested in structural graph theory, in particular graph linkages, degree-boundedness, and induced subgraphs.

1 Sept

Welcome Xiying Du, a new member of the IBS Discrete Mathematics Group The IBS Discrete Mathematics Group welcomes Dr. Xiying Du, a new research fellow at the IBS Discrete Mathematics Group, starting on September 1, 2026....

dimag.ibs.re.krWelcome William J. Wesley, a new members of the IBS Discrete Mathematics GroupThe IBS Discrete Mathematics Group welcomes Dr. William J. Wesley, a new research fellow at the IBS Discrete Mathematics Group, starting September 1, 2026. He received his Ph.D. from the University of California, Davis under the supervision of Prof. Jesús A. De Loera. Until recently, he was an SEW Visiting Assistant Professor at the University of California, San Diego. His research is focused primarily on computational Ramsey theory, and he is more broadly interested in combinatorics, algebra, and optimization.

1 Sept

Welcome William J. Wesley, a new members of the IBS Discrete Mathematics Group The IBS Discrete Mathematics Group welcomes Dr. William J. Wesley, a new research fellow at the IBS Discrete Mathematics Group, starting September 1, 2026....

dimag.ibs.re.krWelcome Mingyuan Rong, a new member of IBS ECOPROThe IBS Discrete Mathematics Group welcomes Dr. Mingyuan Rong, a new research fellow at the IBS Extremal Combinatorics and Probability Group, starting September 1, 2026. Mingyuan Rong received his Ph.D. from the University of Science and Technology of China under the supervision of Prof. Jie Ma. Until recently, he was a Visiting Student Researcher at the University of Warwick, working with Prof. Oleg Pikhurko. He is interested in extremal set theory and extremal graph theory.

1 Sept

Welcome Mingyuan Rong, a new member of IBS ECOPRO The IBS Discrete Mathematics Group welcomes Dr. Mingyuan Rong, a new research fellow at the IBS Extremal Combinatorics and Probability Group, starting September 1, 2026....

arxiv.orgCountable Graphs with Finite Path-width: Characterisation and UniversalityWe study path-width and the closely related parameter line-width in countably infinite graphs. Our first result characterises the graphs of finite path-width: they are the graphs that do not have infi...

31 Aug

#New_arXiv_paper *Tony Huynh*, Freddie Illingworth, Nikolai Karol, Florian Lehner, Chun-Hung Liu, János Pach, and David R. Wood, Countable graphs with finite path-width: Characterisation and universality, 2026. arxiv.org/abs/2608.27752