- Series
- Atlanta Combinatorics Colloquium
- Time
- Friday, November 20, 2026 - 4:00pm for 1 hour (actually 50 minutes)
- Location
- Skiles 005
- Speaker
- Felix Joos – Heidelberg University – joos@uni-heidelberg.de – https://web.ifi.uni-heidelberg.de/tcs/joos
- Organizer
- Tom Kelly
Fix a graph or uniform hypergraph $F$ and consider the following simple
process. Start with the complete (hyper)graph $K_n$ on $n$ vertices and
repeatedly remove the edge set of a copy of $F$, chosen uniformly at
random among all copies present at that time. Stop when no copy of $F$
is left. This is the $F$-removal process, and the key question is when
it ends, that is, how many edges are left at the end.
This question has proven to be very hard. In 2015, Bohman, Frieze and
Lubetzky famously proved that the triangle-removal process typically
ends with $n^{3/2+o(1)}$ edges. Until now, the answer was not known for
any other $F$.
We determine when the $F$-removal process ends for many choices of $F$.
This includes cliques, where it confirms a well-known conjecture of
Bennett and Bohman on the final number of edges. This is joint work with
Kühn.