Friday Set Theory Seminar (HUJI)
We shall meet this Friday (May 1st) in the Hebrew University
math department building in Room 110, at 10 am.
Speaker: Péter Komjáth (Budapest, Eotvos University)
Title: Independent sets in infinite chordal graphs
Abstract: Let X be a graph which does not contain an induced circuit of length 4. If X contains arbitrarily large independent sets below $\kappa$ then it contains an independent set of size $\kappa$ for $\kappa=\aleph_0$ or singular. If, however, $\kappa$ is strongly inaccessible, then a counterexample exists iff there is a $\kappa$-Suslin-tree.