# Séminaires : Séminaire Général de Logique

 Equipe(s) : lm, Responsables : S. Anscombe, O. Finkel, A. Khélif, A. Vignati Email des responsables : sylvy.anscombe@imj-prg.fr, vignati@imj-prg.fr Salle : 1013 Adresse : Sophie Germain Description

 Orateur(s) Gianluca Paolini - Università di Torino, Titre Torsion-Free Abelian Groups are Borel Complete Date 12/05/2021 Horaire 16:00 à 17:15 Diffusion https://u-paris.zoom.us/rec/share/Bvb9JgR_S_zMpZhQzj7nHRbYH46thPYoHl1mezO1llZaVDWiUY8I9g7_O-bpCZvZ.w-zryZbLlLrIXU_o?startTime=1620828132000 Résume We prove that the Borel space of torsion-free Abelian groups with domain $\omega$ 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. Salle 1013 Adresse Sophie Germain
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