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

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Orateur(s) Chris Laskowski - University of Maryland ,
Titre Borel complexity and potential canonical Scott sentences
Horaire15:10 à 16:10
RésumeGiven a first order theory or a sentence $\Phi$ of $L_\omega_1,\omega$, we define the class of potential canonical Scott sentences of $\Phi$. Simply by comparing cardinalities, we obtain new results about the Borel complexity of $(Mod(\Phi),\iso)$, the class of countable models of $\Phi$. In particular, we find examples of first order theories T for which Mod(T) is not Borel complete, yet the isomorphism relation on Mod(T) is not Borel.
This is joint work with Douglas Ulrich and Richard Rast.
AdresseSophie Germain