The EKR property for flag pure simplicial complexes without boundary

Jorge Olarte, Francisco Santos, Jonathan Spreer and Christian Stump

Abstract

We prove that the family of facets of a pure simplicial complex of dimension up to three satisfies the Erdős-Ko-Rado property whenever it is flag and has no boundary ridges. We conjecture the same to be true in arbitrary dimension and give evidence for this conjecture. Our motivation is that complexes with these two properties include flag pseudo-manifolds and cluster complexes.

AMS Subject Classification: Primary 05E45; secondary 05D05, 05C35.