Indestructibility of some compactness principles over models of PFA
Abstract
We show that (Proper Forcing Axiom) implies that adding any number of Cohen subsets of will not add an -Aronszajn tree or a weak -Kurepa tree, and moreover no -centered forcing can add a weak -Kurepa tree (a tree of height and size with at least cofinal branches). This partially answers an open problem whether ccc forcings can add -Aronszajn or -Kurepa trees. We actually prove more: We show that a consequence of , namely the guessing model principle, , which is equivalent to the ineffable slender tree property, , is preserved by adding any number of Cohen subsets of . And moreover, implies that no -centered forcing can add a weak -Kurepa tree. For more generality, we study the principle at an arbitrary regular cardinal (we denote this principle ), and as an application we show that there is a model in which there are no weak -Kurepa trees and no -Aronszajn trees.
Keywords
Cite
@article{arxiv.2208.02684,
title = {Indestructibility of some compactness principles over models of PFA},
author = {Radek Honzik and Chris Lambie-Hanson and Šárka Stejskalová},
journal= {arXiv preprint arXiv:2208.02684},
year = {2022}
}
Comments
18 pages