### Zhihan Jin (金之涵), The Helly number of Hamming balls and related problems

Room B332 IBS (기초과학연구원)We prove the following variant of Helly’s classical theorem for Hamming balls with a bounded radius. For $n > t$ and any (finite or infinite) set $X$, if in a family of Hamming balls of radius $t$ in $X$, every subfamily of at most $2^{t+1}$ balls have a common point, so do all members of …