Kurt Gödel Research Center

2009 seminar talk: Cardinal characteristics and projective wellorders

Talk held by Vera Fischer (KGRC) at the KGRC seminar on 2009-10-29.

Abstract

Using countable support iteration of S-proper posets, we show that the existence of a Δ¹₃ definable wellorder of the reals is consistent with each of the following: d < c, b < a = s, b < g. This is a joint work with Sy Friedman.