# Andrew Suk "Hypergraph Ramsey numbers and an old problem of Erdős and Hajnal"

**Andrew Suk** from University of California San Diego will
give the talk "Hypergraph Ramsey numbers and an old problem of Erdős and Hajnal" on the labs' Big Seminar.

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:**

The Ramsey number $r_k(s,n)$ is the minimum integer $N$, such that for any red/blue coloring of the $k$-tuples of ${1,2,...,N}$, there are s integers such that every $k$-tuple among them is red, or there are $n$ integers such that every $k$-tuple among them is blue. In this talk, I will discuss known upper and lower bounds for $r_k(s,n)$. I will also discuss another closely related function that was introduced by Erdős and Hajnal in 1972.

## 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.