We show that the Proper Forcing Axiom implies the Singular Cardinal Hypothesis. The proof uses the reflection principle MRP introduced by Moore in [11].
Abstract. We prove new upper bound theorems on the consistency strengths of SPFA(), SPFA(-linked) and SPFA(+ -cc). Our results are in terms of (, )-subcompactness, which is a new l...
The purpose of this paper is to present some results which suggest that the Singular Cardinals Hypothesis follows from the Proper Forcing Axiom. What will be proved is that a form ...
Abstract. A new axiom is proposed, the Ground Axiom, asserting that the universe is not a nontrivial set forcing extension of any inner model. The Ground Axiom is first-order expr...