1999/08/29 by Paul C. Eklof, Saharon Shelah, Eklof, Paul C. +1
Mathematics · #03E35 #03E75 #18G15 #20K20 #55N10 #Advanced Topology and Set Theory #Commutative Algebra (math.AC) #FOS: Mathematics #Geometric and Algebraic Topology #Homotopy and Cohomology in Algebraic Topology #Logic (math.LO) #Primary 20K35 #Rings and Algebras (math.RA) #Secondary 13L05 #math.AC #math.LO #math.RA #msc:03E35 #msc:03E75 #msc:13L05 #msc:18G15 #msc:20K20 #msc:20K35 #msc:55N10
paper · pdf · doi:10.48550/arxiv.math/9908157
published as J. Pure Appl. Algebra 156 No. 2-3 (2001) 199--214
arxiv created 1999/08/29 · openalex publication_date 1999/08/29 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We prove that it is consistent that there is a non-reflexive Whitehead group, in fact one whose dual group is free. We also prove that it is consistent that there is a group A such that Ext(A,Z) is torsion and Hom(A,Z)=0. As an application we show the consistency of the existence of new co-Moore spaces.