Planting Kurepa trees and killing Jech-Kunen trees in a model by using one inaccessible cardinal

by Jin and Shelah. [JiSh:469]
Fundamenta Math, 1992
By an omega_1 --tree we mean a tree of power omega_1 and height omega_1 . Under CH and 2^{omega_1}> omega_2 we call an omega_1 --tree a Jech--Kunen tree if it has kappa many branches for some kappa strictly between omega_1 and 2^{omega_1} . In this paper we prove that, assuming the existence of one inaccessible cardinal, (1) it is consistent with CH plus 2^{omega_1}> omega_2 that there exist Kurepa trees and there are no Jech--Kunen trees, (2) it is consistent with CH plus 2^{omega_1}= omega_4 that only Kurepa trees with omega_3 many branches exist.


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