Siiri Kivimaki

collaborators

3 papers

math.LO2025

Aronszajn trees and maximality

Omer Ben-Neria, Siiri KivimÃ¤ki, Menachem Magidor +1

Assuming the consistency of a weakly compact cardinal above a regular uncountable cardinal $I^¼$ , we prove the consistency of the existence of a wide $I^¼^{+}$ -Aronszajn tree, i.e. a t…

math.LO2025

Universal countably chromatic graph

Siiri KivimÃ¤ki

We show that the existence of a universal countably chromatic graph of size $ℵ_{1}$ together with the failure of continuum hypothesis is consistent. The proof is a forcing itera…

math.LO2025

Universal wide Aronszajn tree

Siiri KivimÃ¤ki

A wide Aronszajn tree is a tree of size $ℵ_{1}$ with no uncountable branches. Assuming the consistency of the existence of a weakly compact cardinal, we show the consistency of…