On March 31, 2020, Ringi Kim (김린기) from KAIST presented his work on the strong clique number of graphs with Eun-Kyung Cho, Ilkyoo Choi, and Boram Park. The title of his talk is “The strong clique number of graphs with forbidden cycles“.

## Due to COVID-19, the organizers decided to postpone the conference “Seymour is Seventy” to be held in Lyon, France, June 15-19, 2020

Due to COVID-19, the organizers decided to postpone the conference “Seymour is Seventy” to be held in Lyon, France, June 15-19, 2020. We hope to run a similar event in the summer of 2021 instead. Specific decisions on the dates are to be made when the situation clarifies.

Conference website: https://dimag.ibs.re.kr/seymour70/

## Kevin Hendrey gave a talk on covering the space of permutations by Hamming balls of small radius at the Discrete Math Seminar

On March 24, 2020, Kevin Hendrey from IBS discrete mathematics group presented a talk on his work on covering the Hamming permutation space by balls of small radius. The title of his talk was “Covering radius in the Hamming permutation space“.

## Dabeen Lee (이다빈) gave a talk on the generalization of the Chvátal-Gomory closure at the Discrete Math Seminar

On March 17, 2020, Dabeen Lee (이다빈) from IBS discrete mathematics group presented a talk on his result proving that the closure of a polyhedron by some generalization of the Chvátal-Gomory cuts gives a polyhedron. The title of his talk is “On a generalization of the Chvátal-Gomory closure“.

## Eun-Kyung Cho (조은경) gave a talk on the problem of decomposing a graph into a d-degenerate graph and a graph of bounded maximum degree at the Discrete Math Seminar

On March 3, 2020, Eun-Kyung Cho (조은경) from Hankuk University of Foreign Studies presented a talk on the existence of a decomposition of a planar graph into two edge-disjoint subgraphs, one of which is d-degenerate and the other has maximum degree at most h at the discrete math seminar. The title of her talk was “Decomposition of a planar graph into a *d*-degenerate graph and a graph with maximum degree at most *h*“. She will visit the IBS discrete math group until March 6.

## Xin Zhang (张欣) gave a talk on the problem of partitioning a graph into forests of the almost equal size at the Discrete Math Seminar

On February 25, 2020, Xin Zhang (张欣) from Xidian University, China gave a talk on the problem of equitable tree-k-coloring of graphs and its variations. The title of his talk is “On the equitable tree-coloring of graphs with low degeneracy“. He is currently visiting the IBS discrete mathematics group for 1 year until August 2020 for his sabbatical leave.

## Dong Yeap Kang presented his work on random perturbed graphs at the discrete math seminar

On February 18, 2020, Dong Yeap Kang from KAIST & IBS Discrete Mathematics Group gave a talk on random perturbed graphs. The title of his talk is “Fragile minor-monotone parameters under random edge perturbation“. Dong Yeap will receive the Ph.D. degree at the end of this month from KAIST and will move to University of Birmingham, UK as a postdoc.

## The registration for the conference “Seymour is Seventy” (June 15-19) is now open! The deadline for early bird registration is April 12, 2020.

The registration for the conference “Seymour is Seventy” is now open.

- Deadline for early bird registration : April 12, 2020.
- Registration fees : 250 euros (includes coffee breaks, lunches, and the banquet)
- For accompanying persons, it is possible to register only for the banquet for 70 euros
- To register, follow the link from the website https://dimag.ibs.re.kr/seymour70/

The website also has a list of suggested hotels in Lyon.

## Seymour is Seventy

A conference honouring the seventieth birthday of Paul Seymour

At ENS de Lyon, France

From June 15th to June 19th, 2020.

## Invited speakers

Noga Alon, Princeton University / Tel Aviv University

Maria Chudnovsky, Princeton University

Julia Chuzhoy, Toyota Technological Institute at Chicago

Gérard Cornuéjols, Carnegie Mellon University

Matt DeVos, Simon Fraser University

Guoli Ding, Louisiana State University

Jacob Fox, Stanford University

Jim Geelen, University of Waterloo

András Gyárfás, Hungarian Academy of Sciences

Alexandr V. Kostochka, University of Illinois at Urbana-Champaign

Chun-Hung Liu, Texas A&M University

Sergey Norin, McGill University

Sang-il Oum, IBS Discrete Mathematics Group / KAIST

Bruce Reed, McGill University

Alexander Schrijver, University of Amsterdam / CWI Amsterdam

Alex Scott, University of Oxford

Sophie Spirkl, Princeton University

Benny Sudakov, ETH Zurich

Stéphan Thomassé, ENS de Lyon

Carsten Thomassen, Technical University of Denmark

Kristina Vušković, University of Leeds

Paul Wollan, University of Rome “La Sapienza”

## Dillon Mayhew gave a talk on analogues of Courcelle’s theorem, in particular to hypergraphs and matroids at the discrete math seminar

On January 28, 2020, Dillon Mayhew from Victoria University of Wellington, New Zealand gave a talk on problems and results motivated by Courcelle’s theorem, with an emphasis on hypergraphs and matroids. The title of his talk is “Courcelle’s Theorem for hypergraphs“.

## Adam Zsolt Wagner gave a talk on an extremal problem in Z_{2^n} at the discrete math seminar

On January 20, 2020, Adam Zsolt Wagner from ETH Zurich gave a talk on the largest subset of $\mathbb Z_{2^n}$ having no projective $d$-cube. The title of his talk was “The largest projective cube-free subsets of $Z_{2^n}$“. He has been visiting IBS discrete mathematics group for a week and will leave on this Wednesday.