Logic Seminar - Saharon Shelah

Torsion-Free Abelian Groups are Borel Complete


Abstract: 
We prove that the Borel space of torsion-free Abelian groups with domain ω is Borel complete, i.e., the isomorphism relation on this Borel space is as complicated as possible, as an isomorphism relation. This solves a long-standing open problem in descriptive set theory, which dates back to the seminal paper on Borel reducibility of Friedman and Stanley from 1989.

Date: 

Wed, 19/05/2021 - 11:00 to 13:00

Location: 

https://huji.zoom.us/j/82821066522?pwd=aVJnTkxBYktycHdzNFN5WDV0R2FkZz09