2011 seminar talk: Cardinal Characteristics, Projective Wellorders and Large Continuum

Talk held by Vera Fischer (KGRC) at the KGRC seminar on 2011-10-13.

Abstract

We present a method for controlling cardinal characteristics in the presence of a projective wellorder and \(2^\aleph_0>\aleph_2\). This also answers a question of Harrington by showing that the existence of a (lightface) \(\Delta^1_3\) wellorder of the reals is consistent with Martin's axiom and \(2^\aleph_0=\aleph_3\). This is joint work with Sy-David Friedman and Lyubomyr Zdomskyy.