# Fedor Petrov “List colorings of direct products”

July 9, 2020
19.00 MSK (UTC +3)

# Fedor Petrov "List colorings of direct products"

Fedor Petrov from Steklov Mathematical Institute will give the talk "List colorings of direct products" on the labs' Big Seminar.

The talk will be held in zoom
Meeting ID: 279-059-822
Password: first 6 decimal places of $\pi$ after the decimal point

You can also write to Alexander Polyanskii (alexander.polyanskii@yandex.ru) or to Maksim Zhukovskii (zhukmax@gmail.com) if you want to be added to mailing list.

Abstract:

Let $G=C_n\times C_m$ be a toroidal grid (that is, 4-regular graph), where $nm$ is even. We prove that this graph $G$ is 3-choosable. We also prove some more general results about list colorings of direct products. The proofs are algebraic, the starting point is Alon — Tarsi application of Combinatorial Nullstellensatz, and the main difficulty is to prove that the corresponding coefficient of the graph polynomial is non-zero.

The talk is based on joint results with Alexey Gordeev, Zhiguo Li and Zeling Shao. No preliminary knowledge is required.

## Watch the video:

Everyone is invited to attend. The language of the lecture is English. The event is aimed at master and graduate students, as well as researchers in the field of combinatorics.