Club isomorphisms on higher Aronszajn trees (1708.00528v3)

Abstract: We prove the consistency, assuming an ineffable cardinal, that any two normal countably closed $\omega_2$-Aronszajn trees are club isomorphic. This work generalizes to higher cardinals the property of Abraham-Shelah that any two normal $\omega_1$-Aronszajn trees are club isomorphic, which follows from $\textsf{PFA}$. The statement that any two normal countably closed $\omega_2$-Aronszajn trees are club isomorphic implies that there are no $\omega_2$-Suslin trees, so our proof also expands on the method of Laver-Shelah for obtaining the $\omega_2$-Suslin hypothesis.