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.
Password: first 6 decimal places of $\pi$ after the decimal point
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.