Kurepa trees, continuous images, and perfect set properties
Abstract
Building upon work of L\"ucke and Schlicht, we study (higher) Kurepa trees through the lens of higher descriptive set theory, focusing in particular on various perfect set properties and representations of sets of branches through trees as continuous images of function spaces. Answering a question of L\"ucke and Schlicht, we prove that it is consistent with CH that there exist ω2-Kurepa trees and yet, for every ω2-Kurepa tree T ⊂eq <ω2ω2, the set [T] ⊂eq ω2ω2 of cofinal branches through T is not a continuous image of ω2ω2. We also produce models indicating that the existence of Kurepa trees is not necessary to produce closed subsets of ω1ω1 failing to satisfy strong perfect set properties, and prove a number of consistency results regarding full and superthin trees.
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