The IBS Discrete Mathematics Group welcomes Haotian Yang, a new visiting student of the IBS Extremal Combinatorics and Probability Group. He is currently an undergraduate student of Shandong University. He arrived at IBS on August 6, 2023 and will stay with us until February 1, 2024.

## Daniel Kráľ gave a talk on common graphs with large chromatic numbers at the Discrete Math Seminar

On August 2, 2023, Daniel Kráľ from Masaryk University gave a talk on constructing common graphs with large chromatic numbers at the Discrete Math Seminar. The title of his talk was “High chromatic common graphs.”

## Dong Yeap Kang (강동엽) gave a talk on the existence of a largest possible matching in a random subhypergraph of a k-uniform hypergraph with the codegree condition at the Discrete Math Seminar

On July 25, 2022, Dong Yeap Kang (강동엽) from the IBS Extremal Combinatorics and Probability Group gave a talk at the Discrete Math Seminar on the existence of a largest possible matching in a random subhypergraph of a k-uniform hypergraph with the codegree condition. The title of his talk was “Hamilton cycles and optimal matchings in a random subgraph of uniform Dirac hypergraphs.”

## Wojciech Samotij gave lectures for 5 days in a summer school at IBS

From July 17 to July 21, 2023, Wojciech Samotij from Tel Aviv University gave a lecture series at IBS on the method of hypergraph containers. This summer school was organized by the IBS Extremal Combinatorics and Probability Group and attended by about 40 people offline and more than 100 people online.

## Andrzej Grzesik gave a talk on the rainow Turán problems at the Discrete Math Seminar

On July 18, 2023, Andrzej Grzesik from Jagiellonian University gave a talk at the Discrete Math Seminar on the rainbow version of Turán problems. The title of his talk was “rainbow Turán problems.”

## Open Symposium at the Discrete Mathematics Group

On July 13, 2023, the Open Symposium at the Discrete Mathematics Group was held. There were four talks by the members of the Discrete Mathematics Group.

9:40-10:05 | Obstructions for dense analogs of tree-depth | Sang-il OUM |

10:05-10:20 | Structural and extremal results for twin-width | Kevin HENDREY |

10:20-10:35 | Down-sets in combinatorial posets | Rutger CAMPBELL |

10:35-10:50 | Reuniting 𝜒-boundedness with polynomial 𝜒-boundedness | Linda COOK |

## Xuding Zhu gave a talk on the list version of the 1-2-3 conjecture and the usage of Combinatorial Nullstellensatz at the Discrete Math Seminar

On July 10, 2023, Xuding Zhu from Zhejiang Normal University gave a talk at the Discrete Math Seminar on the 1-2-3 conjecture of Karoński, Łuczak, and Thomason, its list version by Bartnicki, Grytczuk, and Niwczyk, and the usage of Combinatorial Nullstellensatz. The title of his talk was “List version of 1-2-3 conjecture.”

## Tuan Tran gave a talk on a Sauer-Shelah-type lemma in the study of the maximal pattern entropy of a theoretical dynamical system at the Discrete Math Seminar

On July 4, 2023, Tuan Tran from the University of Science and Technology of China gave a talk on a Sauer-Shelah-type lemma in the study of the maximal pattern entropy of a theoretical dynamical system and its connection to a recent result in communication complexity at the Discrete Math Seminar. The title of his talk was “Complexity of null dynamical systems.”

## Chong Shangguan gave a talk on the hat guessing game on graphs at the Discrete Math Seminar

On June 27, 2023, Chong Shangguan (上官冲) from Shandong University gave a talk at the Discrete Math Seminar on the maximum number of colors of hats so that at least one of the players can correctly guess his or her hat color while only seeing the colors of their neighbors on a graph. The title of his talk was “the hat guessing number of graphs.”

## Welcome Zhuo Wu from the Univeristy of Warwick, a new visiting student of ECOPRO

The IBS Discrete Mathematics Group welcomes Zhuo Wu (吴茁) from the University of Warwick, a new visiting student of the IBS Extremal Combinatorics and Probability Group (ECOPRO). He will stay with us for 1 year.