Algebraic Geometry Seminar
by Spencer Unger (University of Toronto)
Clausen and Scholze showed that a condensed form of Whitehead's problem has a positive answer. Recently, Bergfalk, Lambie-Hanson and Saroch gave a set theoretic formulation and proof of this theorem. We give an alternative set theoretic proof which shows a close connection with a proof of Shelah's theorem that V=L implies that all Whitehead groups are free.