Mikhaylo Tyomkin (Prága, Cambridge): Weak saturation in graphs and hypergraphs

Abstract: For two r-uniform hypergraphs G and H we say that G is weakly H-saturated if the missing edges in G can be filled one by one, creating a new copy of H at every step. The quantity wsat(n,H), introduced by Bollobas in 1965, measures the smallest size of a weakly H-saturated r-graph of order n.
I will discuss some recent results in this area, based on joint work with Asaf Shapira and (separately) with Martin Tancer and Denys Bulavka.