Indestructibility of some compactness principles over models of PFA

Radek Honzik, Chris Lambie-Hanson, Šárka Stejskalová

We show that $\mathsf{PFA}$ (Proper Forcing Axiom) implies that adding any number of Cohen subsets of $\omega$ will not add an ${\omega }_2$-Aronszajn tree or a weak ${\omega }_1$-Kurepa tree, and more…